I have one PC and one 7940 IP Phone on the far side of a ASA5505. I created a VPN to an ASA5510 using the Easy VPN configuration (client mode not NEM). Everything works. Call quality is excellent. The only problem is on the very first call from the remote phone after the VPN comes up, I cannot hear the called party. After I hang up and call again the called party comes through loud and clear.
I notice that on the 5505 the client mode VPN starts on demand when the first IP traffic is sent. The connection opens up to 10 IPSEC tunnels. I am assuming one for each remote subnet. I can only assume that I cannot hear the remote party because of the fact that the tunnel to the far phone is not open when the call is initiated and sound from the called phone fails to reach the remote phone because of some timing issue.
Though I have note tested this yet, I will assume that I will have the same problem when calling phones on subnets that do not yet have an IPSEC tunnel.
Is this an inherent limitation of this VPN configuration? Is there a work-around?
Your advice is very much appreciated.