Using OCS 2007 R2 CWA with Lync Server 2010
At this time, there are going to be a few scenarios where you may need to deploy the R2 version of Communicator Web Access with Lync Server 2010. The core reason here, is that the RTM Version of Lync Server 2010 contains a feature on the front end called Lync Web App. Eventually, Lync Web App will become a full featured web client, however, today it is only used for users to join online meetings from the web. There is no ability to access Lync Web App from a URL and sign-in, or use it as a instant messaging too. This is planned to be released SP1 of the product, that timeframe is unknown right now.
To fill this gap, customers will have to deploy the OCS 2007 R2 CWA role, which can register against a Lync Server 2010 Pool. This post will show you how to configure OCS 2007 R2 CWA to work in your Lync Server 2010 environment.
Preparing the Environment
The most important piece of information in this blog, is that the Schema Prep for OCS 2007 R2 must be run in the environment before the Lync Server 2010 Schema Prep, or you will not be able to install the R2 version of CWA. If this is a deployment where there have not been prior installs of OCS 2007 R2, you will need to obtain this media, and run that Schema Prep before your Lync deployment starts, so it is very important to plan for this in your design/planning phase of your project.
Also, to get straight to the point for this blog, I am going to assume you have prepared the schema in the correct order, have your Lync Server 2010 environment online, and have already installed the CWA Role on a server. I will walk through creating the virtual directory, as well as integrating it with your Lync environment.
Use this Deployment Guide to install and configure the CWA role
Creating the OCS 2007 R2 Virtual Web Server
One you have the CWA role installed, and a valid certificate installed on the server, you must configure the virtual web server that clients will access.
I will walk you through the process for creating an External web server, however the same process applies for the Internal web server. The difference being the types of authentication allowed, external allows forms, where as internal also allows NTLM authentication.
Login to your R2 CWA server, and open the Communicator Web Access Admin Console
Once in the admin console, right click on your server and choose Create Virtual Web Server
Navigate through the setup wizard, choose only your Web Server Type, in my case I am choosing External. Make sure to select a valid HTTPS certificate when prompted.
When you get to this section, Specify IP Address and Port it is important to note that this is the IP and listening port for your web server, not the communication between Lync and your CWA server, we will get to that next.
After entering a description for your virtual web server, the most important part of this wizard is the Specify a Listening Port section. This port defines what this application will listen on, and communicate with your Lync front end on. Because of the change in ports between OCS R2 and Lync, previously used values like 5070, or 5071 as you will see in older blog posts of mine do not work. You must pick a port that is not being used by an application currently. For my example I am using 4790.This can be any port, as long as your Lync front end and this server can communicate on that port.
Next, define your next hop pool, choose the appropriate Lync pool as your next hop and leave the port to default 5061.
Complete the wizard and start the virtual server.
Your settings should look similar to this
Now that you have completed this, you will need to make Lync aware of this server.
As you will find in the OCS 2007 R2 to Lync Server 2010 Migration Guide, you must merge your Legacy (OCS 2007 R2 components in to your Lync Topology.
Configuring Lync Server 2010
Now that we have our CWA server configured, we must make the Lync topology aware of this server. To do so, we will merge the legacy topology in to our Lync topology. This is possible through PowerShell using the Merge-CSLegacyTopology cmdlet, however I will be using the GUI.
Before completing this task, you must install the OCS WMI Backwards Compatibility tool, this can be found on the install media, called ocswmibc.msi
First, navigate to your Lync front end and open the Topology Builder.
If you already have coexistence with a R2 environment you will be very familiar with this process, and you will also see the BackCompatSite listed.
Right click where it says Lync Server 2010 and choose Merge 2007 or 2007 R2 Topology
In this post, I am assuming there are no R2 pools, and we are just importing the CWA server and web site. Because of that, you will actually leave the wizard blank when it asks for servers. This wizard will connect to servers in your environment and pull configuration data out of WMI, and input them into this BackCompatSite that will reside on the CMS. This is the major change from OCS 2007 R2 to Lync, is what used to be in WMI, is now in the CMS. You can find plenty of resources to get into more detail about that on Nexthop.
Verify the setting selected in the wizard, and choose Next to merge your legacy topology.
Everything should complete, choose Finish and you will now see your new site.
Expand BackCompatSite and expand TrustedApplicationServers for this blog post, we are concerned only with the trusted application servers, this is where your CWA, and other R2 server roles like group chat will appear.
Once you have verified that your R2 CWA server appears correctly, right click where it says Lync Server 2010 and choose Publish Topology.
Once you have published your topology, we will have one last step to verify our web server was imported correctly.
Open the Lync Server Management Shell and run the following command: Get-CSTrustedApplication
This command will return trusted applications that are associated with Trusted Application Servers and Trusted Application Pools in your environment, you may have many depending on your topology. However the two we are looking for, involve CWA.
Your output should return something similar to below:
I have crossed out my server names, however there should be the FQDN of your CWA server where I have marked.
The two entries represent the external facing web site that users hit, as well as the port that is used to communicate with the Lync front end, as you can see highlighted below, the port you assigned should be listed there.
You should now be able to login to CWA as a Lync Server 2010 user! If you run into issues, make sure to check out this blog relating to the SPN error related to CWA service accounts in R2.
Also, make sure that your CWA server is on the latest release of OCS 2007 R2 patches which can be found here: