Lync Support Guidelines
Lync Server 2010 brings a welcome change for many organizations in terms of the support policy offered for virtualization. In Microsoft Office Communications Server 2007 R2, only a few workloads were certified for virtualization. In a nutshell, any component that used a type of media was not allowed to be virtualized. This didn’t mean those features wouldn’t function in a virtual environment; it just meant Microsoft would not officially support a deployment with virtualized servers handling media because it had not tested or designed the product for those scenarios. This meant that web conferencing, A/V conferencing, and telephony features were not supported in a virtual deployment in OCS.
With Lync Server 2010, nearly all scenarios can be virtualized with only a few exceptions. The most welcome change is that the web conferencing, A/V conferencing, and telephony integration features are now supported. This means that Front-End Servers handling media and Mediation Servers handling SIP trunks or media gateway integration can now be deployed in a virtual machine. The roles and features supported for Lync Server 2010 virtualization are listed here:
• Standard Edition Front-End Server—Supported for presence, IM, Enterprise Voice, A/V, and conferencing
• Enterprise Edition Front-End Server—Supported for presence, IM, Enterprise Voice, and A/V
• A/V Conferencing Server—Supported for A/V conferencing
• Enterprise Edition Back-End Server—Supported for SQL Server store and file share server
• Edge Server—Supported for remote access, federation, public IM connectivity, presence, IM, Enterprise Voice, and A/V
• Director—Supported for authentication and routing
• Monitoring Server—Supported for the monitoring service and collocated SQL Server store
• Archiving Server—Supported for the archiving service and collocated SQL server store
Note
If archiving or monitoring communications from a virtualized Standard Edition Front-End server, the archiving and monitoring roles must be deployed on a physical server to fall within the support boundaries. Microsoft has not provided an explanation for this anomaly, but it is explicitly called out.
The only roles that cannot be virtualized for use in Lync Server 2010 are the IP-PSTN gateways or the survivable branch appliances. Considering most of these appliances would require a physical telephony connection that would be impossible in a virtual environment, this should not be an issue for most organizations.
This support shift should open the option for many organizations to fully virtualize Lync deployments. However, there are still some significant support boundaries as listed here:
• Hyper-V 2008 R2 or VMware vSphere 4 Only—The only supported virtualization platforms at this time are Windows Server 2008 R2 Hyper-V or VMware vSphere 4.0 products. This should include the Hyper-V 2008 R2 standalone free product and both the ESX and ESXi products from VMware. This means that older versions such as Microsoft Virtual Sever 2005, Microsoft Windows Server 2008 Hyper-V, and VMware ESX 3.5 are not supported for use with Lync Server 2010.
• No Live Migration—Live migration or vMotion of Lync virtual servers is not a supported feature. Because media traffic heavily depends on low latency and CPU processing, moving a Lync VM between hosts can lead to a poor experience for users by either degrading or completely disconnecting a media stream.
• Cannot mix physical and virtual machines within the same pool—There are some additional guidelines when mixing physical and virtual servers for Lync, but the most basic one is that a pool cannot contain a mix of physical and virtual servers. All servers in a single Front-End, Edge, Director, or Mediation pool must either be physical or virtual to be supported.
• Virtual Front-End pool required—To virtualize roles such as the Director, Edge Server, or A/V Conferencing Server, the associated Enterprise or Standard Edition Front-End Server must also be virtualized. This means that if an organization deploys the Front-End Servers on physical machines, the Director or Edge Server cannot be virtualized. This negates a common scenario where it might make sense to use physical hardware for a front-end pool, yet virtualize a less intensive role such as a Director. The opposite case is perfectly valid. Organizations can virtualize the front-end pool, but use physical hardware for a Director or Edge Server.