Topic Last Modified: 2011-05-16

In addition to the software support described in the other sections of this Supportability documentation, Microsoft Lync Server 2010 has the following support limitations:

• Lync Server 2010 supports Domain Name System (DNS) and hardware load balancing for specific server roles. It also supports application load balancing for Mediation Servers, where appropriate. For details about when to use each, see the Planning documentation.
  
  
• Lync Server 2010 uses the Distribution List Expansion Protocol (DLX) to expand distribution lists. This protocol also specifies the web service method that is used to get the membership of a distribution list. Microsoft Exchange Server supports dynamic groups that do not have members statically assigned to them. Instead, they store queries that are evaluated when the group is expanded. DLX does not support dynamic distribution lists.
  
  
• The Enable User Wizard does not support automatic conversion of non-English characters to a SIP-compliant URI, so you must modify the SIP address manually.
  
  
• For servers running antivirus software, include all servers running Lync Server 2010 in the exception list in order to provide optimal performance and audio quality. For details, see Specifying Anti-Virus Scanning Exclusions in the Security documentation.
  
  
• If you use IPsec, we recommend disabling IPsec over the port ranges used for audio and video traffic. For details, see IPsec Exceptions in the Planning documentation.
  
  
• If your organization uses a Quality of Service (QoS) infrastructure, the media subsystem is designed to work within this existing infrastructure. For details about implementing QoS, see Enabling Quality of Service (QoS) in the Operations documentation.
  
  
• Use of the operating system firewall is supported. Lync Server 2010 manages the firewall exceptions for the operating system firewall, except for Microsoft SQL Server database software. For details about SQL Server firewall requirements, see the SQL Server documentation.
  
  
• The external interfaces used to implement support for external user access must be on a separate subnet, not on the same network as the internal interfaces.
  
  
• Lync Server 2010 does not support two-factor authentication. However, if you deploy Lync Server in a network environment that already provides two-factor authentication (for example, a VPN with two-factor authentication), Lync Server works in that environment.
  
  
• Lync Server 2010 and Microsoft Exchange Server 2010 Service Pack 1 (SP1) operate with support for Federal Information Processing Standard (FIPS) 140-2 algorithms if the Windows Server 2008 Service Pack 2 (SP2) Windows Server 2008 R2 operating systems are configured to use the FIPS 140-2 algorithms for system cryptography. To implement FIPS support, you must configure each server running Lync Server 2010 to support it. For details about FIPS-compliant algorithms and how to implement FIPS support, see Microsoft Knowledge Base article 811833, “The effects of enabling the “System cryptography: Use FIPS compliant algorithms for encryption, hashing, and signing" security setting in Windows XP and in later versions of Windows,” at http://go.microsoft.com/fwlink/?linkid=3052&kbid=811833. For details about FIPS 140-2 support and limitations in Exchange 2010, see “Exchange 2010 SP1 and Support for FIPS Compliant Algorithms” at http://go.microsoft.com/fwlink/?LinkId=205335.
  
  

Lync Server 2010 requires the installation of other software on specific components prior to or during deployment. This includes software that is available with the operating system, downloadable software, and software that is automatically installed during installation of Lync Server 2010. Following is a list of additional software that can be required:

• Windows Update
  
  
• Message Queuing Server and Message Queuing Directory Service Integration
  
  
• Microsoft .NET 3.5 with Service Pack 1 (SP1) Framework
  
  
• Microsoft Visual C++ 2008 Redistributable
  
  
• Microsoft Visual J# version 2.0 Redistributable
  
  
• URL Rewrite Module version 2.0 Redistributable
  
  
• Windows Media Format Runtime
  
  
• Windows PowerShell version 2.0
  
  
• Windows Installer version 4.5
  
  
• Microsoft Silverlight 4 browser plug-in (Silverlight 4.0.50524.0 or the latest version for Lync Server Control Panel)
  
  
• Active Directory Domain Services (AD DS) tools
  
  
• SQL Server
  
  

Some of these software requirements only apply to specific server roles or components. For details about these software requirements, see Additional Software Requirements in the Planning documentation.