Calling to SIP-Softphone outside LAN

Hi,

I have configured Asterisk in office, now i want to make a call from my SIP-Softphone to my remote branch office SIP-Softphone , both offices have Proxy-Servers, how can I configure such extention, please giude me, is there any example configuration for such case?

TIA.

You will need to open the coresponding SIP and RTP ports on both offices incoming.

Then you just need to make that each SIP phone can register with the asterisk server and if so then all is good. Also make sure you have set nat=yes in the SIP.conf