Thursday, January 12, 2012

Microsoft Lync Dial In Conferencing Problem

I'm sorry, I am having trouble accessing the system right now, Goodbye.......

If I never hear that phrase again it will be too soon. We recently implemented Microsoft Lync for IM, Presence, and Conferencing between Lync clients. That seems to work great, in fact I think it is one of the best and affordable options available for those features. The rub for me comes in when the subject of using Lync as a phone system is brought up (hold your opinions until later).

Since I am not very comfortable with Lync as a phone system and I have to support these systems I have been working on integrating Lync and Cisco Unified Communications Manager. As many of you will know the best option for bringing that integration is through CUCILync. So far, CUCILync seems to work pretty good, but there are definitely some caveats of integrating the two systems.

Now you know what my communications platform is shaping up to be. Essentially, I want to use Cisco for voice and point to point video calls then use Lync for IM, Presence, and Conferencing.

I got all of this working and when I started testing Lync Dial-in Conferencing I could only get it to work when joining the meeting using a Lync client (which is NOT dial-in).

Here's the flow:

Dial Into a Meeting That is In Progress (Leader has joined)
1. I start a meeting using my Lync client.
2. I dial into the meeting from the PSTN.
3. I hear the auto attendant and go through the menus to log in as a guest.
4. I can see a guest in my meeting via my Lync client.
5. The PSTN call shows connected, but there is no audio.
6. Approx. 45 seconds passes and the auto attendant says "I'm sorry, I am having trouble accessing the system right now, Goodbye."
7. The PSTN call drops, but my meeting stays in progress and other participants using the Lync client still work.

Dial Into a Meeting That is NOT In Progress (Leader has NOT joined)
1. I dial into the meeting before joining with my Lync client. At this point the PSTN call is the only participant and the call is being held in the lobby.
2. I can listen to hold music on the PSTN call for as long as I would like and the call will not drop.
3. I join the meeting as a leader from my Lync client.
4. My PSTN call is placed in the meeting.
5. I can see a guest has joined the meeting in my Lync client
6. The PSTN call is connected, but again no audio.
7. Approx. 45 seconds passes and the auto attendant says "I'm sorry, I am having trouble accessing the system right now, Goodbye."
8. The PSTN call drops, but my meeting stays in progress and other participants using the Lync client still work.

This little problem took about a week to figure out, and I did have a ticket open with Microsoft. Hopefully, this article will save you some time. Originally, when our Lync conferencing server was set up we were using Public conferences so each user would always have the same conference ID number. It should also be mentioned that Public conferences is the default setting.

Through days of going through logs with Microsoft we found that this option doesn't seem to work well with PSTN callers dialing in. We had to change the default conference type from public to private.

Here's the Lync Server Management Shell commands I used:

1. Set-CsMeetingConfiguration -AssignedConferenceTypeByDefault $false
This command sets the default meeting type.
True = Public meetings by default
False = Private meetings by default
The Lync default value is True, I had to change it to False.

2. Set-CsMeetingConfiguration -EnableAssignedConferenceType $false
This command indicates whether users are allowed to schedule public meetings. Again, the difference between public and private is the conference ID number. Public uses the same conference ID every time. Private uses a new conference ID every time.
True = Allowed to schedule public meetings
False = Not allowed to schedule public meetings
The Lync default value is True, I had to change it to False.

After changing these Shell commands I could successfully dial into a Lync conference and participate from the PSTN. This little incident just further solidified my love hate relationship with the Microsoft PowerShell. Sure, its easy to make big changes with a single command, but first you have to find and identify the obscure command to use. I could be wrong, but it is my understanding that there is no way to make these changes in the Lync Control Panel GUI.


2 comments:

  1. I've had this same issue with a Lync setup against an Asterisk PBX.

    The trunk had to be configured with alaw/ulaw and RFC2833 dtmfmode in order to get the dialin conferance to work. :)

    dtmfmode=RFC2833
    disallow=all
    allow=alaw&ulaw

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  2. Lync dial in conferencing provider http://www.communiqueconferencing.com/microsoft-lync-dial-in-conferencing.asp

    ReplyDelete