Further update.
Having ascertained that there is an active session and comms between my VSS and Vodafone, I got onto the VF helpdesk. They were very helpful and actually looked from their end to see what was happening. Apparently my VSS is not responding to their attempts to establish the VPN, hence no data is passing. If I look in the logs, I can see they attempt to establish a session every minute or so but clearly something is happening in the router that is preventing onward comms to the VSS. Since my VSS works fine on a BT router VF (reasonably) conclude that the issue is in the Draytek router. So back to Draytek support but no progress here. It's seems to be on me to further diagnose the issue and tell Draytek what is wrong with their router. I'd buy a 2920 but not sure if that will work either though. So folks, it seems that if you want to have a running VSS it's risky with a Draytek router.
Someone suggested Draytek speak direct to VF (surely the best way to fix this once and for all). VF are open to this idea. Any chance Draytek could get this sorted?
