CUPC CTI: phone control does not always work

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Aug 24th, 2009
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Hi everybody,

I have a CTI problem with my Personal Communicator/Presence Server installation.

I use CUPC to control my IP Phone (7942) but sometimes the CTI feature suddenly doesn't work anymore and the icon in the upper right corner (where you can switch between no phone, softphone, ip phone) greys out. If I restart the CUPC client the icon reverts to softphone mode and the ip phone icon is still greyed out. This happens for all users simultaneously. Everything apart from CTI works perfectly.

The funny thing is that CUPC goes back to normal mode after some time (after 5 minutes or so) and CTI with ip phone works again.

There is a transparent L2 firewall (Cisco Firewall Service Module) between the presence server and the client running personal communicator. The firewall is configured as follows:

- permit ip any any in both directions

- sip inspection disabled

My next action would be to remove the firewall between server and client, but this is not so easy (since it is a live system with other traffice going through the firewall).

So I was wondering if anybody out there is/was experiencing the same issues.

Could this whole thing be related to some firewall session timers? Any other ideas?

Software versions


FWSM Firewall 4.0(4)



CUPC 7.0(2)

Any help greatly appreciated. Thanks.


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Overall Rating: 4 (1 ratings)
htluo Mon, 08/24/2009 - 07:56
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On CUCM > System > LDAP > LDAP Authentication, what port is being used? (if you're using LDAP authentication).


Lukas Auer Mon, 08/24/2009 - 22:03
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I do use LDAP authentication and it uses the standard port 389.

I have two LDAP server entries in case that matters.

htluo Tue, 08/25/2009 - 07:43
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This problem is usually caused by LDAP referral. Please change the port to 3268 (default Global Catalog port). Then restart CTIManager (on all CUCM servers).

This should fix the problem.


Lukas Auer Fri, 08/28/2009 - 07:39
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Hi Michael,

thank you very much for your super fast reply.

I did change the LDAP authentication port to 3268 in my lab environment and everything worked fine (like you said). I could get back to this problem in my productive environment only today. And believe it or not, no user reported any further problems with CUPC CTI since last week.

So, for now, I decided to leave the port as it is (389). But I will definitely keep your solution in mind! Thanks again. I hope your post also helps others.



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