No problem. The GPO's Policies are configured to specify lync.exe, communicator.exe, etc...

I responded to Varun. Hope that information helps.

There can only ever be 1 MAPI Network. The DAG chooses the NICs that are configured to register in DNS and have a valid DNS record. All the replication NICs need to have DNS registration disabled. If multiple NICs are registering in DNS, that can potentially cause the DAG to have some issues.

For proper NIC/Network configuration, see the following link: http://technet.microsoft.com/en-us/library/dd6381...

I'll add this at some point.

If 2 users on the internet cannot do media to each other, they should automatically be able to fallback to using the Edge Server as the relay. If this is not working, I suspect there's some kind of misconfiguration with the environment from an audio/video standpoint. When clients authenticate remotely, their ICE SDP candidate list will contain their private IP, their public IP, and the Edge Server's relay list. You can see what is in the SDP candidate list via SIPStack traces and look for the Invite and 183 messages for candidates.

I haven't heard of it being fixed. What I have started doing is in the QOS Policy for Edge Servers, I change the Source IP to the Edge Server. That way, the External Edge NIC won't try to do anything with the QOS Policy.

Yes. You should be able to by creating a new privacy configuration and assigning it to the Identity of Site:Sitename. Similar to what I show in my Client Policies article here: http://www.shudnow.net/2010/10/28/lync-2010-clien....

Depends on several factors. Are users active in both sites? If so, are databases active in both sites? If so, is mail for users in the second site have their MX records going into the other site? And don't forget about replication traffic? For users active in the second site, are they doing centralized webmail.domain.com which is going to the primary site and proxying traffic to the site they are in?

As you can see, there are definitely bandwidth consumption considerations that need to be accounted for. There are two calculators which can help here:
1. Client Network Bandwidth Calculator: http://blogs.technet.com/b/exchange/archive/2012/...
2. Exchange 2010 Mailbox Server Role Requirements Calculator: http://blogs.technet.com/b/exchange/archive/2009/...

I have seen a similar issue with inbound calls intermittingly not working but outbound calls working fine. What I ended up needing to do is disable RTCP.

With Cisco integration using a Cisco Voice Gateway or CUCM, it's required to disable RTCP.

Check out the following blog article from VoIPNorm: http://voipnorm.blogspot.co.uk/2011/05/important-...

Try the test voice routing feature and make sure the non-did users are getting the proper voice policies, usages, and hitting the correct voice route with the caller id override.