LCS - common questions

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When I talk to customers about Live Communications Server (LCS) and Office Communicator (MOC), I often get asked the same questions.

I've addressed most of these below but feel free to ask more by replying to this post -  as more questions are asked I will add them to this page.

1. What are the system requirements for LCS?

2. What clients are supported

  • Office Communicator
  • Windows Messenger 5.1 *
  • Communicator Web Access
  • Communicator Mobile

* While Live Communications Server 2005 SP1 continues to support Microsoft Windows Messenger 5.1 for presence and instant messaging scenarios, Communicator 2005 is the preferred client for enterprise-to-enterprise federation, telephony, and public IM connection scenarios.

3. What versions of Office does Live Communications Server work with?

  • There are a couple of points to consider here:
    • MOC 2005 will presence-enable Office 2003 and newer
    • Smart-tags require Office 2003 SP2 or newer
    • LCS/MOC do not require Office - they can exist independently to provide presence and RTC capabilities

4. What is the difference between Standard and Enterprise editions?

  • Standard Edition is best for small and mid-size companies, or smaller enterprise organisations, with user data stored locally and support for up to 15,000 active users per server. Enterprise Edition is built for large organisations, with user data stored in a back-end SQL Server database and support for more than 100,000 active users per server pool. For more information, see the Live Communications Server Feature Comparison.

5. What versions of SharePoint does LCS work with?

  • 2003 and newer

6. How do I federate my LCS server with Microsoft?

  • Make sure your LCS infrastructure meets the following requirements:
    • Live Communications Server 2005 with Service Pack 1 must be installed
    • Live Communications Server Access Proxy must be installed
    • Public interface of the Access Proxy must be accessible to the Microsoft Access Proxy. Do a DNS look up against sipfed.microsoft.com for the current IP if ACL reuired
    • _sipfederationtls._tcp.sip-domain.com must be published of type SRV in public DNS pointing to the access proxy's FQDN on port 5061
    • Certificate used on the Public interface of the Access Proxy must be signed by a public Certificate Authority
    • Certificate common name must match the FQDN of the Access Proxy
    • Certificate must be 128bit
    • Branding.am script must be configured on the Access Proxy
    • Network of Origin icon must be 16x16 Pixels, 96 dots per inch, and PNG format
    • Network of Origin icon must be published on a SSL web site
  • For more information please reference the below links:
  • If you meet the above requirements, contact your Microsoft Account Manager, or me by using the form on this blog, to discuss federation with Microsoft

7. Which Public IM networks does LCS work with?

  • MSN, Windows Live, Yahoo and AOL

8. Can I trial Public IM Connectivity?

  • Yes there is a free, 60 day, 10 seat Public IM Connectivity trial. To qualify for the trial, participants must be either a Select, Enterprise, or Open Value customer. Since Public IM Connectivity is dependent on Live Communications Server 2005 with SP1, the trial participant must either have licenses for or be running Live Communications Server 2005 with SP1. To request a trial, please contact your Microsoft account manager.

9. When will web conferencing be part of LCS?

  • We currently have a hosted web-conferencing service called LiveMeeting
  • Office Communications Server 2007 (currently scheduled for Q2 CY2007) will have on-premise web-conferencing capabilities