Topology Basics You Must Know Before Planning for Lync Server 2010

In preparation for the Exam 70-665: PRO: Microsoft Lync Server 2010, Administrator I found this article on TechNet useful: http://technet.microsoft.com/en-us/library/gg398552.aspx. It’ s about need to know basics and numbers when planning your Microsoft supported Lync design. Here is a summary with the numbers you must know before taking the Lync PRO Exam:

Site Types

  • Central Site
    • Contains at least one Front End Pool or Standard Edition Server
    • Is mandatory in a Lync Server Deployment
  • Branch Site
    • Is connected to exactly one Central Site and contain one of the following
    • A PSTN gateway and, optionally, a Mediation Server.
      • Designed for branch sites with between 1 and 25 users
    • Survivable Branch Appliance (SBA)
      • Is an industry-standard blade server with a Microsoft Lync Server 2010 Registrar and Mediation Server running on Windows Server 2008 R2
      • The SBA also contains a PSTN gateway
      • Designed for branch sites with between 25 and 1000 users
    • Survivable Branch Server (SBS)
      • Is a server running Windows Server that meets specified hardware requirements, and that has Lync Server 2010 Registrar and Mediation Server software installed on it
      • Does not contain a PSTN gateway
      • Designed for branch sites with between 1000 and 5000 users

Server Roles

  • Standard Edition Server
    • Uses local SQL Express database to host users
    • One Standard Edition server supports as many as 5,000 users
    • In virtual deployments this is reduced to about 2,500 users
    • Can be part of a backup pool topology
  • Front End Server and Back End Server
    • Front End pool is a set of Front End Servers, configured identically, that work together to provide services for a common group of users
      • One Front End pool in the deployment also runs the Central Management Server
      • The Central Management Server also provides Lync Server Management Shell and file transfer capabilities
    • Back End Servers do not run any Lync Server software
      • Can be a single SQL server, but its recommended to run a cluster of two or more
      • Information stored in the Back End Server databases includes
        • presence information
        • users’ Contacts lists
        • conferencing data including persistent data about the state of all current conferences
        • conference scheduling data
    • Front End Server scalability
      • One Front End Server for every 10,000 users homed in the pool
      • In virtual deployments this is reduced to about 5,000 users
      • The maximum number of users in one Front End pool is 80,000, if more than this, deploy an additional pool
  • A/V Conferencing Server
    • It can be collocated with Front End Server, or deployed separately as a single server or A/V Conferencing Server pool
    • One A/V Conferencing Server deployed as a single server for each 20,000 users at a site
  • EDGE Server
    • Server enables your users to communicate and collaborate with users outside the organization’s firewalls
    • Can be deployed with
      • One external IP
      • Three external IP’s
      • Can be behind NAT
      • But when in HA scenario, AV EDGE need to be directly routable
    • Deploy one Edge Server for every 15,000 users you expect to access a site remotely
    • In virtual deployments this is reduced to about 7,500 users
  • Mediation Server
    • Mediation Server translates signaling and, in some configurations, media between your internal Lync Server infrastructure and
      • Public switched telephone network (PSTN) gateway
      • IP-PBX
      • Session Initiation Protocol (SIP) trunk
    • Estimating Voice Usage and Traffic
      • For Light traffic (one PSTN call per user per hour) figure 15 users per port
      • For Medium traffic (2 PSTN calls per user per hour) figure 10 users per port
      • For Heavy traffic (3 or more PSTN per user calls per hour) figure 5 users per port
  • Monitoring Server
    • Monitoring Server collects data about the quality of your network media and collects call error records (CERs), which you can use to troubleshoot failed calls
    • can support up to 250,000 users if not collocated with Archiving Server
    • If collocated, it can support up to 100,000 users
  • Archiving Server
    • Enables you to archive IM communications and meeting content for compliance reasons
    • If you do not have legal compliance concerns, you do not need to deploy Archiving Server
    • Archiving Server can support up to 500,000 users if not collocated with Monitoring Server
    • If collocated, it can support up to 100,000 users
  • Director
    • Can authenticate Lync Server user requests, but do not home user accounts, or provide presence or conferencing services
    • Most useful in deployments that enable external user access, where the Director can authenticate requests before sending them on to internal servers
    • Directors can also improve performance in organizations with multiple Front End pools
    • Deploy one Director for every 15,000 users who will access a site remote
    • In virtual deployments this is reduced to about 7,500 users

One thought on “Topology Basics You Must Know Before Planning for Lync Server 2010

  1. You can only deploy SBS/SBA in a branch site, which means non-critical roles like monitoring/archiving etc. also needs a central site. This constraint cannot be easily seen in the definition of central and branch site.

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