Cisco Cisco IOS Software Release 12.0(18)S

The UTI functionality in IOS Release 12.0(18)S is not supported in the 12.0(18)ST release. However, 
in IOS Release 12.0(19)S and later, all UTI functionality supported in the S train is also supported in 
the ST train.

This feature module describes the Universal Transport Interface (UTI) and includes the following 
sections:

12.0(18)S

This feature was introduced.

12.0(19)S

Support was added for Frame Relay point-to-point subinterfaces.

Support was added for Ingress Encapsulation and Egress Decapsulation 
(facing the customer network site) in the following line cards:

1 port Gigabit Ethernet (Engine 1)
3 port Gigabit Ethernet (Engine 2)

12.0(19)SP

This feature was introduced on Cisco 10720 Internet routers.

Support for UTI VLANs was added to Cisco 10720 Internet routers.

12.0(20)SP

Support for UTI VLAN Rewrite was added to Cisco 10720 Internet 
routers.

12.0(21)S

Support for UTI VLANs was added to Cisco 12000 series Internet routers.

Support for Ingress Encapsulation and Egress Decapsulation facing the 
customer network site was added for the following Engine 0 line cards:

2 port STM-1/OC-3 Channelized E1/T1 (Engine 0)
6 port Channelized T3 (Engine 0)
6 port DS3
12 port DS3
6 port E3
12 port E3

12.0(21)SP

Support for UTI VLAN rewrite was added to Cisco 10720 Internet routers.

Support for UTI keepalive was added for UTI tunnels configured between 
a Cisco 10720 Internet router and a Cisco 7000 series or Cisco 12000 
series Internet router.