Break out group report 96/03/13, La Jolla, Ca.
Basic Formats & forwarding
        Paul Franz

Could we/ should we nail down the tagged frame format and frowarding rules for:
        1-layer address model?
        2-layer address model?
     - - - - - - -
I. Should we do it at all (is it premature)?
 -->yes, we need to do it now.
        -Need to begin long lead-time designs
        -Propriettory solutins exist.
        -Ethernet vs. 802.3 all over again?
BUT: Recognize there are risks associated with early format standardization.
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II. Can a single solution cover the application space?
One-layer:
        -Well-understood extension to bridged LANs
        -Minimum BW overhead (4 bytes vs 16/20)
        -Practical for 1000's of hosts, 100Mb links
        -Covers enough of the application space that it will get built with
        of without 802.1
Two-layer:
        -Strong benefits at Gbps data rates
        -Scalability fratures important to get to 10,000's of hosts
           (denver objective)
        -Better fit for ATM networks?
        -Tunnelling can provide additional features
                -carrying foreign MAC frames and address spaces
                -SRB support?
          but it raises additional issues
                -convergence, stability
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Priority: 1-layer model
        -better understanding -->potential for quick standardization
        -least bandwidth overhead
        -the only one which can meet time-to-market requirements
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Resolved:
p802.1 intends to standardize vLAN-tagged frame formats and
forwarding rules for both 1-layer and 2-layer addressing models,
with priority given to completing the 1-layer model ASAP.

The frame formats for 1-layer addressing will be:

Enet/802.3
DA    SA    EtherType   vLAN ID    ...remainder of frame...  new CRC
 6     6       2           2                                   4

802.5 / FDDI
DA    SA    (routing)   SNAP-OUI   EtherType  vLAN ID ...remainder... new CRC
 6     6      ---          6           2         2
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Further Resolved:
Forwarding Model:
On receipt of a frame, a switch will apply a set of rules outside
the scope of this resolution to map the frame to a single vLAN.

Forwarding rule:
Forwarding decisions will be made as if there were a separate
filtering / forwarding datavase for each vLAN.

Note:
The 16-bit vLAN ID does not imply that a switch must
support 64K active vLANs.