Voip sip over wan registretation problem

[kam.yee01]

Hi All 

Happy Holidays 

I have a 2811 router with some basic Voip configuration, im able to register phone via SCCP and sip as long im inside the network, but if i try to register with my smartphone (Zoiper) over my 3g connection its alway fail. I think im missing some kind of sip trunk or config. step.

can anybody help me? 

PS: sorry for my english

[Jaime Valencia]

Assuming you're using CME, you would need some sort of VPN solution to register your smartphone with a SIP client to your CME.

[kam.yee01]

Even if im pointing to my public IP? 

Thank you for your quick answer.