Subject: RE: C, D terms of GS

From: Andrew Smith <[email-masked]>
Date: Wed, 13 Oct 1999 15:33:39 -0700

You wrote:
> -----Original Message-----
> From: Navin kumar Agrawal [mailto:[email-masked]]
> Sent: Friday, October 01, 1999 4:45 AM
> To: Int-Serv Mailing List
> Subject: C, D terms of GS 
...
> In my case, the link layer media is Ethernet but the it is not used in
> the conventional shared media form. Meaning, it is used in the
> point-to-point form. So I guess, there is no need to implement SBM. 

I assume you mean "it is used in the full-duplex form" rather than just
point-to-point: even if you have a point-to-point link it might be running
half-duplex and so there may well be two senders competing for bandwidth. It
is only when you go to full-duplex that you have a single sender that can
administer the full bandwidth of the link. 

However, you still should use SBM protocol, even in this case, in order to
make sure that the RSVP messages (and hence the correct accounting for
bandwidth and resources) get to go through the right nodes along the layer-2
path between the layer-3 sender (or layer-3 router sending onto the subnet)
and the layer-3 receiver (or next hop layer-3 router). The implementation of
SBM for the full-duplex case is simplified only in the sense that there is
no need to elect who is the DSBM for the segment: in this case the answer is
always "me".

See the documents at http://www.ietf.org/html.charters/issll-charter.html
for more details.

[this part of the discussion should really be moved to ISSLL list, CC'ed
above - let's drop int-serv from this sub-thread].

Andrew

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Andrew Smith                              tel: +1 (408) 579-2821
Extreme Networks                          fax: +1 (408) 579-3000
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