Our setup is this. Call comes in via SIP Trunk, routes to CallManager through ASA and back out through to the remote site via VPN. Yeah, it's a complex setup I know.
The problem is that when a caller calls and gets connected with a user, the calling party can hear what the IP phone user is saying but the IP phone user cannot hear anything. If you look at the phone for sending/receiving packets, it is sending but receiving packets are not incrementing. This will happen intermittently (mostly about 75% of the time). The caller will get connected, everything will be working and then the other side goes silent.
My policy map is allowing sip across and the ACL is allowing everything across from the voice subnet. The phones never lose connectivity. I can ping fine from the voice subnet to the remote phone side.
inspect dns migrated_dns_map_1
inspect h323 h225
inspect h323 ras
inspect icmp error
Both ASA's are running 8.0(4)29. Any suggestions?