Wednesday, June 29, 2011

Lync 2010 Director and Pool Resiliency settings

You might have noticed the pool resiliency settings in your Topology builder, and I recently was tasked with insuring that clients attaching to the director are offered a primary and secondary registrar.

I did some research and found two great blog articles that you should read regarding Lync and pool resiliency:
So here we see my resiliency settings for our US pool:

And here our resiliency topology settings for our EU pool:

The checkbox for "Enable Failover and Failback" is not very well documented, however I found the best documentation of these settings is in the Set-CsService Technet article.
If I point a Lync client manually at my Director Pool, and take a sipstack trace from the server they hit, I can see only one Contact: line:

Here's the Get-CsUserPoolInfo for this user:

So with this configuration I was hoping to see two servers in the sip trace, one for ee01 and one for corp14ukpool, but this won't happen until you check the boxes above for Enable Failover and Failback. Not sure why this needs to be checked to enable. This leads me to believe selecting a resiliency pool alone does nothing?

Two ways to address this:

  1. Check the boxes in your Topology and republish
  2. Set via Lync powershell cmdlet Set-CsRegistrar as found here - you can confirm your settings are in place with Get-CsService -Registrar
Once this is completed, your SIP trace on your director should show multiple connections: