Monthly Archives: December 2013

Lync Backup and Restore

I can’t tell you how many clients I’ve walked into with Microsoft Lync 2010 and 2013 already deployed who aren’t performing proper backups.  I can tell you that it’s 100%.  It seems that a lot of people just don’t know and a lot of consultancies out there really aren’t communicating the proper methodologies.  People are relying on SQL backups and virtual machine copies and to be honest,  these may not cut it.  Worse, they may simply not be supported.  For anyone with Microsoft Lync, I’d suggest reviewing the TechNet article titled Backing Up and Restoring Lync Server 2013.  It outlines the supported methodologies for backup and restore and includes the PowerShell commands to do so.

The best way to execute these commands are within a PowerShell script within a scheduled task.  While the one we use at my firm is highly modified and not publicly available, I can recommend Lasse Wedø scripts which are available for download from the TechNet Gallery.  Occasionally these scripts can have difficulty with multiple pools, but are easily modified to avoid this pitfall.  Links are below.

Lync and Early Offer vs Delayed Offer

Another team member asked me today if Lync was “early offer” or “delayed offer” and why it would matter.  He had been asked this by a Cisco partner configuring the CUCM side and wasn’t sure what he was being asked.

Simply put, the difference between the two is when the SDP (Session Description Protocol) information is sent.  The information in the SDP headers will establish accepted audio codecs such as G.711.  Early-offer refers to the SDP information being sent within the SIP INVITE message, this allows the calling party to specify it’s codec right at the start.  With delayed-offer, we withhold the SDP information and have the called party reply with it’s SDP first in the 200 OK response.

So, what does Lync use?  Early-offer, and this the standard for most VoIP (even non-Lync) deployments.  Can delayed-offer be used?  In short, kind of but not without some issues.  I’ve seen reports of audio delays and at least with Lync 2010, media bypass was not supported with delayed-offer.

So what should you say when asked?  Early-offer.