Unique to an SDH framed port is the ability to configure a single STS3 path instead of three STS1 paths. When as STS3 path is configured, the VTs are configured using tributary units (TUs). One or more TUs can be combined into a tributary unit group (TUG) (see the STS3 branch in Figure: OC3 Channelization using SONET and SDH).
When an STS3 path is configured on an SDH port, the three TUGs in the following configuration are created by default. Each TUG can be considered the equivalent of an STS1 path.
port 1/1/1
sonet-sdh
framing sdh
path sts3
exit
group tug3-1 payload tu3
group tug3-2 payload tu3
group tug3-3 payload tu3
This section provides information on the following topics: