Asterisk (1.8-beta2) and SIP IPv4/IPv6 dual-stack possibilities

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On Wed, Aug 4, 2010 at 10:44 AM, Wouter Schoot wrote:
> Dear list,
> I’m trying to get Asterisk to work dual-stack on Linux and I’m left with
> a question.
> Imagine that a user (on the road) connects to Asterisk from various
> places. Many of them probably don’t have IPv6 support yet. However, his
> house and office do have IPv6 connectivity. I would like to make sure
> that whenever IPv6 is available, the connection will be made over IPv6,
> but offer IPv4 as a “fallback” option.
> The pitfall, in my opinion, is to create one sip.conf entry for that
> user which supports the voicecalls over IPv4 and IPv6. However, settings
> like nat=, directmedia= and/or canreinvite= seem to be addressfamily
> unrelated. I want to configure it in a way that when I connect using
> IPv6, no NAT options should be set and the mediapath (almost) always
> should be directly between the peers and not over the Asterisk server
> (so, “nat=no” and “canreinvite=yes”).
> But, when a user comes via IPv4, changes are that he’s on NAT. When that
> happens obviously the connections should traverse the NAT using options
> like “nat=yes” and “canreinvite=no”.
> There’s little to no documentation available as far as my google-skills
> go. There’s some in sip.conf, and I couldn’t find anything on the website.
> Does anyone have some pointers for me, either for the configuration of
> the sip.conf entry or for more documentation on this?
> Best regards,
> Wouter Schoot

I’m interested in this as well. I tried binding Asterisk to both IPv4
and IPv6 addresses, but Asterisk keeps printing the following warnings

WARNING[3542]: chan_sip.c:3183 ast_sip_ouraddrfor: Address remapping
activated in sip.conf but we’re using IPv6, which doesn’t need it.
Please remove “localnet” and/or “externaddr” settings.

I need localnet and externaddr for IPv4 clients behind NAT. I also
want IPv6 support for clients that support it. It seems that it is not
possible to run Asterisk in a dual stack configuration and support
clients behind NAT.