AppleTalk Phase 2: OUI in Ethernet to FDDI Bridges



I have a question about the bridging problem with AppleTalk Phase 2 and
FDDI. I found some information that says the IEEE 802.1 committee is
currently formalizing the use of OUI in Ethernet to FDDI bridges that will
define what to do if a bridge encounters SNAP headers with OUI=0. What is
the status of this?

The IEEE 802.1 committee has adopted the proposal which we, in conjunction
with DEC, brought before them to resolve the conflict in using OUI 0. The
802.1 committee has moved the 802.1h specification to the "recommended
practice" status which is just short of being a fully adopted and ratified
standard.

The 802.1h specification defines how an Ethernet to FDDI translational
bridge should operate in the presence of packets that use OUI 0. This is
basically a simple filter mechanism which is implemented in the bridge that
checks the packets OUI:

- If it's 0, it then checks to see if the packet type is AppleTalk.

- If it's an AppleTalk packet, then it doesn't do any translation.

The key here is to make sure that any potential FDDI bridge vendors have
implemented the 802.1h specification.



Published Date: Feb 18, 2012