Registration problem after external ip change

Hello,
I had a working pbx, but our provider needed to change our public ip address. I have changed the externip parameter, incoming calls work fine, but I can´t get outgoing calls to work. SIP debug shows this:

<--- SIP read from UDP:xx.xx.xx.x:5060 ---> SIP/2.0 403 Forbidden Via: SIP/2.0/UDP xx.xx.106.57:5060;received=xx.xx.106.53;branch=z9hG4bK39e58b5a;rport=5060 From: ;tag=as0b17c1ae To: ;tag=aprqngfrt-ck1smd10000c6 Call-ID: [email protected]:5060 CSeq: 102 INVITE

I think that the problem is that the “received” parameter shows the old ip address, but I just can´t find out how to change it.

Can you help me?

Thanks

Just want to verify that you changed the “External IP” address in the SIP settings page.

Yes, that was the first thing I did. And if I remember correctly, the only one, I haven´t found anything else related.