Richard

The Management Model of the Centralized Network Architecture

IETF 75th meeting, Stockholm

draft-richard-opsawg-cna-mib-00

For the Network Access Technologies such as PON, WLAN and so on, there is a Generic Management Model behind them.

The presentation is to discuss the Model and give an example using SNMP MIB.

  

Preface

Typical Network Access Technologies Centralized Network Architecture A Generic Management Model MIB Objects for the Model Next Steps Need Your Guidance

Agenda

Typical Network Access Technologies (1/3)

OLT

POS

ONU

Passive Optical Network (PON)

PON defines an architectures of fiber to the home.

• OLT (Optical Line Termination) provides the interface between the PON and the service providers’ network• ONU (Optical Network Units) terminates the PON and offer interfaces such as xDSL, Ethernet to users • OLT can manage and control the ONUs

according to IEEE 802.3ah and IEEE 802.1ag

Typical Network Access Technologies (2/3)

AC

Centralized WLAN Architecture

IETF CAPWAP WG defines RFCs for it.

• AC (Access Controller) manages and controls multiple WTPs (Wireless Terminal Point) by the tunnel between WTP and AC.• WTP can forward the station’s data to AC by the tunnel.• WTP use certain wireless technologies such as 802.11 radio interface to communicate with the station.

WTP

station

Typical Network Access Technologies (3/3)

The PON and Centralized WLAN Architecture give

some typical examples to the Network Access

Technologies, the multiple access units (ONU, WTP)

under control by a controller unit (OLT, AC) is a  

an emerging trend.

There are generic models behinds • Network Topology• The Operation and Management Model

Typical Network Access Technologies Centralized Network Architecture A Generic Management Model MIB Objects for the Model Next Steps Need Your Guidance

Agenda

Centralized Network Architecture

Access Controller (AC)

Terminal Point (TP)

Station

1 2 3 4

AC manages multiple TPs through a

tunnel protocol.

Tunnel offers a management channel

to the AC

The interfaces on the TP are important

entities which offers the access service

to the station

TP are under management by the AC

Through the tunnel

The Centralized network architecture (CNA) offers the access service to stations (user) by distributing functions among AC and multiple TPs.

ONU WTP

OLT

AC

Ethernet, 802.11, 3G…

Typical Network Access Technologies Centralized Network Architecture A Generic Management Model MIB Objects for the Model Next Steps Need Your Guidance

Agenda

Generic Management Model (1/2)

To manage a CNA, the basic operation steps are:

1) The operator prepares the configurations for TPs to be managed

before they connect to the AC and can change TPs' configuration after

they connect to the AC. The configuration for a TP is identified by

TP’s base MAC address.

2) The TP discovers AC and establishs the tunnel with AC.

3) TP downloads configuration by match its base MAC address with

configuration’s Id.

4) TP MAY not run SNMP service, while AC SHOULD. TP reports

Its status info to AC through the tunnel.

AC provides the management Interfaces

to the operators

Generic Management Model (2/2)The following management objects are important:

1) AC

Such as the number Of TPs

connecting to AC.

2) TP

Such as status, software version,

current configuration

3) Interfaces on the TP

Such as if Name, status, configuration

4) Tunnel

Such as peer of the tunnel,

the establishment time

5) Station

Such as Id, the interface attached

AC

TP1

STA1

1 2 3 4

STA2

TP2

1 2 3 4

STA3

SNMP, Netconf

Typical Network Access Technologies Centralized Network Architecture A Generic Management Model MIB Objects for the Model Next Steps Need Your Guidance

Agenda

MIB Operation Steps

Create TP profile to prepareConfiguration

Specify a TP profile used by which TPs

Use the MIBs such as the Network Access Technologies’ to configureparameters for TPs and their interfaces

TP boots up and connects to AC throughthe tunnel

It triggers the AC automatically creates

the “TP Virtual Interface”.

To allow multiple TPs share a TP profile

A access technology such as IEEE

802.11 usually already defines the MIBs,

We should reuse it.

Through the SNMP to query TP, station,

SNMP Agent on the AC

It triggers the AC automatically creates

the “TP Profile Interface”.

TP Template Interface

For any network access technology, the configuration and management of interface is very important, and a technology usually already defines the MIB modules on their own.

For example, the MIB tables such as Dot11OperationTable [IEEE.802-11.2007] are able to support WLAN radio interface configuration, while the MIB tables such as adslLineTable [RFC2662] are able to support ADSL interface configuration.

In such MIBs, the tables of the interface parameters

usually use the ifIndex as the Index. To prepare the configuration

for the TP’s interfaces, it need the logic interfaces on the AC:

TP Template Interfaces. Creation of the interface is triggered by

TP profile.

TP Virtual InterfaceFor each PHY interface on the TP, it can have a TP Virtual Interface

Corresponding to it on the AC.

TP1

1

TP2

1 211 12 13

MAPPING

PHY Interface identified by Id

TP Virtual Interface identified by ifIndex

It looks like that PHY interfaces are located on the AC, and PHY location of the TP (interface) is hidden to the operator.

AC

IfIndex is used as a common handler for a corresponding interfaces in the draft and the specific network access technologies' MIB modules

AC

Differences between the logic Interfaces

TP Template Interface TP Virtual Interface

Function To help the operator to do configuration, and it is related to

the TP profile

Look like an interface corresponding to the “real” PHY interface on the TP, and operator could use it (by ifIndex) to query the PHY interface’s info.

Event to Create

Once the operator creates a TP profile

Once TP connects to the AC, and gets Configuration

Interface status

Keep the up status to allow configuration

Status is same as PHY interface on the TP (as TP could report its info to the AC through the management tunnel )

TP Profile

CnaTpProfileEntry ::= SEQUENCE {

cnaTpProfileId CnaTpProfileIdTC,

cnaTpProfileName SnmpAdminString,

cnaTpProfileTpModelNumber SnmpAdminString,

cnaTpProfileTpName OCTET STRING,

cnaTpProfileTpLocation OCTET STRING,

cnaTpProfileRowStatus RowStatus }

A TP profile is used to make configurations such as the name of a TP before and after it connects to the AC.

The profile could be shared by multiple TPs (TP is identified by base MAC).

The tunnel protocol message received from the TP MUST contains its base MAC address. The AC uses the base MAC address to find the corresponding TP profile for a specific TP.

Create the TP Template Interfaces (3/4)

CnaTemplateIfMappingEntry ::= SEQUENCE { cnaTemplateIfMappingIfId CnaInterfaceIdTC, cnaTemplateIfMappingTemplateIfIndex InterfaceIndex, cnaTemplateIfMappingPhyIfType IANAifType}

Another important function of TP profile is to trigger the creation

of TP Template Interfaces on the AC. To implement this function, a TP

profile MUST include the TP's model name [RFC4133], which reflects

the number of PHY interfaces on the TP. In this way, the creation of

a TP profile triggers the AC to automatically create the same number

of TP Template Interfaces corresponding to the TP's PHY interfaces

without manual intervention.

CnaTemplateIfMappingEntry keeps the mapping between Interface Id

And the ifIndex of TP Template Interface.

Reusing of the Entity MIB

To model a TP, besides its status, the properties such

as the model name are well defined by the Entity MIB

[RFC4133]. It should reuse such existing standards.

From the ENTITY-MIB module's perspective,

the overall physical entity (AC) is

a 'compound' of multiple physical entities

(that is, the TPs connected to AC),

and all entities are each identified

by a Physical index.

When the draft models a TP object, it also keeps the mapping

value to the Physical index. Through it, the operator could query

the model name, hardware version through the ENTITY-MIB.

AC

TP1

STA1

1 2 3 4

STA2

TP2

1 2 3 4

STA3

Each TP

Identified by Physical Index

Typical Network Access Technologies Centralized Network Architecture A Generic Management Model MIB Objects for the Model Next Steps Need Your Guidance

Agenda

Next Steps

Current draft draft-richard-opsawg-cna-mib-00.txt

post in the web site is a MIB draft.

David Harrington suggests describing the management

Model as an the Information Model, as described in

RFC3444, and make it apply to SNMP and Netconf.

We would follow it and intend to publish one draft for

Information Model , another one is for SNMP.

Later, we can have a Netconf one.

Typical Network Access Technologies Centralized Network Architecture A Generic Management Model MIB Objects for the Model Next Steps Need Your Guidance

Agenda

Need Your Guidance

You are welcomed if you have an interest

to be co-editor.

Any Question?

Thank You