[Serusers] SIP iptables question

[Dee Lowndes]

I have finally worked out the problem to an iptables issue and was
wondering if anyone had some rules to sort this out.

If two clients are on an external IP it works, if two clients are on an
internal IP it works but if one client is internal and the other is
external then the external guy can hear the internal but the internal
guy hears nowt.

Any idea/modules/rules to get around this?

Thanks in advance,
Dee