Cisco Systems Network Router Guidelines for Selecting an Address Format, ATM Field, Description

Chapter 3 Address and Closed User Group Planning

Planning Address Configuration Settings

Table 3-1 ATM Address Components

ATM Field	Description	Default Values
AFI	Authority Format Identifier (1 byte).	47
ICD	International Code Designator (2 bytes) The default value is the ICD assigned to	0091
	Cisco Systems.
IDI	Initial Domain Identifier (8 bytes). The contents of this field vary depending on the	—
	value of the AFI. For example, with a DCC AESA (AFI=39), the IDI value of Hex
	840F identifies the United States.
HO-DSP	High-Order Domain Specific Part (4 to 12 bytes). The meaning is defined by the	—
	address authority controlling the AESA. This component couples with AFI and IDI
	to route a call to the appropriate switch.
ESI	End System Identifier (6 bytes). This field repeats the PNNI Controller MAC address	PXM45
	when the ATM address identifies the PNNI node. (When an ATM address identifies	MAC address at first
	an ATM end system, the ESI field will be completed through ILMI registration with	boot.
	the end system. In this case, the ESI is typically the MAC address of the ATM CPE.
	The unique ESI field will distinguish that ATM end system [ATM CPE] from all other
	ATM end systems.)
SEL	PNNI selector byte (1 byte). The selector byte is used to identify different target	00
	applications on the node.

Guidelines for Selecting an Address Format

It is important to select a address format plan which meets the future needs and scale of the network. Changing the node ATM address format and addresses after its initial deployment requires major service disruption, and requires complete reconfiguration of the node and all of its connections. Consider the following guidelines when selecting an address format:

•Consider whether a registered address will be required in the future. The default registered address is registered to Cisco and is part of the ATM address.

•If an address format has been chosen for the WAN, or if your WAN will consist of existing nodes for which an address format has been selected, you can select that address format.

•Both Public ATM networks (PSTNs) and Narrowband Integrated Services Digital Networks (N-ISDN) usually use E.164 numbers. PNNI allows end-system reachability to be advertised via the E.164 address prefix.

•In the Data Country Code (DCC) format, each country has a unique DCC value. If you select this address format, your value must match this standard.

•In the International Code Designator (ICD) format, the ICD identifies an organization such as a company or campus. This identification is useful when you are deploying a WAN that will be accessed by several campuses or sites.

•Native E.164 addresses can be embedded in the AESA.

Enter the address format or formats that you select into the Nodal Address Worksheet, Table 3-4, which appears at the end of this chapter.

Note Local AFIs should not be used for addressing within ATM Service Provider networks.

	Cisco PNNI Network Planning Guide for MGX and SES Products, Release 5
Part Number OL-3847-01 Rev. D0, April, 2004		3-5