Office Web Apps Server & Lync Server 2013

Update 4/8/14 - Updated prerequisites for Windows Server 2008 R2.
Update 1/12/13 - Updated with additional information.
Update 11/10/13 - Updated with links to updates for Office Web Apps Server.
Update 3/18/13 - Updated for RTM of Lync Server 2013.
Update 11/14/12 - Updated for RTM of Office Web Apps Server.

The Office Web Apps Server is a required role when deploying Lync Server 2013.  By default when you add conferencing to the pool, you'll notice that in Topology Builder, you will be required to associate the Standard Edition Server or Enterprise Edition pool with an Office Web Apps Server, either new or existing:

However, you can deselect the check box and continue along without associating the Office Web Apps Server.  This is not recommended, as you won't be able to use any features that rely on the Office Web Apps Server.

Defining a New Office Web Apps Server is easy...all you need is the FQDN of the server:

Once the Office Web Apps Server is defined, Topology Builder will let you continue:


So what is the advantage of using an Office Web Apps Server?  From the Overview of Office Web Apps Server TechNet article:

How Lync Server 2013 uses Office Web Apps Server for viewing PowerPoint broadcasts

In Lync Server 2010, PowerPoint presentations are viewed in one of two ways. For users who run Lync 2010, PowerPoint presentations are displayed by using the PowerPoint 97-2003 format and they are viewed by using an embedded copy of the PowerPoint viewer. For users who run Lync Web App, PowerPoint presentations are converted to dynamic HTML files then viewed by using a combination of the customized DHTML files and Silverlight. Although generally effective, this approach did have some limitations:

  • The embedded PowerPoint Viewer (which provided a more optimal viewing experience) is available only on the Windows platform.
  • Many mobile devices (including some of the more popular mobile telephones) do not support Silverlight.
  • Neither the PowerPoint Viewer nor the DHTML/Silverlight approach supports all the features (including slide transitions and embedded video) found in the more recent editions of PowerPoint.

To help address these issues, and to improve the overall experience of anyone who presents or views PowerPoint presentations, Lync Server 2013 uses Office Web Apps Server to handle PowerPoint presentations. Among other advantages, this new approach allows the following capabilities:

  • Higher-resolution displays and better support for PowerPoint capabilities such as animations, slide transitions, and embedded video.
  • Additional mobile devices can access these presentations. That's because Lync Server 2013 uses standard DHTML and JavaScript to broadcast PowerPoint presentations instead of customized DHTML and Silverlight.
  • Users who have appropriate privileges can scroll through a PowerPoint presentation independent of the presentation itself. For example, while Ken Myer is presenting his slide show, Pilar Ackerman can scroll through and view any slide she wishes, all without affecting Ken's presentation.


Now that you know what the Office Web Apps Server does, how do you go about preparing to install it?  From the Deploy Office Web Apps Server TechNet article:

Installing Required Roles and Services

Windows Server 2008 R2 and Windows Server 2012/2012 R2 have slightly different prerequisites.  Be sure to install the correct prerequisites for your operating system.

To prepare a server that runs Windows Server 2008 R2:

Install the following software:

  1. Windows Server 2008 R2 Service Pack 1
  2. .NET Framework 4.5
  3. Windows PowerShell 3.0
  4. Platform update for Windows 7 SP1 and Windows Server 2008 R2 SP1 (KB2670838)

Next, open the Windows PowerShell prompt as an administrator and run the following sample commands to install the required roles and services:

  1. Import-Module ServerManager
  2. And then run:

Add-WindowsFeature Web-Server,Web-WebServer,Web-Common-Http,Web-Static-Content,Web-App-Dev,Web-Asp-Net,Web-Net-Ext,Web-ISAPI-Ext,Web-ISAPI-Filter,Web-Includes,Web-Security,Web-Windows-Auth,Web-Filtering,Web-Stat-Compression,Web-Dyn-Compression,Web-Mgmt-Console,Ink-Handwriting,IH-Ink-Support

To prepare a server that runs Windows Server 2012/2012 R2:

  1. Open the Windows PowerShell prompt as an administrator and run the following sample commands to install the required roles and services.
  1. Import-Module ServerManager
  2. And then run:

Add-WindowsFeature Web-Server,Web-Mgmt-Tools,Web-Mgmt-Console,Web-WebServer,Web-Common-Http,Web-Default-Doc,Web-Static-Content,Web-Performance,Web-Stat-Compression,Web-Dyn-Compression,Web-Security,Web-Filtering,Web-Windows-Auth,Web-App-Dev,Web-Net-Ext45,Web-Asp-Net45,Web-ISAPI-Ext,Web-ISAPI-Filter,Web-Includes,InkandHandwritingServices,NET-WCF-HTTP-Activation45

Installing Updates

Make sure that you also install any updates to the Office Web Apps Server(s).  You will need to download and install the updates listed here: Update center for Office, Office servers, and related products.


When creating the certificate request the Office Web Apps Farm make sure that you include SAN entries for the FQDNs of all of the servers in the farm:

If you don't include all of the Office Web App Server 2013 server FQDNs in the SAN of the certificate, you may see the issues here.


Once you have the Office Web Apps Server installed, updated, and configured, the Lync Server 2013 Front End Servers will discover the Office Web Apps Server and you will see the following events in the Event Log on the Front End Servers: 


What is the User Experience if you Don't Deploy an Office Web Apps Server?

So what happens you define, but haven't yet deployed an Office Web Apps Server in your environment?  The first thing you'll notice is that the Lync Server 2013 Front End Servers will throw the following error in the Event Log:

Office Web Apps Server (WAC) discovery failed, PowerPoint content is disabled.

Attempted Office Web Apps Server discovery Url:
Received error message: The remote name could not be resolved: ''
The number of retries: 2, since 8/7/2012 10:38:06 PM.
Cause: Office Web Apps Server may be unavailable or network connectivity may have been compromised.
Check HTTPS connectivity from this box to the Office Web Apps Server deployment using the discovery Url.


Also, clients will notice the following error message when they try to share a PowerPoint presentation: 


As you can see, the Office Web Apps Server will be an important component in your Lync Server 2013 deployments!  Make sure to plan and include it when installing/migrating to Lync Server 2013.