I've been on skinny broadband for a while now and had set up a 2talk phone line to trial.

All was going swimmingly - so i thought, until Monday when I took the plunge and had my landline ported across and fully committed to cutting the POTS cable.

(Although I'm using a skinny broadband connection, I have no coverage at home for cell phones so having a landline is still pretty important) 

Despite what I thought was some robust field testing, my voip line is pretty much non functioning. It "mostly" registers and I can "mostly" make outgoing calls, but incoming is not working about 95% of the time.

I've got 2 voip phones, a grandstream DP750, a polycom soundpoint 335 - I also installed the 2talk softphone on my mobile - same problems across them all.

I've read almost every post on the double NAT problem, and various settings use to make them work - with no success.

The softphone works 100% when I'm at work on a single NAT'ed ADSL connection, but not at home - so I convinced it's something to do with skinny broadband offering - maybe the awful huawei router.

I've pretty much given up on trying to make the phones work and was thinking the a VPN connection to an external VPN provider might be my only hope. (I really, really don't want to admit defeat and beg Spark for my landline back)

I'd love to hear if anyone has a working solution here. 

Dave