[rbridge] Supporting Heterogeneous Link Types

[Alper Yegin]

5.3. Supporting Heterogeneous Link Types 

   It is easy to support link types other than 802 links with RBridges. 
   However, mixing link types within a single campus raises 
   complexities, such as packet size, incompatible layer 2 addresses, 
   and other layer 2 features (such as priority) that might be lost when

   trying to "bridge" two different link types.

The TRILL charter is specific to IEEE 802.1 Ethernet networks. Due to
lack of sufficient motivation (interworking incompatible L2s) to
complicate the design, I think we can close this issue. Comments
welcome.

Alper