Cant call outbound from branch office

[Khanyasi]

Hello Experts, We are using Vicidial version 2.6-381a with Asterisk 1.4.44-VICI, we have just recently opened new office location we are using snom 710 phone that connects to our vicidial phone server in main branch we don't have phone server in that location, the inbound calls are working IVR is calling okay but when we try to call any internal extensions or outbound calls from that location the phone gives network error and in web interface of snom 710 says registration failed, i have checked the registration code and made sure snom phone is configured the way our other 65 extensions in other locations are configured, i have checked firewall on the router of that location i have also opened ports 5061, 5061 in that router but not sure why i cannot dial out, also the new office location network is PPTP and our head office is VPLS network.

[Khanyasi]

I have got it resolved it was our router MTU settings so just run this script in a browser to allow packets to be fragmented by router just replace ip address with your actual phone ip
192.168.x.x/?settings=save&ip_frag_enable=on