The IP over ATM Mailing List Archive by date

[Andrew Smith <asmith@synoptics.com>]

> From atmpost@matmos.hpl.hp.com Fri Sep 23 14:33:51 1994
> Date: Fri, 23 Sep 1994 13:58:47 +0800
> From: rajeev@trillium.com
> To: ip-atm@matmos.hpl.hp.com
> Subject: Re: Question on RFC1577.
> X-Sun-Charset: US-ASCII
> Content-Length: 3005

> This is a unique feature of common channel signalling protocols (where
            ^^^^^^^^^^^^^^
> signalling is done on a separate channel from data channels) such as
> Q.931, Q.2931 as opposed to the in-channel signalling protocols such
> as X.25 (where data always follows the control packets along the same
> path).

I would call it a "bug", not a feature.

This should be addressed by the IP-over-ATM group in the next rev of 
the document: I think it is an interoperability/protocol issue that
should be covered in the spec. It looks like an extra state variable
is needed per-VCC to cover the "I've accepted the call but have not
heard any packets from the VCC yet" state.

This race condition seems to be exacerbated by 2 identical implementations
both doing the same collision avoidance algorithm at each end of the 
VCC in question.


Andrew


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Andrew Smith					TEL:	+1 408 764 1574
Engineering Group Leader			FAX:	+1 408 988 5525
Distributed Network Systems			E-m:	asmith@synoptics.com
SynOptics Communications Inc.	
Santa Clara, CA
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