[asterisk-users] NAT and externip problem or bug

[Robert Jenkins]

Hi,

I've recently got asterisk running on it's own pc inside my firwewall.
Mostly it's working fine, but there is one silly problem I can't figure out.
(For reference, Asterisk is the latest stable version as of last weekend
14th July. All connectivity is SIP or IAX).

I initially had 'externip' set to my public IP. I have the appropriate 5000
range ports forwarded to the asterisk PC and external calls seem OK.

The 'local' phones are a mixture of Sipura boxes and softphones.

Problem:
No or one-way audio in internal calls.

Reason: Asterisk appears to be using the 'externip' address for all SIP
devices, regardless of their NAT setting.
Once a call starts, some softphones change the address they are responding
to & use the external IP rather than the asterisk PCs local IP on the same
subnet...

I have tried all NAT options and spent quite a while reading everything I
can find about sip.conf, but I can't so far find any way of changing this
behaviour.

All the internal phones work fine if I comment out the externip line, but
then the connections outside the firewall are likely to have problems.

Is there any way of configuring externip on a per-device basis, or should it
only have effect on NATed devices?

Thanks,
Robert Jenkins.