Capacity and sizing planning

The capacity planning process can help you consider a number of factors before you can install. You need to know whether you are installing a small-scale deployment or an enterprise-scale deployment, number of concurrent users in chat, meetings, audio and video, and whether users reside in different geographies, and the size of contact lists. In the case of an enterprise-scale deployment, you must also decide if you will be using clustered servers to distribute the load or multiple separate servers that function independently. The size of your deployment affects installation choices. For expert help, contact your IBM® account representative who can connect you with the IBM Techline Capacity Planning Process.

Plan your deployment to meet the following requirements:
  • Must meet the supported performance and concurrency numbers developed in capacity planning
  • Easily expandable and scalable to a larger population
  • Easily expandable to support all offerings: Sametime® Communicate, Sametime Conference, IBM Sametime Unified Telephony
  • Easily expandable to integrate with IBM Connections, IBM WebSphere® Portal, Microsoft Office
  • Easy to operate and manage
To begin sizing your Sametime deployment, understand that social business is changing the way people think about business. You need to know and plan for your users:
  • How many will use the Desktop (UIM) client?
  • How many will use the Sametime Mobile?
  • How many will use the embedded Sametime client in IBM Notes®?
  • How many will use their own iOS or Android mobile device?
  • Is your deployment exclusively internal and mobile, or will you have to include external customers and vendors?

Remember the 97/3 rule for chat versus meetings. This rule is useful for sizing and scoping servers. Of those people who could be logged into chat, 97% will be at any given time logged in to presence and chat. Of those who could be participating in meetings, 3% will be at any given time.

As a general rule, the number of concurrent users is 30,000 chat and awareness connections per IBM Sametime Community Server. But if you enable file transfer among chat clients, you will have more traffic going through your Sametime Community Server. Your Sametime Community Server may also be doing antivirus checking of file transfers so this may change this number.

Meeting servers can handle hundreds of concurrent meetings per server, including chat in meetings, audio and video in meetings, and document sharing. Most people planning a deployment will add servers for high availability rather than meeting capacity because of 3% rule. You can have thousands of concurrent meeting participants per server .

What computer resources, CPU, and RAM do you need? Consult the system requirements for recommended hardware and software. Contact your IBM Account representative to work with IBM Techline who can provide detailed analysis of your hardware and RAM needs.

Sametime Community Server capacity

A Sametime Community Server installed on its own computer can handle 30,000 connections. However, if you install a MUX server on a separate computer in front of the Sametime Community Server, your Sametime Community Server can handle 100,000 active connections. The server capacity numbers are approximations and meant to provide a rough estimate of the possible load-handling improvement if you deploy Community Server multiplexers on separate computers. The actual server capacity is affected by variables such as the average number of users in the contact lists of all Sametime clients and the number of instant messages that users send.

For concurrency details for all other Sametime servers, contact your IBM account representative who can connect you with the IBM Techline Capacity Planning Process.