[asterisk-users] Dualstack

[Pawel Kuzak]

I have an Asterisk (v10.2.0) running and bound to address "::". I think 
this way he listens and answers to requests send to the IPv4 and IPv6 
address (haven't check that with IPv6 yet). What I want to achieve is, 
that he handles signaling via IPv4, but RTP via IPv6.
In my setup, I have a user agent (Dualstack) that generates an INVITE 
and sends it out via IPv6. In the SDP part the user agent expects the 
RTP traffic on its IPv6 address as well. Between the user agent and the 
Asterisk, I have a proxy that handles the signaling part, and translates 
from IPv6 to IPv4 and vice versa. The Asterisk accepts that request 
(IPv4) and does everything well, except that in his SDP offer, he 
inserts his IPv4 address (I think that's because he received the request 
via IPv4).
The result of this is:
The user agent sends RTP traffic via IPv4 to the Asterisk.
The Asterisk sends RTP traffic via IPv6 to the user agent.

Signaling: UA <---- (IPv6) ----> Proxy <---- (IPv4) ----> Asterisk
RTP: UA ------------------- (IPv4) --------------------> Asterisk
         UA <----------------- (IPv6) ---------------------- Asterisk

Does anybody know how I can achieve that Asterisk does input his IPv6 
address in the SDP offer and uses that for incoming RTP, if he sees, 
that the user agent also uses an IPv6 address in his SDP offer?
Maybe there is an easy way and I've just overseen a configuration 
option. Or do I have to patch the sources?

Thanks in advance!