Bridges on SLMS devices

Zhone’s SLMS devices use two types of bridges — symmetric bridges which have the same bridging behavior and asymmetric bridge which have different bridging behavior.

The bridge interfaces for symmetric bridges provide the same bridging behavior (bridge interfaces for TLS are the one example of a symmetric bridge interface) and bridge interfaces for asymmetric bridges provide different bridging behavior.

Uplink and downlink bridge configurations are the most common asymmetric bridges but intralink bridges are also asymmetric bridges. The different behavior for these four bridge types are useful in creating network bridges.

Symmetric bridges use TLS and wire bridge interfaces:

Asymmetric bridges use three different bridge interface types:

About asymmetric bridges

Asymmetric bridges are made up of one uplink and at least one downlink or intralink.

A single bridge asymmetric bridge may use all three asymmetric bridge interface types — uplink, downlink, and intralink — however, a single bridge may only have one uplink. The system may have multiple intralinks per bridge, but other SLMS devices may only have one intralink. There may be multiple downlinks.

Most commonly there is one uplink and multiple downlinks as you would have with a line concentrator which splits a high capacity upstream link into mulitple lower capacity downstream links. Intralink bridge interfaces are used for subtending other devices. Intralinks have different learning behavior than uplinks or downlinks.

When setting up Internet access for multiple subscribers you configure the system as a line concentrator. With the line concentrator model you create an asymmetric bridge with a high capacity link upstream configured to be the uplink, and have many downlinks configured for the subscribers.

For more information

For more information about bridging on Zhone devices see the manuals on Zhone website http://www.zhone.com/support/manuals/.

October 9, 2011