Lync designing & planning is intricate part and right decision can help organization to get better ROI. This article may help Solution Architects, Consultants and System Administrator to choose best Lync server/pool model. Number of Lync servers in a pool, collocated or distributed model of Lync roles typically depends on No. of Lync users, their activities and different geo locations.
|Lync 2013 Server Pools||Number of Servers||Supported No. of End users||Remarks|
|Lync 2013 Front End pool (Collocated with A/V conferencing, Mediation Server, A/M server)||12||80,000||Max. Conferences size is limited to 250 users, Media Bypass is required to support all users with condition of 60 % users are enable for EV and only 40% calls are UC-PSTN calls.|
|Lync 2013 Front End Pool (A/V only)||2||Large conferences b/w 250 – 1000 users|
|Lync 2013 Mediation Pool||12||80,000||100% users are enabled for EV and 80% calls are UC-PSTN calls. 12 servers are required if Media by pass in not enable/supported for deployed EV connectivity. No. of servers will reduce based on Media bypass configuration according to the %.|
|Lync 2013 Persistent Chat||8 (4 active & 4 Passive)||80,000||1, 50,000 users can be enabled for pChat and 80,000 users can use concurrent. Only pChat pool can be stretched b/w sites to achieve DR. For more details check Lync 2013 HA|
|Lync 2013 Edge Server||4 – 8||80,000||Depends on how many users will access Lync services simultaneously, 3-4 servers for 30-40% & 7-8 servers for 100%|
|Lync Director (optional)||3 – 8||80,000||Depends on remote users, 3 servers for 30% remote users and 8 servers for 100% remote users.|
|SQL Server||2*||80,000||*2 for each backend databases|
Important: Above data has provided for physical servers, minor change can happen if you use virtualization as per MS guidelines. It does not take any accountability of DR plan/scenarios. If you are planning for DR also, please account overhead of DR users if available.