It’s time to update! Microsoft released Lync Server 2013’s Cumulative Update 5 on the 7th:
Updates for Lync Server 2013 (CU5) – Microsoft Knowledge Base
Download Lync Server 2013 Cumulative Update 5 – Microsoft Downloads

CU5, like its predecessors, contains fixes for a lot of issues users may experience. Which issues? Tom Arbuthnot documented them in a quick & neat list on his “Tom Talks UC” blog.
Lync Server 2013 CU5 / August 2014 5.0.8308.733 Details and Download – Tom Talks UC

Tom also points out that there are some fixes included in CU5 not listed on Microsoft’s KB page (or buried deep in the documentation). I was particularly happy to see these two:

  • 2967629 Significant bandwidth usage increase by SIP traffic in a Lync Server 2013 environment
  • 2967630 Callee receives a missed call notification after answering a call on an IP telephone in a Lync Server 2013 environment

Because at one point or another, we’ve dealt with both of them.FailedCall

“Significant bandwidth usage increase by SIP traffic in a Lync Server 2013 environment”
A few months ago, one of our clients experienced Lync 2013 clients frequently dropping connection. At the time we thought it was a bandwidth issue, and increased bandwidth accordingly. The drops diminished, but didn’t go away 100%. Their Lync Server seemed like Godzilla, endlessly chewing through bandwidth and demanding more.

We resolved the issue by a complete rebuild of the topology and clean installs of the Lync 2013 clients. This CU5 update suggests that the problem originated with a bug in either CU3 or CU4. Perhaps re-applying those updates during our rebuild helped us. Either way, now we have CU5 to correct this “bandwidth greed” issue.

“Callee receives a missed call notification after answering a call on an IP telephone in a Lync Server 2013 environment”
Mediation Server is very picky about its configuration details. All numbers must be exactly to standard, consistent for all endpoints, and tested in just about every possible call method. And even then, sometimes it just doesn’t want to behave. Like that one cell satellite that routes your New York call to New Jersey every time.

Overall it’s a good thing Mediation Server is so specific – it helps your calls reach the intended person (and even the intended device). This error however shows that, like any technology, it can guess wrong.

From the KB page: “This issue occurs because Mediation Server deals with the SIP reason header incorrectly, and then generates a missed call notification.”

We’ve experienced this error often enough to where we tried to correct it at the source. (None of our Lync Server clients have reported any such error to us–it seems confined to our own system.) We did fix it by removing Mediation Server from our Lync Server topology and rebuilding it. Same hardware, same SIP line, same phone numbers…it just wanted a rebuild.

Hopefully this fix in CU5 will spare everyone else the grief of:

  1. Picking up the phone after 1 ring
  2. Hearing nothing on the line. Hello? Hello??
  3. And watching a “Missed Call” email appear. For no reason.

Never Wait on Any Server Issues

Most readers here definitely keep up on server updates. Don’t want to get out of date, right?

This probably goes without saying. But just in case – if you do run Lync Server (or any server) and it’s not functioning at 100%, do not leave minor issues sitting!

We all want to fix major issues and get the servers back to running. Maybe a minor issue pops up, but it doesn’t disrupt daily operation, so you decide to leave it alone for now.

Don’t. Waiting for an issue to self-correct, or hoping a future software patch will fix it, is not an administrative strategy. If you experience an issue, try to correct it immediately, even if it isn’t disrupting normal operations.

Remember, CU5 was just released last week. CU4 was released back in January. Nearly 8 months between them. That’s a long time to let issues linger inside your Lync Server.

Keep Lync Server 2013 Updated and It Will Take Care of Your Communications

Hope these stories encourage you to update as soon as possible. Again, the links for Cumulative Update 5:
Updates for Lync Server 2013 (CU5) – Microsoft Knowledge Base
Download Lync Server 2013 Cumulative Update 5 – Microsoft Downloads

The Importance of Updating: Lync Server 2013 Cumulative Update 5 is Here
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2 thoughts on “The Importance of Updating: Lync Server 2013 Cumulative Update 5 is Here

  • August 24, 2014 at 9:56 pm
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    Actually, maybe it wasn’t technically a CU, but they did come out with a quarterly update in April (https://support.microsoft.com/kb/2938505) — which fixed some very significant problems with response groups and the conferencing attendant. We had many of our call answering issues with response groups go away after this update. So, hopefully most people using either conferencing or RG didn’t wait for this CU since January to fix these issues.

    Reply
    • August 25, 2014 at 7:27 am
      Permalink

      You’re right, the April update wasn’t technically a CU, but it was definitely a necessary Lync Server update. Glad to hear it helped with RG issues. Could you email me with more detail on your issue? I’d be interested in blogging about it, if you don’t mind. Please email me directly at chris.williams@planetmagpie.com. Thanks!

      Reply

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