Cisco Call Mgr / Avaya PBX

Unanswered Question
Feb 17th, 2010

Dear community

we are trying to get several Call Managers talking to each other and to an Avaya PBX through H.323 and a Cisco Gatekeeper. Calls in between the Call Managers work fine now but we can't get the Cisco / Avaya piece to work - calls do not get established.

Here comes the Cisco Gatekeeper config:

zone local UK5_GK eu.abccorp
zone local BE_GK eu.abccorp
zone local NL_GK eu.abccorp
zone local AT_GK eu.abccorp
zone local CH2_GK eu.abccorp
zone local IT_GK eu.abccorp
zone remote US_GK eu.abccorp 1719
zone prefix US_GK 001*
zone prefix NL_GK 0031*
zone prefix BE_GK 0032*
zone prefix IT_GK 0039*
zone prefix CH2_GK 0041*
zone prefix AT_GK 0043*
gw-type-prefix 1#* gw ipaddr 1720
gw-type-prefix 2#* gw ipaddr 1720
gw-type-prefix 3#* gw ipaddr 1720
gw-type-prefix 7#* gw ipaddr 1720
gw-type-prefix 8#*
gw-type-prefix 9#* gw ipaddr 1720 gw ipaddr 1720
lrq forward-queries add-hop-count
bandwidth interzone default 10000000
bandwidth remote 10000000
bandwidth check-destination
no shutdown

I have tried a call from Austria to ths US. In the debug I can see the following information:

  • Admission Request from Austria to the Gatekeeper
  • Location request message from the Gatekeeper to the US
  • Location confirm message
  • Admission confirm message from the Gatekeeper
  • Disengage Request to the Gatekeeper

Does someone have this configuration working and can help?

Thanks a lot in advance!

I have this problem too.
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k6lw Wed, 04/14/2010 - 22:37

I just spent most of today trying to get a H323 gateway established between

our Avaya PBX and my CUCM 7. Not sure why, but we changed the port from 1720 to

7007 and calls from Cisco to Avaya worked every time. However no calls from the Avaya reached the Call Manager

. That is until the Avaya transmit port was changed to 1720. At that point calls flow correctly in both directions.

Now for the question: Why does CM7 allow you to change the port if it only

listens to the gateway on port 1720? Is there some other place where the listening side port can be changed from

the default of 1720?


Aaron Harrison Thu, 04/15/2010 - 00:25


On the CallManager you are specifying where to send the H.323 packets to reach the Avaya - so when you enter 7007, it's because the Avaya is listening on port 7007 rather than the well-known port 1720.

CallManager is listenting to the well-known port, so you have to configure the Avaya to contact port 1720.

You might be able to change the port that CCM listens on, but I really wouldn't - if you add any other H.323 gateways or devices the chances are that it will use 1720, and you'll find you have to change everything to use 7007. Some kit may not even allow you to do this.



Please rate helpful posts...

k6lw Fri, 04/16/2010 - 08:28

It would be nice if the documentation was modified to
tell you that changing the default port assignment only
affects the UCM TX. In the AVAYA world both TX and RX can be changed.
There is a reason to have 65000+ ports to connect to.
"Most" security folks will tell you to NOT use the defaults
as it makes it easier to hack the systems.

From the help page:
Signaling Port      
This field applies only to H.323 devices.
The value designates the H.225 signaling port that this device uses.

Default value specifies 1720. Valid values range from 1 to 65535.

*Setting only affects TX. RX still takes place on 1720.

allan.thomas Fri, 04/16/2010 - 10:43


The positive aspect is that you were able to resolve the problem, the question however is why the default was changed on the Avaya to 7007?  The following is taken from the Avaya Integration Guide which stipulates to retain the near-end listen port (1720):

Configure H.323 Signaling Group
This section focuses on the parameter settings recommended for the H.323 signaling group and
IP trunk group used to connect with the Cisco Unified CallManager.

Signaling group 3 will be created to establish an H.323 signaling link between the C-LAN in
the Avaya G650 Media Gateway and the Cisco Unified CallManager. The signaling group
number is not relevant; use any available signaling group number. Use the add signalinggroup
3 command to add the signaling group.

This signaling group uses the C-LAN whose node-name is C-LAN as the near end, and the
Cisco Unified CallManager node-name CallManager5.1 as the far end. Retain the default
near-end listen port (1720) and enter 1720 as the far-end listen port. The Calls Share IP
Signaling Connection field should remain set to the default n setting. The Direct IP-IP Audio
Connections field can be set to yes to allow the final media path for a call to be direct from the
Avaya IP telephones to Cisco IP telephones.

The far-end network region field can optionally be populated with a network region number to
associate with the Cisco Unified CallManager. For the signaling group shown here, the far-end
network region is set to 3 so that the calls between region 1 and region 3 will use codec set 3 as



k6lw Fri, 04/16/2010 - 10:54

Reason for change:
Have Avaya already interfaced with CM3 and IPCC Enterprise.
Am upgrading to UCM7 and need to maintain the IPCC portion.
Both CM3 and UCM7 talk to the same IP address, thus
different "ports" to monitor. Avaya tech suggested using new port. We however were not
aware, and it isn't listed in the help pages or documentation that changing the port on UCM only
changes the TX side. I am now into my third week of what should have been
a "simple" upgrade due to "undocumented features". Plan to cut over tonight.


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