Call preservation in H323

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Apr 24th, 2007
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I am having a Call Manager cluster having H323 trunk to a Voice Gateway. There are 2 Call Managers, Publihser and 1 Subscriber in this cluster. I wanted to know what will be the call behaviour for the PSTN calls.

Suppose the Primary Call Manager is Subsriber and the Secindary is Publisher.

1) IP Phone has made a PSTN call. What will happen if the subscriber is down ? Will the call get disconnected ?

2) What happens when both the Publisher and the Subscriber goes down ?

Can anyone please explain and give me any link for this ?



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Overall Rating: 5 (2 ratings)
johnnylingo Wed, 05/02/2007 - 12:51
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Here's a question...when I do "call preserve", I get the following warning message:

Warning: Configuring media inactivity detection to avoid hung calls is highly recommended.

I'd like to read more about this, but unfortunately the link to "Configuring Media Inactive Call Detection" in the guide doesn't seem to be working. Can anybody explain this? My Config:

voice service voip

allow-connections h323 to h323

fax protocol pass-through g711ulaw


no h225 timeout keepalive

call preserve

session transport udp

modem passthrough nse codec g711ulaw


johnnylingo Thu, 05/03/2007 - 23:25
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Ouch..that's a little more complicated that I was expecting, but indeed it must be done otherwise the call will hang until both sides hang up. Thank you.


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