I am having the following issue with a videoconference call. I have an ASA-5520 in transparent firewall mode in the middle of a LAN connections between two campus.
When I remove the firewall the videoconference works fine.
When the firewall is connected the call can not be completed.
The call originating station first contacts a gatekeeper in order to establish the call. I captured the traffic between this station and the gatekeeper using a sniffer and I found that the problem is that apparently there are segments lost in the communication. This problem appears in every SYN,ACK packet received from the gatekeeper, therefore the station responds with a RST of the connection.
ASA is running software 8.0(2).
Does anybody know if there is some way to fix this issue from configuration?
I am completely sure there is no problem with access-lists and I am not inspecting H323, H225, ras, etc...
Attached is a copy of the sniffer capture.