I have walked into a situation where my new company is wants to upgrade to Lync 2013 Enterprise from OCS 2007 R2. My main area of concern is the SIP domain. The primary SIP domain (sip.123.com) is what OCS and Exchange 2010 uses; currently Lync 2013 is using the same SIP domain but only has a Front End deployed. I am trying to figure out the best process to bring up a Lync Edge server all using the same SIP domain (for a few months) I would like for the Lync users to enjoy mobility services and have it set up in advance for when I add the remainder of OCS client into Lync.
I prefer to stay away from having to use our secondary SIP domain (sip.456.com) as I want to utilize the full features with Exchange 2010 in Lync.