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Video Conference issue --- Call drop after hour --- H.225 Timeout??

Hi guys, can you help me with that?

Issue: After 60 minutes exactly call drop between Polycoms.

Scenario:

POLYCOM -- GW/Firewall: 3845 -- POLYCOM

Call from Polycom to Polycom's IP.

I try to modify with commands like:

ip inspect tcp idle-time "x"

h323

  h225 timeout tcp call-idle never

  h225 timeout t302 2

  h225 timeout setup 3

  call preserve

So, the result its the same...

Any ideas???

1 ACCEPTED SOLUTION

Accepted Solutions
Cisco Employee

Video Conference issue --- Call drop after hour --- H.225 Timeou

I think this is due to the firewall. The h323 call is set up it is on port 1720 but after that the call continues on the higher RTP ports. There is no keep alive mechanism over port 1720 so the firewall considers it dead by default after 1 hour and kills your call.


 
  One option would be move to SIP.

You can also try increasing the TCP idle time
 
  rtr-01(config)#ip inspect tcp idle-time ?
    <1-2147483>  Timeout in seconds

Regards,

Jesse

2 REPLIES
Cisco Employee

Video Conference issue --- Call drop after hour --- H.225 Timeou

I think this is due to the firewall. The h323 call is set up it is on port 1720 but after that the call continues on the higher RTP ports. There is no keep alive mechanism over port 1720 so the firewall considers it dead by default after 1 hour and kills your call.


 
  One option would be move to SIP.

You can also try increasing the TCP idle time
 
  rtr-01(config)#ip inspect tcp idle-time ?
    <1-2147483>  Timeout in seconds

Regards,

Jesse

Video Conference issue --- Call drop after hour --- H.225 Timeou

Hi Mauro,

whatever Jesse has pointed is right...the initial call setup ports were 1720 (h.323) or 5060/5061 (SIP).

once the call setup happens the media routing done via different ports and the initial setup ports are not used any more.

Firewall as a security measure closes the initial signaling port which is idle for long time. However during the call when the party tries to exchange the keep alive messages and its not reached to other side the other party would think that the remote party has disconnected the call.

For this reason we never recommed to use TCP/H.323/SIP packet inspection. If you use them then you should atleast put sufficient high value so that it doesn't affect your call.

Thanks

Alok

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