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Monthly Archives: January 2011

How to allow domain users to connect to Lync 2010 or OCS 2007 from Clients running on non-domain computers

I had a situation in our company where we have exceptional few users who got Domain credentials but they are working on Computers that are not joined to the domain.

However these computers run over the LAN or WAN, can communicate with the internal DNS and got the certificate chain of the CA imported to them and they use DOMAIN\UID and password credentials to login to mail , MOSS and everything is working fine.

When I installed the OCS 2007 R2 client on their machines and tried to login with the same behavior as mail using DOMAIN\UID, I was not able to log in and I received the below event log warning:

“Communicator was unable to authenticate because an authenticating authority was not reachable.”


The server may be asking for Kerberos authentication and Communicator is not able to find the Kerberos Domain Controller in order to generate credentials and authenticate.  The network administrator will need to change the configuration on the server to utilize only NTLM authentication before Communicator can login from this location properly, or connectivity will need to be made available to an authenticating authority”

Also as for testing I removed the OCS 2007 R2 client and installed the new Lync RC client on the same machine, I know it is not supported scenario but I was just testing it. Now the user was able to login but it disconnects after 10 seconds then reconnects again , it keep in this loop. I also found the same warning in the event log.

I know why this is happening and I know it would have been solved from the beginning if i forced the OCS to use NTLM only rather than Kerberos but this was not something i can force.

So in the end the Solution was this problem was simple:

Ensure that the users when singing in to communicator 2007 or Lync 2010 to include the “.local” in the domain.local\username part of the authentication and not DOMAIN\username.

Communicator for Mac 2011 Deployment Guide

Features Available:

  • Calendar based presence.
  • Presence in other Office for Mac applications.
  • Outlook Out of office messages in Mac Communicator.
  • Invite multiple people to conference.
  • Join conf: meetings from an outlook Invite.
  • Enterprise Voice supported.
  • OCS 2007 R2 support (OCS 2007 RTM is not).

Not available:

  • Access Level for Contacts.
  • Call forwarding.
  • Receiving calls on mobile devices.
  • Voicemail access from Mac Communicator.
  • Scheduling of conferences in Outlook.
  • Desktop sharing.
  • No mention of Live Meeting.

I am extremely pleased with the progress the Mac Communicator team has made.

I expect the user experience with Lync to fill in some of the holes above with the Reach client. Finally, the Mac user can join the rest of the Unified Communications fun!

Here is the link to the Mac Communicator Deployment Guide. Enjoy!

Lync 2010 Collocated Mediation Server vs. Dedicated Mediation Server

Learn why we should collocate or not collocate Mediation Servers with Front End Servers in Microsoft Lync Server 2010 via

Publishing Lync Server 2010 Simple URLs and Web Components with Forefront TMG 2010

PowerShell Script to create new user, enable for Exchange, UM and Lync Server

RANDY WINTLE created this PowerShell as a sample of how to create new user, enable for Exchange, UM and Lync Server.

There are a couple good takeaways from this script, it remotes into Exchange 2010 and Lync Server 2010 PowerShell sessions, so nothing except PowerShell 2.0 is required on the client side, which is standard with Windows 7. It also shows how you can simultaneously use Exchange and Lync PowerShell commands in the same script to get things done.

This was developed specifically for your internal needs; you will probably have to add/remove variables and requirements:

Mike Stacy writes “ Side-by-side error when running DHCPUtil.exe with Lync Server 2010”

In trying to run DHCPUtil.exe from your Windows Server 2008 x64 DHCP server with the appropriate command line parameters in order to configure DHCP for Lync Server, you may run across the following error:

The application has failed to start because its side-by-side configuration is incorrect. Please see the application event log or use the command-line sxstrace.exe tool for more detail.

Reviewing the app log reveals the following:

Solution:  Install vcredist_x64.exe from the Lync Server media and run DHCPUtil.exe again.

Step by Step Lync and Exchange UM Integration

Using DHCPUtil for Lync Phone Edition DHCP Server Configuration

Lync 2010 vs OCS 2007 R2 vs OCS 2007 R1 Client Supportability Matrix

If you have been reading Jeff’s Post then you will know that Lync Client is not supported with OCS, for further details I have prepared this Table to list the supported clients against servers:

How to update Lync Server Configuration from CMS after topology Change

Aifter updating the topology in the topology builder I found that setup instructed me to run the setup again and run the step “setup or Remove Lync Server Components” to update the local server configuration from the CMS.

Looks like I found a way to update the local configuration from the CMS which is using the cmdlet: enable-cscomputer, of course you can use get-cscomputer and pipe it to enable-cscomputer.

This will allow you to rapidly update your servers local configuration if you have large amount of servers.