We are experiencing a conferencing issue, and merging of 2 calls issue (make first call, put on hold, make second call, select merge calls, first call drops)  randomly, sometimes from the handset, and sometimes from the Lync 2010 client.  Here is the event log:

Conference rollover failed.

Conference: 'sip:client@emailaddress.ca;gruu;opaque=app:conf:focus:id:4HBLJ737' MCU Type: 'audio-video' Existing Mcu: 'https://server.domain.ca:444/liveserver/avmcu/'

Cause: Conference rollover occurs when an MCU becomes unavailable or is restarted. A rollover failure indicates that no MCU is available for the requested MCU type.
Resolution:
This operation will be automatically retried. This error can be ignored if MCU outage is planned. Otherwise ensure that at least one MCU for the specified type is available and that there are no connectivity issues between this server and the MCU.

This problem is intermittent.  We are extremely frustrated as many of our clients use the conferencing/merging calls functionality daily, and need to have this working rock solid.  Has anyone else been able to resolve this issue?

Hi,

I would like to confirm if all mierge calls are successful. Do you have only one front end server that collocated with A/V Conferencing server?

Hi Kent,

Thank you for your reply. 

To be clear:  the first call is established successfully, the second call is established successfully (Every time); however the merge of the two calls is not always successful.

We have two front end servers with all services collocated.

This issue is pretty rock solid but only during business hours. It works perfectly before 9 a.m. and works often during lunch hour and then work again after 4 p.m. but between 9-12 and 1-4 it is pretty much never work.

When merging 2 calls, 2 windows should become one with list of 3 participants. Usually it happens within 1-2 seconds. When it does not work, here is what I get:

As you can see, somehow Lync server FQDN is getting added to the list of participants, and this is how I know that merge is going to fail. Also usually it takes long time and second windows says "Connecting" for long time, sometimes 30-50 seconds, and at the end all parties get disconnected and everything fails.

This is very frustrating issue. We recently re-built entire Lync environment from scratch by using brand new servers, and the issue still there. I have now Microsoft case open and waiting for them to call me back. It looks like Microsoft is last resort now...

Jennifer did you ever get a solution for this merge call issue from Microsoft? We are having a very similar issue at the company I work for. Let me know.

Yes, we did.

It was a known issue with USB tethering.  What type of phones are you using?  Apparently the new phones don't have the same power as some of the older ones.

For merging calls, we encourage the users that need to merge more than two calls to use their headsets, change their default device to their headset, and use the Lync client.  It works like a charm!

We are using Polycom CX5100's in our automated conference rooms. They act as the microphone for the audio in Lync and have a built in 360 degree camera for video. Can you elaborate more on power issue? Thanks!

Hi Jennifer,

You stated this was a "known issue" with USB tethered phones. Can you tell me where you read this or heard about this? Known issue by whom? The company you bought the phones from or Microsoft? Need to try to get more information on this topice. Let me know.

Thanks!

We opened a ticket with Microsoft, and they advised it was a known issue.

Unfortunately I don't have any more information that that.

Jennifer,

I have an active ticket open with MS right now on this issue. Were you the person that opened the ticket with them back when you had this issue? If not can you tell me the name of the person who did so I can have them try to find the old ticket for reference?

Thanks,

Brett