Recording Jabber - Overlapping Voices

[Andriel]

Hello, I'm having this situation:
In the call center we have PCs with softphones installed (Jabber) that replicate the traffic to a recorder in another site.
Randomly, we are seeing high levels of Jitter in the flow that is replicated to the communication recorder between the client (source) and the operator (destination).
This causes a phase shift when listening to the conversation recorded between the client and the operator, without being affected the real time call.
The Jitter is observed in the port of the PC that replicates the traffic (from the origin), so I asume it's not a network issue.
This happens in PCs with different features and versions of Jabber, at different times of the day.

Some PCs has Windows 7 Pro SP1 64bits, 8G Ram and Intel Core i5, without heavy workload, with Jabber 12.5 or 11.7.

Any idea?

Best regards,

[Jonathan Schulenberg]

You’re seeing transmit jitter for only the BIB recording leg while the real call is not experiencing that same symptom? That’s _really_ strange; I would have expected equal behavior for all three transmitted RTP streams.

A long shot but does the computer have anti-malware software that may be attempting to perform IPS or a similar traffic inspection technique? A common tactic of those tools is to buffer multiple packets in an effort to match rules more effectively.

[Andriel]

Thanks Jonathan, I was consulting about the possibility of disabling some AV modules in one of the affected PCs to evaluate the behavior.

Next week, I will bring new feedback.

[touma.kayal]

Hi,

I am facing same issue when it comes to recording using BIB from jabber client . Did you find any root cause?? Noting that if I use CIPC  the overlapping will not appear at the recording server.

To note that the overlapping happens in a way that sometimes you hear the good bye at the middle of the conversation.

Appreciate if you can relay your findings, if any.

Regards,

[Andriel]

Hi Touma, we haven´t found a solution yet.

We are treating the issue with the TAC and requesting a performance analysis of some PCs to find correlated events.

I´ll be updating the post!

[touma.kayal]

Hi Andriel,

Are you facing this issue on each and every call?? Actually I am recording only PSTN calls. And once I route the calls through a 3945 router I face the issue. If I route the call through a 4331 router the call gets recorded without overlap .

Are facing any close symptoms??

Regards,

[Andriel · Accepted solution]

Hi, thank you all for the comments.
At the end of November, we were able to solve the problem by disabling the VAD in the Gateway with the "no vad" command (in the dial-peers involved in the call).

Regards!

[amit.patel@anuntatech.com]

Hi Andriek, I am facing same issue, we are using 3945 gateways and we have "no vad" command already across all dial peers, can you please help me with your experience to resolve this issue please.

Regards 

Amit 

[AnkitAshwani20]

Hi Amit, 

We are also facing same issue ONLY ON JABBER. CIPC is fine. 

So there is an incoming call from CUBE TO Jabber , Both actual call RTP is fine however Jabber to Recording RTP (specially carrying PSTN voice) is having high jitter and sync issue. 

VAD is disabled on CUCM and CUBE. Can you suggest how did you resolved it. 

[amit.patel@anuntatech.com]

Hi Touma, I am facing same issue, we are using 3945 gateways and we have "no vad" command already across all dial peers, can you please help me with your experience to resolve this issue please.

Regards, 

Amit Patel