I was recently asked by Verba to help test their call recording solution with Lync endpoints. Specifically they were interested to know if the Polycom Group Series devices could be recorded using Verba when registered as Lync endpoints.

In the past I have produced a few basic overview videos on Youtube describing how to configure and operate Polycom Realpresence devices as Lync endpoints and have recently update the material to include the new Group series devices. https://www.youtube.com/watch?v=hVMyuqqe2Y0

It’s pretty early days but I thought it would be useful to document what we have found so far, particularly as the pressure of other commitments means this activity may have to take a back seat for a week or so.

The installation of Verba was pretty pain free and achieved in about half a day with the help of the Verba support team. In very simple terms I installed an additional Windows server which runs the Verba software and installed an agent onto the front end server (testing was done in a single standard edition environment). The way call recording works for Lync is by intercepting the SDP traffic at the Front End (can also be intercepted at the Edge server) and rewriting such that media is sent via a proxy (the Verba server) where it can be recorded. This isn’t the only option but was deemed the simplest for these purposes.

Security groups in AD are used to determine which calls get recorded. I have it set so that any calls involving the user accounts used by the Polycom devices will be captured.

The specific use case we are interested in is whether we can record Video calls between two Group series devices when both are using Lync. You may question why we would use Lync to connect two Polycom VC units but the advantage is being able to bring additional 3rd parties into the call who may be using Lync on any platform.

With a fairly vanilla installation we found that any conference calls involving the Group Series are recorded successfully. (However, an observation is that when taking part in a conference call the resolution selected by Lync is generally pretty low quality 640×360 typically being used used.)

When the Polycom units do a point to point call image quality is much better, 1080p, but Verba is unable to record this video. Interestingly Lync monitoring server doesn’t contain any media information regarding these calls so it looks like Lync is used for signalling but then the video codec used is unknown to both Lync monitoring and Verba(?)

Finally, when a Polycom endpoint calls or receives a point to point call with a PC Lync client, the call resolution is reported as 1080p and Verba is able to successfully record the call.

The Polycom call statistics for these two point to point calls show that when the call is successful the reported codec is SVC-HP, when the recording fails it is reported as H264-HP

This is as far as I have taken testing so far. I spoke with Polycom support to see if there was a way to configure the group series to force the use of the SVC-HP codec on all calls but they inform me not.

I will continue to investigate why the resolution selected during conference calls is such low quality compared to point to point, interestingly I believe this was also a characteristic of the HDX devices when participating in Lync conference calls.

Verba are also investigating the same issues so I plan to report back in more detail in the future, hopefully with news of a resolution for Polycom to Polycom point to point calls.


For a brief overview of the use of Verba please see the video below