Cisco Cisco IOS Software Releases 12.1 EX

This document describes the H.323 Support for Virtual Interfaces that was introduced in Cisco IOS 
Release 12.1(2)T. This document contains the following sections:

The H.323 Support for Virtual Interfaces feature allows users to configure the IP address of the gateway, 
so that the IP address include in the H.323 packet is deterministic and consistently indicates the same 
address for the source. 

In previous releases of the Cisco IOS software, the source address included in the H.323 packet could 
vary depending on the protocol (RAS, H.225, H.245, or RTP). This makes it difficult to configure 
firewall applications to work with H.323 messages. 

The H.323 Support for Virtual Interfaces feature addresses that difficulty by allowing the user to 
explicitly configure an IP address to be used for all protocols.

12.1(2)T

This feature was introduced.

12.1(5)XM2

Support was added for the Cisco AS5350 and Cisco AS5400 universal 
gateways.