|NOTE: This product is no longer being sold and might not be supported. View the End-of-Life Notice to learn:
The Cisco IOS® Software Release 12.1 T is an early deployment release delivering the latest Cisco IOS Software functionality and platform support.
Cisco IOS Software Release 12.1 T, unlike the parallel 12.1 release, will integrate new features with every maintenance release. This Technology (T) release will reach End of Engineering when the next Cisco IOS Software major release becomes available. Ongoing support for the functionality introduced in Release 12.1 T will be carried forward into the next release.