A Unified Communication Blog
Get Adobe Flash player

We now have our backend servers up and running and one of the frontend servers, so in this post we will install the two WAC servers in a farm. (see the topology in http://exchangepro.dk/2013/09/21/creating-the-lync-server-2013-ha-topology-part-6/).


The Office Web Apps Servers or WAC is used in Lync Server 2013 for streaming PowerPoint content from Lync meetings to the participates. This means that the participants can see the nice features like animations, sounds, videos that might be inside the presentations.

When a presenter starts a presentation from a Lync meeting the content is uploaded to the Lync FileStore. From there the WAC servers will access the content, and begin to stream the PowerPoint to the participants.

The same WAC servers that we use in Lync can also be used by Exchange 2013 and SharePoint 2013, to provide an web experience for the Office applications. For now, I will only use them for Lync. (but keep coming back and I will show you how to use them with Exchange 2013).

However, back to the installation.


The specs of my Office Web Apps Servers (WAC) is:

  • 2 vCPU
  • 8 GB RAM
  • 100 GB Disk Space
  • Windows Server 2012


We will start by installing the roles and features that is needed by Office Web Apps.

Login to the server and open PowerShell

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 –restart


After the server has restarted download the Office Web Apps Server 2013 (find it here: http://exchangepro.dk/updates/useful-tools/)

Mount the wacserver.img file

Double click setup.exe to start the installation

Read the EULA and accept if you cant. If not watch the latest Startrek movie instead.

Click Install Now

Click on Close

When the installation is finished you should update the WAC server to with the latest fixes – http://exchangepro.dk/updates/useful-tools/


When that is done we need to request a certificate which can be used to secure the communication.

Open an mmc console

Add the Local Computer Certificate store

Navigate to Personal

Right click on Personale and select All Tasks -> Advanced Operations -> Create Custom Request

Click Next

Click Next

Choose your custom Web Server Template from the drop down and click Next

Click on the little arrow and select properties

The certificate will be used on both WAC servers, and also later on in Exchange 2013, so the select Common Name

Type the Public FQDN name for the wac server.

In Alternative name, select DNS and type the two internal FQDN names for the WAC servers, and the wacfarm name.

Add also the public FQDN, which will be used when configuring Exchange 2013.

Select the general pane and type a friendly name for the certificate (important)

Select the Private Key and make sure that “Make private key exportable” is select. Then press OK

Select Next

Click on Browse

Type a name for the request file and click Save

Click Finish

Open Internet Explorer and navigate to your certificate server, and click on request a certificate

Click on advanced certificate request

Select Submit a certificate request by….

Paste the content of the request file you created before and select you web server certificate

Click Download Certificate

Save the certificate

Back in the mmc select All Tasks ->Import

Select Next

Browse to the certificate and click next

Select Next

Select Finish

Click OK

You have imported the certificate

Double click on the certificate and make sure you have the private key

Click OK

You should now export the certificate so that it can be reused on the second wac server and we will also use on the HLB’s

Right click on the certificate and select All Tasks ->Export

Select Next

Click on Yes, export the private key and click Next

Click Next

Type a password and click Next

Click on Browse and give the exported certificate a name and click Next

Click Finish

Click OK

We are now ready to configure the first WAC server which is done from Powershell.

Open Powershell and run this command

New-OfficeWebAppsFarm -InternalURL “https://wacfarm01.exchangepro.local” -ExternalUrl “https://cswebapp.exchangepro.dk”-CertificateName “Office Web Apps”

Install the second Office Web Apps server and update it.

On the second server import the certificate that you exported before into the local computer store.

When all that is done, open powershell on the second server and run this, command to add the computer to wac farm.

New-OfficeWebAppsMachine -MachineToJoin “wac01.exchangepro.local”


Because we don’t have an Hardware loadbalancer yet, I will configure the DNS so that it points to the first WAC server


To check that the Office Web Apps is working and that Lync can use it login to the frontend server.

Open services and restart “Lync Server Web Conferencing” service

Open Event viewer and navigate to Lync Server.

Find eventid 41032 and make sure that the discovery is successful.

Lync is now ready to use the Office Web Apps servers.


In the next post I will continue to install more Lync servers, so stay tune.



Lync 2013 High Availability

Part 1: http://exchangepro.dk/2013/08/28/install-a-sql-2012-mirroring-cluster-for-use-with-lync-2013-part-1/

Part 2: http://exchangepro.dk/2013/08/29/install-a-sql-2012-witness-server-for-use-with-lync-2013-part-2/

Part 3: http://exchangepro.dk/2013/09/01/configure-a-sql-2012-mirroring-cluster-for-use-with-lync-2013-part-3/

Part 4: http://exchangepro.dk/2013/09/14/deploy-a-lync-2013-file-store-part-4/

Part 5: http://exchangepro.dk/2013/09/19/prepare-your-servers-for-lync-server-2013-ha-part-5/

Part 6: http://exchangepro.dk/2013/09/21/creating-the-lync-server-2013-ha-topology-part-6/

Part 7: http://exchangepro.dk/2013/09/30/install-the-first-frontend-server-part-7/

Part 8: http://exchangepro.dk/2013/10/06/update-the-frontend-server-part-8/

Part 10: http://exchangepro.dk/2013/10/21/deploy-the-director-servers-in-lync-2013-ha/

Part 11: http://exchangepro.dk/2013/10/25/install-the-access-edge-ha-servers-part-11/

Part 12: http://exchangepro.dk/2013/11/05/deploy-reverse-proxy-using-kemp-hardware-load-balancer-part-12/

Part 13: http://exchangepro.dk/2013/11/14/adding-additional-frontend-servers-to-lync-ha-part-13/

Part 14: http://exchangepro.dk/2013/11/26/setup-load-balancers-for-the-internal-lync-servers-part-14/

Part 15: http://exchangepro.dk/2013/11/26/load-balance-the-office-web-apps-server-part-15/

Part 16: http://exchangepro.dk/2013/11/26/load-balance-the-lync-frontend-web-services-part-16/

Part 17: http://exchangepro.dk/2013/11/28/load-balance-the-lync-frontend-services-part-17/

Part 18: http://exchangepro.dk/2013/12/15/load-balance-the-lync-director-servers-part-18/

Part 19: http://exchangepro.dk/2013/12/15/load-balance-lync-access-edge-internal-nic-part-19/

Part 20: http://exchangepro.dk/2013/12/29/load-balance-lync-access-edge-external-nic-part-20/

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>


Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Join 77 other subscribers

Follow me on Twitter