Microsoft Lync



Fast forward a few years the lync presence not showing has grown up too. Lync has a new name Skype for Business. Outlook added a few digits to its name. But problem remains the same. I have gone with suggested solutions, which you can try too


Lync Conference URLs do expire

 A question was posed to me today about lync conference url. The customer wanted to know how long a lync online meeting invite url will be valid for. The answer to this question was not readily available in my head. I had to turn to my one of my best friends for answers. Almost as usual, all questions have answers, the question is actually whether you like the answer or not.

For a one-time scheduled meeting, the expiry time is the scheduled end time plus 14 days.
For a recurring scheduled meeting with an end date, the expiry time is the scheduled end time of the last meeting occurrence plus 14 days.
For an ad hoc IM or A/V conference, the expiry time is 8 hours.
For a recurring scheduled meeting without a specified end date, the expiry time is 6 months after the last meeting activation.

Also note that from the tests conducted, the meeting may be available well after the periods stated above but there is no guarantee that the urls will work past the deadlines.


Call Cannot be completed

This is one of the problems encountered from time to time. Usually the problems shows up when I have forgotten how I solved it the last time. So this time around, the problem gets page on site. One of my users was failing to make Lync to PSTN calls. In all the previous cases, the users could make PSTN calls but could not receive calls from PSTN. The cause was duplicate numbers. This normally happens when two support agents assign the same number to two different users on the same day and most likely same time. 

Really is it possible in Lync to have duplicate numbers. Yes it is very possible. If you run Lync in a small domain then this might not be an issue for you. However for the guys out the with multiple domain controllers spread across the globe where replication is sometimes a pain (1min is a pain). You will most likely encounter this.  

 So the question is why did this call fail.

To answer this question, I enabled logging on the Lync client and asked the user to make a call. After the call failure, I collected the log and set on my mission using snooper to confirm my suspicion. Below I noticed the call failed because it was forbidden

Details of the error indicated error below and immediately I knew duplicate number had been assigned.

 ms-diagnostics: 4002;reason="Multiple users associated with the source phone number


Locating the duplicate number

Lync control panel is not helpful in locating duplicate numbers, most likely because this is not expected. Instead I used Lync control panel to identify the number assigned to my customer Funeka. That number is critical for the next step to find out who else was assigned that number. So I turned to dsquery and ran the command below to locate the duplicate assignment.


dsquery * domainroot -filter "(&(objectCategory=Person)(objectClass=User)(msRTCSIP-Line=tel:+27xxxxx5689*))" -attr sAMAccountNAME msRTCSIP-Line -limit 0

Powershell fans the command below requires activedirectory module

get-aduser -ldapfilter "(&(objectCategory=Person)(objectClass=User)(msRTCSIP-Line=Tel:+27xxxx5689))" | select samAccountName,Name 

The one below is for those using lync server management shell

get-csaduser -ldapfilter "(&(objectCategory=Person)(objectClass=User)(msRTCSIP-Line=Tel:+27xxxx5689))" | select samAccountName,Name 


At this point the duplicate entries were printed out and I immediately went to my Lync control panel and reassigned a new number to one of users identified.

Well just because you joined the party today, does not mean the party started today. There are people out there who heard about Lync 2010 and thought that was the first edition of Lync. If you happen to be one of them, sadly you are mistaken. Microsoft Lync' humble beginning started off as Live Communications Server. 

On this page, you will find all the versions of Lync and revisions in the table. This work is by no means official. Its just what I managed to put up together and is not endorsed by Microsoft.


RTM Version


Live Communications Server 2003 (2003)



Office Communications Server 2005 (2005)



Office Communications Server 2007 (2007)



Office Communications Server 2007 R2(2009)



Lync 2010 (2010)



Lync 2013 (2012)








Don't know what I am talking about? but you do know about LinkedIn celebrities, Twitter celebrities and Facebook Celebrities. Then don't worry Lync also Celebrities and being a member of the Lync celebrity is by invitation only. This is exactly what one of my lync users found today. The user's followers were having difficulties following her today. Below is the message received by the followers.

Why did this happen?

Yes this is a known problem and Microsoft has covered it here. Lync 2010 comes with a set limit on how many followers you can have. This number is 200. Yes can only have 200 followers unless you have formally requested your Lync administrator to increase this number.


Who has been here?