I'm having intermittent issues with VPN flashed phones successfully building the VPN tunnel, allowing me to get to the call server and enter the extension and password and then sitting there saying registering. Some work fine and others fail. When I do a list reg I see the failing extension registered, but with no TCP socket. What I've done so far is changed the ip-network=reg where it has the field 'near end establishes TCP socket'. The very first phone I was having the issue with suddenly worked when I did that, but subsequent phones failed. I've flipped the setting a few times and now it's not working. What can I check for this? This is a big issue for a set of folks that have these.