Lync in coexistence with CUCM part 4 (what a mess my lab is...?)

I didn't think I was going to write more posts on this subject, but I was obviously wrong. I've read through all of the comments on my posts (and some in my mailbox and on twitter), and have tried to answer all of them to the best of my knowledge. (And keep on answer if questions come in)

After a few more months of experience, and a couple of customer implementations in the "bank", I have opened my eyes for a third option for your coexistence. This time I'm trying out RCC through the Cisco Presence server. And to my surprise, I think this might be the best option for users who do not need to have enterprise voice when they're not in their office.

RCC through Cisco presence will give the user the best of two worlds:
- All of Lync integration options for Outlook and exchange
- Direct control of your Cisco IP Phone through click to dial
- Answer your phone through Lync
- Phone status update to the Lync client (when logged into lync)

I am not going to write a big how-to with screen-shots all, as I found the Cisco documentation very well written, but I am going to write a few pointer you might find helpful.

Here are a few things that will help you understand, and hopefully implement a RCC integration successfully.

About domain names: The Lync SIP address and the presence SIP address must be different, as you create an application server and routes to the application in Lync. This was a hassle in older versions of Presence and OCS, but in Lync we specify the Presence server name as the route to macth (and not only the domain, which would be in conflict with the Lync sip address).

About certificates and security: I skipped the entire section 8 and 9 of the document, and made it work without the security. I would recommend doing the security for a live environment, but for a lab it's not necessary at all.

About the plugin in section 10: This plugin will give the user some enhanced experience of the integration, but it's really not needed for the basic functionality.

About configuring the user in Lync: Of the different ways of configuring the Lync user, I have found the following string to be the best:
tel:xxxx;phone-context=dialstring;device=SEP0002FD3BB5C as it leaves out any issue with shared lines in CUCM

About authentication: There are several ways you can authenticate to the presence server, but here is what I found is an easy option:
- Make sure the user's email address and sip address is the same
- Integrate your CUCM (and presence) with your active directory
- Have your CUCM synchronize the email address.
This way, the email address will be what the RCC will use for authentication.
(I say this, because I've seen a lot of implementations where sign in name may differ in the two worlds :)

About topology: Here is the most important bit of information. Read the Cisco doc carefully, and you'll notice the application server you create is created with the ip-address of The RCC will not work with the "all ip-addresses" as this address represents. You must enter the ip-address of the cup server. Follow the simple instruction in the doc, and you'll be good to go. miss it, and you'll fail.... (as I did at my first attempt).

I hope this post may be of help to you in your labs. I might create a how-to, with screen shots, if there is any interest for it at a later point. (But if you google it, there are several out there already).