Hi

We have recently migrated from OCS2007 to Lync 2013. Really having a hard time understanding the topology.

We have a frontend , edge, and wac server. Ignoring the wac server for now but it seems to work.

Where can I find docs on where the client connects, routing etc etc. We are only using it for IM and video conference. No telephony or UC.

Give you and example. A user is external, connects with the Lync Client.  Looks up the External FE.. as well as the Edge server. Connects. Can send and recieve messages. When he tries to start a video call he tries to connect to the ip of the internal user. This is not possible (private addresses so not even routeable). How can he send IMs but not video?

I have found a few deployment white papers but nothing about how the product actually works.

Thoughts?

Thanks

Drew

Drew,

There most likely isn't an exact document you are looking for in terms of this.  You can check out the protocol poster for example:

http://www.microsoft.com/en-us/download/details.aspx?id=6797

Which will give you some details.  In terms of the edge connectivity, what you really want to read is ICE/STUN/TURN documentation.  You could check out Master Alan Shen's Next Hop article for details:

http://blogs.technet.com/b/nexthop/archive/2009/04/03/ocs-2007-r2-what-s-new-for-media-traversal.aspx

Although it's about OCS, its still applies to the world of Lync.  In terms of your question:

How can he send IMs but not video?

The answer is they are taking two paths/doing two different things.  IM is basic, it's external client to edge server to front-end server to internal client.  It's all done via signaling (5061) and requires very little magic.  Media establishment on the other hand is a very different beast.  So what you need to make sure is that the user is getting successful MRAS credentials and information.  In the trace, the candidate list for the internal user should have both their internal address and also an edge server AV address that is allocated during call setup.  If you are missing the edge server AV address in the candidate list, then you have a problem with the client reaching the edge for MRAS/Media connectivity.

Hopefully that helps a little bit.

Thanks,

Richard

Also check out Jeff's post on STUN/TURN for more info.

http://blog.schertz.name/2012/10/lync-edge-stun-turn/

Richard

Hi,Sam,

Just want to add some info.

For the Audio/Video connect scenario,you also can read through Elan Shudnow's great article ,although it's talking about Lync 2010,it's also available for Lync 2013.

Regards,

Sharon

WOW! Great stuff... I am going to back up a second and ask a question that I thought of last night (and Sharon touched on)

In terms of topology and routing, is there a big difference between 2010 and 2013?  For example, aside from the way databases are clustered, there is not a huge difference between exchange 2007 and 2010 until you dive fairly deeply. Is 2010 documentation of any value to me or is it a completely different beast?

Thanks again

Drew

In terms of signaling/media negotiation, it hasn't changed really.  Obviously codec changes happened but that doesn't affect connectivity.

Thanks,

Richard

Thanks..  I  really wish I could figure this out.  I have two laptops side by side.. connect video one to the other.. works.. disconnect and try again.. works.. disconnect and try again.. works.. disconnect and try again one guy doesnt get the others video.. disconnect.. same.. disconnect no one gets video (but the cams are working.. I see the previous). IM and audio work. Network connectivity is good. Updated the Camera drivers nothing. Lenovo says we have the latest Display drivers. At what point does this become a call to MS?