Cisco Cisco IOS Software Release 12.0(22)S

MPLS Class of Service is now referred to as MPLS Quality of Service. This transition reflects the growth 
of MPLS to encompass a wider meaning and highlight the path towards future enhancements.

This feature module describes the use of the MPLS class of service (CoS) functionality in an MPLS 
network. The document contains the following major sections:

MPLS CoS functionality enables network administrators to provide differentiated services across an 
MPLS network. Network administrators can satisfy a wide range of networking requirements by 
specifying the class of service applicable to each transmitted IP packet. Different classes of service can 
be established for IP packets by setting the IP precedence bit in the header of each packet. 

12.0(5)T

This feature was introduced as MPLS Class of Service.

12.0(10)ST

This feature was updated and integrated into Cisco IOS Release 
12.0(10)ST. MPLS CoS support was added for Cisco 12000 series routers. 
Configuration tasks and examples for Cisco 7200 and 7500 series routers 
were modified; configuration tasks and examples for Cisco12000 series 
routers were added.

12.0(22)S

This feature was renamed to MPLS Quality of Service and integrated into 
Cisco IOS Release 12.0(22)S.