Tell Asterisk and PJSIP to Speak IPv6
The configuration described here happens in the pjsip.conf file within transport and endpoint sections. For more information about the transport side of things see PJSIP Transport Selection
Bind PJSIP to a specific interface
To configure res_pjsip for communication over an IPv6 interface you must modify the bind address for your transports in pjsip.conf.
[transport-udp6] type=transport protocol=udp bind=[fe80::5e26:aff:fe4b:4399] [transport-tcp6] type=transport protocol=tcp bind=[fe80::5e26:aff:fe4b:4399]
Bind PJSIP to the first available IPv6 interface
A transport can be configured to automatically bind to the first available IPv6 interface. You use "::" as the bind address.
[transport-auto-ipv6] type=transport protocol=udp bind=::
Configure a PJSIP endpoint to use RTP over IPv6
If the communication involves an endpoint (almost always) then the endpoint must be configured to allow RTP via ipv6.
[mytrunk] type=endpoint transport=transport-udp6 context=from-external disallow=all allow=ulaw rtp_ipv6=yes