Subject: Re: IPv6 over ATM encapsulation

From: Bryan Gleeson <[email-masked]>
Date: Thu, 20 Nov 1997 13:53:49 -0800 (PST)

Andy, Grenville,

>Grenville and I were just discussing draft-ietf-ion-ipv6-atm-00.txt on
>the phone, and we talked about the possibility of removing the null
>encapsulation option.  I suggested removing it because it adds an
>additional configuration option and complexity to the spec, and code to
>implementations.  In addition, it makes it more difficult to
>interoperate with IPv6 over Frame Relay via FR/ATM interworking.  In
>fact, in the forthcoming IPv6 over FR draft, null encapsulation will
>not be an option; RFC 1490 encapsulation will be required.

Is this for PVCs and/or SVCs ? If for SVCs does it imply that the
use of BLLI negotiation is prohibited ? For SVCs I don't think 
there is any point in prohibiting two co-operating systems from 
using it if they want to, since it adds no burden on those that only
use LLC (since being the default, LLC must always be in the list of 
proposed encaps), and that is what the current signalling for 
IPV4/ATM allows. Even if the spec was silent on the matter the 
negotiation of non-default encapsulations would be allowed as a 
signalling capability.

Bryan

---

From: "Andrew G. Malis" <[email-masked]>
Date: Thu, 20 Nov 1997 17:06:46 -0500 (EST)

Bryan,

> >encapsulation option.

You raised some excellent points.  To be frank, I primarly had section
3.1.1 (null encapsulation for PVCs) in mind.  However, if you read
section 3.2.3 (null encapsulation for SVCs), Grenville discusses some
interesting restrictions on when null encapsulation can and cannot be
used.

So, given your discussion, I am mostly interested in removing the use
of null encapsulation for PVCs.  However, given the restrictions in
section 3.2.3, do you think it makes sense to support it for SVCs as
well? 

Cheers,
Andy
________________________________________________________________________
Andrew G. Malis  [email-masked]  phone:978 952-7414   fax:978 392-1484
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