Cisco Jabber Phone Services not working on certain PCs

[ashley_dew]

Hello,

We have implemented Jabber on CUCM 12.5 and the PCs are connecting to Jabber service. Some PCs can connect successfully to all services while some PCs can connect only to CUPS while the login succeeds, Phone services, CTI dones.

Telnet and ping to cucm service is successful from PCs with issue. All PCs are windows 10.

We are suspecting may be a security application A/V DLP which is blocking and I don't have access to the Security softwares admnistration. 

Furthermore, on one of PC with issue, we have a phenomenon whereby all telnet to CUCM goes through even if the service is not up for example.

I am suspecting a security application is intercepting and proxying the connection. I am needing some help to identify the security application. Is there a way to identify the application intercepting the traffic ie capture, windows ?

We are in lockdown and WFH situation and  the issue is really blocking.

Thanks for your help and for a clue.

[Adam Pawlowski]

I don't know if there's a way to pick the network stack apart on the machine. You could take a packet capture to examine the traffic from the machine if you can, which could give you an idea what is happening. It's possible to look at the Jabber log as well to see if messaging is being manipulated or what it thinks is happening.More or less though you'd be able to prove that something is going wrong, but I don't know how it will help prove a case definitively without assistance from whomever manages that security application.

[Roger Kallberg]

As Adam wrote a packet capture and the logs collected from the client by taking a problem report in Jabber would likely be the best place to start. In the logs in the PRT you should be able to tell where it goes wrong with the communication from Jabber.

[Sergey 1907]

For CTI work, port tcp 2748 must be accessible from Jabber Client to CUCM and Deskphone (not or!).

[Nithin Eluvathingal · Accepted solution]

Collect Jabber Logs and run it on CSA tool.