Repost: Lync Web App explained and updated #Lync

With the release of Lync Server 2010, Microsoft did some changes to the Web experience. You could say that they removed Communicator Web Access (CWA) from Office Communications Server 2007 R2, built it up again and put it back in. In other words, there is no more “stand alone web Instant Message (IM) / CWA thing”
But there is the:


When you configure your Lync environment, there are three simple URLs to set and that’s basically all you have to do, no more extra servers and requiring a separate windows server box.
One of these url´s is the “” aka Lync Web App aka LWA

LWA is now a Silverlight 4.0 browser plug-in based meeting client and not a chat only / IM client like CWA was.

So what if you want to just IM people like in the good old days from lets say a internet coffee shop? Well there are still some options.

  1. Upgrade your Exchange Server to Exchange Server 2010 sp1 and you can now send IM´s directly from inside the Outlook Web App. (details are further down in this post)
  2. Use an old CWA server together with Lync Server 2010 (also good for all those iDialog and Communicator for java / nokia users) (see for info on how to set this up.)
  3. Build your own client.

How do you access Lync Web Access?

There are basically two ways you can access LWA from. The first one is to create a meeting in Outlook and then click the Online Meeting button.


Outlook will then add the meeting information together with the full LWA url to the meeting invitation. Clicking that link will open LWA.

The second way to access LWA is from within Lync 2010:

1. From the Lync client, click the down arrow at the top right and select “meet now”.  This will create a new conference call.


2. Click the “Join Information and Meeting Options” at the top of the conference call


Click “Join Information and Meeting Options” and copy the Meeting link to a browser, email, etc.  It will look like this:

When a user clicks a meeting link, the join meeting page detects if a Lync client is already installed on the computer. If it finds a client, the default client opens and joins the meeting (you can close the client and click “Try Lync Web App” in the browser if you want to try the LWA instead).
If a client is not installed, the join meeting page displays options for joining the meeting with alternate clients.
The join meeting scenarios are as follows:

  • If Microsoft Lync 2010 or Microsoft Lync 2010 Attendant is installed, the client starts and joins the meeting.
  • If neither Lync 2010 nor Lync 2010 Attendant is installed and Lync 2010 Attendee is installed, Lync 2010 Attendee starts and joins the meeting.
  • If no Lync client is installed, the meeting join page opens and gives the user the following options:
    • Use Lync Web App.
    • Download Lync 2010 Attendee. (This link is hidden by default.)
    • Use a previous version of Office Communicator. (This link is hidden by default.)

(For the scenario in which no client is installed, you can configure the meeting join page by using the Microsoft Lync Server 2010 Control Panel (the Web Service page in the Security group). You can also configure the same settings by using the New-CsWebServiceConfiguration or Set-CsWebServiceConfiguration Lync Server Management Shell cmdlets with the ShowDownloadCommunicatorAttendeeLink and ShowJoinUsingLegacyClientLink parameters. )

The join meeting page always contains the option to use Microsoft Lync Web App so joining a meeting for a first time user is just a simple 3 click to join experience.clip_image005

Clicking Lync Web App will open the Lync Web App in a new window, so make sure to disable popup blocker for the URL (in most browsers a reminder will open if you have a pop up blocker active)


From in here there are two options.

  1. Join as a guest
  2. Join using your corporate credentials


Joining as a Guest will put you on hold in the meeting Lobby (these settings can be configured on the Lync Server or in Outlook, to enable guests to jump right in to the meeting instead of waiting in the lobby.)


(Clicking Meeting Options in Outlook enables you to change access right to the meeting.)


But if you are the leader or if you are an internal user, choose the second option to authenticate yourself with your corporate credentials.



TIP 1: A common error is that the Lync web app fails when connecting from the internet and starts to show internal URLs after launching the LWA. If this happens there is probably something wrong with the port redirection since the Lync IIS server by default uses port 443 for internal clients, and 4443 for the external clients.

TIP 2: Try to add ?sl= at the end of the url. It will then look something like this: this will bypass the Lync client check and let you choose how to access LWA.


Lync Web App functions

The available Lync Web App in-meeting features include the following:

  • Dial-in and dial-out (“Call me”) audio conferencing (requires pstn connection)
    • Audio is not sent over a web connection and in the browser, its sent via the PSTN for the best user experience.
  • Detailed meeting roster
  • Multiparty instant messaging (IM)
  • Desktop and program sharing, including giving control to participants (available for Windows only; not available for Macintosh)
  • Collaboration features, including whiteboards, polls, file sharing, and navigating PowerPoint presentations uploaded by others

Desktop Sharing in Lync Web App

If you want to share your desktop, you need to install the LWA Plugin which is a Microsoft ActiveX control. The first time a user initiate a sharing session, they will be prompted to download the required ActiveX control.



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The above picture to the left is LWA, the right one is the full Lync 2010 client experience

What’s seems to be missing so far is to share a PowerPoint presentation and audio / video!

For the PowerPoint, you could always just share your desktop or the PowerPoint program and show it to them that way.
And if you are the presenter, you probably use the full Lync client or the Attendee client instead of LWA anyway.

Make sure to look through the Microsoft Lync 2010 Web App Training guides that can be found on the link.


For audio there are three options if you have enabled Enterprise Voice (if not you can always just call each other in a traditional phone conference or on your mobiles), clicking Phone shows these options:

“Option 1: The conference calls you” is for LWA to call your phone or a number of your choice. (It might be a good idea to turn this option of for unauthenticated users, and that can be done in the Conferencing Policy)

“Option 2: Join audio using Communicator” is only available if you have a client installed

“Option 3: Dial in to the conference” is for you to dial in to the conference on the number and id supplied.



Lync Experience from within Outlook Web App 2010

This is the Exchange 2010 Outlook Web App experience for basic IM functionality < p>clip_image024

In the upper right corner you have your own presence controls.

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Your contact list can be found on the left side and there is also an option to add contacts from within the OWA.

Just double click on a user that is online to start an IM session and as you can see this also works perfectly fine in any of the mayor browsers.

Configuring Lync RC and Exchange 2010 Sp1 to Enable OWA as a Lync Endpoint

Ilse Van Criekinge have a nice step by step guide on how to configure OWA in Exchange 2010 SP1 as a Lync endpoint, to enable users to send IMs from within OWA.

There is also the Managing Outlook Web App and Instant Messaging Integration page on Technet describing how to do this for both Office Communications Server 2007 and for Lync Server 2010

Supported Operating systems and browsers for LWA

And last, a list of supported Operating systems and browsers for LWA.

Operating System and Browser Requirements for Microsoft Lync Web App

Operating system

Internet Explorer 8

Internet Explorer 7

Internet Explorer 6

Firefox 3.X

Safari 5.X

Safari 4.X

The 64-bit and 32-bit versions of Windows 7






The 64-bit and 32-bit editions of Windows Vista with Service Pack 2 (SP2)






Windows XP with Service Pack 3 (SP3) 32-bit Edition






Windows XP with SP2 x64 Edition






Windows Server 2008 R2




Windows Server 2003 (except IA-64)





Windows Server 2000 with Service Pack 4 (SP4)





Mac OS 10.4.8+ (Intel-based)





Deploying Lync Web App:

Configure the Meeting Join Page:

Configure Outlook Web App and Lync Server 2010 Integration:

Lync Web App Features:

Understanding Outlook Web App and Instant Messaging Integration:

Lync Client Comparison Tables:

Microsoft Lync 2010 Web App Training