1.5Mb DTI/PRI: Description, Installation and Maintenance

Meridian 1X11 Release 25.40

Succession Communication Server for Enterprise 1000X21 Release 2.0

1.5Mb DTI/PRIDescription, Installation and Maintenance

Document Number: 553-3011-310Document Release: Standard 14.00Date: November 2002

Year Publish FCC TM

Copyright © 1992–2002 Nortel NetworksAll Rights Reserved

Printed in Canada

Information is subject to change without notice. Nortel Networks reserves the right to make changes in design or components as progress in engineering and manufacturing may warrant. This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to Part 15 of the FCC rules, and the radio interference regulations of Industry Canada. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses and can radiate radio frequency energy, and if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at their own expense.

SL-1, Meridian 1, and Succession are trademarks of Nortel Networks.

Title page

Page 3 of 114

1.5Mb DTI/PRI Description, Installation and Maintenance

Revision historyNovember 2002

Standard 14.00. This document is up-issued to support Meridian 1 Release 25.40 and Succession Communication Server for Enterprise 1000, Release 2.0.

January 2002Standard 13.00. This document is up-issued to support Meridian 1, Release 25.40.

December 2000 Standard 12.00. This document is up-issued to support Option 11C IP Expansion field trials Release 25.3x.

April 2000Standard 11.00. This document is up-issued to support Release 25.0x. Document changes include removal of redundant content; references to equipment types except Options 11C, 51C, 61C, and 81C; and references to previous software releases.

May 1999Standard 10.00. This document is up-issued to support Generic Release 24.0x.

October 1997Standard 9.00. This document is up-issued to support Generic Release 23.0x.

September 1996Standard 8.00. This document is up-issued to support Generic Release 22.0x.

November 1995Standard 7.00. This document is up-issued to support Generic Release 21.1x.

Page 4 of 114 Revision History

553-3011-310 Standard 14.00 November 2002

July 1995Standard 6.00. This document is up-issued to support Generic Release 21.0x.

December 1994Standard 5.00. This document is up-issued to support Generic Release 20.0x.

July 1994Standard 4.00. This document is up-issued to support Generic Release 19.0x.

February 1994Standard 3.00. This document is up-issued to support Generic Release 18.0x.

January 1993Standard 2.00. This document is up-issued to support Generic Release 17.0x.

April 1992Standard 1.00. This document is issued to support Generic Release 16.0x.

Contents Page 5 of 114


Contents

About this document . . . . . . . . . . . . . . . . . . . . . . . 7Subject . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Applicable systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Intended audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Related information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

PRI implementation . . . . . . . . . . . . . . . . . . . . . . . . . 9Contents .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Reference list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Hardware requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Hardware description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Install PRI hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

DTI implementation . . . . . . . . . . . . . . . . . . . . . . . . . 45Contents .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Reference list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45



Install DTI hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Software enable the DTI/PRI cards .. . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Page 6 of 114 Contents


DTI/PRI maintenance . . . . . . . . . . . . . . . . . . . . . . . 59Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Reference list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Monitor DTI/PRI operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

DTI/PRI maintenance tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

ISL implementation . . . . . . . . . . . . . . . . . . . . . . . . 93Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Reference list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93


Basic ISL implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

ISL maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 107Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

Reference list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

ISL maintenance tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Page 7 of 114


8

About this documentThis document is a global document. Contact your system supplier or your Nortel Networks representative to verify that the hardware and software described is supported in your area.

SubjectThe 1.5 Mb DTI/PRI Description, Installation and Maintenance Guide contains specific information on how to configure 1.5 Mb ISDN DTI/PRI on Meridian 1, Option 11C, or Succession Communication Server for Enterprise (CSE) 1000.

Applicable systemsThis document applies to a Meridian 1 large system (Option 51C, 61C, or 81C), a Meridian 1 small system (Option 11C or 11C Mini), and a Succession Communication Server for Enterprise (CSE) 1000 system. For the purposes of this document, all of these systems are referred to generically as “system.”

Intended audience This document is intended for individuals responsible for planning, engineering, and administration of the applicable system.

Related informationFor general information, and for information on software features, refer to Networking Features and Services (553-2901-301).

Page 8 of 114 About this document


For specific circuit card information, refer to the Circuit Card Reference Guide (553-3023-211).

Page 9 of 114


44

PRI implementation

ContentsThis section contains information on the following topics:

Reference list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9



Install PRI hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Reference listThe following are the references in this section:

• Networking Features and Services (553-2901-301)

• Software Input/Output: Administration (553-3001-311)

• Option 11C and 11C Mini Technical Reference Guide (553-3011-100)

• Option 11C Planning and Installation (553-3021-210)

• Installation and Configuration (553-3023-210)

OverviewDigital trunks are supported in the Option 11C main cabinet, the IP expansion cabinet, and the Succession CSE 1000 Media Gateway chassis.

Page 10 of 114 PRI implementation


This chapter provides the information required to install PRI on a system:

• hardware and software installation

• implementation procedures for basic call service

While either the hardware or software can be installed first, the PRI cannot be enabled and tested until both are completed.

Hardware requirements

Circuit cards

To implement PRI on the system, the hardware shown in Table 1 is required.

Table 1Required circuit cards

Circuit card Description

NTRB21 DTI/PRI TMDI card. (recommended for Succession CSE 1000).

NTAK09 DTI/PRI circuit card.

NTAK20 Clock-controller daughterboard. Option 11C supports only one active clock controller per system or IP expansion cabinet.

Note: Every cabinet/Media Gateway that contains a digital trunk must contain a clock controller. Succession CSE 1000 supports only one active clock controller per Media Gateway.

NTAK93 D-channel-handler interface (DCH) daughterboard.

NTBK51BA Downloadable D-channel daughterboard (DDCH). Connects to the NTAK09 DTI/PRI card.

PRI implementation Page 11 of 114


Cables

The following cables are required for PRI connections:

• PRI to external T1 cable

• NTBK04 carrier cable

• NT8D97 50 foot extension (if needed)

Channel Service Units (CSU)

When connecting the DTI/PRI to the public network, CSUs are required by most operating companies. One CSU is required per PRI. Suitable CSUs which support 64 Kbps clear and Bipolar 8 Zero Substitution (B8ZS) are available from vendors such as Verilink, Digitalink, Kentrox, and Tellabs.

Note: Contact your Nortel Networks Sales representative for specific local CSU requirements.

Hardware description

Media Gateway/Media Gateway Expansion

The Media Gateway and Media Gateway Expansion contain physical card slots, numbered 1 to 10. When configuring the Succession CSE 1000 system, the physical card slot numbers must be transposed to logical card slot numbers. For example, to configure a card physically located in slot two of Media Gateway one, use logical slot 12. To configure a card physically located in slot two of Media Gateway two, use logical Slot 22.



Table 2 on page 12 maps physical card slot numbers to logical card numbers for the Media Gateway and Media Gateway Expansion and reflects added support for the Media Gateway and Media Gateway Expansion physical card slot 4.

Table 2Media Gateway and Media Gateway Expansion slot assignments

Media Gateway/Media Gateway Expansion

First Second Third Fourth

Physicalcardslot

Logicalcardslot

Physicalcardslot

Logicalcardslot

Physicalcardslot

Logicalcardslot

Physicalcardslot

Logicalcardslot

MediaGateway

1 11 1 21 1 31 1 41

2 12 2 22 2 32 2 42

3 13 3 23 3 33 3 43

4 14 4 24 4 34 4 44

5 * 5 * 5 * 5 *

6 * 6 * 6 * 6 *

MediaGateway

Expansion

7 17 7 27 7 37 7 47

8 18 8 28 8 38 8 48

9 19 9 29 9 39 9 49

10 20 10 30 10 40 10 50

Legend* Not supported.



NTRB21 TMDI card

The NTRB21 TMDI card provides 1.5 MBit/s Digital Trunk Interface or Primary Rate Interface functionality on the system. The NTRB21 has a built-in, downloadable D-channel which can occupy any single card slot (1-9) in the Option 11C main cabinet. In an IP expansion cabinet, the card can be placed in slots 11-19, 21-29, 31-39 or 41-49 of the first, second, third and fourth expansion cabinets, respectively.

For Succession CSE 1000, the card can be placed in slots 11-14, 21-24, 31-34, 41-44 of of the first, second, third and fourth Media Gateways, respectively.

Note: For Succession CSE 1000, physical card slots are numbered 1-4 on the first, second, third and fourth Media Gateways.

The Media Gateway Expansion does not support digital trunks (DTI/PRI).

Note 1: For CISPR B group cabinets, the active Clock Controller (NTAK20) can only occupy slots 1-3, 11-13, 21-23, 31-33, or 41-43 in an Option 11C cabinet. For FCC and/or CISPR A group cabinets, this limitation does not exist.

Note 2: The NTRB21can be equipped with the NTAK09 DTI/PRI card (with the NTBK51 downloadable D-channel daughterboard) and the NTAK93 DCHI daughterboard.

Figure 1 on page 14 shows a faceplate of the NTRB21 TMDI card.



Figure 1NTRB21 TMDI card faceplate

TMDI

Rx

Tx

OOSACT

REDYELLBKCCDCH

................................................................

MAINT

RS232 Monitor Port



NTAK09 DTI/PRI circuit card

The NTAK09 Digital Trunk Interface/Primary Rate Interface (DTI/PRI) card provides the physical interface for the DS-1 facility T-1 carrier on the system. It is required for PRI and DTI operation and is also used for ISL shared-mode applications.

Shelf slot assignment

The DTI/PRI card occupies any single card slot (1-9) in the Option 11C main cabinet. On IP expansion cabinets, it can be placed in slots 11-19, 21-29, 31-39, 41-49 of the first, second, third, and fourth expansion cabinets, respectively. Figure 2 on page 16 shows the faceplate layout, the location of the switch and the position of the daughterboards and connectors. See “DTI/PRI maintenance” on page 59 in this guide for information about the faceplate LEDs.

For Succession CSE 1000, the NTAK09 card can be placed in slots 11-14, 21-24, 31-34, 41-44 of of the first, second, third and fourth Media Gateways, respectively.


Digital trunk cards are not supported in the Media Gateway Expansion.



Figure 2NTAK09 DTI/PRI circuit card

DISACTREDYELLBKCCDCH

RCV

XMT

NTAK09

1.5 MBDTI/PRI

ON

1 2 3 4DC

H F

/WLE

N 0

LEN

1Le

n 2

SWON

1 2 3 4D

CH

F/W

LEN

0LE

N 1

Len

2553-8294.EPS

SW

Stiffeners

ConnectorSockets

LEDs

BantamJacks

StandoffsSwitch



NTAK20 Clock Controller (CC) daughterboard

Digital Trunking requires synchronized clocking so a shift in one clock source results in an equivalent shift of the same size and direction in all parts of the network. Synchronization is accomplished with the NTAK20 clock controller circuit card in each Main and IP expansion cabinet/Media Gateway.

Note: Clocking slips can occur between systems that are clocked from different COs, if the COs are not synchronized. The slips can degrade voice quality.

The Clock Controller circuitry synchronizes the system to an external reference clock and generates and distributes the clock to the system. Option 11C can function either as a slave to an external clock or as a clocking master. The NTAK20AA version of the clock controller meets AT&T Stratum 3 and Bell Canada Node Category D specifications. The NTAK20BA version meets CCITT stratum 4 specifications.

Clocking modes

The system supports a single clock controller that can operate in one of two modes: tracking or non-tracking (also known as free-run).

IMPORTANT!

Every Option 11C cabinet or Media Gateway chassis that contains a digital trunk must contain a clock controller.

If an Option 11C is equipped with digital trunks, it is recommended that at least one digital trunk be placed in the main cabinet. For Succession CSE 1000 systems, the digital trunk must be placed in the Media Gateway.



Tracking mode

In tracking mode, one or possibly two DTI/PRI cards supply a clock reference to a clock controller daughterboard. When operating in tracking mode, one DTI/PRI is defined as the primary reference source for clock synchronization, while the other is defined as the secondary reference source (PREF and SREF in LD 73).

There are two stages to clock controller tracking:

• tracking a reference, and

• locked onto a reference.

When tracking a reference, the clock controller uses an algorithm to match its frequency to the frequency of the incoming clock. When the frequencies are very nearly matched, the clock controller locks onto the reference. The clock controller makes small adjustments to its own frequency until incoming and system frequencies correspond.

If the incoming clock reference is stable, the internal clock controller tracks it, locks onto it, and matches frequencies exactly. Occasionally, however, environmental circumstances cause the external or internal clocks to drift. When this happens, the internal clock controller briefly enters the tracking stage. The green LED flashes momentarily until the clock controller locks onto the reference once again.

If the incoming reference is unstable, the internal clock controller is continuously in the tracking stage, with the LED flashing green all the time. This condition does not present a problem, rather, it shows that the clock controller is continually attempting to lock onto the signal. If slips are occurring, however, there is a problem with the clock controller or the incoming line.

Free-run (non-tracking)

In free-run mode, the clock controller does not synchronize on any source, it provides its own internal clock to the system. This mode can be used when the system is used as a master clock source for other systems in the network. Free-run mode is undesirable if the system is intended to be a slave. It can occur, however, when both the primary and secondary clock sources are lost due to hardware faults or when invoked by using software commands.



Shelf slot assignment

For Succession CSE 1000, the NTAK20 card can be placed in slots 11-14, 21-24, 31-34, 41-44 of of the first, second, third and fourth Media Gateways, respectively.


On non-CISPR B system cabinets, the NTAK20 can be placed in slots 1-9 of the Option 11C main cabinet. On cabinets NTAK11Dx and NTAK11Fx, the active NTAK20 must be placed in slots 1-3 (slots 4-10 cannot be used.)

On non-CISPR B IP expansion cabinets, the NTAK20 can be placed in slots 11-19, 21-29, 31-39, 41-49 of the first, second, third, and fourth expansion cabinets, respectively.

Clock controller LED states

The clock controller LED, on the NTAK09 or NTRB21 faceplates, is in various states, depending on the status of the clock controller.

Table 3Clock controller LEDs

LED Clock controller

On (Red) NTAK20 is equipped and disabled.

On (Green) NTAK20 is equipped and is either locked to a reference or in free run mode.

Flashing (Green)

NTAK20 is equipped and attempting to lock (tracking mode) to a reference. If the LED flashes continuously over an extended period of time, check the CC STAT in LD60. If the CC is tracking this can be an acceptable state. Check for slips and related clock controller error conditions. If none exist, then this state is acceptable, and the flashing is identifying jitter on the reference.

Off NTAK20 is not equipped.



NTAK93 D-channel Handler Interface (DCHI) daughterboard

The NTAK93 DCHI daughterboard interfaces with the system Central Processing Unit (CPU) and mounts on the NTAK09 DTI/PRI circuit card for PRI or ISL shared mode applications. The DCHI is responsible for performing the Q.921 layer 2 protocol information. It transfers layer 3 signaling information between two adjacent network switches.

The NTAK93 DCH daughterboard, when installed on the NTAK09 circuit card, is addressed in the same slot as the NTAK09. The NTAK93 can use SDI I/O addresses 0 to 79 and port 1.

Note: I/O addresses 0, 1, 2, 8 and 9 are preconfigured on the Option 11C and must not conflict with the I/O addresses on the NTAK93 card.

A minimum of one NTAK93 is required for each PRI link. If more than one PRI link connects to the same end location, a single DCHI circuit card can support up to a maximum of sixteen PRI connections for the Option 11C and Succession CSE 1000 system. This allows a total of 382 B-channels or PRI trunks to be supported if a backup D-channel is also used. A total of 383 B-channels or PRI trunks are supported if a backup channel is not used.

NTBK51BA Downloadable D-channel (DDCH) daughterboard

The NTBK51BA DDCH daughterboard interfaces with the Option 11C Central Processing Unit (CPU) and mounts on the NTAK09 DTI/PRI circuit card for PRI D-channel applications. The DDCH is equivalent to the MSDL card used on the larger Meridian 1 systems, but it only supports D-channel applications (no SDI or ESDI).

The NTBK51BA DDCH daughterboard, when installed on the NTAK09 circuit card, is addressed in the same slot as the NTAK09.

A minimum of one NTBK51BA is required for each PRI link. If more than one PRI link connects to the same end location, a single DDCH circuit card can support up to a maximum of sixteen PRI connections for the Option 11C Succession CSE 1000 system. This allows a total of 382 B-channels or PRI trunks to be supported if a backup D-channel is also used. A total of 383 B-channels or PRI trunks are supported if a backup channel is not used.



For more information on expansion daughterboards, refer to Option 11C and 11C Mini Technical Reference Guide (553-3011-100).

Install PRI hardware

Insert/remove the NTRB21 TMDI card

Insert the NTRB21 TMDI circuit card into card slot 1-9 in the Option 11C Main cabinet, or in slots 11-19, 21-29, 31-39, 41-49 of the first, second, third, and fourth Expansion cabinets, respectively.

For Succession CSE 1000, the NTRB21 TMDI circuit card can be placed in slots 11-14, 21-24, 31-34, 41-44 of of the first, second, third and fourth Media Gateways, respectively.


The NTRB21 card is installed only in the Media Gateway. It is not supported in the Media Gateway Expansion.

Procedure 1Inserting the NTRB21 TMDI card

Check for available card slots in the base cabinet and print the configuration record to determine which slots can be used. To do this, use PRT CFN in LD 22. Then, use the following steps:

1 If in PRI mode, enter the following command in LD 96 to software disable the D-channel:

DIS DCH x

Where x is the DCH port number that was assigned in LD 17.

2 If the Clock Controller is enabled, enter the following command in LD 60 to software disable it:

DIS CC 0

3 Hold the NTRB21 by the lock latch, unlock the latch, and slide the card into the cabinet.



Note 1: For Option 11C, insert the NTRB21 TMDI circuit card into card slot 1-9 in the main cabinet, or in slots 11-19, 21-29, 31-39, 41-49 of the first, second, third, and fourth expansion cabinets, respectively.

Note 2: For Succession CSE 1000, insert the NTRB21 TMDI circuit card into card slot 11-14 of the Media Gateway.

4 Enter the following command in LD 96 to enable the TMDI card:

ENL TMDI x ALL

Where x is the NTRB21 TMDI card number (DLOP). The card number associated with a NTRB21 TMDI card is based on the slot in which the card is installed.

5 Within about 30 seconds, the D-channel layer 3 should be established. To confirm, enter the following command in LD 96 to request the current status of the D-channel:

STAT DCH (N)

The system response is:

DCH N EST OPER

This means that the D-channel is established and operational.

End of Procedure

Procedure 2Removing the NTRB21 TMDI card

1 If in PRI mode, enter the following command in LD 96 to software disable the D-channel:

DIS DCH x

Where x is the DCH port number that was assigned in LD 17.

2 If the Clock Controller is enabled, enter the following command in LD 60 to software disable it:

DIS CC 0

3 Enter the following command in LD 96 to disable the NTRB21 TMDI card:

DIS TMDI x All




4 Hold the NTRB21 by the lock latch, unlock the latch, and slide the card out from the cabinet.

End of Procedure

Procedure 3Mounting the NTAK20 daughterboard on the NTRB21

Mount the NTAK20 daughterboard on the NTRB21. Work on a flat surface when mounting or removing daughterboards.

1 Visually inspect the connector pins on the underside of the daughterboard. Re-align any bent pins prior to mounting.

2 Place the NTRB21 down flat on an anti-static pad.

3 From an overhead view, with the daughterboard parallel above the NTRB21 and the connector pins aligned over the connector sockets, line up the mounting holes on the daughterboard (Figure 3 on page 24) with the tops of the standoffs on the NTRB21.

4 Slowly lower the daughterboard towards the NTRB21, keeping the standoffs in line with all four holes, until the holes are resting on the tops of the four standoffs.

If more than a very slight amount of pressure is required at this point, the connector pins cannot be aligned with the connector socket. If so, lift the daughterboard off the NTRB21 and return to step 2.

5 Gently apply pressure along the edge of the board where the connector is located until the standoffs at the two corners adjacent to the connector snap into a locked position. Then press down on the two corners on the opposite side until they also lock into place.

End of Procedure



Figure 3NTAK20 daughterboard installation

Procedure 4Mounting the NTAK93 or NTBK51 daughterboard on the NTAK09

Mount the NTAK93 DCHI or NTBK51 DDCH daughterboard before the NTAK20 daughterboard. Work on a flat surface when mounting or removing daughterboards.

1 Visually inspect the connector pins on the underside of the daughterboard. Re-align any bent pins prior to mounting.

2 Place the NTAK09 down flat on an anti-static pad.

OOSACTREDYELLBKCCDCH

RCV

XMT

NTRB21

TMDI

SWON

1 2 3 4

DC

H F

/WL

EN

0L

EN

1L

en 2

553-9024

Stiffeners

NTAK20Clock

Controller

Mounting Holes

Connector Socket

Connector Pins

LEDs

BantamJacks

Standoffs



3 From an overhead view, with the daughterboard parallel above the NTAK09 and the connector pins aligned over the connector sockets, align the mounting holes on the daughterboard (Figure 4 on page 26) with the tops of the standoffs on the NTAK09.

4 Slowly lower the daughterboard toward the NTAK09, keeping the standoffs in line with all four holes, until the holes rest on top of the four standoffs.

Note: If more than a very slight amount of pressure is required at this point, the connector pins are not aligned with the connector socket. If so, lift the daughterboard off the NTAK09 and return to step 2.

5 Gently apply pressure along the edge of the board where the connector is located until the standoffs at the two corners adjacent to the connector snap into a locked position. Then press down on the two corners on the opposite side until they also are locked into place.

End of Procedure



Figure 4Daughterboard installation

NTAK20Clock

Controller

NTAK93DCHI

orNTBK51BA

DDCH

DISACTREDYELLBKCCDCH

RCV

XMT

NTAK09

1.5 MBDTI/PRI

ON

1 2 3 4DC

H F

/WL

EN

0L

EN

1L

en

2

SWON

1 2 3 4

DC

H F

/WL

EN

0L

EN

1L

en

2

553-8295.EPS

SW

Stiffeners

Mounting Holes

Connector Socket

Connector Pins

LEDs

BantamJacks

StandoffsSwitch



Procedure 5Removing the daughterboards from the NTAK09

Use these guidelines to remove the NTAK20 CC and the NTAK93 DCHI or NTBK51 DDCH daughterboards from the NTAK09 DTI/PRI card. Because of the physical layout of the mother and daughterboards, the NTAK20 should be removed before the NTAK93 or NTBK51.

1 Starting at the two corners opposite the connector, gently lift each corner out of the locking groove of the standoff.

2 At the two corners adjacent to the connector, gently lift the entire side until the mounting holes are clear of the locking groove of the standoff.

3 To remove the connector pins, grasp the edge of the board adjacent to the connector and lift gently.

If more than one NTAK09 card is installed, the additional cards might not carry daughterboards, depending on the system configuration. At least one NTAK20 (per system) is always required.

End of Procedure

Set the switches

Set the switches on the NTAK09 DTI/PRI card according to the Table 4.

Table 4NTAK09 switch settings

Distance to digital cross-connect

1DCH F/W

2(LEN 0)

3(LEN 1)

4(LEN 2)

0 - 133 feet Off Off Off On

133 - 266 feet Off On On Off

266 - 399 feet Off Off On Off

399 - 533 feet Off On Off Off

533 - 655 feet Off Off Off Off



Procedure 6Installing the NTAK09

1 Check for available card slots in the base cabinet/Media Gateway and print the configuration record to determine which slots can be used. To do this, enter the following command in LD 22:

PRT CFN

2 Insert the NTAK09 circuit card into slots 1-9 in the main cabinet, or in slots 11-19, 21-29, 31-39, 41-49 of the first, second, third, and fourth IP expansion cabinets, respectively.

Note: For Succession CSE 1000, the NTAK09 card can be placed in slots 11-14, 21-24, 31-34, 41-44 of of the first, second, third and fourth Media Gateways, respectively. For Succession CSE 1000, physical card slots are numbered 1-4 on the first, second, third and fourth Media Gateways. The NTAK09 card is installed only in the Media Gateway. It is not supported in the Media Gateway Expansion.

End of Procedure

Procedure 7Connecting the cables

For Option 11C, connect the NTBK04 cable to the 50-pin Amphenol below the card slot in which the NTAK09 circuit card is installed. Connect the other end of the cable to the CSU or DSX-1 cross connect.

For Succession CSE 1000, connect the NTBK04 cable to a 50-pin amphenol on the rear of the Media Gateway chassis. The amphenol connectors are labelled with the card slot numbers to which they correspond.

The NTBK04 is twenty feet long. If additional distance is required, the NT8D97AX fifty-foot extension is available up to a 600 foot maximum. The only cable required to support the NTAK09 circuit card is the NTBK04.



If you require pinout information on the NTBK04 cable, refer to Table 5.

End of Procedure

Software enable the DTI/PRI cards

Procedure 8Enabling the DTI/PRI cards

1 Enter the following command in LD 96 to enable the NTRB21 TMDI card:

ENL TMDI x ALL

Where x is the NTRB21 TMDI card number (DLOP). The card number associated with a NTRB21 TMDI card is based on the slot in which the card is installed (1-49).

2 If in PRI mode, enter the following command in LD 96 to software enable the D-channel:

ENL DCH y

Where y is the DCH port number that was assigned in LD 17.


Table 5DS-1 line interface pinout for NTBK04 cable

From 50-pin MDF connector to DB-15

Signal name Description

pin 48 pin 1 T transmit tip to network

pin 23 pin 9 R transmit ring to network

pin 25 pin 2 FGND frame ground

pin 49 pin 3 T1 receive tip from network

pin 24 pin 11 R1 receive ring from network



STAT DCH (N)


DCH N EST OPER


End of Procedure

Procedure 9Enabling the NTAK09 card

Use step 1 to enable the NTAK09 DTI/PRI card. If the clock controller and D-channel interface are not enabled in step 1, go to step 2.

1 Enter the following command in LD 60 to software enable all NTAK09 DTI/PRI cards:

ENLL C

Where C is the DTI/PRI card number (DLOP). The card number associated with a DTI/PRI card is based on the slot in which the card is installed.

Note: The DCHI and PRI cards must be implemented prior to software enabling the NTAK09. Refer to the procedure “Implementing basic PRI” on page 31 for further information.

Under normal conditions, this step enables the clock controller and D-channel interface. If enable fails, go to step 2.

2 Optional: Enter the following command in LD 60 to software enable clock tracking on the primary digital card:

ENL CC 0

3 Enter the following command in LD 96 to software enable the NTAK93 (DCHI) daughterboard:

ENL DCHI N

Where N is the DCHI I/O address.


STAT DCH (N)




DCH N EST OPER


End of Procedure

Procedure 10Implementing basic PRI

Use this procedure to configure the PRI cards, DCHI interface, DCH link and ISDN trunk route and trunks (B-channels) that are required to implement PRI between systems. No feature applications other than Basic Call Service are included in the implementation.

PRI cards must be configured before defining the DCH links or PRI applications.

Prompts which do not show a response can be left at default. For more information on any of these prompts, refer to Software Input/Output: Administration (553-3001-311).

Before installing PRI cards in an IP expansion cabinet/Media Gateway, first configure the expansion cabinet/Media Gateway for IP connectivity. Refer to Overlay 117 in the Software Input/Output: Maintenance (553-3001-511) for further information.

To implement PRI on the system:

1 Add a PRI card. See “Define clock synchronization. See “LD 73 — Defining system timers and clock controller parameters” on page 39.” on page 31.

2 Add a DCHI card. See “LD 17 — Adding a PRI card” on page 32.

3 Define a PRI customer. See “LD 15 — Defining a PRI customer” on page 35.

4 Define a PRI service route. See “LD 16 — Configuring an ISDN service route” on page 37.

5 Define service channels (B-channels) PRI trunks. See “LD 14 — Defining service channels and PRI trunks” on page 38.

6 Define clock synchronization. See “LD 73 — Defining system timers and clock controller parameters” on page 39.

End of Procedure



LD 17 — Adding a PRI card

Prompt Response Description

REQ CHG Change data.

TYPE CFN Configuration data block.

CEQU YES Changes to common equipment.

PRI XX The PRI digital card number, where:xx = 1-9 (main cabinet), 11-19 (IP expansion cabinet1), 21-29 (IP expansion cabinet 2), 31-39 (IP expansion cabinet 3), 41-49 (IP expansion cabinet 4.)

LD 17 — Adding a D-channel interface (Part 1 of 3)


REQ CHG Change existing data.

TYPE ADAN Action Device And Number.

- ADAN NEW DCH xxCHG DCH xxOUT DCH xx

Add a primary D-channel (any unused SDI port.)Change a primary D-channel.Out the primary D-channel, where:

xx =0-79.

- CTYP DCHI

MSDL

TMDI

DCHI = D-channel configuration for the NTAK09 card or NTAK93.MSDL = the NTBK51 Downloadable D-channel daughterboard.TMDI = D-channel configuration on TMDI (NTRB21) card.



- CDNO 1-50 Card slot number to be used as the primary DDCH/DCHI.

Card slots 10, 20, 30, 40, and 50 are only applicable for D-channel configuration of ISL or VNS.

- PORT 1 PORT must be set to 1.

- DES <CR> Designator.

- USR PRI D-channel is for ISDN PRI only.

- IFC xx Interface type.

- - DCHL xx PRI card number that carries the D-channel. Must match the entry made for the “CDNO” associated with the “DCHI” prompt above, where:

xx = 1-9 for main cabinet, 11-19 for IP expansion cabinet 1, 21-29 for IP expansion cabinet 2, 31-39 for IP expansion cabinet 3, and 41-49 for IP expansion cabinet 4.

For Succession CSE 1000, xx = 11-14 Media Gateway 1, 21-24 for Media Gateway 2, 31-34 for Media Gateway 3 and 41-44 for Media Gateway 4.

- OTBF 1-(16)-127 Number of output request buffers. Note: for a single PRI link, leave this prompt at default (16). Add 5 output request buffers per additional link.

- DRAT 64KC D-channel transmission rate.

- SIDE NET (USR) Prompted only if IFC is set to SL1.NET = network, the controlling switch.USR = slave to the controller.





- RLS XX X11 (x21 for Succession CSE 1000) software release of far-end. This is the current software release of the far-end. If the far-end has an incompatible release of software, it prevents the sending of application messages, that is for Network Ring Again.

- RCAP ND2 Remote capability.

- OVLR YES (NO) Allow or disallow overlap receiving on a D-channel. Default is NO. Enter carriage return if settings are to be left at default.

- LAPD YES (NO) Change LAPD parameters. Enter carriage return if timers are to be left at default. The following timers are prompted only if LAPD is set to YES. (They can all be left at default during initial set-up.)

- - T23 1-(20)-31 Interface guard timer checks how long the interface takes to respond. In units of 0.5 seconds (default 20 = 10 seconds).

- - T200 2-(3)-40 Retransmission timer in units of 0.5 seconds (default 3 = 1.5 seconds).

- - N200 1-(3)-8 Maximum number of retransmissions.

- - N201 4(260) Maximum number of octets in information field.

- - K 1-(7)-32 Maximum number of outstanding unacknowledged frames (NAKS).





LD 15 — Defining a PRI customer (Part 1 of 2)


REQ: NEWCHG

Add new data.Change existing data.

TYPE NET Networking Data.

CUST 0-31 Customer number.

LDN0 xxxx Listed Directory number 0 must be defined for ISDN PRI DID service.

The length of LDN0 determines the number of trailing digits translated as the dialed DN on PRI DID routes.

Up to seven digits can be entered if DNXP option 150 is equipped. Otherwise, up to four digits can be entered.

AC2 ESN Access Code 2. Enter incoming ISDN call types (NARS network translation types) for which AC2 must be inserted when INAC = YES in LD 16 Route Data Block.

Multiple responses are allowed. Prompted only if NARS is equipped. If a NARS call type is not entered here, it is defaulted to AC1.

NPA E.164 National.

NXX E.164 Subscriber.

INTL International.

SPN Special Number.

LOC Location Code.

ISDN YES Customer is equipped with ISDN.



- PNI (0) 1-32700 Private Network Identifier. Each customer data block must have a unique PNI when multi-customer option is equipped. PNI = 1 is typical for CUST = 0. It must be matched by the PNI in the far-end RDB.

Note: using the default value of PNI = 0, prevents operation of features like NRAG, NACD and NMS.

- HNPA NPA Telephone area code for this system. Sent as part of setup message as calling line identification.

- HNXX NXX Telephone local exchange code for this system. Sent as part of setup message as calling line identification.

- - HLOC XXX Home location code (NARS), prompted when PRA = YES.

- - LSC 1-9999 One to four digit Local Steering Code, if required in the Coordinated Dialing Plan (CDP). LSCs are required only if the CDP DNs are longer than the local PDNs.

The CLID sent for a CDP call is composed of the LSC defined in LD 15 plus the PDN of the calling set. Various ISDN network features depend on the CLID as the “return address” for sending feature control messages.

Multiple LSCs can be defined in LD 87 for CDP, but only one LSC can be defined here for CLID.

LD 15 — Defining a PRI customer (Part 2 of 2)




LD 16 — Configuring an ISDN service route (Part 1 of 2)


REQ NEWCHG


TYPE RDB Route data block.

TKTP xxx Trunk type.

DTRK YES Digital trunk route.

- DGTP PRI 1.5 Mb PRI. Prompted only if PRA = YES in LD15.

ISDN YES ISDN option.

- MODE PRA Route used for PRA only.

- - PNI (0) 1-32700 Private Network Identifier. Each customer data block must have a unique PNI when multi-customer option is equipped. PNI = 1 is typical for CUST = 0. It must be matched by the PNI in the far-end RDB.

Note: Using the default value of PNI = 0, prevents operation of features like NRAG, NACD and NMS.

IFC xx Interface type.

- CHTY BCH Signalling type - prompted if DTRK is YES. D-channel signalling for B-channels.

- CTYP <CR> Call Type. Enter the call type to be associated with the outgoing route for direct dialing using the trunk access code (instead of NARS access code).

See the Software Input/Output: Administration (553-3001-311) for a listing of possible responses.



- INAC YES Insert ESN Access Code based on NARS/BARS call type for incoming calls on Tie routes only. If NARS is equipped, this feature inserts AC1 or AC2, depending on the responses to AC2 in LD 15 Customer Data Block.

For NARS/BARS call types, INAC bypasses incoming digit insertion specified by INST in LD 16 Route Data Block.

Unknown call types, including CDP steering codes, are not affected by INAC, and do not bypass digit insertion specified by INST.

INAC must be set to YES to support features such as Network ACD and Network Message Services, which depend on non-call associated TCAP facility messages.

LD 14 — Defining service channels and PRI trunks (Part 1 of 2)


REQ NEWCHG


When assigning several members at once use the multiple create command NEW XX.

TYPE TIE Tie Trunk only, allowed between MSL-1.

LD 16 — Configuring an ISDN service route (Part 2 of 2)




TN c ch Enter the PRI trunk card (c) and channel number (ch).

Where: c = 1-9 for main cabinet, 11-19 for IP expansion cabinet 1, 21-29 for IP expansion cabinet 2, 31-39 for IP expansion cabinet 3, and 41-49 for IP expansion cabinet 4.

For Succession CSE 1000, c = 11-14 Media Gateway 1, 21-24 for Media Gateway 2, 31-34 for Media Gateway 3 and 41-44 for Media Gateway 4.

ch = 1-30

RTMB 0-127 1-510 Route number and member number.

LD 73 — Defining system timers and clock controller parameters (Part 1 of 5)


REQ CHG Change data.

TYPE PRI 1.5 Mb PRI.

FEAT SYTI System timers.

... just option 11 and mini (will be 1-4 here)

CC1 xx Card slot number for Clock Controller 1.

For Option 11C:

xx = 11-19

For Option 11C Mini:

xx = 11-14

For Succession CSE 1000 Media Gateway 1:

xx = 11-14

LD 14 — Defining service channels and PRI trunks (Part 2 of 2)




PREF CC1 xx Card slot number of PRI card containing the prImary clock reference for IP expansion cabinet 1 and Media Gateway 1.

For Option 11C:

xx = 11-19


xx = 11-14


xx = 11-14

SREF CC1 xx Card slot number of PRI card containing the secondary clock reference for IP expansion cabinet 1 and Media Gateway 1.

For Option 11C:xx = 11-19

For Option 11C Mini:xx = 11-14

For Succession CSE 1000 Media Gateway 1:xx = 11-14

















































CCAR 0-(15) Clock Controller Audit Rate. Enter the time (in minutes) between normal CC audits.





Page 45 of 114


58

DTI implementation


Reference list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45



Install DTI hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Software enable the DTI/PRI cards. . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Reference listThere are no references for this chapter.

OverviewThis chapter provides the information required to install DTI on a system, including:


• implementation procedures for basic call service

This chapter covers the most common type of Nortel Networks DTI installation, a 24-channel Digital Trunk Interface (DTI) installation between two systems, or a system and a central office.

Page 46 of 114 DTI implementation


Since Release 25.30 software, digital trunks are supported in Option 11C IP expansion cabinets.

Hardware requirementsTo implement DTI on the system, hardware listed in Table 6 is required:

Cables

The following cables are required for DTI connections:

• DTI to external T1 cable

• NTBK04 carrier cable

• NT8D97 50 foot extension (if needed)

Channel Service Units (CSU)

When connecting the DTI/PRI to the public network, Channel Service Units (CSUs) are required by most operating companies. One CSU is required per DTI. Suitable CSUs which support 64 Kbps clear and Bipolar 8 Zero Substitution (B8ZS) are available from vendors such as Verilink, Digitalink, Kentrox and Tellabs.

Table 6DTI hardware

Item Description

NTRB21 DTI/PRI TMDI card

NTAK09 DTI/PRI Circuit card

NTAK20 Clock Controller Daughter board. Note: The Option 11C supports only one active Clock Controller per IP Expansion cabinet. Succession CSE 1000 supports only one active clock controller per Media Gateway.

NTBK04 Carrier Cable

DTI implementation Page 47 of 114


Note: Contact your Nortel Networks Sales representative for specific local CSU requirements.

Hardware descriptionRefer to “Hardware description” on page 11.

Install DTI hardwareFor information on how to install the NTRB21 DTI/PRI card, refer to “Insert/remove the NTRB21 TMDI card” on page 21 of the “Install PRI hardware” chapter. For information on how to install the NTAK09 DTI/PRI card, refer to “Installing the NTAK09” on page 28.

For information on how to install the NTAK20 Clock Controller, refer to “Mounting the NTAK20 daughterboard on the NTRB21” on page 23.

Set the switches

Set the switches on the NTAK09 DTI/PRI card according to Table 7.

Table 7NTAK09 switch settings

Distance to digital cross-connect

1DCH F/W

2(LEN 0)

3(LEN 1)

4(LEN 2)

0 - 133 feet Off Off Off On

133 - 266 feet Off On On Off

266 - 399 feet Off Off On Off

399 - 533 feet Off On Off Off

533 - 655 feet Off Off Off Off



Connect the cables

For Option 11C, connect the NTBK04 cable to the 50-pin amphenol below the card slot in which the NTAK09 circuit card is installed. Connect the other end of the cable to the CSU or DSX-1 cross connect.

For Succession CSE 1000, connect the NTBK04 cable to a 50-pin amphenol on the rear of the Media Gateway chassis. The amphenol connectors are labelled with the card slot numbers to which they correspond.

The NTBK04 is twenty feet long. If additional distance is required, the NT8D97AX fifty-foot extension is available up to a 600 foot maximum. The only cable required to support the NTAK09 circuit card is the NTBK04.

If you require pinout information on the NTBK04 cable, refer to Table 8.

Software enable the DTI/PRI cardsProcedure 11Enabling the NTRB21 TMDI card

1 Enter the following command in LD 96 to enable the NTRB21 TMDI card:

ENL TMDI x ALL

Table 8DS-1 line interface pinout for NTBK04 cable

From 50-pin MDF connector

to DB-15 Signal name

Description

pin 48 pin 1 T transmit tip to network

pin 23 pin 9 R transmit ring to network

pin 25 pin 2 FGND frame ground

pin 49 pin 3 T1 receive tip from network

pin 24 pin 11 R1 receive ring from network




2 If in DTI mode, enter the following command in LD 96 to software enable the D-channel:

ENL DCH y

Where y is the DCH port number that was assigned in LD 17.


STAT DCH (N)


DCH N EST OPER


End of Procedure

Procedure 12Enabling the NTAK09 card

Use step 1 to enable NTAK09 DTI/PRI card. If the clock controller and D-channel interface are not enabled in step 1, go to step 2.

1 Enter the following command in LD 60 to software enable all NTAK09 DTI/PRI cards:

ENLL C

Where C is the DTI/PRI card number (DLOP). The card number associated with a DTI/PRI card is based on the slot in which the card is installed.

2 The DCHI and DTI cards must be implemented prior to software enabling the NTAK09. Refer to the section “Implementing basic PRI” on page 31 for further information.

3 Under normal conditions, this step enables the clock controller and D-channel interface. If enable fails, go to step 2.

4 Optional: Enter the following command in LD 60 to enable clock tracking on the primary digital card:



ENL CC 0

5 Enter the following command in LD 96 to software enable the NTAK93 (DCHI) daughterboard:

ENL DCHI N

Where N is the DCHI I/O address.


STAT DCH (N)


DCH N EST OPER


End of Procedure

Procedure 13Implementing DTI

Use this procedure to implement the DTI software interface between systems or between a system and a central office.

1 Add a DTI card. Refer to “LD 17 — Adding a DTI card” on page 50.

2 Configure a DTI trunk route. Refer to “LD 16 — Configuring a DTI trunk route” on page 52.

3 Configure the trunks. Refer to “LD 14 — Configuring the trunks” on page 53.

4 Assign clock’s reference source. Refer to “LD 73 — Assigning a clock's reference source” on page 53.

LD 17 — Adding a DTI card (Part 1 of 3)






...

PARM YES

...

PCML (MU) A System PCM law. Default is MU law.

...

CEQU YES Changes to common equipment.

DLOP c dd ff Where:

• c is the DTI/PRI digital card number 1-9 (main cabinet), 11-19 (IP expansion cabinet1), 21-29 (IP expansion cabinet 2), 31-39 (IP expansion cabinet 3), 41-49 (IP expansion cabinet 4)

For Succession CSE 1000, 11-14 (Media Gateway 1), 21-24 (Media Gateway 2), 31-34 (Media Gateway 3), 41-44 (Media Gateway 4).

• dd is the number of data calls allowed (0-24) on this DTI (default 24).

• ff is the frame format used (D2,D3,D4,ESF) where default is ESF.

MODE TRK Select Digital Trunk Interface mode.

TMDI [YES] NO Whether the card is a TMDI card.

YALM DG2 (FDL) Yellow alarm method — prompted only if the frame format is ESF — Must match the far-end.

Use FDL with ESF and use DG2 with non-ESF. If not prompted then DG2 is set automatically.





TRSH 0-15 The maintenance and threshold table to be used for this DTI card, as configured in LD 73.

T1TE (0), 1, 2 T1 Transmit Equalization (0=0-200 ft., 1=200-400 ft, 2=400-700 ft). Only for TMDI = YES.

LD 16 — Configuring a DTI trunk route


REQ NEWCHG



TKTP Create a trunk route.

COT Central Office Trunk data block.

WAT WATS Trunk data block.

DID Direct Inward Dial Trunk data block.

TIE Tie Trunk data block.

FEX Foreign Exchange = Trunk data block.

DTRK YES Digital trunk route.





LD 14 — Configuring the trunks


REQ NEWCHG


TYPE XXX One of the trunk types defined in step 3.

TN c ch Enter the DTI/PRI trunk card (c) and channel number (ch), where:c = 1-9 (main cabinet), 11-19 (IP expansion cabinet 1), 21-29 (IP expansion cabinet 2), 31-39 (IP expansion cabinet 3), 41-49 (IP expansion cabinet 4)

For Succession CSE 1000, 11-14 (Media Gateway 1), 21-24 (Media Gateway 2), 31-34 (Media Gateway 3), 41-44 (Media Gateway 4)ch = 1-24

RTMB RRR MMM Route (created in step 3) (RRR) and member number (MMM).

LD 73 — Assigning a clock's reference source (Part 1 of 5)



TYPE DDB Digital Data Block.

CC0 1-9 Card slot number for Clock Controller 0.

PREF CCO 1-9 Card slot number of DTI card containing the primary clock reference for the main cabinet (this is the system clock).



SREF CC0 1-9 Card slot number of DTI card containing the secondary clock reference for the main cabinet (this is the system clock).


For Option 11C:

xx = 11-19


xx = 11-14


xx = 11-14


For Option 11C:

xx = 11-19


xx = 11-14


xx = 11-14

























































Page 59 of 114


92

DTI/PRI maintenance


Reference list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Monitor DTI/PRI operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

DTI/PRI maintenance tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64


• Software Input/Output: System Messages (553-3001-411)

OverviewFrom a maintenance perspective, DTI/PRI operation consists of these major elements:

• hardware and software states

• near-end and far-end status

• link and/or span integrity

• clocking status

• frame alignment

Page 60 of 114 DTI/PRI maintenance


PRI operation is monitored and reported on through maintenance messages, out-of-service alarms, and circuit card faceplate LEDs. Bantam monitor jacks are located on the faceplate of the NTAK09.

System maintenance provides several tools, either manual or automatic, for maintaining effective PRI operation. These tools are service change and maintenance commands that are accessible through the software overlays and resident diagnostic routines.

Monitor DTI/PRI operation

Maintenance messages

The following sections describe the maintenance messages that may appear on the system maintenance TTY as a result of DTI or PRI operation.

D-channel status and error conditions are reported as DCH messages. PRI status and error conditions are shown in Table 9. (Additional information on PRI and DCH messages can be found in the Software Input/Output: System Messages (553-3001-411).

Message descriptions

Maintenance messages provide near and far-end switch status. Both service and service acknowledge messages are supported on PRI B-channels and ISL channels.

Table 9Maintenance messages

Message Meaning

DTA Digital Trunk Alarms (Resident Monitor)

DTC Resident CC Monitor

DTI Digital Trunk Interface and CC (LD60)

PRI Primary Rate Interface

DTI/PRI maintenance Page 61 of 114


Service and service acknowledge messages for B-channels and ISL channels are supported between:

• System to system: ISL and PRI

• System to DMS-100: PRI only


• System to AT&T ESS4 and ESS5: PRI only

The status reported by the service and service acknowledge messages for B-channels and ISL channels are:

• in-service

• maintenance

• out-of-service

Near-end and far-end sub-categories are defined for each maintenance status. See Table 10 for possible combinations of near-end and far-end statuses, and the channel capability for each status. When the near-end and far-end status does not match, the more severe maintenance status takes effect over the less severe maintenance status.

Table 10Maintenance message and status combinations

Near-end status Far-end statusB or ISL channel capability

In-service In-service Incoming and outgoing call allowed

In-service Maintenance Incoming calls allowed only

In-service Out-of-service Not allowed to use

Maintenance N/A Not allowed to use

Out-of-service N/A Not allowed to use



Note: Enabling/Disabling of Service Messages must be coordinated between the two ends. Enabling Service Messages at one end and not the other results in B-channels being placed out-of-service.

Message functions

Service messages are used to monitor the following:

• D-channel establishment

• D-channel sanity polling

• B-channel or ISL channel status change

• Channel status audit

D-channel establishment

When the D-channel establishes, the B-channel status is supported by sending service messages for each B-channel controlled by a D-channel. This messaging allows the far-end to synchronize its channel states. The service messages are sent when the system brings up the D-channel automatically or an administrator brings up the D-channel manually by using LD 96.

D-channel sanity polling

If a D-channel has been idle for 30 seconds, a service message is sent to poll the sanity of the link. The service message is sent regardless of whether the near-end is configured as master or slave.

B-channel or ISL channel status change

Whenever there is a status change for a B-channel or an ISL channel, the new status is reported to the far-end via a service message. Status change can occur through service change or maintenance operations, such as the addition or deletion of a channel in LD 14, or disabling of the associated loop, shelf, card or unit in LD 30, LD 32, LD 36, LD 41, or LD 60.

Channel status audit

LD 30 is enhanced to allow channel status audit to be initiated. The channels associated with each D-channel are examined and their status is reported to the far-end via service messages.



Activating service messages

Activate the service messages in LD 96 on a per D-channel basis. The backup D-channel (if equipped) automatically operates in the same mode as the primary D-channel. The commands are listed in Table 11.

Note: D-channels on each side of the link must be disabled to enable service messages.

Alarms

DTI/PRI yellow alarm (remote alarm)

A yellow alarm on the system, indicated by the state of the YELLOW LED on the PRI/DTI circuit card, is notification of a red alarm at the far-end (remote end). The fact that the PRI/DTI circuit card is receiving the yellow alarm pattern indicates that there is a T1 connection, but the far-end is not ready.

It is possible, however, that the T1 connection is one-way only — that is, receiving only, since this end is receiving the alarm. The yellow alarm is transported in one of two ways: using digit-2 or the facility data link (DG2 or FDL).

When the PRI/DTI circuit card receives a yellow alarm, the channels are placed into the maintenance busy state.

Table 11D-channel messages

Command Description

ENL SERV N turns on the support of service and service acknowledge messages for DCH link N.

DIS SERV N turns off the support of service and service acknowledge messages for DCH link N.

STAT SERV (N) displays the current service and service acknowledge message SERV setting for individual DCH N or DCH.



Each time a yellow alarm is generated, a counter is incriminated. When the yellow alarm 24-hour threshold (prompt RALM in LD 73) is reached, the PRI/DTI circuit card must be restored to service manually.

DTI/PRI red alarm (local alarm)

A red alarm (local alarm) indicates that the digital trunks or B-channels have been taken out-of-service (OOS) due to a loss of frame alignment lasting more than three seconds, or due to some facility performance OOS threshold being exceeded.

Maintenance and OOS messages are discussed later in this chapter.

DTI/PRI maintenance tools

Maintenance commands

Table 12 on page 65 through Table 14 on page 67 provide quick reference lists of important DTI/PRI commands. Table 15 on page 68 and Table 16 on page 70 pertain to the NTRB51 TMDI card.

WARNING

The user must disable the D-channel and clock-controller daughterboards before unseating circuit cards. Otherwise, the system performs INIT and momentarily interrupts call processing.



WARNING

Extreme care must be taken when enabling the D-channel message monitoring option due to the possible heavy volume of messages during normal traffic. Use this command only during very light or no traffic conditions for trouble-shooting purposes. Remember to disable the monitoring tool when you are finished — it does not time-out. Monitor enabled status is saved by EDD and remains enabled even after a SYSLOAD.

The port (TTY) performing the monitoring must have MTC and BUG programmed.

Table 12DTI/PRI commands (LD 60)

Command Action

DISI C Disable DTI/PRI card when idle.

DISL C Force disable DTI/PRI card.

ENLL C Enable DTI/PRI card.

LCNT (C) List alarm counters.

RCNT (C) Reset alarm counters.

SLFT (C) Do DTI/PRI self-test.

STAT (C) List DTI/PRI status.

RLBK Remote loopback.



Table 13D-channel commands (LD 96) (Part 1 of 2)

Command Action

DIS DCH N Disable DCHI port N.

DIS MSGI N Disable monitoring of incoming D-channel messages on link N. Monitor remains active until disabled.

DIS MSGO N Disable monitoring of outgoing D-channel messages on link N. Monitor remains active until disabled.

DIS AUTO N Disable autorecovery of the D-channel. Hardware may still respond to recovery initiated from the far-end.

ENL AUTO N Enable autorecovery of the D-channel. Software periodically commands hardware to establish the layer 2 link.

ENL DCH N Enable DCHI port N.

ENL MSGI N Enable monitoring of incoming D-channel messages on link N. Use only under light traffic.

ENL MSGO N Enable monitoring of outgoing D-channel messages on link N. Use only under light traffic.

EST DCH N Establish D-channel N.

PLOG DCH N Print D-channel statistics log N.

RLS DCH N Release D-channel N.

SDCH Release a D-channel and switch D-channels.

RST DCH N Reset D-channel N.

STAT DCH (N) Print D-channel status (link status).

STAT MSGI (N) Print incoming message monitor status.



STAT MSGO (N) Print outgoing message monitor status.

TEST-100/101/200/201 See DCH tests in NTP.

STAT SERV Print the current service and service acknowledge message for DCHI N.

ENL SERV N Enable service messages for DCHI N.

DIS SERV N Disable service messages for DCHI N.

Table 14Downloadable D-channel (DDCH) commands (LD 96) (Part 1 of 2)

Command Action

DIS MSDL X (ALL) Disable DCHI card X.

ENL MSDL X (FDL, ALL)

Enable DCHI card X, with or without Force Download.

RST MSDL X Reset MSDL card X.

STAT MSDL X (X (full)) Get MSDL status X, or a “FULL STATUS”.

SLFT MSDL X Execute a self test on MSDL card X.

DIS LLB X Disable local loop back on MSDL DCH X.

DIS RLB X Disable remote loop back on MSDL DCH X.

DIS TEST X Disable Test mode on MSDL DCH X.

ENL LLB X Enable local loop on MSDL DCH X.

ENL RLB X Enable remote loop on MSDL DCH X.

ENL TEST X Enable Test mode on MSDL DCH X.

PCON DCH X Print configuration parameters on MSDL DCH X.


Command Action



Note: “X” represents the D-channel device number.

TMDI maintenance commands

The Maintenance Overlays for the TMDI card have been enhanced. Overlay 60 is no longer used for TMDI card and loop maintenance. Only Overlay 96 is used to handle enabling and disabling of TMDI cards and their associated loop. Following are the descriptions of Overlay 96 command enhancements for TMDI:

PMES DCH X Print incoming layer 3 messages on MSDL DCH X.

PTRF DCH X Print traffic report on MSDL DCHX.

TEST LLB X Start local loop back test on MSDL DCH X.

TEST RLB X Start remote loop back test on MSDL DCH X.

Table 15TMDI maintenance commands (Part 1 of 2)

Command Description

DIS TMDI x Disable TMDI card x.

DIS TMDI x ALL Disables the TMDI card and various applications on the TMDI. If a DCH is configured on the TMDI, the DCH is released and the DCH application is disabled. The TMDI associated loop is also disabled. Active calls are force disconnected. All channels are disabled.

Table 14Downloadable D-channel (DDCH) commands (LD 96) (Part 2 of 2)

Command Action



ENL TMDI x (FDL) Enable TMDI card x and force a download. This command only works if TMDI is disabled (loop also disabled). It attempts to force download all required applications to TMDI card and then re-enable the card. When download is completed without error, ENL TMDI x ALL or ENLL x in Overlay 60 is required to re-enable the TMDI L1 application and the loop.Under normal conditions, option FDL to force download f/w to the TMDI card is not required. If the TMDI card does not have the latest f/w, the f/w is automatically downloaded after ENLTMDI x command is enabled. Force download f/w to the TMDI is only required if a new PSDL file is created for TMDI f/w. Once the f/w is downloaded, it burns into the flash on the card. If this card is disabled and re-enabled again, force download to the card is not necessary.

ENL TMDI x ALL Enable the TMDI card and various applications on the card. Also enables the associated loop. If a DCH is configured on the TMDI, a background audit enables and establishes the DCH, once the loop is up. DCH layer 3 should be established within about 30 seconds.

RST TMDI x Reset TMDI card x.

SLFT TMDI x Invoke self-test on TMDI card x.

STAT TMDI (x FULL) Get TMDI status.

Table 15TMDI maintenance commands (Part 2 of 2)

Command Description



D-channel monitoring on the TMDI card

D-channel status and error conditions are reported as DCH messages. These messages can be found in the Software Input/Output: System Messages (553-3001-411).

Table 16D-channel monitoring commands

Command Action

DIS TMDI x MSGI Disable monitoring of incoming D-channel messages on TMDI card x.

DIS TMDI x MSGO Disable monitoring of outgoing D-channel messages on TMDI card x.

ENL TMDI x ALL MSGI Enable monitoring of incoming D-channel messages on TMDI card x.

ENL TMDI x ALL MSGO Enable monitoring of outgoing D-channel messages on link TMDI card x.

ENL TMDI x ALL DBG Enable debugging on TMDI card x.

DIS TMDI x DBG Disable debugging on TMDI card x.

PSWD TMDI Print passwords.

STAT TMDI x MON Print monitoring commands for TMDI card x.

Table 17Clock controller commands (LD 60) (Part 1 of 2)

Command Action

DIS CC N Disable clock controller N.

ENL CC N Enable clock controller N.



NTAK09 DTI/PRI power on self-test

When power is applied to the NTAK09 DTI/PRI circuit card, the card performs a self test. The LEDs directly associated with the NTAK09 circuit card are DIS, ACT, RED, YEL, and LBK. The clock controller LED is also included in the power on self test (see Table 18).

Table 18 provides the state of the NTAK09 LEDs during the self-test procedure.

SSCK N Status of clock controller N.

TRCK XXXX N Set clock controller tracking.

Where xxxx =

PCK = Track primary clock reference source.

SCLK = Track secondary clock reference source.

FRUN = Free run mode.

Table 18NTAK09 LED states during self-test

Action LED State

Power up system Top five LEDs on for eleven seconds.

Self-test in progress Top five LEDs go off for one second.

If the self-test passes, the top five LEDs flash on and off three times.

If the self-test detects a partial failure, the top five LEDs flash on and off five times.

When the self-test is completed, the LEDs are set to their appropriate states.

Table 17Clock controller commands (LD 60) (Part 2 of 2)

Command Action



NTAK20 power on self-test

The clock controller daughterboard LED is the second LED from the bottom on the faceplate of the NTAK09 DTI/PRI card.

When power is applied to the NTAK20 clock controller, the LED is initially off for two seconds. If the self-test passes, the LED turns red and flashes on and off twice.

When the self-test completes, the LED remains red until the clock controller is enabled. When enabled, the clock controller LED turns green or flashes green.

NTAK93 self-test

The NTAK93 DCHI daughterboard LED is the bottom LED on the faceplate of the NTAK09 DTI/PRI card.

The NTAK93 DCHI daughterboard does not perform a self-test when power is applied to it. When power is applied, it turns red and remains steadily lit, indicating the D-channel is disabled. When the D-channel is enabled, the LED turns green and remains steadily lit.

Self-tests of the NTAK93 daughterboard are invoked manually by commands in LD 96.

DTI/PRI local self-test

The local self-test, also called a local loopback test, checks speech path continuity, zero code suppression, remote alarm detection, and A and B bit signalling. This test is performed manually on a per-loop (or link 24 channels) or per-channel basis. The local loopback test performs a local logical loopback and does not require any external loopback of the T-1 signal.

Restrictions and limitations

You must disable the DCHI and DTI/PRI before performing the self-test on the entire DTI/PRI card. Individual channels must be disabled before performing a self-test on a particular channel.



Procedure 14Self-testing the DTI/PRI card

To perform a self-test on the entire DTI/PRI card:

1 Enter the following command in LD 96 to disable the DCHI:

DIS DCH N

2 Enter the following command in LD 60 to disable the DTI/PRI card and run the self-test:

DISL C

SLFT C (entire card)

To self-test individual channels, follow the same procedure as above, but use the following commands:

DSCH C CH

SLFT C CH (specific channel)

End of Procedure

DTI/PRI automatic local loopback test

There are two types of automatic local loopback tests:

• ATLP 0 (disable auto loop test in daily routine: LD 60)

• ATLP 1 (enable auto loop test in daily routine: LD 60)

The automatic loop test checks the same functions as the manual self-test, but runs automatically as part of the midnight routines.

ATLP 0 disables one idle channel at random and performs a single channel self-test. This channel cannot be specified; it is selected by software.

ATLP 1 attempts to test the whole DTI/PRI loop. If ATLP 1 finds all channels in the target link idle, it takes the whole link down and tests it. The node where the self-test is performed sends out a Yellow Alarm while the link is down.

Ensure that LD 73 TRSH RALM is not exceeded at the far-end due to the automatic loop test. If TRSH RALM (default = 3) is exceeded at the far-end, trunks remain out of service.



Remote loopback and remote self test

The remote loopback and the remote self test are performed manually per loop (or per system card).

Remote loopback

The RLBK C command puts the DTI/PRI into loopback toward the far-end so a remote self-test can be performed on equipment at the far-end.

Note: The DTI/PRI loop (card) being tested must be disabled.

Remote loopback test

The remote self test, also called the external loopback test, checks the integrity of the DTI/PRI through an external T-1 loopback. If the Remote Loopback command (RLBK) is executed at the far-end system prior to executing the Remote self-test command (RMST) at the near-end, the integrity of the DS-1 facility is tested from end-to-end.

Note: The DTI/PRI channel or loop (card) being tested must be disabled.

Procedure 15Coordinating the tests

1 When a technician at the far-end requests a remote loopback on the local system:

a. Enter the following command in LD 96 to disable the DCHI (for PRI DCHL or BCHL):

DIS DCH N

b. Enter the following command in LD 60 to disable the DTI/PRI card and activate remote loopback mode:

DISL C

RLBK C

2 To run the remote self-test (external loopback test) through a loopback on the far-end system:



a. Call a technician at the far-end. Ask for remote loopback mode on the facility to be tested.

b. When loopback mode at the far-end is confirmed, enter the following command in LD 96 to disable the DCHI (for PRI DCHL or BCHL):

DIS DCH N

c. Enter the following command in LD 96 to disable the DTI/PRI card and run loopback test:

DISL C

RMST C

Note: The Remote self-test (external loopback test) can be run through any loopback that is external to the DTI/PRI card. The loopback can range from a loopback connector plugged into the NTBK04 cable to a remote loopback on the far-end DTI/PRI, or at any point in between on the DS-1 facility.

Figure 5 on page 76 shows the relationship between the remote loopback test and the link diagnostic test.

End of Procedure



Figure 5DTI/PRI link diagnostic and remote loopback tests

CSE 1000 Media Gateway Far End Switch

NTAK93

NTAK09

RMST LRunning remoteloop - back test

RLBK LIn loop - back mode(Link Diagnostic test)

Note: The remote loop-backtest cannot be performed

until the far-end is put into

the link diagnostic mode

(loop-back mode).

Note: The switch must beput into link diagnostic

mode (loop-back mode).

553-8298



DTI/PRI error detection

Bit error rate

Bit error rate monitoring detects errors in transmission (see Figure 6). There are two methods of bit error monitoring: bipolar violation tracking and Cyclic Redundancy Check (CRC).

If the D2, D3, or D4 framing format is selected in LD 17 prompt DLOP, then bipolar violation tracking is implemented. If the Extended Superframe (ESF) format is selected, CRC is implemented.

Bipolar Violation (BPV) trackingIn a bipolar pulse stream, pulses alternate in polarity. A bipolar violation has occurred if, after transmission, two pulses of the same polarity are received in succession (this could be caused by an electrical disturbance such as noise).

Note: Bipolar 8 Zero Substitution (B8ZS) introduces intentional bipolar violations. The T1 equipment must treat them as such and disregard them. This explains why B8ZS can only be used if all the equipment on the T1 span (end-to-end) supports it. Otherwise, the intentional BPVs take the link down.

Figure 6Bipolar violations

553-8300.EPS

Normal

Error



Cyclic Redundancy Check (CRC)The Extended Superframe Format (ESF) contains a checksum of all data in the frame. The receiving side uses the checksum to verify the data.

The primary difference between BPV and CRC is that bipolar violation tracking indicates errors in the local span, while CRC indicates errors on an end-to-end span. For example, on a satellite link, BPV only detects errors in the span between the system and the satellite connection. Since CRC traverses the entire span, it indicates an end-to-end bit error rate.

DTI/PRI hardware detects BPV or CRC errors. It sends an overflow (OVFL) message to the system CPU each time 1024 BPV or CRC errors are detected. Running the midnight routines prints the number of overflows and clears the counter.

Bit error rate threshold messages

There are three bit error rate thresholds set in LD 73, using one of two prompts: BIPV or BIPC. When a threshold is reached, a DTA message is produced (see Figure 7 on page 79).

Table 19Bit error rate messages

Message Explanation

DTA011 Bit error rate maintenance threshold has been reached.

DTA012 Bit error rate out of service limit has been reached.

DTA013 Too many bit error rate out-of-service occurrences in the last 24 hours.



Figure 7BIPV and BIPC thresholds

BIPV 1-(3)-4 1-(2)-4

BIPC 0-(2)-128

DTA 011--maintenance threshold A warning message is printed

DTA 012--out-of-service threshold The PRI is taken out of service and red alarm (local alarm) is raised. The PRI is restored automatically when performance improves (indicated by DTA 014)

DTA 013--24 hour out-of-service limit. Maximum number of times a PRI can be taken out of service (DTA 012) in 24 hours. When this count is reached, the PRI will not be restored to service automatically. When BIPC is set to zero, the PRI will not be taken out-of-service



Frame slip

Digital signals must have accurate clock synchronization for data to be interleaved into, or extracted from, the appropriate timeslot during multiplexing and de-multiplexing operations. A frame slip is defined as the repetition or deletion of the 193 data bits of a DS-1 frame due to a sufficiently large discrepancy in the read and write rates at the buffer (clocks aren't operating at exactly the same speed).

When data bits are written into (added to) a buffer at a slightly higher rate than that at which they are being read (emptied), sooner or later the buffer overflows. This is a slip-frame deletion.

In the opposite situation, when data bits are written (added) into a buffer at slightly lower rate than that at which they are read (emptied), eventually the buffer runs dry or underflows. This is also a slip-frame repetition.

Either occurrence is called a slip (or a controlled slip). The system contains a buffer large enough to hold about 2 full DS-1 frames (193 * 2 = 386). It is normally kept half-full (1 frame). Slippage impacts data transfer as shown in Table 20. The degradations shown in Table 20 can be controlled or avoided with proper clock (network) synchronization.

Table 20Impact of slip on service types

Service Potential Impact

Encrypted Text Encryption key must be resent.

Video Freeze frame for several seconds. Loud pop on audio.

Digital Data Deletion or repetition of Data. Possible Misframe.

Facsimile Deletion of 4-8 scan lines. Drop Call.

Voice Band Data Transmission Errors for 0.01 to 2 s. Drop Call.

Voice Possible Click.



Types of synchronization

Clock synchronization can be either tracking on the primary or secondary reference clock or free run (non-tracking). In LD 73 (prompts PREF and SREF), the DTI/PRI which supports the clock controller daughterboard is defined as the primary clock reference.

Another DTI/PRI may be defined as the secondary clock reference. The clock controller synchronizes from the primary or secondary's incoming pulse stream. The clock controller supplies clocking to all the other DTI/PRI loops.

DTI/PRI hardware detects frame slips in tracking and free-run modes. For tracking mode, running the midnight routines prints the number of overflows and clears the counter. For free-run mode, running the midnight routines prints the number of frame deletions and repetitions and clears the counters.

Tracking modeThere are two thresholds set in LD 73 as described below.Also see Figure 8 on page 82.

LD 73 — SRTK prompt


SRTK 1-(5)-24 1-(30)-3600

Slip rate maintenance (in hours) and out-of-service threshold (per hour).

These are the frame slip rate thresholds for the tracking mode. The first value is the maintenance threshold; the elapsed time (in hours) in which 2 frame slips occur (default is two slips in five hours). The second value is the out-of-service threshold; or the number of slips allowed in one hour (default is 30 slips in 1 hour).

When a threshold is reached, a DTA messages is output as follows:

DTA015:Frame slip --- tracking --- maintenance limit.

DTA016:Frame slip --- tracking --- out of service limit.



Figure 8Frame slip tracking thresholds

SRTK 1-(5)-24 1-(30)-3600


DTA 016--out-of-service threshold. The PRI is taken out of service and red alarm (local alarm) is raised. The Slip Rate Improvement monitoring (SRIM and SRMM) will be invoked. A loop in the improvement state is always in non-tracking mode even if it was in trackinmode before frame slippage exceeded the out of service threshold.



Free run (non-tracking) modeA maintenance threshold and an out-of-service threshold are set in LD 73 as described below. Also, see Figure 9 on page 84 for additional information.

LD 73 — SRNT prompt


SRNT 1-(15)-1024 1-(3)-1024

Non-tracking slip rate maintenance and out-of-service thresholds.

These are frame slip rate thresholds for the non-tracking mode. The first value is the maintenance threshold in seconds, the amount of time in which 10 slips occur (default is 10 slips in 15 seconds). The second value is the out-of-service threshold in seconds, the amount of time in which 10 slips occur (default is 10 slips in three seconds).

When these thresholds are reached, DTA messages are output. Related DTA messages are described below. See Figure 9.

DTA017:Frame slip --- free run (non-tracking) --- maintenance limit.

DTA018:Frame slip --- free run (non-tracking) --- out-of-service limit.



Figure 9Frame slip non-tracking thresholds

Frame slippage improvement timers

Once the frame slip out-of-service threshold has been reached, the DTI/PRI software invokes a Slip Rate Improvement mechanism to monitor the slippage and return the DTI/PRI card to service if a specific criterion has been met. The criterion used to determine that the slip rate has improved enough to return a DTI/PRI card to service is that the maintenance threshold is exceeded less than M (the LD 73 prompt SRMM defines M) times in N (the LD 73 prompt SRIM defines N).

It is important to realize that this monitoring applies to both tracking and non-tracking modes. Note that a DTI/PRI card in the Slip Rate Improvement state is always in non-tracking mode, even if it was in tracking mode before frame slippage exceeded the out-of-service threshold.

SRNT 1-(15)-1024 1-(3)-1024

DTA 017--maintenance thresholdA warning message is printed

DTA 018--out-of-service threshold.The PRI is taken out-of-service and red alarm (local alarm) is raised.The Slip Rate Improvement (SRIM and SRMM) monitoring is invoked.



There are two thresholds set in LD 73 as described in Table 21.

LD 73 — SRIM and SRMM prompts


SRIM (1)-127 Slip Rate Improvement time in minutes.

After the tracking or non-tracking mode frame slippage out-of-service threshold is exceeded, the slip rate is monitored for improvement. If the non-tracking maintenance threshold exceeds SRMM or fewer times in the duration of this timer, then the trunks are returned to service. Otherwise, this timer is reset and monitoring continues.

SRMM 1-(2)-127 Slip Rate exceeded maintenance limit.

Number of times the Slip Rate exceeds the maintenance limit while waiting for Slip Rate Improvement during the time window specified at the SRIM prompt.

While waiting for Slip Rate Improvement one of three DTA messages is output as shown in Table 21 on page 85.

Table 21Frame slip improvement timers (Part 1 of 2)

SRIM (1)-127

DTA 026 - Frame slip out-of-service limit has been reached while monitoring frame slip improvement. Trunks remain out-of-service, and improvement timer is restarted.

DTA 028 - Frame slip maintenance limit has been reached while monitoring frame slip improvement. Trunks remain out-of-service, and improvement timer is restarted.



Frame alignment

Loss of frame alignment occurs when the DTI/PRI card stops receiving the framing pattern on the DS-1 byte stream for a pre-defined period of time (three seconds). See Figure 10 on page 87 and Figure 11 on page 88. This condition can occur as a result of the far-end of the T1 span going completely out-of service or any other reason resulting in losing the incoming DS-1 pulse stream.

Loss of frame alignment thresholds DTI/PRI hardware detects out-of-frame conditions. Running the midnight routines prints the number of occurrences when frame alignment was lost and clears the counters.

DTA 029 - Frame slip improvement timer has expired, Slip Rate Improvement Criteria has been met. Trunks are being returned to service.

SRMM 1-(2)-127

Table 21Frame slip improvement timers (Part 2 of 2)



There are three frame alignment thresholds set in LD 73. When a maintenance or out-of-service threshold is reached, a DTA message is output as shown in Figure 10.

Figure 10Frame alignment thresholds

Table 22DTA message output

DTA019 Frame alignment maintenance limit.

DTA020 Frame alignment out of service limit.

LFAL 1-(17)-10240 1-(511)-10240

LFAC 0-(3)-128


DTA 020--out-of-service threshold The PRI is taken out of service and red alarm (local alarm) is raised. A red alarm due to DTA 020 must be cleared manually.

24 hour out-of-service limit. Maximum number of times a PRI can be taken out of service (DTA 020) in 24 hours. When this count is reached, the PRI will not be restored to service automatically. When LFAC is set to zero, the PRI will not be taken out-of-service.



If a loss of frame alignment condition persists for three seconds, the affected DTI/PRI card is taken out-of-service and a red alarm (local alarm) is raised. See Figure 11.

If the loss of frame alignment condition clears at least 15 seconds, the DTI/PRI is automatically restored to service. The following DTA message is generated:

Figure 11Loss of frame alignment

Alarm threshold recommendations for digital trunks

If a digital trunk is present in an IP expansion cabinet, link outages due to data network performance degradation between the main cabinet and the expansion cabinet causes alarms on the far-end of the digital trunk. If link outages are frequent, alarm thresholds on the far-end may need to be increased to prevent the trunk from being placed in a state requiring manual intervention to recover.

Clock operation

The system supports a single clock controller that can operate in one of two modes: tracking or non-tracking (also known as free-run).

Table 23DTA message output

DTA021 Loss of frame alignment has persisted for 3 seconds.

DTA 021--loss of frame alignment.

DTA 022--loss of frame alignment cleared

3 seconds

15 seconds



Tracking mode

In tracking mode, one or possibly two DTI/PRI cards supply a clock reference to a clock controller daughterboard. When operating in tracking mode, one DTI/PRI is defined as the primary reference source for clock synchronization, while the other is defined as the secondary reference source (PREF and SREF in LD 73).

There are two stages to clock controller tracking:

• tracking a reference, and

• locked onto a reference.

When tracking a reference, the clock controller uses an algorithm to match its frequency to the frequency of the incoming clock. When the frequencies very nearly match, the clock controller locks onto the reference. The clock controller makes small adjustments to its own frequency until both the incoming and system frequencies correspond.

If the incoming clock reference is stable, the internal clock controller tracks it, locks onto it, and matches frequencies exactly. Occasionally, however, environmental circumstances cause the external or internal clocks to drift. When this happens, the internal clock controller briefly enters the tracking stage. The green LED flashes momentarily until the clock controller locks onto the reference again.

If the incoming reference is unstable, the internal clock controller remains in the tracking stage, with the LED flashing green all the time. This condition does not present a problem, rather, it shows that the clock controller continually attempts to lock onto the signal. If slips occur, however, there is a problem with the clock controller or the incoming line.

Free-run (non-tracking)

In free-run mode, the clock controller does not synchronize on any source. It provides its own internal clock to the system. This mode can be used when the system serves as a master clock source for other systems in the network. Free-run mode is undesirable if the system is intended to be a slave. It can occur, however, when both the primary and secondary clock sources are lost due to hardware faults or when invoked by software commands.



Reference clock errors

System software checks every 15 minutes to see if a clock controller or reference clock error has occurred.

In tracking mode, the clock controller tracks on one reference clock. If a clock controller error is detected, or if there is a problem with the reference clocks, the system switches to free-run mode.

A reference clock error occurs when there is a problem with clock driver or with the reference system clock at the far-end. If the clock controller detects a reference clock error, with only one of the reference clocks, the reference clock switches to the usable clock.

Figure 12Clock controller primary and secondary tracking

Automatic clock recovery

Automatic switchover of the primary and secondary reference clocks is always enabled in the system.

553-8301

DTI/PRI

DTI/PRI

CC

PrimaryReferenceThe primary reference clock is supplied by the DTI/PRI which supports the Clock Controller daughter board.

SecondaryReferenceThe secondary reference clock may be supplied by any other DTI/PRI and is routed to the Clock Controller internal to the system.



Note: EREF and MREF commands in LD 60, which control the enabling and disabling of automatic clock recovery, are not supported on the system.

Procedure 16Replacing equipment

Use the following procedure before you reseat any one or more of the following: the NTAK09, the NTAK20, or the NTAK93.

1 If the NTAK93 DCHI daughterboard is installed, enter the following command in LD 96 to software disable the D-channel (DCHI):

DIS DCH x

Where X is the DCHI port number that was assigned in LD17.

2 If the NTAK20 Clock Controller daughterboard is installed, enter the following command in LD 60 to software disable it:

DIS CC 0

Where CC is the card slot number of the NTAK09 that supported the NTAK20 Clock Controller.

3 Enter the following command in LD 60 to software disable the DTI/PRI card:

DISL X

Where X is the card slot number of the NTAK09 DTI/PRI.

4 To replace the NTAK09 by the lock latches, unlock the latches and slide the card out of the cabinet. Once out of the slot you can remove any of the daughterboards.

Note: To avoid damage to the circuit cards from electrostatic discharge, wear the wrist strap connected to the inside of your cabinet when you handle the circuit cards. Figure 13 on page 92 shows the connection point for the wrist strap.

a. To remove the NTAK20 Clock Controller daughterboard, grasp the NTAK20 at opposite corners and gently “wiggle” it back and forth until all four corners are free. Do not bend the connector pins.

b. To remove the NTAK93 Clock Controller daughterboard, grasp the NTAK93 at opposite corners and gently “wiggle” it back and forth until all four corners are free. Once the corners are free of the stand-off, grasp the NTAK93 by its upper and lower right corners and slowly lift



the right side of the NTAK93 up and away from the NTAK09 connectors, being careful not to bend any of the pins.

5 To replace the NTAK09 DTI/PRI card, NTAK20 Clock Controller or NTAK93 DCHI, refer to “PRI implementation” on page 9 and “DTI implementation” on page 45 as required. Be sure to set any switches and install any daughterboards as required.

6 Tag any defective or damaged equipment with a description of the problem and package it for return to a repair center.

End of Procedure

Figure 13Wrist strap connection to the cabinet

wrist strap

J3

INTER

J1 J2 J4 J5 J6 J7 J8 J9 J10

SDI

AUX

553-8289.EPS

Page 93 of 114


106

ISL implementation


Reference list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93


Basic ISL implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99



OverviewThis chapter contains the information required to implement ISL on the system. It describes:


• hardware and software configuration for basic call service

Two modes of ISL are available: shared and dedicated. This chapter covers the most common type of Nortel Networks ISL installation, an ISDN Signaling Link (ISL) installation in dedicated mode using dedicated and leased lines.

Page 94 of 114 ISL implementation


Hardware requirementsTo implement ISL regardless of operation mode, analog or digital Tie lines are used as B-channels:

• NT8D15 or NT8D14 Analog Tie Trunk cards

• NTAK09 Digital trunk cards (for shared mode)

• NTAK02 SDI/DCH card (for dedicated mode)

Shared mode

In shared mode, PRI hardware plus the existing Tie line interface card is required.

Dedicated mode

Dedicated mode requires modems. See Figure 14 on page 95 and Figure 15 on page 96 for details.

The requirements for using a leased line are

Table 24Leased line requirements

Hardware Comments

NTAK02 D-channel Handler Interface (DCHI) Card for ISL mode.

Modem Modem capable of the following: (such as Ventel 2400-33 or 2400 Plus II)

- minimum of 2400 baud

- synchronous operation

- must support leased line (also known as private line or point-to-point) operation

NTAK19BA Four port break out cable.

ISL implementation Page 95 of 114


Figure 14ISL in dedicated mode using leased line

Using dial-up modems

The requirements for using a dial-up modem are:

Table 25Dial-up modem requirements (Part 1 of 2)

Hardware Comments

NT8D09 500 set line card.

NTAK02 D-channel Handler Interface (DCHI) Card (for ISL mode).

CSE 1000 Media Gateway Meridian 1 or SL1ISL D-channel leased lines

ISL Analog/Digital

TIE trunks

¥¥

DCHI DCHIDCHImodem modem

553-8291



Figure 15ISL in dedicated mode using dial-up modem

Modem Modem capable of the following: (such as Ventel 2400-33 or 2400 Plus II)

- minimum of 2400 baud

- synchronous operation

- modems are programmed such that one modem originates the call while the other auto-answers

- auto-dial capability

NTAK19BA Four port break out cable.

Table 25Dial-up modem requirements (Part 2 of 2)

Hardware Comments

Option 11

DCHI

Meridian 1 or SL1

DCHI

ISL D-channel

modem

ISL TIE trunksTIE

twisted

pair

TIE

TIE

modem

twisted pair

500

line

TIE

500 line

553-8292



ISL hardware installation (dedicated mode)Use Procedure 17 to install hardware for an ISDN Signaling Link (ISL) in dedicated mode using dedicated leased lines. For shared mode, hardware installation is identical to the PRI installation found in “PRI implementation” on page 9, with the addition of analog or digital Tie Trunks or both.

The NTAK02 connects to a modem via the NTAK19BA four-port cable. Only ports 1 and 3 are available for use as DCHIs.

Procedure 17Installing ISL hardware

1 Set option switches/jumpers on the NTAK02 card as shown in Table 26 and Table 27 on page 98 for mode of operation (RS232 or RS422 and DTE or DCE.)

Table 26NTAK02 switch setting

Port 0 Port 1 SW 1-1 SW 1-2

SDI DCH OFF OFF

SDI DPNSS OFF ON

— ESDI ON ON

Port 2 Port 3 SW 1-3 SW 1-4

SDI DCH OFF OFF

SDI DPNSS OFF ON

— ESDI ON ON



2 Install the NTAK02 in any available slot 1-10 of the Option 11C main cabinet or slot 11-14 of Media Gateway 1.


3 Install the NTAK19BA four-port cable on the 50-pin Amphenol connector associated with the slot the NTAK02 is installed in.

4 If the installation is a dedicated mode using leased line modem configuration, the D-channel connects the DCHI with the far-end modem over a dedicated leased line. The modems must have a minimum transmission rate of 2400 baud and must support leased line capability and synchronous mode, 2-wire or 4-wire operation.

Table 27NTAK02 jumper settings

Unit Jumper location Strap for DTE Strap for DCE

Unit 0 J10 C - B B - A

Unit 1 J7J6

C - BC - B

B - AB - A

Unit 2 J5 C - B B - A

Unit 3 J4J3

C - BC - B

B - AB - A

Unit Jumper location RS422 RS232

Unit 0 — — —

Unit 1 J9J8

C - BC - B

B - AB - A

Unit 2 — — —

Unit 3 J2J1

C - BC - B

B - AB - A



Modems such as Ventel 2400 Plus II can be used. You must specify 4-wire operation when ordering. Otherwise, the modem is factory shipped for 2-wire operation.

Note: The Hayes Smart modem 2400 cannot be used on leased lines.

5 If the installation is a dedicated mode using dial-up modem (such as Hayes 2400, Ventel 2400 or Gandalf 2400) configuration, the DCHI is connected to a modem that is connected to a 500 set line card. The call is connected to the far-end via the 500 set-to-Tie Trunk path.

Note: Dedicated mode using leased line modems is the preferred method.

6 Set up the D-channel. Configure the modem at one end in the auto-dial mode so it automatically initiates a call to the other end at power-up. The auto-dial number must be coordinated with the far-end switch. The originating modem must have this auto-dial number stored internally as part of the modem configuration routine. The far-end modem must be configured for auto-answer.

End of Procedure\

Basic ISL implementation

Implement dedicated mode

UseProcedure 18 to configure basic ISL capability. It applies to analog Tie Trunks that are used as B-channels. When DTI/PRI trunks are also used, LD 17 digital loop (DLOP) and LD 73 (digital data block-DDB) must also be configured with the appropriate clocking and threshold settings.

The DCHI in this case uses the NTAK02 circuit card and does not support ISDN PRI signaling. The DCHI is reserved for ISL use only. The D-channel can communicate with the far-end by means of a dedicated leased line modem or dial-up modem.

For ISL dedicated mode using a dial-up modem, a 500 set, Tie Trunk route and member have to be configured (used for D-channel).



Procedure 18Implementing dedicated mode

Configuring dedicated mode involves four major steps:

1 Configure the D-channel for ISL (LD 17).

2 Enable ISDN option (LD 15).

3 Enable the ISL option on a per route basis, assigning a D-channel for each route (LD 16).

4 Assign a channel identification to each trunk with the ISL option (LD 17).

LD 17 — Configuring the D-channel for ISL (Part 1 of 2)


REQ NEWCHG



ADAN NEW DCH 0-79

Add primary D-channel.

CTYP DCHI D-channel card type.

CDNO 1-9, 11-19, 21-29, 31-39, 41-49

Card slot in which the card supporting the DCHI resides.

PORT 1 Must be set to 1.

USR PRI D-channel for ISDN PRI only.

IFC SL1 Interface type.

DCHL 1-9 PRI card number (Must match entry for CDNO).

SIDE NET (USR) Net: network, the controlling switch.

User: slave to controller.



RLS XX Software release of far-end. This is the current software release of the far-end. If the far-end has an incompatible release of software, it prevents the sending of application messages, for example, Network Ring Again.

CLOK D-channel clock type for signaling.

EXT Source of D-channel clock is external to DCHI card (in this case, the DTI/PRI circuit card). Normally, EXT is used for PRI/ISL.

Do not confuse this clock with the E1 span Clock Controller found on the NTAK10/79. This clock is in reference to the DCHI synchronous mode of operation. Note: If directly connecting two DCHI ports without modems, set “CLOK” to “EXT” on one side and “INT” on the other.

LAPD YES(NO) Change LAPD parameters. Enter <cr> to leave timers at default value. The following timers are prompted only if LAPD is set to YES. The following can all be left at default during initial set-up.

T23 1-(20)-31 Interface guard timer checks how long the interface takes to respond. In units of 0.5 seconds (default 20 = 10 seconds).

T200 2-(3)-40 Retransmission timer in units of 0.5 seconds (default 3 = 1.5 seconds).

N200 1-(3)-8 Maximum number of retransmissions.

N201 4(260) Maximum number of octets in information field.

K 1-(7)-32 Maximum number of outstanding unacknowledged frames (NAKS).

LD 17 — Configuring the D-channel for ISL (Part 2 of 2)




LD 73 — Configuring the D-channel for ISL


REQ NEWCHG


TYPE DDB Digital data block.

TRSH 0-15 Assign a threshold set or table.

RALM 1-(3)-128 Yellow alarm 24-hour threshold.

BIPC 1-(2)-128 24-hour bit rate violation threshold.

LFAC 1-(3)-128 24-hour loss of frame alignment threshold.

BIPV 1-(3)-4 1-(2)-4

Bit rate (bipolar violation and CRC) monitoring limits for maintenance and out-of-service thresholds.

SRTK 1-(5)-24 1-(30)-3600

Frame slip-tracking-monitoring limits (in hours).

SRNT 1-(15)10241-(3)-1024

Non-tracking slip-rate monitoring maintenance and out-of-service thresholds.

LFAL 1-(17)-102401-(511)-10240

Loss of frame alignment monitoring limits.

SRIM (1)-127 Slip rate improvement timer.

SRMM 1-(2)-127 Maximum number of times the slip rate exceeds the maintenance limit.



LD 15 — Enabling ISDN option (Part 1 of 2)


REQ: NEWCHG


TYPE: NET Networking data.


ISDN YES Customer is equipped with ISDN.

PNI 1-32700 Customer private network identifier. This number MUST be unique to this customer in the private network. It is used to as part of the setup message for feature operation such as Network Ring Again and Network ACD.

HNPA NPA Telephone area code for this system. Sent as part of setup message as calling line identification.

HNXX NXX Telephone local exchange code for this system. Sent as part of setup message as calling line identification.

HLOC XXX Home location code (NARS).

LSC 1-9999 One to four digit Local Steering Code established in the Coordinated Dialing Plan (CDP). The LSC prompt is required for Calling Line I.D. and Network ACD.

AC2 Access Code 2. Enter call types (type of number) that use access code 2. Multiple responses are permitted. This prompt only appears on NARS equipped systems. If a call type is not entered here, it is automatically defaulted to access code 1.

NPA E.164 National.

NXX E.164 Subscriber.



.

INTL International.

SPN Special Number.

LOC Location Code.

LD 16 — Enabling ISL option on a per-route basis, assigning a D-channel for each route (Part 1 of 2)


REQ: NEWCHG




ROUT 0-30,32-127 Route number.

TKTP TIE Tie Trunk route.

DTRK YES/NO Enter YES if this is a Digital Trunk Interface (DTI or PRI).

ISDN YES ISDN option.

MODE ISLD Route for ISL application.

DCHI XX DCHI port number in CFN which carries the D-channel for this Tie Trunk route.

PNI 1-32700 Customer private network identifier. Must be the same as the CDB PNI at the far-end.

IFC Interface type.

LD 15 — Enabling ISDN option (Part 2 of 2)




SL1 Meridian SL1.

CTYP <CR> Call Type. Enter the call type to be associated with the outgoing route for direct dialing using the trunk access code (instead of NARS access code). See the Software Input/Output: System Messages (553-3001-411) for a list of valid responses.

INAC YES Insert Access Code. Permits the NARS AC1 or AC2 access code to be re-inserted automatically on an incoming ESN call.

LD 14 — Assigning a channel identification to each trunk with the ISL option


REQ: NEWCHG


TYPE TIE Tie Trunk type.

TN CC UU Card (CC) and Unit (UU) to be associated with this trunk data.

RTMB RRR MMM Route (created in step 3) (RRR) and member number (MMM).

CHID 1-192 Channel identifier for ISL channels (remove with Xnn) must be coordinated with far-end (no default value).

LD 16 — Enabling ISL option on a per-route basis, assigning a D-channel for each route (Part 2 of 2)




Implement shared mode

The same DTI/PRI software implementation sequence can be used as for Dedicated mode with the following exceptions:

LD 17


USR SHA D-channel for ISL in “shared” mode, used for both ISDN PRI and ISL.

ISLM 1-192 Number of ISL B-channel (trunks) controlled by the D-channel (no default value).

LD 16


IFC SL1 Interface type must be SL1 (this is the only type supported for ISL).

MODE ISLD Tie route used for ISL members.

DCHI 0-15 DCHI port number.

LD 14


CHID 1-192 Channel identifier for ISL channels. Must be coordinated with the far-end.

Page 107 of 114


114

ISL maintenance


Reference list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

ISL maintenance tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111



OverviewFrom a maintenance perspective, ISL operation consists of these elements:

• hardware and software states

• near-end and far-end status

• link and/or span integrity

ISL operation is monitored and reported on through service messages.

System maintenance provides several tools, manual or automatic, for maintaining effective ISL operation. These tools are service commands (accessible through the software overlays) and diagnostic routines.

Page 108 of 114 ISL maintenance



The following sections describe service messages that can appear on the system maintenance TTY as a result of ISL operation.

D-channel status and error conditions are reported as DCH messages. PRI status and error conditions are reported in the messages found in Table 28. Additional information on DCH and PRI messages can be found in the Software Input/Output: System Messages (553-3001-411).

Message descriptions

Service messages provide near and far-end switch status. Both service and service acknowledge messages are supported on PRI B-channels and ISL channels.

Service and service acknowledge messages for B-channels and ISL channels are supported:

• System to system: ISL and PRI



• System to AT&T ESS4 and ESS5: PRI only

Table 28Status messages

Message Meaning

DTA Digital Trunks

DTI Digital Trunk Interface

PRI Primary Rate Interface

ISL maintenance Page 109 of 114


Service and service acknowledge messages for B-channels and ISL channels report the following status types:

• in-service

• maintenance

• out-of-service

Near-end and far-end sub-categories are defined for each maintenance status. See Table 29 for possible combinations of near-end and far-end status and the channel capability for each status. When near-end and far-end status do not match, the more severe maintenance status takes effect.

Message functions

Service messages are used to monitor the following:

• D-channel establishment

• D-channel sanity polling

• B-channel or ISL channel status change

• Channel status audit

Table 29Maintenance message and status combinations

Near-end status Far-end statusB or ISL channel capability

In-service In-service Incoming and outgoing call allowed

In-service Maintenance Incoming calls allowed only

In-service Out-of-service Not allowed to use

Maintenance N/A Not allowed to use

Out-of-service N/A Not allowed to use



D-channel establishment

When the D-channel establishes, the B-channel status is supported by sending service messages for each B-channel controlled by a D-channel. This allows the far-end to synchronize its channel states. These services messages are sent when the D-channel is brought up automatically by the system or manually in LD 96.

D-channel sanity polling

If a D-channel has been idle for 30 seconds, a service message is sent to poll the sanity of the link. The service message is sent regardless of whether the near-end is configured as master or slave.

B-channel or ISL channel status change

Whenever there is a status change for a B-channel or an ISL channel, the new status is reported to the far-end via a service message. Status change can occur through service change or maintenance operations, such as the addition or deletion of a channel in LD 14, or disabling of the associated loop, shelf, card or unit in LD 30, LD 32, LD 36, LD 41 or LD 60.

Channel status audit

LD 30 is enhanced to allow channel status audit to be initiated. The channels associated with each D-channel are examined and their status is reported to the far-end via service messages.



Activate service messages

You activate the service messages in LD 96 on a D-channel basis. The commands are:

ISL maintenance tools

Maintenance commands

Table 31 on page 112 provides a quick reference list of important ISL commands.

Table 30D-channel messages

Command Description

ENL SERV N Turns on the support of service and service acknowledge messages for DCH link N.

DIS SERV N Turns off the support of service and service acknowledge messages for DCH link N.

STAT SERV (N) Displays the current service and service acknowledge message SERV setting for individual DCH N or DCH.

WARNING

Ensure that other TTYs and D-channels residing on the NTAK02 are disabled.



IMPORTANT!

Extreme care must be taken when enabling D-channel message monitoring option due to the possible heavy volume of messages during normal traffic. Use this command only during very light or no traffic conditions for trouble-shooting purposes. Remember to disable the monitoring tool when you are finished.

The port (TTY) performing the monitoring must have MTTC programmed.


Command Action

DIS DCH N Disable DCHI port N.

DIS MSGI N disable incoming D-channel messages on link N *.

DIS MSGO N Disable outgoing D-channel messages on link N *.

DIS AUTO ON Disable the D-channel.

ENL AUTO ON Auto enable the D-channel after SYSLOAD.

ENL DCH N Enable DCHI port N.

ENL MSGI N Enable incoming D-channel messages on link N *.

ENL MSGO N Enable outgoing D-channel messages on link N *.

EST DCH N Establish D-channel N.

PLOG DCHI N Print D-channel statistics log N.

RLS DCH N Release D-channel N.

SDCH Release a D-channel and switch D-channels.




D-channel status and error conditions are reported as DCH messages. These messages can be found in the Software Input/Output: System Messages (553-3001-411).

Maintenance testing

ISL back-to-back (without modems)

For maintenance reasons or testing purposes it is sometimes necessary to connect ISL back to back (without modems). Use the following diagram to accomplish the connection. This connection is normally done within the same system in a lab environment.

RST DCH N Reset D-channel N.

STAT DCH (N) Print D-channel status (link status).

STAT MSGI (N) Print incoming message monitor status.

STAT MSGO (N) Print outgoing message monitor status.

TEST-100/101/200/201 See DCH tests in NTP.

STAT SERV Print the current service and service acknowledge message for DCHI N.

ENL SERV N Enable service messages for DCHI N.

DIS SERV N Disable service messages for DCHI N.


Command Action



Figure 16ISL back-to-back connection

NTAK02

Port 1, DCHI Y

Port 3, DCHI X

In LD 17:

DCHI X DCHI Y

INTERNAL CLOCK EXTERNAL CLOCK

SLAVE MASTER

553-8293

Family Product Manual Contacts Copyright FCC notice Trademarks Document number Product release Document release Date Publish

Meridian 1 and Succession Communication Server for Enterprise 1000

1.5Mb DTI/PRIDescription, Installation and Maintenance

Copyright © 1992–2002 Nortel NetworksAll Rights ReservedInformation is subject to change without notice. Nortel Networks reserves the right to make changes in design or components as progress in engineering and manufacturing may warrant. This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to Part 15 of the FCC rules, and the radio interference regulations of Industry Canada. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses and can radiate radio frequency energy, and if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at their own expense.SL-1, Meridian 1, and Succession are trademarks of Nortel Networks.Publication number: 553-3011-310Document release: Standard 14.00Date: November 2002Printed in Canada

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1.5Mb DTI/PRI: Description, Installation and Maintenance