Have a few AVM's and Drayteks dotted round UK and Ireland using Blueface as the sip providor with no issues, but have just setup a SOHO office in Dubai. The ISP's drop SIP traffic, so have a VPN back to the UK with certain routes including SIP.BLUEFACE.IE over the VPN. Using a handheld SIP phone and Xlite on a PC, they all register fine and the couple of users can make calls using them, but i cannot get the Draytek 2820vn to register using its built in SIP registration. i am using fw 3.3.3

I know the routing is correct otherwise the Xlite and sip phone wouldnt work, but i dont think the SIP registration from the Draytek itself is going over the VPN but straight out the internet.

Does anyone know how i can prove if the 2820vn is trying to register over the VPN or if there are any tricks involved in making sure that registration takes place over the VPN?