[Asterisk-Dev] [Bounty] IPv6 support in Asterisk

[Olle E. Johansson]

This issue is interesting. There are some scenarios that I don't know if
they have been addressed in the SIP community:

I have IPv4, you have IPv6/v4 with dual stacks. My Asterisk queries DNS
in IPv4,
gets an IPv6 address in the first SRV record, IPv4 in the next. (You
have a IPv6/ipv4 proxy/gw somewhere)
Asterisk will only read the first (another bug) and fail since I haven't
got IPv6.
-- If we fix the SRV record issues, we should propably use the second
one in this case, so we need to be protocol aware.

I have IPv4, you have only IPv6. My Asterisk queries DNS in IPv4, gets
an IPv4 answer with an IPv6 address as the first and only SRV record.
The call will fail.
-- Is there a standard way of using an IPv4 to IPv6 proxy/gw in this case?
-- Can Asterisk be that gw?

I have IPv6, you have IPv6 - both have dual stacks.
I call you, get SRV records with IPv4 and IPv6. Asterisk only reads the
IPv4 (first one ) and sets up the call on IPv4.
-- If we fix the SRV record problem - how should we prioritize, or
should we at all?

There are a lot of other issues when there are IPv4/IPv6 gateways in the
network, especially when it comes to how chan_sip picks an interface to
send on and addresses to use. It's a challenging topic!

/O