Lync Server 2013 Guidance Series: Troubleshooting Office Web Server Connectivity

Introduction

As part of these blog series I will be sharing information, about Lync Server 2013. The information will include operational guidance such backup-restore, patch updating, and handy deployment tips.

In this post we shall discuss how to test connectivity to Office Web App server used in Lync Server 2013 environment for PowerPoint presentation. In most environments there would be SharePoint Administrator or separate Admin managing the Office Web App Server. As Lync Engineer or Administrator your assistance might be required to isolate the problem. A single Office Web app installation can be shared between SharePoint and Lync Servers.

To troubleshoot the Lync Server and Office Web App server connectivity we shall first see how Lync Server detects the Office Web App server

Office Web App server detection in Lync Server

Once the Lync Admin has added the Office Web App server to topology and published the topology

The RTCDATAMCU component or the Lync Server Web Conferencing service running on the Lync Front-end server will try and connect to the Office Web App server discovery URL published in Lync Topology, this is an HTTPS connection. (e.g.. https://wac.contoso.com/hosting/discovery/)

1) Once Lync Server Web Conferencing service is able to connect to the Office Web App server discovery URL (eg. https://wac.contoso.com) it will check if PowerPoint content is enabled if Yes we can see the following event id in the event viewer Lync Frontend server.

Log Name: Lync Server
Source: LS Data MCU
Event ID: 41034
Task Category: (1018)
Level: Information
Keywords: Classic
User: N/A
Description:
Web Conferencing Server has successfully discovered Office Web Apps Server, PowerPoint content is enabled

2) Then Lync Server Web Conferencing service will check for the presenter and attendee pages

Office Web Apps Server internal presenter page
Office Web Apps Server internal attendee page
Office Web Apps Server external presenter page
Office Web Apps Server external attendee page

Once this detection succeeds we should see the following event if on the Lync Frontend server

Log Name: Lync Server
Source: LS Data MCU
Event ID: 41032
Task Category: (1018)
Level: Information
Keywords: Classic
User: N/A
Description:
Web Conferencing Server Office Web Apps Server (WAC) discovery has succeeded

Office Web Apps Server internal presenter page: https://wac.contoso.com/m/Presenter.aspx?a=0\&e=true&
Office Web Apps Server internal attendee page: https://wac.contoso.com/m/ParticipantFrame.aspx?a=0\&e=true&
Office Web Apps Server external presenter page: https://wac.contoso.com/m/Presenter.aspx?a=0\&e=true&
Office Web Apps Server external attendee page: https://wac.contoso.com/m/ParticipantFrame.aspx?a=0\&e=true&

If any one of the above detection fails we would see the following event id on the Lync Frontend server

Log Name: Lync Server
Source: LS Data MCU
Event ID: 41033
Task Category: (1018)
Level: Error
Keywords: Classic
User: N/A
Description:
Office Web Apps Server (WAC) discovery failed, PowerPoint content is disabled.

Attempted Office Web Apps Server discovery Url: https://wac.contoso.com/hosting/discovery/
Received error message: Wac discovery did not return any Powerpoint actions for HTTPS zone
The number of retries: 8046,
Cause: Office Web Apps Server may be unavailable or network connectivity may have been compromised.
Resolution:
Check HTTPS connectivity from this box to the Office Web Apps Server deployment using the discovery Url.

Troubleshooting

The first troubleshooting step would be to verify that we are able to browse Office Web Apps Server discovery Url mentioned in Error event id 41033 (e.g. https://wac.contoso.com/hosting/discovery/ )

When you browse Office Web Apps Server discovery Url front the Lync frontend server ideally We should see Web Application Open Platform Interface Protocol (WOPI)-discovery XML file in the web browser. shown below

<?xml version="1.0" encoding="UTF-8"?>
<wopi-discovery><net-zone
name="internal-https"><app name="Excel" checkLicense="true"
favIconUrl="https://wac.contoso.com/x/_layouts/images/FavIcon_Excel.ico"><action
name="view"
urlsrc="https://wac.contoso.com/x/_layouts/xlviewerinternal.aspx?<ui=UI_LLCC&><rs=DC_LLCC&>"
default="true" ext="ods"/><action name="view"
urlsrc="https://wac.contoso.com/x/_layouts/xlviewerinternal.aspx?<ui=UI_LLCC&><rs=DC_LLCC&>"
default="true" ext="xls"/><action name="view"
 

If we are unable to browse Office Web Apps Server discovery Url, verify the information entered in the Lync topology is correct. We could use a https debugging tools such as Fiddler or network tracing utility such as wire shark to troubleshoot this further. Involve in the Office Web Apps Server Admin to check IIS logs on the Office Web Apps Server.

If we are able to browse the Office Web Apps Server discovery Url manually and are still getting Error event id 41033 on the Lync frontend server

On the Office Web Apps Server open Windows PowerShell as administrator run the Get-OfficeWebAppsFarm cmdlet shown below is an sample output of the cmdlet with important parameter

PS C:\Windows\system32> Get-OfficeWebAppsFarm
FarmOU :
InternalURL : https://wacint.contoso.com/
ExternalURL : https://wac.contoso.com/
AllowHTTP : True
SSLOffloaded : True
CertificateName : WAC
EditingEnabled : True

Please verify that Office Web Apps Server discovery Url is point either to InternalURL or ExternalURL from the Get-OfficeWebAppsFarm cmdlet

Also CertificateName parameter displays the friendly name of the certificate used by the Office Web Apps verify the certificate has entry for the InternalURL or ExternalURL name.

If the Get-OfficeWebAppsFarm cmdlet doesn’t display a result please verify the Office Web Apps Server service is running. if yes then refer to Deploy Office Web Apps Server documentation to configure Office Web Apps Server.

Once the change has been made to Office Web Apps Server in Lync Topology or on the Office Web Apps Server to reinitiate detection process immediately by the Lync front-end server restart the Lync Server Web Conferencing service on the Lync Front-end servers