According to Apple and Google’s app review guideline, all apps need to support IPv6-only network, 

so I tried to enable ipv6 support on my freeswitch server.

In my development environment, a server with both ipv4 and ipv6 address is ready. 

Server Info:

Also, profile external-ipv6 and internal-ipv6 for freeswitch had also enabled.

In addition, a pure-ipv6 network(no NAT64) is also ready for test.

As the test result, clients could access to server via ipv6-only network for registration(sip package showed in server with siptrack),

but failed to make calls in same network. 

Freeswitch log showed a failure in originate, which returned an 606 USER NOT REGISTERED. 

Both clients was showed in “show registrations” with correct ipv6 address, but Sofia couldn’t get contact string(got 606 in sofia_contact).

Is there any additional settings need for Sofia to enable ipv6 support? Any suggestion would be appreciated.

Regards.