internet calls disconnect

[shabana]

i have multiple endpoint on the LAN when calling another on the internet, the call always disconnect after 20 to 30 min.

(the call connects normally with audio/video)

i tried to decrease the TCP keep alive message on the HDX to 900 sec (15 min). but the same it disconnected after 32 min max.

what could be the problem? what i need to instrcut the Network administrators to check?

[drifter]

you can do the following test:

1:point to point calling,seeing how long can the call last?

2:check the firewall settings about bandwith control.

[shabana]

point to point calls disconnetec after time between 20 to 30 min. max time it could stay in the call is 32 min.

the call disconnect even i'm calling on 256K.  the custmer had 20Mbps so i don't think it is a bandwidth problem.

[hjuliao]

Hello,

Have the firewall administrator check the TCP session timeout.  In H.323 call setup happens on TCP port 1720. When the call connects this port stays open and idle. Most firewall will see this as an issue and close the session.

[shabana]

the network administrator set the timout  of H.323 and H.225 to Unlimited, but the call still disconnecting after the same duration