Area Address Assignment. Lucent Technologies DMX Access Multiplexer

: IS-IS Level 2 Routing Guidelines

Area Address Assignment

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Area address

The area address is the first 26 characters of each DMX Network

Services Access Point (NSAP). [DMX supports a fixed-length 40character (20-byte) NSAP only.] The first eight characters of the

NSAPs are always the same and cannot be changed. The remaining

18 characters of the NSAP area address are provisionable but only the

Area field should be changed to assign a node to a different area. The remainder of the NSAP includes the System Identifier field, which is unique to each node, and the Selector (SEL) field.

The following table provides a break-down of an NSAP.

Table C-1 Area Addresses

NSAP Field: AFI IDI

1 2

IDI

PAD

DFI

1 Bytes:

Default Value:

(hex)

39 840 F 80 not provisionable

Organization

ID

RES RD Area

System

Identifier

SEL

3 2 2 2 6 1

000000 0000 0000 0000 user provisionable none not

00 provisionable

A group of nodes are assigned to an area by changing each node’s

NSAP Area field to the same value. The entire NSAP area address must be identical for all nodes in an area and different from the NSAP area addresses for all other areas.

If more than one separate area with the same area address exists, routing to these areas from other areas would not be predictable and couldn’t be expected to function properly.

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Issue 8.0 September 2006

Area Address Assignment

: IS-IS Level 2 Routing Guidelines

Area field

The Area field consists of four hexadecimal characters, with a default value of 0000 (hex). TL1 command

ENT-ULSDCC-L3

can be used to change the Area field.

Area Terminology

Despite the technical differences between the area address and the Area field described previously, the term area address is commonly used to refer to the Area field value. Thus, for convenience, the term area address is used throughout this document.

Multiple area addresses

Multiple area addressing is the capability for a node to be assigned more than one area address. The provisioning of multiple area addresses is not supported on DMX, directly. However, if multiple area addresses are provisioned in another node, DMX would recognize its own primary area address plus up to two other area addresses. The use of multiple area addresses is not recommended.

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