You need to recommend changes to the Lync infrastructure to ensure that internal users can sign in to Lync 2010 if a Lync Server 2010 Front End Server fails. Which two actions should include in the recommendation? (Each correct answer presents part of the solution. Choose two.)
A.
For each Front End Server, configure a Service Location (SRV) record that uses an Alias (CNAME) record.
B.
Deploy a Director pool.
C.
For each Front End Server, configure a Service Location (SRV) record that uses a Host (A) record.
D.
Associate a backup registrar with each Front End Server.
Michael,The way presense works is a sicbbruse message is sent from the users client to the front end server they are connected to. This message tells the FE that that user wants to receive messages (either via NOTIFY or BENOTIFY) about the persons listed in the sicbbruse message. This process happens as a batch at signin (you can look for SUBSCRIBE in the UCCAPI Log of the client). As far as how the FE and Edge handle the multiple subscriptions to a single external user, I’m not sure, I’ve never looked at it. But my guess is the FE’s send one sicbbruse to the edge for each remote contact, and when the presence information is sent back either in response to that request directly or later as an update (still based on the original subscripe) the Edge passes back to the FE and the FE back to the user. The only difference in this process for a GTalk or XMPP user would be the edge sends to the XMPP server instead of the remoted parties edge server.If you are looking for exacts on how all of that works I recommend logging as I have not seen it documented anywhere.HTH-kevin