Cisco Cisco IOS Software Release 12.0(22)S

The carrier supporting carrier feature enables one MPLS VPN-based service provider to allow other 
service providers to use a segment of its backbone network. This document includes the following 
sections:

Carrier supporting carrier is a term used to describe a situation where one service provider allows 
another service provider to use a segment of its backbone network. The service provider that provides 
the segment of the backbone network to the other provider is called the backbone carrier. The service 
provider that uses the segment of the backbone network is called the customer carrier. 

12.0(14)ST

This feature was introduced in Cisco IOS Release 12.0(14)ST. 

12.0(16)ST

Support for the Cisco 12000 series routers (Engine 0) for the Cisco IOS 
12.0 ST release was added. 

12.2(8)T

This feature was integrated into Cisco IOS Release 12.2(8)T. Support was 
added for the Cisco 12.2 T release for the following platforms: Cisco 3640 
series, Cisco 3660 series, Cisco 4500 series, Cisco uBR7200 series, and 
the Cisco MGX Route Processor Module 

12.0(21)ST

Support for the Cisco 12000 Series routers for the Cisco IOS 12.0 ST 
release was added. (See 

 for specific line cards supported.)

12.0(22)S

This feature was integrated into Cisco IOS Release 12.0(22)S. Support for 
the Cisco 12000 series line cards was added. (See 

 for specific line 

cards supported.)