Re: [Sipping] RFC 6157 actually updates RFC 3263 too - dual stack DNS lookups

Iñaki Baz Castillo <ibc@aliax.net> Mon, 03 October 2011 20:31 UTC

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Date: Mon, 03 Oct 2011 22:34:42 +0200
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From: Iñaki Baz Castillo <ibc@aliax.net>
To: "Olle E. Johansson" <oej@edvina.net>
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Cc: sipping@ietf.org
Subject: Re: [Sipping] RFC 6157 actually updates RFC 3263 too - dual stack DNS lookups
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2011/10/3 Olle E. Johansson <oej@edvina.net>:
> The clause about a dual-stack user agent clearly doesn't follow RFC 3263,
> since it implies "and" instead of "or". There's no MUST, SHOULD or MAY
> language applied here, so it seems like this is an oversight - not that RFC
> 6157 is wrong, but that there should have been a more clear update to RFC
> 3263.
> Nitpicking, but I think it's important to clarify the DNS functionality in
> regards to dual stacks. In addition, I think there's a need for a BCP to
> explain how a domain can indicate
> preference of address family - ipv4 or ipv6 - by using SRV entries.

I expect that any vendor implementing SIP over IPv4 and IPv6 should
also implement DNS A and AAAA. But I agree that there should be a
mention to it somewhere in a RFC (not a "or" but an "and").

-- 
Iñaki Baz Castillo
<ibc@aliax.net>