We are having a problem with a pair of Avaya IP office 500 telephone switches - both running version 4.2 (14). They are on two seperate sites which are connected via an IPSEC site to site VPN (Cisco ASA 5505 to Cisco 1801). Call establishing and call quality are both fine but the call will only ever last for 60 seconds exactly at which stage it drops out. I've checked the logs on both the router and ASA and no relevant traffic is being dropped.
The ACL matching interesting traffic is matching all IP between the two subnets in question.
When the two Avaya switches are connected back to back (i.e. without the VPN) the calls do not dropout.
Can anyone help?