Port 5060 seems "occupied" for 2nd external sip-cl

Hi, all!

I have an asterisk box inside my router/firewall. The Firewall has port 5060-61 set up to point to the asterisk box (among others).

I can nicely connect to my Voip-provider via port 5060, and I have one external sip-phone connecting via port 5060 nicely (both show as connected on port 5060 when using “sip show peers”.

The problem is when I try to connect a 2nd external sip phone, set up to make contact via the 5060-port. It cannot connect to the asterisk server. But when I change this to 5061 on the sip-phone, then it connects nicely (but it stays connected on a completely different port (60037) when I check “sip sip peers”. (Edit: I was a little quick, its seems that the new external sip-phone is connected via port 5060 (even though the initial contact was made via 5061), but the first external sip-phone gets reassigned from port 5060 to port 60037…)

This is a little bit unconvenient, that I need to have a different port assign in the (external) sip-phones. So I guess there is something I am missing?

Thanks for any comments!