Transparent Interconnection of Lots of Links (TRILL) Single Area Border RBridge Nickname for Multilevel

A major issue in multilevel TRILL is how to manage RBridge nicknames. In this document, the area border RBridge uses a single nickname in both Level 1 and Level 2. RBridges in Level 2 must obtain unique nicknames but RBridges in different Level 1 areas may have the same nicknames.