What is Group Chat Server in OCS R2?

I have had quite a bit of interest in education with the new OCS R2 Group Chat Server functionality.


We are just starting to use this internally and people are really liking this great new way of collaboration and idea sharing vs. traditional email threads, etc. I am all for unclogging the inbox!

What is Group Chat Server?

Group Chat Server is a new server role in OCS 2007 R2 and is based upon our Parlano acquisition a few years ago.

The chat server essentially allows users and admins to create chat rooms that persistently maintain conversations within a room. This way chat room users can come and go yet still see the conversations being discussed while they were away.


Breakdown of features:

  • On-going topic based discussions

  • Simultaneous participation in multiple chat topics

  • Easy to organize and view

  • Archived and searchable

  • Federated Group Chat with customers and partners

How could I use Group Chat Server in Education?

Many uses in Education here are a few ideas I have seen:

  • Class chat rooms - students join a class chat room and collaborate with other students, professor and grad students.  Can also be used for office hours.

  • School topic chat rooms - School district creates a chat channel such as ‘Civil War Discussion’ and then all the students within different schools in a school district can collaborate and discuss topics.

  • IT helpdesk peer to peer

  • End user helpdesk chat room

  • Tutoring chat rooms

  • Teachers, Professors chat rooms – a school district could setup a History Teachers chat room and teachers could share thoughts, lesson plans, best practices, collaborate

  • Graduate students – projects, etc.

  • Research - campus research working on a cancer research,etc.

What HW do I need for a Group Chat server?

System Component

Minimum Requirement (same as SE)


Dual processor, quad-core 2.0 GHz +




2x 72 GB, 15K or 10K RPM, RAID 0 (striped) or equivalent

Can I run Group Chat Server collocated with other R2 roles?

No, GC server must be run as stand alone and cannot be collocated.

How does it scale?

You can scale Group Chat servers up to a maximum of two servers for redundancy.


From the performance data I could find, both GC servers can handle 40 messages a second, up to 1000 users per chat room, with 60,000 concurrent chat users. Results may vary based on HW, load, bandwidth, etc.

Update 10/2: a new QFE for Group Chat update is required to scale to 60,000 concurrent users. See here.

What are the Group Chat Server requirements?

A single Group Chat server requires three service accounts:

  • Lookup service

  • Channel service

  • Web service

A SQL Server database for chat data

If compliance is required, the single-server topology must also include:

  • Compliance service

  • A SQL Server database, which can be either the same database as the Group Chat database or a separate database on the Compliance server

Windows Server 2003 SP2 / Windows Server 2008 Components:

  • 64-bit only (English only for now)

  • Internet Information Services (IIS). Hosts the Web Service for the purpose of posting files to chat rooms.

  • ASP.NET 2.0. Web application that is part of the .NET Framework and is used to build dynamic Web sites, Web applications, and XML Web services.

  • Message Queuing. Receives information from IIS and any Channel services in the system. This information is archived by the Compliance service, if deployed. But must be installed even if compliance is not installed

  • Microsoft Web Services Enhancements (WSE) 3.0

  • Microsoft® .NET Framework 3.0

  • Visual C ++ 2008 Redistributable Runtime

  • Microsoft Unified Communications Managed API (UCMA) v2.0

  • SSL Certificate from the same CA used for OCS 2007 R2

    • Download Certificate Chain and install it under Trusted Root Certification Authorities.

    • Request and Install Certificate

Other requirements:

  • SQL 2005 or SQL 2008 must be installed on another server

  • Certificate must be installed before Group Chat installation

  • OCS R2 pool required as a prerequisite

  • GC Service accounts must be member of local administrators on GC server

  • SQL client tools installed on GC server

  • IIS on GC server needs Anonymous enabled and read/write to file repository folder

Client requirements

There are two Group Chat client components. Group Chat Console and Group Chat Administrator Console.

Operating System:

  • Windows Vista with Service Pack 1

  • Windows XP with Service Pack 2

Software components:

  • Microsoft .NET Framework 3.5 SP1

  • Microsoft Visual C++ Runtime 2 (Versions 2.0.50727.761 and earlier are not supported)

Reboot is required

What ports do I need?





Group Chat Server



Used for secure file transfer with the Group Chat Web service.

Group Chat Server



Used for peer server synchronization/WCF ports for the Lookup Server.

Group Chat Server



Used for peer server synchronization/WCF ports for the Channel Server.

Group Chat Server



Used for listening port for the Channel service.

Group Chat Server



Used to communicate to internal servers using SIP/TLS.

Can I access Group Chat server from off campus without VPN?

Yes, via the Edge Access role. Additionally, federated OCS users can be allowed access to chat rooms.

More references for Group Chat Server:

Group Chat quick reference guide here.

Grab the Group Chat client deployment guide here.

Group Chat server deployment reference here.

Where are the bits for Group Chat Server?

They aren’t on the OCS R2 install DVD. There is a separate download:

  • Download Group Chat server here

  • Download Group Chat Console and Admin  here and here.

Note: In order for Group Chat Server to work, OCS 2007 R2 to be in place first (see flow diagrams above). Grab a 180-day eval copy here.

Comments (19)

  1. Anonymous says:

    This was a question coming from an education customer in Minnesota deploying OCS R2 Group Chat Server:

  2. Anonymous says:

    Mark, you mentioned above in your post that Group Chat cannot be collocated with other R2 roles.  Can you elaborate?

    We already had OCS running on a single server.  Before seeing this blog, we installed and now have a working instance of Group Chat on this same server.  Did I read you blog incorrectly in that both cannot (or should not) co-exist on the same server?  If I did read correctly, what danger can we run into by having them reside on the same server?

    Even with virtualization, to have a single server for OCS, another dedicated one for Group Chat and another dedicated one (potentially) for Group Chat Compliance (and not even taking into account eventual multiple servers for redundnacy), it seems that the TCO would be pretty high to have all these separate servers.


  3. Anonymous says:

    I have had quite a bit of interest in education with the new OCS R2 Group Chat Server functionality.

  4. markga says:


    They are still working out the plans there.

  5. markga says:


    You can install the cert on the HW Lb. It is basically a web cert template. The other option is to install the same cert on both front ends with the FQDN being the load balanced VIP.

    See here for more cert info:



    The details for next release are still being worked out.

  6. Anonymous says:

    Tell me more about external access in Group Chat?  Does this work simply through the Edge Server?  How about file transfers?  Would I need to publish the web address and make it available externally through ISA?

  7. markga says:


    I haven’t seen a Gchat only deployment as typically folks want to leverage IM, Conferencing, voice components of OCS as well. If you are planning Gchat only, we still require OCS front ends to proxy the SIP request to the Gchat server, to allow for off campus Gchat access via Edge, and to incorporate presence into Gchat server.

    Right now, only 2 Gchat servers are supported. Remember that number is concurrent not total number of Gchat users therefore you could provision quite a bit of Chat users.

  8. markga says:


    I haven’t seen this work with PIC users however I believe it will work with OCS federated users.

    I haven’t seen a roadmap for Group Chat server yet so I can’t speak to futures at this point.

  9. markga says:


    The only option for Mac at this point is via 3rd party GC browser support like with Formicary:


  10. Phil says:

    I love the idea of group chat but its a different client to Office communicator.  any plans to integrate the two into one client?

  11. Tim says:

    May I know what kind of Certificates and how many certs we need when we deploying 2 x Group Chat servers in the 3rd party load balancer

  12. jim says:

    Any plans on integrating the clients together in the next release?

    Our department would like to use one client rather than considering something like Jabber.

  13. David Lloyd says:

    In a GChat only environment what does the OCS2007 server that the users are shown connecting to in the diagrams above actually do?

    Is it acting as a pool manager / comminication federation layer?  Can I add more pairs of Chat servers to extend my user base to beyond 20,000 concurrent users?

  14. Geo says:

    Is there a way to configure the Group Chat history retention policy? IE it will only keep a week or two of history before it purges the history from the persistant chat channel?

  15. Mark McClelland says:

    To those people looking for a single-client experience, I thought it might be worth mentioning that the Group Chat client includes its own support for person-to-person IM.  For people who use Communicator only for person-to-person text IM and want to add Group Chat capabilities, the Group Chat client can actually replace Communicator.  You can also use GPO settings to turn off text-IM in Communicator, making Group Chat your preferred IM client while still allowing you to use Communicator to make voice calls.

  16. But what our company wants is a least group chat appearing in a tab to MOC. Is there palns to do that?

  17. Diego A. says:

    Hi to all, I’d like to know if there is a way to calculate the storage that is required for the Group Chat Server Instance in SQL, because each time we requiere an instance, the next question is the storage, thanks in advance.

  18. MuhammadM says:

    Can PIC clients (Yahoo, MSN or AOL) participate in Group Chat Channels hosted by us, if NOT, is Microsoft planning to add this functionality in future build of Group Chat?

  19. bill says:

    Have you heard or read anything about Mac client support?

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