Interesting issue. I have one of my remote users that ends up getting one way audio issues to shortly follow with a disconnect of the phone call. The VPN hardware is a 5505 ASA at the remote end and a ASA 5510 on the hub end configured via EZVPN. The IP phone register to a central call manager. The call gets placed and has two ways audio. After a minute or two the one way audio issue comes up and followed by the call disconnecting.
The tunnel stays up and does not effect other traffic. The link is barely being used and is a cable modem with about a 2 meg upload connection.
To add, I have about 30 other remote users set up this way working fine.
Is the issue with the service provider or are there some other config settings I can try on the remote end ASA?