Technical Proposal for IGW HUAWEI_LATEST

Technical Proposal

For IGW

Huawei Technologies Co. Ltd.

MAY 2012

Technical Proposal for IGW

Commercial in Confidence Page 2 of 46

Table of Contents

Table of Contents .............................................................................................................................. 2

1 Huawei proposal for BIG Overview ......................................................................................... 3

1.1 Analysis of BIG IGW Requirements ............................................................................. 3

1.2 Huawei proposal for BIG .............................................................................................. 5

1.2.1 Overview of Proposed Solution ............................................................................ 5

1.2.2 Key Points of Huawei Design ............................................................................... 7

1.2.3 Scalability (IGW) ................................................................................................... 8

1.2.4 High Flexibility Solutions ....................................................................................... 8

1.2.5 System reliability ................................................................................................... 9

1.3 Datacom Solution ....................................................................................................... 17

1.3.1 Bandwidth Capacity and Link Design ................................................................. 18

1.3.2 Datacom Solution Highlights............................................................................... 19

1.4 Huawei Transmission Network Solution ..................................................................... 20

1.4.1 Solution Overview ............................................................................................... 20

1.4.2 Huawei NG-SDH Features ................................................................................. 20

1.5 Power Solution ........................................................................................................... 23

1.5.1 Dimension of Power Solution.............................................................................. 24

1.5.2 Reliability of Power Solution ............................................................................... 24

1.6 Huawei NMS Solution ................................................................................................ 24

1.6.1 Powerful Huawei Network Management ............................................................ 26

1.6.2 Abundant Northbound Interfaces for OSS Integrated Solution .......................... 26

1.7 Lawful Interception Solution ....................................................................................... 28

1.8 Inter-working Solution ................................................................................................. 30

1.8.1 Inter-working with TDM Networks ....................................................................... 30

1.8.2 Inter-working with IP Networks ........................................................................... 30

1.9 Illegal Number Blocking .............................................................................................. 31

1.9.1 The incoming call number is standard number................................................... 32

1.9.2 Illegal incoming number call rejected ................................................................. 33

2 Key Solution Highlights .......................................................................................................... 33

Reliability ................................................................................................................................... 34

Excellent Voice Quality .............................................................................................................. 36

3 Annex A. Abbreviations and Acronyms ................................................................................ 41



1 Huawei proposal for BIG Overview

1.1 Analysis of BIG IGW Requirements

In year 2011, based on the IGW new license released, BIG is going to apply International

Gateway (IGW) license to Bangladesh Telecommunication Regulatory Commission (BTRC).

This is inline with the long term business development and strategy of BIG to boast the revenues

and increase competitiveness. The main responsibilities of the IGW in BIG encompass the

following functions:

Routing/switching international voice calls between ICX and International operators.

Routing inter operator Short Message Service (SMS) as and when necessary

Providing Interface for Lawful Interception (LI) facilities

Providing Monitoring Facility of System for BTRC

Provision for Transferring CDRs to BTRC.

Provide bandwidth and infrastructure in favor of VSPs for international connectivity with

overseas carriers

Provide necessary capacities with ICX to terminate the calls of VSPs to ANS through ICXs.

Provide support to VSPs for building-up connectivity with overseas carriers, switching of the

incoming calls for call termination to ANS operators through ICX, monitoring of bandwidth

utilization, extraction and storage of Call Detail Record (CDR), sending CDR to National

Monitoring Center (NMC) for online and offline monitoring and analysis, storage and

analysis of Traffic Data, Log files, Call Accounting, Signaling and QoS related information

With these new business requirements, BIG is urgently in need to deploy a reliable, cost-efficient,

scalable and robust IGW Network. The deployment of the IGW is crucial to BIG business in the

future in terms of revenues and strategy. The successfulness of BIG IGW will propel BIG to be

experienced and efficient Class-4 and IGW operator, with huge revenues stream. As the largest

and top ILEC, BIG’s ultimate transformation strategy is moving towards ALL-IP Next Generation

Network (NGN).

BIG requires the vendor to supply, install, testing and commission the International Gateway

(IGW) with Core Network, Transmission, Datacom and other facilities on turn-key basis. The BIG

future network is an IP-based network which is fully compliant with ETSI and ITU-T standards.

The IGW covers one Point of Presence (PoP) in Dhaka, the Core Network, transmission,

Datacom and other facilities should be deployed and distributed in this PoP. The future target

architecture of BIG is shown in the following figure.



Figure 1 – BIG Target IGW Architecture

With extensive experience and deep insights in IGW deployment, Huawei has made out this

proposal based on thorough understanding of the requirements in IGW license document. The

key points of Huawei understanding of the tender document requirements are summarized as

the following.

1.1.1.1 Main Driver of IGW Deployment

1.1.1.1.1 One of the most notable drivers is to fulfill BTRC urgent and stringent requirements on

IGW with the tight timeline given.

1.1.1.1.2 Increase revenues stream and improve the bottom-line of the profitability of BIG

1.1.1.1.3 Insufficient capacity of current network architecture, including PSTN switch,

transmission, datacom and other facilities to support large IGW requirements.

1.1.1.1.4 BIG also want to deploy a Network which is reliable, scalable, cost-efficient and

future-oriented.

1.1.1.2 The Key Points of BIG IGW Requirments

1.1.1.2.1 Large capacity and able to scale with future growth

The IGW solution required by BIG is of large capacity and should be able to scale to support

higher capacity with modular expansion method. The network elements proposed for IGW

should support network expansion without any software and hardware upgrade.

1.1.1.2.2 Field-proven



The network elements proposed, including Core network, transmission and datacom must

be field proven. They should be commercially deployed in overseas market and running

stably for past few years.

1.1.1.2.3 Feature-rich

The BIG IGW solution should be feature-rich and support a host of features, including

software and hardware features. The IGW should support different routing, translation,

signaling analysis, statistics monitoring and traffic measurement features based on the

requirements in the tender document.

1.1.1.2.4 Low TCO

The IGW solution shall provide an advantageous OPEX savings and CAPEX in long term

perspective. The IGW solution should require a comprehensive construction of IGW with

minimum investment as BIG prefer one time investment.

1.2 Huawei proposal for BIG

1.2.1 Overview of Proposed Solution

Huawei proposes to use Softx3000, UMG8900, SE2600, OSN3500，NTP Server, NE40E-X3,

S9300, S3300, N/U2000, Eudemon 1000E to construct a world-class IGW network for BIG. It is

the best-in-breed solution in the industry as the proposed network elements are the most reliable

and feature-rich. The proposed solution is targeted to provide the most reliable, scalable and

robust platform for BIG large interconnection traffic purpose. Various advanced technologies and

techniques are embedded in the proposed solution. Huawei proposed BIG IGW solution and

interconnection is shown below.



Figure 2 – Proposed IGW Network Topology for BIG

The key ideas of Huawei proposed IGW solution are based on the following important network

components:

– Softswitch base on CPCI platform as the call control of the IGW.

– Media Gateway as the signaling and media adaptation gateway.

In the proposed IGW solution, all the equipments will be deployed in Dhaka, one Softx3000

process the call control and forwarding. The Media Gateway will be connected with ICX or other

TDM Networks. The Softx3000 will link to the International Operators by SIP/H.323 trunks

through I-SBC (SE2600).

Huawei NMS, N2000 will be centrally deployed in Dhaka, will manage IGW Core Network

elements, U2000 will manage the Datacom elements.

Two Gateway routers, four LAN switches and three Firewall will be installed at Dhaka IGW site

which will form the IP core for the proposed IGW system. One LAN switch will be installed at the

BTRC site to provide connectivity for the monitoring equipment. The Soft Switch and the Media

Gateway will be connected to the IP core with suitable IP interface (GE/FE). Fire walls are

provided to ensure network security.

One NTP server will be installed in the proposed IGW for keeping time synchronization. The

Billing system will be installed at the proposed IGW site for processing, generating and



management of Bills. The mediation devices collect the raw CDRs from the switching network

elements, pre-process the raw CDRs applying the business rules and distribute them to the

appropriate devices for further process in order to generate the Bills. There will be sufficient

storage capacity and security in the billing system hardware for storing the billing data.

Appropriate monitoring devices (O & M Control Console) will be installed at BTRC for viewing

real-time traffic and call data and for saving traffic data, log files and CDR dumps. The monitoring

system to be provided is also capable of online and offline monitoring and analyzing of the CDR,

Call Accounting, Signaling, QoS and others.

Huawei has developed an end-to-end IGW solution in accordance with ETSI and ITU-T

standards. Huawei has been very actively participating in ETSI and ITU-T and other related

standards organizations and forums. The compliance to these standards allows BIG to safely

roll-out an end-to-end IGW network without any network issues. All the interface, including

bearer and signaling interfaces are designed in accordance to the international standardization.

The availability of these standard-conforming interfaces will allow BIG for a smooth

commissioning and inter-working with its existing network environment to the near future next

generation target network ensuring feature inter-working and end-to-end interoperability.

Product Entity in the

Tender

Functionality of Entity Units Sites

Softx3000 Softswitch Call Control 1 Dhaka

UMG8900 Media Gateway Media and signaling

adaptation

1 Dhaka

XPTU LI LI Interface Conversion 1 Dhaka

N2000 Core Network NMS NMS 1 Dhaka

NTP Server NTP 1 Dhaka

OSN3500 MUX 1 Dhaka

SE2600 SBC Session Border Controller 1 Dhaka

Table 1 Huawei IGW Solution Product Model

The solution based on the following dimension parameter:

1. Average Holding time (for all calls): 60 second

2. Erlang/trunk: 0.70

1.2.2 Key Points of Huawei Design

The IGW solution proposed is embedded with various advanced technologies and designs that

set BIG on par with the global IGW operators in the world. The solution is proposed after careful

study of the current network environment and application in Bangladesh as well as full

consideration of the requirements of a world-class IGW network stated in the BIG IGW tender

document, encompass NGN, transmission, datacom and SMS gateway.



1.2.3 Scalability (IGW)

The traffic model for IGW solution:

1. Huawei propose the BIG IGW as the following traffic:

Site Name STM-1 E1 Erl/Trunk Average

Holding time (s)

Percentage of IP call

Dhaka 6 2 0.70 60 90%

Table 2 IGW Traffic Capacity

2. Capacity of whole systems:

Site Name TDM Trunks No. of CCS7 Sig IP Trunks Total BHCA Total Erl

Dhaka 11000 30 9000 600K 10K

Table 3 IGW Traffic Capacity

The total Trunks is 20K and the total BHCA reach to 600K under the 60s average holding time

and 0.70Erl/trunks.

3. MUX Capacity:

STM-16 STM-4 STM-1 FE

Dhaka 4 24 0

Table 4 MUX Traffic Capacity

1.2.4 High Flexibility Solutions

TDM&IP Dual Bearer

TDM&IP Dual Bearer solution can help the operator migrate his network from TDM based to IP

based smoothly.

The TDM&IP dual bearers are classified into inter-Softswitch dual bearers and intra-Softswitch

inter-MGW dual bearers.

The TDM/IP dual bearer service provides a basis for the seamless upgrade from TDM

networking to IP networking. The features of the service are as follows:

Inter-Softswitch dual bearer: A mixture of ISUP (TDM bearer), TUP (TDM bearer),is supported in

an office direction. When routing a call out of the office, the system can select a route based on

the preference policy of the bearer network.

Intra- Softswitch inter-MGW dual bearer: IP (mesh connection) and TDM bearers are used

between intra-softswitch MGWs. When connecting an intra- Softswitch call, the system can



select a route based on the data configuration and the preference policy of the bearer network.

1.2.5 System reliability

1.2.5.1 Redundancy and Reliability of Hardware

Distributed Hardware Structure

The SOFTX3000 adopts the distributed hardware structure. The modular design of the functions

realizes the distributed processing. The functions of the modules are independent of each other,

and are controlled by different processors. The fault in one processor does not affect the

operation of the whole system.

Redundancy Design

The hardware of the SOFTX3000 adopts designs such as active/standby mode, load sharing

mode, and redundancy configuration, to ensure reliability of the hardware system.

The main parts in the SOFTX3000 adopt the multi-processor backup design. For

example, the SMU, FCCU, CDB, BSG/MSG, and iGWB have two processors working in

active/standby mode. In normal conditions, the active processor controls the running of

the module, and the standby processor synchronizes with the active one in real time.

When the active processor is faulty, the standby one takes over the service at once. The

standby processor takes the place of the faulty active processor to control the operation

of the system without interrupting the service.

The service modules and interface modules of the SOFTX3000 adopt load sharing mode.

That is, two or more boards share the related functions during the normal working. Once

a board becomes faulty, the other boards take over the tasks of the faulty board provided

that certain performance indexes, such as call loss, are ensured.

The IP interface of the SOFTX3000 supports physical backup, thereby ensuring reliability

of the IP routes between the SOFTX3000 and the IP bearer network.

Derating Design

This design is to lower the values of the electric stress and heat stress to the values smaller than

the rated values when the electronic components run. Through this, the following purposes can

be achieved:

Postponing degeneration of the parameters

Prolonging their service lives

Enhancing their reliability

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Maintainability Design

The maintainability design aims to meet the specified quantitative and qualitative demands on

maintainability, especially the demand on reducing maintenance time. The maintenance design

covers the following:

Product design and maintenance simplification

Reachability

Standardization and exchangeability

Modularization

Error prevention design and identifier

Testing and diagnosis technology

Human and environment factors

These are described as follows:

The boards are designed to be hot-pluggable to reduce board replacement time.

No cable is led out from the front panel, thus facilitating board removal and assembly, and

decreasing maintenance time.

When a module in the system is faulty, the maintenance terminal detects and reports the

fault.

The local maintenance MML operation terminal helps the maintenance staff to locate and

rectify faults quickly and easily.

Selection and Usage of Components

The selection and usage of components are key to ensure component reliability.

For the SOFTX3000, the component types, specifications, and suppliers are selected based on

the demands on product reliability. The focus is on component replacement and unification. The

component unification and reliability model analysis is used to reduce the number of components

used and improve system running, after the components pass the aging test. Thus, the

components are of high quality ensuring the reliability of the hardware system.

Power Reliability

To improve the reliability of the power supply system, the following techniques are employed in

the SOFTX3000:






Distributed power supply: Two power supply systems work in the redundancy backup

mode. The systems have the protection functions against lightening, power failure, over

and under voltage, and over and under current. When the power fails, the whole system

can restart within five minutes.

The power module of the subrack adopts 2+2 backup design. When one power module is

faulty, it does not affect the operation of the system.

Overvoltage and overcurrent protection measures are applied to +5 V / -48 V power input

and external interfaces (such as E1 interfaces). These measures comply with Appendix B

of ITU-T Recommendation G.703 and relative specifications.

The UMG8900 supports 1+1 backup mode, N+1 backup mod and load-sharing mode for

hardware design, provides the high reliability hardware platform.

The bearer processing board and interface board support 1+1 and load-sharing mode.

The call control board supports 1+1 backup mode.

The main control board and clock cascading support 1+1 backup.

The UMG8900 supports backup of FE/GE ports and reliable networking with the L2/L3

LAN Switch, router and MSTP. If any peer network element fails, services are not

interrupted.

TDM SDH / SONET support 1+1 backup, N:1 backup and load-sharing mode.

1.2.5.2 Software Reliability

The SOFTX3000 ensures the software running status by taking measures, such as protection

measures, error tolerance measures, and fault monitoring measures.

Compliance with the CMM Flow

Huawei strictly follows the Capability Maturity Model (CMM) procedures throughout the

development of the SOFTX3000, from requirement analysis, system design to software test.

Code walk-through, inspection, review, unit test, system test, and other useful quality assurance

measures taken in the SOFTX3000 development improve the reliability of the software

considerably.

Protective Measures

The software of the SOFTX3000 applies a modular structure in hierarchical mode. All software

modules are developed based on a loose coupling mechanism, minimizing a faulty module's

impact on other modules. In addition, the software of the SOFTX3000 is added with functions of





detecting, isolating, and correcting errors; in an emergency condition, the SOFTX3000 can

provide an approach for quickly locating the faults.

Fault Tolerance

To prevent impact on the system by certain software faults, the SOFTX3000 adopts the following

measures for the key software:

Scheduled detection

Real-time monitoring of tasks

Storage protection

Data check

Saving of operation logs

These measures improve the fault tolerance of the software, that is, the self-healing ability in the

case of software error.

Troubleshooting

The SOFTX3000 automatically detects and diagnoses hardware and software faults. It can

isolate, switch over, restart, or reload the faulty hardware.

Supporting Hot Patches

Sometimes the host software must be modified when the equipment is running in order to

remove system bugs, add new functions, and adhere to service requirements. The traditional

way is to stop the equipment for upgrading. This, however, affects the service processing and

communication quality. The SOFTX3000 supports installation of hot patches to the host software.

In this way, the host software can be upgraded without interrupting the services, thus improving

the communication quality.

The UMG8900 provides the distribution of software modules designed and high-reliability

software architecture to implement the highly reliable protection.

The realization of the distributed processing module designed to support the software

fault detection and isolation.

Support the overload protection feature. When the system overloads, it starts the

self-protection mechanism, shielding some traffic, and ensure secure and reliable

operation of the system.<}0{><0}






1.2.5.3 Reliability of Charging

Hardware Reliability of Charging Gateway

In the iGWB system, key devices are redundant for backup. This ensures that services are not

interrupted when a fault occurs in the system.

Two-Node System

In the iGWB two-node system, each pair of boards work in active/standby mode. The

automatic switchover mechanism ensures system reliability and service continuity.

Redundant Disks Using RAID

The iGWB adopts the most commonly used RAID technology. It configures local disks as

RAID 1 to prevent data loss in case of a disk failure.

Dual-Network and Dual-Plane Architecture

iGWB server communicates with the SOFTX3000, SMU through the Base plane, Fabric

plane, and external network interfaces. This dual-plane architecture improves system

reliability. It is provide the following functions.

The SOFTX3000 is connected to iGWB through the primary and secondary links on the

Base plane to form two planes.

The primary and secondary boards are connected to the SMU through the Base plane

and then connected to the NMC through the SMU.

Data on disks are synchronized between the primary and secondary boards through the

Fabric plane.

The primary and secondary boards provide an independent external network interface for

connecting to the BC and uploading CDR files to the BC through FTP or SFTP. For

network isolation purpose, this network interface is only used to access the charging

network to ensure the network security.




Figure 3 – Hierarchical Storage of the Bills

From the time a call is completed to the time the CDR information is transferred to the billing

center, there are four levels of CDR buffer against CDR data loss due to abnormal causes. The

four levels are: host CDR pool buffer, original CDR file buffer, final CDR file buffer and automatic

CDR file backup on the IGWB server.

Host CDR pool buffer: The host CDR pool stores the original CDRs.

Original CDR file buffer: After being transferred from the host CDR pool to the IGWB

Server, the original CDRs are stored first in the hard disk as the level-two buffer.

Final CDR file buffer: After processing the original CDRs, the IGWB Server saves the

final CDR data to be sent to the billing center to carry out the level-three buffer.

Automatic backup in IGWB Server: The IGWB Server adopts 1+1 backup mode. The

active server regularly backs up the CDR data in the hard disk to the standby server to

carry out the level-four buffer.

The primary and secondary boards provide an independent external network interface for

connecting to the third-party server and backing up CDR files to the third-party server

through FTP or SFTP. The network interface is independent to ensure network security.



Software Reliability of Charging Gateway

The iGWB software adopts automatic fault detection, data security, a virtual IP address to

improve system reliability.

Automatic Fault Detection

The system automatically detects the running status of software and hardware and

submits faults if it occur. You can view the running status and faults of software and

hardware on the client.

If a hardware fault occurs in a key component or a fault is not rectified automatically, the

primary and secondary servers are switched over to ensure normal running of the

system.

If a software (such as a process) fault occurs or a fault is not rectified automatically, the

active and standby processes are automatically switched over to ensure normal running

of the system.

Data Security

The CDRs on the primary and secondary boards are synchronized in real time through

the CDR synchronization mechanism.

Local disks are set to a RAID mode to ensure security of important data such as charging

information, original CDRs, final CDRs, and status information.

System data is stored in different paths for redundancy backup. When an exception

occurs, system data is loaded and checked automatically.

To protect important data, the iGWB provides automatic backup of charging data.

Virtual IP Address

The virtual IP address technology is used to ensure normal connections between the

SOFTX3000 and the BS after the primary and secondary boards of the iGWB are switched

over.

Transmitting CDRs between the SOFTX3000 and the iGWB

The SOFTX3000 sends the CDRs to the iGWB in real time through UDP over two Base

planes.

Receiving CDRs by the primary and secondary boards of the iGWB

The iGWB uses CDR synchronization technology to synchronize CDR files on the primary

and secondary boards of the iGWB.




Sliding Window Protocol

CDRs are transmitted between the SOFTX3000 and the iGWB through the Sliding Window

Protocol. The SOFTX3000 sends some CDRs to the iGWB. After receiving the CDRs, the

iGWBchecks and filters the CDRs and then stores the CDRs in the window. After the CDR

data is written into the hard disk completely, the iGWB responds to the SOFTX3000. Then

the SOFTX3000 continues to send new CDRs. To ensure transmission efficiency, the

iGWB can receive and check new CDRs while storing CDR data.

The key data about the sliding window status in the iGWB is written into the hard disk in

time. When the iGWB is restarted or the primary and secondary servers are switched over,

no CDR is lost or duplicate during transmission.

CDR Processing Reliability

Three modules are involved in the CDR processing from receiving CDRs to generating final

CDRs. The iGWB creates a reliable CDR processing task between the three modules.

CDRs are processed in the unit of the package. After original CDRs are stored successfully,

the information about CDR packages is also stored in the hard disk. After original CDRs are

processed and stored as final CDRs, the package numbers are also stored. When the

iGWB is restarted, the iGWB can calculate the package number of the original CDRs that

are not processed based on the package numbers of final CDRs. Then the iGWB continues

to process the remaining original CDRs.

CDR Distribution

When CDR files are distributed in PULL mode, the billing center fetches CDRs

from the iGWB. The iGWB provides the FTP or SFTP user name and password to

the billing center and opens the read and write authorities of the directory where

the second copy of final CDRs is stored.

When CDR files are distributed in PUSH mode, the iGWB sends CDRs to the

billing center. The billing center provides the FTP or SFTP user name and

password to the iGWB and opens the directory where the final CDRs are stored.

CDR Backup

CDR backup further ensures CDR reliability. The iGWB automatically backs up CDR files

on other storage devices through the LAN or WAN to improve data security.

1.2.5.4 Data Reliability

The SOFTX3000 provides the following data protection mechanisms:

The SOFTX3000 supports a synchronous data backup mechanism between the active

and standby modules in real time. Whenever an active module is down, the standby



module is automatically switched to be the active one. All programs and data on the

module are immediately brought into effect.

The SOFTX3000 supports the backup of data from the database of the active processor

to a flash memory. This enables quick restart of the active processor after data is

obtained from the flash memory.

The SOFTX3000 supports the automatic CDR backup mechanism.

The OMU conducts a regular CRC of the mainframe data. If the data of the mainframe is

not consistent with that of the background, the BAM server starts a setting procedure to

the foreground. If the setting procedure fails after preset attempts, an alarm is generated

to remind the operation staff to restore the data.

1.3 Datacom Solution

The proposed architecture of the datacom network is presented in this chapter. Two Core

Routers, Two Core LAN Switch, Three Firewall to be used in Dhaka. Brief description of the

network as stated below:

a) Core Routers

There will be two routers as Core Routers to be installed at Dhaka. These routers will be

connected each other by transmission resources (1GE) in the uplink and in downlink they are

connected with Core LAN Switch or Media Gateway directly.

b) Core LAN Switch

There will also be two LAN switches as Core LAN Switched to be installed at Dhaka. In

Dhaka site, these switches will be connected with Core Router for uplink and in the down link

they will connect with Media Gateway by multiple GE interfaces, Soft switch by multiple FE

interfaces. VRRP (Virtual Router Redundancy Protocol) is deployed between the connections

of all sites Core Router and Switches to implement the redundancy mechanism.

c) Firewall

There will be one firewall to protect the network elements and provide secure access or

connectivity for remote users. Firewall will be used between the network of NGN Switch

platform and Billing Center/NMS, BTRC and LEA.

Another 2 firewall will be deployed between Core Routers and Lanswitch to protect the

network elements from the International Attack.

Detail network diagram for BIG IGW IP Core Network is shown in the following Figure:



Figure 5– IP Core Network Diagram

Equipment Place:

1. Core Router ( Dhaka)

2. Core LAN Switch ( Dhaka)

3. Firewall ( Dhaka)

Equipment List:

1. Core Router = NE40E (2Units)

2. Core LAN Switch = S9300 (2 Units)

3. Firewall = E1000E (1 Unit)

1.3.1 Bandwidth Capacity and Link Design

For voice service, the compression code of media compression arithmetic can adopt

different standards. Adopting different formats of message encapsulation, the formats and

efficiency of media message encapsulation in different packet bearer network (such as

Ethernet, IP, ATM) are different and should be determined by the actual bearer network.



Compared with media traffic, the bandwidth of signaling traffic is very small. But it demands

higher for transmission reliability and low time delay.

Take the Dhaka Site as an example, according to the calculation of NGN core network

designing and planning table for all NGN and IP Equipment interface will be as below:

MGW – Core LAN Switch

Media traffic: GE optical link, load balancing mode

Soft Switch – Core LAN Switch

Signaling traffic: FE electrical link, active/standby mode

Core LAN Switch – Core Router

GE optical link

Core LAN Switch – Firewall

GE optical link

Firewall – BTRC, LEA, BILLING/NMS

FE electrical link

1.3.2 Datacom Solution Highlights

There will be five routers as Core Routers to be installed at four locations (Dhaka, Other 3

cities). These routers will be connected each other by transmission resources in the uplink

and in the downlink they are connect with Core LAN Switch via GE interface as well.

There will also be two switches as Core LAN Switch to be installed at Dhaka. These switches

will be connected with Core Router for uplink and in the down link they will connect with Media

Gateway by multiple GE interfaces, Soft switch by multiple FE interface.

Equipment Reliability

The hardware and software design greatly affect the reliability of the equipment. The Huawei

proposed NE40E routers adopt carrier class design and the availability of the system can

reach 99.999%. It has a passive backplane. All of the key parts such as main control board,

switching fabric, power supply and fan, have redundant design and are all hot swappable.

There is no single point of failure in the system. Besides, Huawei has implemented a large

number of reliability software features on the routers, including Non-Stop Forwarding,

Graceful Restart, Hot Patching and etc.

Network Reliability

To construct a high-reliable network, besides deploying high-reliable equipment, the

high-reliable characteristics of equipment should be effectively considered and applied in the

network layout to organize a high-reliable network with full redundancy capability.



Service Access Reliability

Service access solution is also very important to ensure end to end service reliability.

Normally, the end service system (e.g. MGW or Softswitch) has dual connections to the

IP/MPLS network, and it has two working modes, one is active backup mode, another is load

sharing mode. For active backup mode, the end service system has one IP address for two

interfaces, for load sharing mode, the end service system has one IP address per interface.

To access service systems working in load sharing mode, we proposes that the end service

systems be directly connected layer 3 equipments so as to protect against the access link

failure.

Enhanced VRRP

Huawei core routers have enhancement on standard VRRP, which uses BFD for fast failure

detection and then trigger VRRP to switchover traffic. With enhanced VRRP, the switchover

time is reduced from more than 3 seconds to less than 50ms. Enhanced VRRP is used to

protect against local PE node failure and local PE-CE link failure.

1.4 Huawei Transmission Network Solution

1.4.1 Solution Overview

Huawei offers next generation SDH products OptiX OSN NG-SDH series OSN 3500, which can

provide SDH/PDH, Ethernet, ATM, and SAN service in a unified single platform. OSN 3500 is

STM-64/16 level equipment. In order to meet the ICX requirement for Transmission equipment,

Huawei offers OptiX OSN 3500 and OptiX iManager U2000 in this proposal.

Following equipments are offered as per requirement:

1. OptiX OSN Series Equipment

OptiX OSN 3500 1 Sets Dhaka

2. Dimension

Site STM-16 STM-4 STM-1 E1 FE

Dhaka-1 0 16 24

ICX will provide the connectivity between ICX and IGW. In ICX site, 2 OSN3500 will be deployed in

Dhaka Site to handle most of the transmission.

1.4.2 Huawei NG-SDH Features

Unified Platform

All the software and service cards, such as SDH, PDH, data cards (Ethernet, ATM, RPR, and SAN)

are universal to each other, which greatly minimize the initial investment, spare parts as well as



maintenance cost. Network traffic upgradeability will be achieved just through modular expansion with

non-traffic affecting pattern, and without replacing the hardware system. Unified product series can

also shorten the time of network deployment and training expenses.

Data awareness Capability

As NG-SDH equipment, OptiX OSN 3500/1500 can provide abundant service interfaces for voice and

data services, such as SDH, PDH, ATM, FE/GE. For Ethernet data traffic Transport, it supports

GE/FE transparent transmission; convergence and L2 switch to address various customers'

requirements via GFP/LCAS/VCAT and supporting MPLS L2 VPN. It can also provide

ESCON/FICON/FC, ATM, WDM, RPR etc.

RPR (Resilient Packet Ring) Solution

The OptiX OSN series is integrated with RPR technology to support access, aggregate and transport

of 10M/100M/1000M Ethernet service. The main features and specifications are listed below.

Supports 10Base-T/100Base-FX/TX, 1000Base-SX/LX to access FE/GE Ethernet traffic

Supports encapsulation of GFP and LAPS protocols.

Supports VCAT (Virtual Concatenation) and LCAS mechanism for bandwidth protection of data traffic

Flexible configuration of the RPR ring from VC-3-1v to VC-4-8v. The mapping granule can be VC-3 or

VC-4.

Destination strip to realize spatial reuse mechanism

Bandwidth fairness Mechanism

Standard WRAPPING and STEERING protection mechanism with switch over time less than 50ms

and the optimized protection technology of WRAPPING+STEERING, which is Huawei patent

technology.

Auto recovery of the topology to plug and play.

Powerful QoS mechanism, support five priorities of A0, A1, B-EIR, B-CIR and C.

Supports MPLS and stack-VLAN technology to provide VPN in the RPR ring, the service can be

EVPL and EVPLAN.

Supports flow-control based on 64K granularity by the CAR (Committed Access Rate) scheme.

Ethernet over SDH Solution

The OptiX OSN series is integrated with Ethernet over SDH Technology to support access aggregate

and transport of10M/100M/1000M Ethernet service. The main features and specifications are listed as

below.

Supports 10Base-T/100Base-FX/TX, 1000Base-SX/LX to access FE/GE Ethernet traffic



Supports Layer 2 switching and the ability to classify Ethernet traffic as defined in IEEE 802.1Q-tag

standard.

Mapping granularity: VC-12-nv, VC-3-nv, and VC-4-nv for Ethernet data, huge access and

transmission capacity up to 2.5Gbps per Ethernet service card.

Supports transparent transmission and convergence from FE to FE, FE to GE and GE to GE for

Ethernet traffic.

Supports Layer 2 VPN function and implements the EPL(Ethernet Private Line) , EVPL(Ethernet

Virtual Private Line), EPLn/EPLAN(Ethernet Private LAN) and EVPLn/EVPLAN(Ethernet Virtual

Private LAN) services.

Supports Link Capacity Adjustment Scheme (LCAS), achieving dynamic capacity adjustment of

transmission bandwidth and protection of concatenated group..

Support encapsulate protocols such as Generic Framing Procedure (GFP),High-level Data Link

Control (HDLC) and Link Access Procedure-SDH (LAPS).

High Traffic Grooming Capacity

It supports large capacity high/low order cross-connect, Multi-ADM design, and flexible add-dropping

capability. With high traffic grooming capacity, it supports STM-1/4/16/64 Mesh, ring, star and chain

topology.

Best for IP/ATM DSLAM Transport

The OSN series provides good transport solution for DSLAM. OSN support ATM solution, Ethernet

over SDH, RPR and WDM transport solutions for both ATM-based and IP-based DSLAMs. Different

solutions can be used for different requirements on bandwidth, and can be smoothly shifted from one

solution to another, so as to protect your investment.

Highly Integrated Platform

OSN series products support highly integrated large capacity traffic service boards with low power

consumption.

It also adopts OADM upgradeability just inserting new WDM cards on the existing platform without

replacing the hardware system. Therefore, NGSDH is the future-proof solution because these

features greatly preserve the original investment of your network.

Best for Lease line services

NG-SDH is the best for leased line services for business customers. So far, three different types of

leased line services are available over the OSN series products: the TDM leased line (transparent

transport mode), Ethernet private line (transparent transport mode) and Ethernet virtual private line

(Bandwidth is shared and VALN/LSP is used to isolate data of different users. Ethernet leased line

services can be very flexible in bandwidth, and can be either in the transparent mode or in the

bandwidth shared mode.



Upgradeability (ASON -based platform)

OSN 3500/1500 are ASON-based platform, can be smoothly evolved into intelligent network just by

software upgrade. It supports intelligent features such as protection and restoration, Automatic

Topology and Resources discovery, automatic end to end service provisioning, SLA services etc.

Service provisioning in traditional SDH has been a manual, lengthy, and costly process. To manually

provision an end-to-end high-speed connection, a service provider must determine which SDH rings

the connection traverses and provision bandwidth on each ring manually. If any ring is at full capacity,

the carrier must find an alternative ring path or upgrade the capacity of a ring and propagate the

information to all sites manually. These are very time-consuming processes and can even take

months. The deployment of ASON–based nodes allows carriers to automate the provisioning and

management of the network and promises to lower the cost of operation by reducing service activation

times from few weeks to seconds via Point & click on EMS/NMS.

Several ASON-based networks which had been deployed by Huawei worldwide are in commercial

operation and these types of ASON-ready Huawei OSN series products has been deployed over 30

countries.

Operable & manageable Platform

Service boards are compatible to save spare part and operation cost, Hot-swappable SFP optical

modules, Remote board information collection and remote maintenance, In-service software upgrade,

IP over DCC, OSI over DCC for multi vendor interoperability and end to end service provisioning.

With highly integrated NP chips, full compatibility in hardware and software, special consideration for

Operation & maintenance, smoothly scalable to ASON networks (Automatic switching optical network),

OptiX OSN series will bring significant cost saving for BTCL in terms of CapEx and OpEx.

1.5 Power Solution

Huawei proposed power system covers stable, uninterrupted and efficient industry leading Rectifier

System, Battery Backup and Inverter System. TP481000D is a huge capacity AC&DC power system,

which convert AC to DC and supply -48V DC power to the telecommunication equipments in core

room. The TP481000D power system is usually composed of AC power distribution frames, DC

power distribution frames, rectifier frames, rectifier modules (SMR) and monitoring units (CSU).The

power system, using 48V/100A rectifier modules, can reach 6000A output by expansion. Huawei

proposed battery solution covers 8 hours backup comprising 2 sets of battery banks. Huawei

proposed inverter system is a high performance system suitable for the telecommunication

equipments which requires uninterrupted power solution. Our proposed Inverter System can be

monitored by LCD display for the proper monitoring and efficient usage.



1.5.1 Dimension of Power Solution

The following table shows the power consumption requirement for Dhaka:

Product Quantity AC Power Requirement (W) DC Power Requirement (W)

Softx3000 1 334 1410.5

UMG8900 1 - 738

XPTU 1 250

SE2600 1 300 985

OSN3500 1 - 300

Total 634 3683.5

1.5.2 Reliability of Power Solution

For the reliability and uninterrupted DC power system, our proposed solution is based on the N+1

rectifier system design. The required rectifier system has been calculated based on the DC power

requirement for the load and battery charging current. Then the rectifier system has been provided as

N+1 redundancy.

For the reliability and uninterrupted AC power system, our proposed solution is based on the N+1

inverter system design. The required inverter system has been calculated based on the AC power

requirement for the load and the proposed inverter system has been provided as N+1 redundancy.

Besides, 8 hours battery backup has been provided comprising 2 sets of battery banks for the

uninterrupted Power Supply in case of the failure of commercial power. Sufficient CBs and fuses have

also been provided considering redundancy.

1.6 Huawei NMS Solution

Huawei O&M, iManager N2000 supports the monitoring and management of Softx3000 and

UMG8900 based on the same server. iManager N2000, which is the centralized element

management system (EMS) with centralized management functionalities on Huawei network

elements, including alarm management, performance management, configuration management,

software management, security management, etc. All these important functionalities equipped in

Huawei EMS as they are crucial for effective monitoring and management of BIG ICX. The detailed

O&M functionalities of the N2000 are illustrated in the diagram below.



Figure 6 – N2000 O&M Functions

Operators can manage and maintain the authorized network elements via the N2000 Client, through

the TCP/IP Ethernet network. N2000 provides open and standard northbound interfaces to be

integrated into upper level NMS system. Huawei can therefore help the operator to build a highly

efficient and well-integrated O&M system. To monitor and manage the datacom and transmission

network, Huawei proposes U2000.



Figure 7 – Inter-working of OSS and EMS

1.6.1 Powerful Huawei Network Management

iManager N2000 & U2000 can manage all the core network elements and the related IP network

equipments.

Characteristics:

Advanced modularized architecture

Abundant northbound interfaces for NMS integration

NE Software management and remote upgrade

Customized performance report based on Web

Alarm correlation

Delivering bulk MML commands to multiple NEs

Network time synchronization through NTP

High Availability system

Inventory information management

Full backup and restoration of N2000 & U2000

Equipment panel and interface tracing

Collection and storage of performance data

Centralized security management

Encrypted transmission in FTP mode based on SSL

Integrated script platform

Distributed system with multiple servers

Reliable and multiform security mechanism

1.6.2 Abundant Northbound Interfaces for OSS Integrated Solution

Huawei proposed NMS provides abundant and flexible northbound interfaces to the NMS. The

flexible northbound interfaces offered by the NMS can help operators to:

Conveniently and quickly construct the operation and maintenance system

Seamlessly integrate Huawei’s mobile NEs into their current O&M system

The integration proposal for configuration, monitoring, performance and backup is as follows:



a) Configuration Tool Integration

Huawei proposed NMS provides configuration north-bound interface to the configuration tools for

inquiring the configuration files. It can export the configuration data into .xml files periodically.

The configuration tools can fetch the configuration files from the directory of the NMS through

FTP.

It supports configuration file importing interface that enables the configuration tools to modify

radio algorithm parameters and neighboring parameters. After updating the parameters, the

configuration tools transfer the configuration file to the NMS. It then parses the file and generates

script files and downloads them to NEs. Then the files are activated on NEs and NEs execute the

modification. When the execution completes, NEs generate result files and notify NMS. It then

collects the result files and combines them. The configuration tool can then get the result file from

the NMS through FTP. The detailed file format and control flow shall be negotiated and confirmed

by TMCZ and Huawei.

b) Monitoring Tool Integration

In Huawei OSS solution, our proposed NMS collects and stores all the alarms of all NEs. The

monitoring tool can collect the alarms from the NMS directly, instead of connecting to each NE. It

provides various alarm north-bound interfaces to the monitoring tools, including alarm ASCII

streaming interface, alarm CORBA interface, alarm file interface and alarm SNMP interface.

The NMS has successful stories of integration with HP TeMIP through alarm CORBA interface,

with IBM Micromuse Netcool through alarm ASCII streaming interface, alarm SNMP interface

and alarm COBRA interface.

c) Performance Tool Integration

In Huawei OSS solution, N2000 and U2000 collects and stores the performance data of all NEs.

The performance tool can collect the performance data from them directly instead of connecting

to each NEs. It provides the performance north-bound file interface to the performance tool.

It has successful stories of integration with IBM Vallent Metrica and Mycom NMS-Proptima

through performance north-bound file interface

d) Backup Tool Integration

Huawei proposed NMS supports to back up configuration data of the network elements and

system data of the NMS itself. The backup tool can get the backup files from the NMS through

FTP.



1.7 Lawful Interception Solution

Huawei Softswitch solution supports LI solution and meets both ETSI and 3GPP specification. In

Huawei proposed solution, Huawei suggests MC (Monitoring Center) are purchased and managed by

national security administration or LEA. The following figure shows Huawei interception solution

logic architecture based on ETSI/3GPP.

Figure 5 – Lawful Interception Solution

Softswitch (Softx3000):

SOFTX3000 provides the support of LI function, and performs call control function for intercepted

calls. It can intercept all the communication and non-communication actions of the intercepted

number in real time. The communication actions include outgoing/incoming traffic,

supplementary service activation, SMS transmission/reception, FAX, etc. For the communication

action, Softswitch can generate and send IRI/CC to LIG/MC. For the non-communication actions,

Softswitch can generate and send IRI to LIG/MC. The LI service will not affect any other

telecommunication services.

MGW (UMG8900):



The MGW is connected to the MC or LIG (modify according to your project) through E1s over

ISUP. It is controlled by the softswitch via H.248 protocol, to duplicate the interception content

(CC) and send to the MC or LIG through E1s in PCM voice format.

LIG:

LIG is Huawei internal terminology. In ETSI/3GPP standards, LIG is called “mediation”. Its main

functions are:

Managing the interception targets, the LI operator can use the LIG client to activate, list,

deactivate the interception targets. This function module is called ADMF in ETSI/3GPP

standards;

Receiving the interception related information from TNE and transferring it to MC. This

function module is called DF2 in ETSI/3GPP standards;

Optional： Receiving the interception call content from TNE and transferring it to MC. This

function module is called DF3 in ETSI/3GPP standards;

Controlling LIG system security and monitoring LIG system activity.

MC:

MC is Huawei internal terminology. In ETSI/3GPP standards, MC is called “LEMF”. Its main

functions are:

Receiving and Storing interception related information from LIG;

Receiving and Storing call content from LIG or TNE;

Intelligently analyzing the stored information, such like restoring the call content, intelligent

show the interception related information.

Interface and Function:

There are two kinds of interfaces in the LI solution: X interface and Handover interface (HI). X

interface is the interface between TNE and LIG, HI is the interface between LIG and MC.

X interface includes X1, X2, and X3 logical channels.

X1: based on TCP or UDP/IP, transmits the commands/responses between TNE and LIG.

LIG/MC can activate/deactivate/inquire targets through this channel. TNE is the server point

while X1 is based on TCP/IP protocol.

X2: based on TCP/IP, provides the interception relative information to LIG, like calls

establish/release PDP activation and so on. LIG is the server point in TCP link.

X3: transmits the Content of Communications, like speech, user packet.

Handover interface includes HI1, HI2, and HI3 logical channels.



HI1:TCP/IP or manual. HI1 interface is the command control interface used to activate or

deactivate intercepted targets.

HI2: based on TCP/IP, MC will receive the IRI through this interface. LIG uses FTP protocol to

delivery IRI to MC according to ETSI/3GPP standards.

HI3: MC receives the intercepted CC (Call Content) through this interface.

1.8 Inter-working Solution

1.8.1 Inter-working with TDM Networks

Huawei has extensive experience in IOT execution and MVI (Multi-Vendor Integration)

deployment both in Huawei’s IOT open lab and in customer network environment. Huawei also

generated plenty of new software applications with our partners. Except the system integration

with our partners, Huawei also has performed the IOT of many standard interfaces with other

mainstream equipment vendors’ products.

Here IGW will connect with ICX or some of the International operators with TDM.

Softx3000 uses ISUP protocol to communicate with the TDM network in Signaling plane.

UMG8900 provides the inter-working functions with the TDM networks through SS7 signaling link,

also provides the necessary codec and media format translation functions. UMG8900 is

embedded with signaling gateway (SGW) function, support inter-working and adaptation from

MTP2, MTP3 to M2UA and M3UA. In this way, the UMG8900 acts as a single connection point to

TDM based networks and no independent SGW is needed. Various signaling protocols

supported by UMG8900 embedded SGW, such as R2, IUA, M2UA, M3UA and ISUP. Please

refer to the figure below for more illustration of the signaling protocol stack supported by

UMG8900.

Figure 8 – UMG8900 Protocol Stack

1.8.2 Inter-working with IP Networks

To inter-work with IP network, one SBC (SE2600) needs to be deployed at the IP network border

to control the voice, video, and data session.

It supports the following features:



Network security

Quality of Service (QoS)

Network Address Translation (NAT)

While working as a I-SBC, SE2600 provides the following functions:

Serving as the SIP/SIP-T trunk and H.323 trunk, the SE2600 can interconnect the

SoftX3000s that are deployed in different networks.

By exchanging trunk signaling, the SE2600 allocates media addresses and port

numbers and generates channels for media streams to help forward media streams.

By handling signaling and media, the SE2600 supports NAT traversal, security defense,

and topology hiding.

Figure 9 - Inter-working with IP Network

1.9 Illegal Number Blocking

Since the VOIP number is illegal number in Bangladesh, Huawei provide the blocking illegal

number function in the expansion proposal. The number blocking function is provided by



softswitch. BIG can configure any of the numbers or number ranges which need to be blocked in

the softswitch. When softswitch found the caller number is in the list of blocked number, the call

will be rejected by softswitch.

The function is incoming caller number discrimination; the number range to be rejected can be

configured in softswitch. When any incoming call go through BIG NGN, the softswitch would

compare the incoming call number with the configured illegal number, when the incoming call

number is the illegal number, the softswitch will reject the call directly.

1.9.1 The incoming call number is standard number.

Figure 11: Standard incoming call number

Subscriber B call subscriber A;

Softswitch will identify the B number with the number range which be configured as illegal;

The B number not included in the illegal number range;

The softswitch transfer the call to the A number normally.



1.9.2 Illegal incoming number call rejected

Figure : illegal incoming call rejected

Subscriber B call subscriber A;

Softswitch will identify the B number with the number range which be configured as illegal;

The B number is included in the illegal number range;

The softswitch rejected the call.

2 Key Solution Highlights

1. High rate

The use of high-speed serial data links and the switching structure brings as wide as 2.5 Tbit/s

bandwidths for data switching.

2. High availability

All boards and back inserted boards are hot swappable, and a redundancy mechanism is

available for essential components such as power supply, fans, management modules, and

boards. This contributes to 99.999% system availability.

3. High expandability



By adding an interface board to a subrack, the operator can increase the number of interfaces on

an board and realize subrack cascading.

4. High scalability

Backplanes can be smoothly upgraded to 10 GE, and the performance of the interface board is

highly scalable.

5. High manageability

The use of standard management buses realizes efficient management of any system

components.

The SOFTX3000 provides advanced hardware technology, featuring modular hardware structure,

large capacity, and high integration.

All boards use advanced integrated circuits such as the ASIC, PLD, and FPGA. This simplifies

the working of the SOFTX3000 and improves the integration of the system.

When serving as the Class-5 only, SOFTX3000 V300R010 supports a maximum of 2 million

subscribers. When serving as the Class4 only, SOFTX3000 V300R010 supports 360K TDM

trunk circuits.

With the distributed hardware structure, high-performance chips, high-speed buses, and high

speed Intel processors, the SOFTX3000 provides powerful processing capabilities.

Reliability

Huawei IGW solution and network elements are all designed to be fully redundancy. All the important

components, including Softx3000, UMG8900, OSN and NE40E are embedded with redundancy

features, including control cards, service processing cards, power supply, fans, bus and software

blocks, are designed to work in redundancy mode. There is no single point of failure in the whole

system. The H.248 connections between Softx3000 and UMG8900 are based on SCTP protocol and

Multi-homing mechanism is used to make it more reliable. SCTP with Multi-homing mechanism is also

been used in the SIGTRAN technology as transmission layer in both Softx3000 and UMG8900.

UMG8900 Protection Capability for TDM Connection

The UMG8900, as a large-capacity and high-density media gateway device, provides large-capacity

SDH/SONET interfaces. The SDH/SONET interfaces serve as the convergence interfaces of the

lower-layer network service, and its security is important. Therefore, the Huawei media gateway,

UMG8900 is designed with the function of SDH/SONET interface protection.

The SDH/SONET interface protection uses the linear multiplex section protection, and the protection

modes consist of the 1+1 backup and 1:N backup. When configuring the SDH/SONET interface

protection, set the optical interface on the master SDH/SONET interface board to the work channel of

the protection group, and that of the slave SDH/SONET interface board to the protection channel. In

this case, when the optical interface of the work channel fails, services are automatically switched to

the optical interface of the protection channel, and the services are not interrupted.



The following figure shows the work mode of the 1+1 backup.

A B

Work channel

Protect channel

Work channel

Protect channel

Figure 20 – 1+1 Backup

In the 1+1 backup mode, each work channel has a dedicated protection channel. The transmitter

sends signals over the two channels, and the receiver receives the signals from the channel with the

signals of a better quality.

The following figure shows the work mode of the 1:N backup.

A B

Bridge Selector BridgeSelector

Protect channel (send)

Work channel 1 (send)

Protect channel (receive)

Work channel 1 (receive)

Work channel 2 (send)

Work channel 2 (receive)

Work channel N (send)

Work channel N (receive)

Figure 21 – N+1 Backup

The difference between the 1: N backup and 1+1 backup is that N channels share one dedicated

slave channel. When the system is normal, service streams are transmitted over the work channel.

When the work channel is disconnected or its performance deteriorates, the transmitter switches to

the protection channel to transmit the service streams and the receiver receives the information over

the protection channel.

IP Interface Load Sharing

The UMG8900 supports the load-sharing working mode of IP interfaces. Two load-sharing IP



interfaces are configured with IP addresses respectively, and separately carry services. These two IP

interface are backup for each other. When a IP interface is faulty, traffic is automatically switched to

the other IP interface. Thus, the normal operating of bearer services is not interrupted.

Bidirectional Forwarding Detection

The UMG8900 supports the Bidirectional Forwarding Detection (BFD) protocol. Through BFD, the

UMG8900 periodically sends UDP-based fault detection packets, to detect and check disconnection

faults of the transmission link, optical interface, and electrical interface, and faults caused by

applications, such as packet loss, error code, and forwarding on the link layer and network layer.

When BFD deployed, the time of link changeover is below 200ms.

Excellent Voice Quality

Huawei IGW solution is embedded with different mechanism to guaranteed high quality of voice

in the network. In the VoIP networks, these factors can affect the voice quality from the following

aspects:

Delay and jitter

Delay and jitter refer to duration when an NE forwards service messages in a

communication network. When a voice packet is transmitted from A to B over the IP

network, time overhead is generated during the process of packet sending, transmitting,

and receiving. End-to-end delay contains codec delay, encapsulation and decapsulation

delay, and network transmission delay. Jitter is mainly caused by the network. The least

intermediate nodes (such as routers and switches) in the end-to-end transmission path

result in the smallest jitter. If a delay exceeds 250 ms, the communication satisfaction

decreases. Therefore, end-to-end delay cannot be longer than 250 ms.

Packet loss ratio

On IP networks, due to causes such as network congestion, service packets that cannot

be transmitted from the source address to the destination address are discarded. The

packet loss ratio is the percentage of lost packets in relating to the whole packets to be

transmitted. IP packets are lost on the IP network in two cases: The packets are lost

during the network transmission, and the routing device discards IP packets when the

network is congested. When the packet loss ratio is greater than 10%, the voice quality is

severely affected.

Echo

Echo indicates that speakers can hear their own voices in the earpiece during the

conversation. Echo is categorized into two types: electrical echo and acoustic echo.

Noise

Noise is any interfering sound, it can be thought of as any undesirable characteristic that



degrades the signal of interest.

level

The voice level is an item used to measure the voice, and its unit is dBm. dBm represents

the decibels of one mW. The voice transmitting and receiving level is another key factor

affecting the voice quality. Therefore, the voice gateway must be able to adjust the voice

level. Usually, the voice level is set to 0 dBm.

Huawei Voice Quality solution

The UMG8900 realizes a series of voice technologies, including dynamic/static

Jitter-Buffer (DJB/SJB), electrical echo cancellation (EEC), acoustic echo cancellation

(AEC), gain control (GC), packet loss compensation (PLC), noise suppression (NS).

Huawei provide these VQE technologies to solve these problems

Figure 22– Voice Quality Solution

Factors Affecting Voice

Quality

Huawei VQE solution

Delay and jitter Dynamic and Static Jitter-Buffer

Packet loss ratio Packet Loss Compensation

Electrical echo Cancellation Electrical echo Cancellation

Acoustic echo Cancellation Acoustic echo Cancellation

Noise Noise Suppression

Level Automatic Gain Control

Dynamic and Static Jitter-Buffer



Figure 23– Jitter-Buffer Processing

When voice streams are transmitted through the Nb interface across multiple MGWs on

an IP network, voice streams jitter occurs at the receiving end due to IP network jitter. To

minimize the impact of the IP network on the voice quality, the UMG8900 adopts the

Jitter-Buffer technology. That is, the UMG8900 buffers the received voice packets and

then outputs them at a regular interval after they re-queue. In this manner, jitter is

defeated and voices can be smoothly received. Please refer to the diagram above for

more illustration.

Generally, the longest Jitter-Buffer modifies the voice packet queue best, which, however,

results in long delay and degrades the voice quality. Therefore, the UMG8900 provides

the adaptive Jitter-Buffer technology to balance jitter and delay. That is, the UMG8900

can adjust the Jitter-Buffer depth against IP network jitter based on the actual jitter

conditions of an IP network.

Dynamic Jitter-Buffer: The DJB is automatically invoked by the system to improve the

voice quality for each VoIP call.

The UMG8900 also supports static Jitter-Buffer which is mainly applied to data services.

Users can set the SJB to 0–300 ms with the relevant command.

Packet Loss Compensation

Owing to network congestion, buffer overflow, and error bits, packages are always lost in

the connectionless network. Real-time data streams such as voice packets have a strict

sequence, and thus discarding is better than retransmission.

The voice compression codec algorithms used by IP calls are always in frame, and they

are sensitive to packet loss. Consecutive frame loss obviously affects the intelligibility,

naturalness, and clearness of the integrated voice at the receiving end. To avoid the

effect of packet loss, the package loss compensation (PLC) algorithm is used. Based on

the dependencies of the context voice information, the lost frames are regenerated during

the decoding, and in this way, the effect of the received voice is guaranteed.



The PLC processing flow is shown in the following figure.

Figure 24 – Packet Loss Compensation Processing

Electrical Echo Cancellation

The echo means that the speaker voice is looped back to the speaker through network

devices. The feature of the echo is that the perceived quality of the speaker is affected,

and that of the hearer is not. In the single-IP telephone system, voice signals are received

and sent through different physical lines, that is, the four-wire circuits, and thus no echo is

generated. When the IP network and the PSTN network are interconnected, at least one

of the two communication parties is the two-wire phone, and two wire four wire

transformation circuits are covered, and the echo is generated.

The reason of the echo generation is as follows:

Full-duplex data transmission allows simultaneously transmitting messages in two

directions in one frequency band, that is, in a digital user loop, use one twisted pair cable

to transmit two signals of different directions. At the two full-duplex ends, the hybrid lines

are used to separate the transmission in two directions. To avoid the reflection of local

and remote signals at the hybrid, you must know the precise impedance of lines. The line

impedance depends on the line parameters; however, usually the precise line

parameters are unknown. In this way, attenuated and distorted transmission signals are

leaked to the input end of a receiver, and the echo arise. This is the electrical echo.

Automatic Gain Control

In the communications system, input voice signals are often collected with microphones.

When gains of the audio enlargement system are fixed, the collected voice signals vary

with the speaker’s distance to the microphone. In this way, remote users hear the voice

with unsteady volume, and the subject quality of voice decreases. To enhance the

subject quality of voice, the automatic gain control (AGC) technology is introduced. The

AGC function can compensate changes of the voice volume, retain the voice level, and

help users enjoy steady, clear conversations. At present, the voice quality enhancement



(VQE) function provided by the UMG8900 has the following functions settings:

Enabling the AGC function or not as a whole.

Enabling the AGC function of the local exchange or other exchanges.

Setting the adjustment maximum value from 3 dB to 12 dB.

Setting the adjustment target level value.

Setting the target level from –23 dBm to –6 dBm.

Noise Suppression

At present, the voice quality enhancement (VQE) function provided by the UMG8900 can

support the noise suppression (NS) function. NS can:

Detect input signals during a conversation.

Identify and eliminate noise.

Provide clear, high-quality voice for users.

Enabling the noise reduction (NR) function or not according to the channel configuration.

The NR can:

Detect the local and remote input signals at the same time, or detect the local

or remote input signals, and identify and eliminate noise.

Set the noise suppression energy from 0 dB to 15 dB.

Automatically adjust the local or remote output voice volume based on the

local or remote input noise to help users in a noisy environment hear pleasant,

clear voice.

Enabling the noise compensation (NC) function or not according to the channel

configuration. The NC can:

Adjust the local and remote input signals, or adjust the local or remote input

signals.

Set the adjusted voice volume gains from 3 dB to 12 dB.

Voice quality specifications of UMG8900

In a good network condition: MOS > 4.0

In a poor network condition: MOS > 3.5

(packet loss rate = 1%, network jitter = 20 ms, delay = 100 ms)



3 Annex A. Abbreviations and Acronyms

Abbreviation Description

ACL Access Control List

AMG Access Media Gateway

AS Application Server

ASL Analog Subscriber Line Board

ASN.1 Abstract Syntax Notation One

ATM Asynchronous Transfer Mode

BAM Back Administration Module

BAS Broadband Access Server

BGCF Breakout Gateway Control Function

BHCA Busy Hour Call Attempt

BRA Basic Rate Access

BFD Bi-directional Forwarding

BAM Back Administration Module

BHCA Busy Hour Call Attempt

CCF Charging Collection Function

CDB Central Database Board

CDR Charging Data Records

CLIP Caller Line Identification Presentation


CMU Connection Maintenance Unit

CN Connection Node

CPU Central Processing Unit

CSCF Call Session Control Function

CDB Central Database Board





DOPRA Distributed Object-oriented Programmable Real-time

Architecture

DCN Data Communication Network

DDI Direct-Dialing-In

DOPRA Distributed Object-oriented Programmable Real-time

Architecture

ECF Event Charging Function

ENIP Enhanced Network Intelligent Network

FRR Fast Reroute

FTAM File Transfer Access and Management Protocol

FTP File Transfer Protocol

FE Fast Ethernet

FTAM File Transfer Access and Management Protocol

FTP File Transfer Protocol

GE Gigabit Ethernet

GUI Graphical User Interface

H.248 H.248/MECAMGO protocol

HONET Home Optical Network

HRB High-speed Routing Board

HSS Home Subscriber Server

HTML Hyper Text Markup Language

IAD Integrated Access Device

IADMS Integrated Access Device Management System

I-CSCF Interrogating CSCF

ID Identity

iGWB iGateWay Bill




iMAP Integrated Management Application Platform

IMS IP Multimedia Subsystem

IM-SSF IP Multimedia Service Switching Function

INAP Intelligent Network Application Part

IP Internet Protocol

ISDN Integrated Services Digital Network

ISO International Organization for Standardization

ITU-T International Telecommunication Union -

Telecommunication Standardization Sector

ISDN Integrated Services Digital Network

L2UA Layer 2 User Adaption Layer

LAN Local Area Network

LDD Label Distribution protocol

LSP Label Switch Path

M3UA Message Transfer Part 3 (MTP3) -User Adaptation Layer

MA Multi-service Access

MCU Multipoint Control Unit

MDC Message Distribution Center

MG Media Gateway

MGCF Media Gateway controller Function

MGCP Media Gateway Control Protocol

MGW Media Gateway

MIB Management Information Base

MML Man Machine Language

MRF Media Resource Function

MRFC Media Resource Function Controller

MRFP Media Resource Function Processor




MRS Media Resource Server

MTBF Mean Time Between Failure

MTP Message Transfer Part

MTTR Mean Time To Repair

NAT Network Address Translation

NGN Next Generation Network

NMS Network Management System

NIC Network Interface Card

NMS Network Management System

NPB Network Processing Board

OLT Optical Line Terminal

ONU Optical Network Unit

OSA Open Service Access

OSS Operating Support System

POTS Plain Old Telephone Service

PSTN Public Switched Telephone Network

PBX Private Branch Exchange

PC Personal Computer

P-CSCF Proxy CSCF

PDH Plesiochronous Digital Hierarchy

PLMN Public Land Mobile Network

POTS Plain Old Telephone Service

PRA Primary Rate Access

PSTN Public Switched Telephone Network

PVM Packet Voice Module

QoS Quality Of Service




RAID Redundant Array of Inexpensive Disks

RM Resource Manager

RPB Resource Processing Board

RPR Ring Packet Resilience

RTP Real-time Transport Protocol

SCF Session Charging Function

S-CSCF Serving CSCF

SDH Synchronous Digital Hierarchy

SG Signaling Gateway

SGW Signaling Gateway

SHLR Smart Home Location Register

SIP Session Initiated Protocol

SMB System Management Board

SNMP Simple Network Management Protocol

SPB Service Processing Board

SQL Structured Query Language

STM-1 Synchronous Transfer Mode 1

SYS System Management Board

STM-1 Synchronous Transfer Mode 1

TDM Time Division Multiplexing

TCP Transmission Control Protocol

TFTP Trivial File Transfer Protocol

TL1 Transaction Language 1

TMG Trunk Media Gateway

TMN Telecommunications Management Network

TSS Test Board




UMS U-SYS Management System

UDP User Datagram Protocol

UMG Universal Media Gateway

URL Uniform Resource Locator

VoIP Voice Over IP

VPN Virtual Private Network

VoIP Voice Over IP

VPN Virtual Private Network

VSP Voice-band Signal Processing Board

VSU Voice-band Signal Unit

VVR Veritas Volume Replication

WAN Wide Area Network

XML Extensible Mark-up Language

Documents

Technical Proposal for IGW HUAWEI_LATEST