I have an issue with my VPN phone 4621 at a remote location. they have a decent internet line, 10mbps, but it seems to not work all the time, I changed the codec to G.729, but havnt messed with the other settings, any recommendation? I have a cisco ASA 5505 that its connected to, with all the fixups off...on both ends. It seems like it wants to work, but only sometimes.