Problems making IIS 7.0 changes for Lync Mobility (MCX)

13 December 2011


I hit a problem when installing the mobility service on Lync running on Windows 2008 (not R2). By default you will be running IIS 7.0 this gives problems with making the changes for the Mobility and Autodiscover services.

The Guide says:

If you use Internet Information Services (IIS) 7.0, you need to perform extra steps to change some ASP.NET settings.

It then goes on to define those steps:

1. Log on to the server as a local administrator.

2. Use a text editor such as Notepad to open the applicationHost.config file, located at C:\Windows\System32\inetsrv\config\applicationHost.config.

3. Search for the following:

<Add name=”CSExtMcxAppPool”

4. At the end of the line, before the ending angle bracket (>), type the following:

CLRConfigFile=”C:\Program Files\Microsoft Lync Server 2010\Web Components\Mcx\Ext\Aspnet_mcx.config”

5. Search for the following:

<Add name=”CSIntMcxAppPool”

6. At the end of the line, before the ending angle bracket (>), type the following:

CLRConfigFile=”C:\Program Files\Microsoft Lync Server 2010\Web Components\Mcx\Int\Aspnet_mcx.config”


However should you try and do step 3 you cannot find <Add name=”CSExtMcxAppPool” this  is because the changes adding these lines are not made until after the you have run the Mobility and Autodiscover services.

Once you run these you can locate the lines and make the changes.

On my system after making the changes and trying to restart IIS to activate the changes IIS would not restart.  Looking in the System Event log there were eight Event ID 2297 errors for different applications pools for example:

The worker process for application pool ‘CSIntConfAppPool’ encountered an error ‘Configuration file is not well-formed XML
‘ trying to read global module configuration data from file ‘\\?\C:\inetpub\temp\apppools\CSIntConfAppPool.config’, line number ‘3’.  Worker process startup aborted.

Further searching showed that the CLRConfigFile parameter that was added when you edited the file was introduced in IIS7.5.

Removing the changes allowed IIS to restart.

After a bit of searching I found a hotfix that addressed adding support for the CLRConfigFile parameter for IIS 7.0.

I applied the hotfix then made the changes to the applicationHost.config file and restarted IIS accepted the changes and restarted without a problem.

Having then gone back to the documentation I thought I’d search for the hotfix in case I’d missed it…… I got a hit 3 pages  from the end saying you should apply the hotfix before making the some changes for high performance. The documentation should have shown this earlier with the original change. I have sent a comment about this documentation problem.


Forwarded Calls don’t contain the Called Party’s number

4 August 2011

When you setup Lync forwarding or simultaneous ring it always passes the original callers number in the FROM field.

Call Flow

In the example shown above +44 123 4567 calls +44 987 6543 the Lync user has setup a call forward to another number +44 765 4321. When you receive the call on +44 765 4321 you see the original caller id +44 123 4567.

SIP Header wise this is what is sent from the Mediation server to the ITSP:


INVITE sip:07654321@;user=phone SIP/2.0
FROM: <;user=phone>;epid=81E23DEAF8;tag=ab6896ea7e
TO: <sip:07654321@;user=phone>
CALL-ID: b983d9b2-c75a-48e3-a702-ec9b5ef98eb0
VIA: SIP/2.0/TCP;branch=z9hG4bK693cdab6
CONTACT: <;transport=Tcp;maddr=;ms-opaque=ed082191311c6e3b>
USER-AGENT: RTCC/ MediationServer
CONTENT-TYPE: application/sdp

As you can see the FROM is set to the external callers number and the TO is set to the forwarded to number. Although this can be useful to the person receiving the call to see where the call is coming from it does however cause issues for some ITSP’s (Internet Telephony Service Providers)

Introduced in CU2 was a fix to allow a REFFERED-BY header to be added however after applying the patch (or even CU3) the header does not appear. It is alluded to here in the KB article

However it mentions that you need to apply 255421 as well which doesn’t exist (I assume this will be corrected). The actual KB article is 2500421  (

Here is explains you need to update the Mediation server config file.

For those of you that have never had to update the config file it is in the Mediation server directory which by default can be found here:

C:\Program Files\Microsoft Lync Server 2010\Mediation Server\MediationServerSvc.exe.config

For the SIP trace above you would modify the file to:

<?xml version=”1.0″ encoding=”utf-8″?>
                <add key=”” value=”true”/>
    <generatePublisherEvidence enabled=”false”/>

Once you save this file (don’t forget you need to run notepad as administrator to save it) you restart the Mediation Server service.

The headers now appear as


INVITE sip:07654321@;user=phone SIP/2.0
FROM: <;user=phone>;epid=DB23987285;tag=c495f66513
TO: <sip:07654321@;user=phone>
CALL-ID: a2c887ef-a162-4b11-87a5-daf222734f18
VIA: SIP/2.0/TCP;branch=z9hG4bK370cbae
CONTACT: <;transport=Tcp;maddr=;ms-opaque=8c6fc24ca0304215>
REFERRED-BY: <tel:+449876543>
USER-AGENT: RTCC/ MediationServer
CONTENT-TYPE: application/sdp


You can see the FROM and TO headers remain the same but you now have a REFFERED-BY header with the called party’s number. The ITSP can then use this value.

Setting Lync 2010 policies (OCS Group Policy) with PowerShell

18 September 2010

Important the following information is based on the Release Candidate and could change on RTM. Please check the latest documentation

With the release of Lync Server 2010 (RC) the settings which were deployed using group policy for OCS 2007 R2 are now for the most part sent using in-band provisioning to the client. There are a few setting which are used for Client bootstrapping and therefore still need to be configured in Group Policy.

The majority of group policy settings have been moved to PowerShell commands:

New-CsClientPolicy Create a new client policy either at site or per-user scope
Set-CsClientPolicy Modify an existing client policy
Grant-CsClientPolicy Assign a client policy to a user or group of users
Remove-CsClientPolicy Remove a client policy from a user of group of users
Get-CsClientPolicy Get information on existing client policies


New-CsClientPolicy -Identity SalesPolicy -DisableEmoticons $True          
-DisableEmailComparisonCheck  $True


Here we are creating a policy called SalesPolicy with 2 settings to turn off Emoticons and to turn off checking that the Outlook and Lync are running under the same account.

Now to apply this to the Sales department we can use the following:

Get-CsUser -LDAPFilter "Department=Sales" | Grant-CsClientPolicy       
-PolicyName SalesPolicy

Here we are getting all the enabled users in AD who have a department of Sales and applying the policy to them.

You can also apply the Client Policy in Lync Control Panel as well


There are a large number of settings for the client policy so I won’t reproduce them here either check the documentation of in the Lync Management Shell use the following command to see all the options:

get-help New-CsClientPolicy -full | more

Licensing for Lync Server 2010

15 September 2010

If you thought licensing for OCS 2007 R2 was complicated we now have the licensing for Lync.

The cost of an Enterprise CAL has come down but no longer includes telephony functions. Telephony in Lync server requires the new Plus CAL in addition to the Standard and Enterprise CALs. At the bottom there is the matrix of what each CAL covered both on R2 and Lync

If you have the Microsoft Enterprise CAL suite the Lync Standard and Enterprise CALs are included but the Plus CAL is still an addition.

The Lync client software is available either standalone or is included in the Office Professional Plus 2010 product.

Depending on your current Software Assurance your current OCS 2007R2 licenses as a qualifying license for Lync.

Having read details it has generated a lot of questions in mind and once I have answers I will update everyone.

IM and PresenceInstant Messaging and Presence

Audio, Video and Web Conferencing

Audio, Video, and Web Conferencing

Enterprise Voice

Enterprise Voice Technology

Lync Server simple URLs

15 September 2010

When you setup the topology for your Lync deployment you need to setup 3 simple URL’s. These URLs are used for administration, dial-in and Meet

The administration URL you keep within your internal network but the Meet and dial-in are required internally and externally. By default these are set to and


This may not seem to be a problem however if you have multiple SIP domains the number of SAN’s you require can become quite costly. A simple solution to these simple URL’s is to change them to use the same sub-domain for example and


Using this format halves the number of SAN’s required at the expense of slightly lengthening the actual URL.

The other consideration is that these URL’s expect you to have split brain DNS as there is no external/internal option for defining these. However if you don’t have split brain DNS the request can route externally and the meeting GRUU that is returned enables you to connect either directly internally or externally.

Wave 14 Official Name and Release Candidate Available for Download

13 September 2010

After months of talking about Wave 14 and CS2010 the product has finally been given its official name ready for release. We now have Microsoft Lync Server 2010. The full rebranding is as follows


If you want to try out the Release Candidate then you can download everything you need from here

Over the next few weeks I’ll be blogging about the new functionality.

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