Date: Fri, 24 May 96 15:48:33 EDT
From: "R. V. Slager (3-4017 / tl:441-4017)" <rvslager@VNET.IBM.COM>
To: p8021@hepnrc.hep.net
Subject:   Spanning Tree protocol on 802.5 LANs


Ref:  Trevor Warwick's note of 20 May 1996, 07:31:52 EDT
      [P802.1-96/083, see d96/d96n083.txt]

(Mike Siegel, one or the 802.5r editors, very kindly supplied me
with the following:)

The term "switch" in Trevor's note is not accurate for discussion within
the standard's body.  The term DTR Concentrator is the architectural
construct in use and this construct has two key parts of interest to this
discussion.  One is a Bridge Relay Function (BRF), which is defined as
ISO/IEC 10038:  1993 SRT compliant bridge.  The other is described in
Annex K of the DTR draft standard and is referred to as a Concentrator
Relay Function (CRF).

I do not believe that Trevor is suggesting that the BRF, currently
defined as an SRT bridge, participate in the SR spanning tree (ie use of
FA, etc.).  However, I do interpret Trevor's note as indicating a desire
to allow the BRF to be defined as a SR Bridge.  That in itself does not
present a technical problem.

It does present a technical problem if an attempt is made to allow the
CRF (regardless of the presence or type of BRF implemented), to
participate in the formation of a spanning tree with SR bridges.

                                      Mike Siegel

For more detail, please contact me or Mike directly, or refer to the
802.5 reflector...
           Rosemary