The Conferencing User Model
Topic Last Modified: 2012-10-22
A critical part of the Lync Server conferencing user model is meeting size. After collecting data from the multiple data points (as described in the previous section), we determined the following:
Most meetings are actually small collaborative meetings with an average of four to six participants
Approximately 80 percent of meetings have fewer than 20 participants.
99.98 percent of meetings have fewer than 100 participants.
In addition to meeting size, the conferencing user model also takes into account a variety of factors, such as:
- Concurrent meetings How many users are expected to be in meetings at the same time?
- Media mix What types of media are available and expected to be used by users in meetings?
- User types Are users internal users, remote users, federated users, or anonymous users?
- Meeting ramp up time How long does it take for all users of a meeting to join a meeting?
For details about the user model, see Lync Server 2013 User Models.
To determine the number of meetings and users to use for testing, we did the following:
Took the total number of users in an organization (for example, 80,000 users) and multiplied it by the meeting concurrency rate (for example, 5% of all users) to determine the total number of users expected to be in meetings at the same time (in this example, 4000 users).
Divided the total number of users by the number of Lync Server 2013, Front End Servers in the deployment (for example, 8 servers) to determine the estimated number of meeting participants per Front End Server (in this example, 500 users per Front End Server).
Divided the number of users per Front End Server by the average meeting size (for example, 4 users) to determine the estimated average number of meetings per Front End Server (in this example, 125 meetings per Front End Server).
To get the per media load on each Front End Server, we estimated the media mix. For example, assuming that 75% of the meetings require more than just audio support and 50% of those meetings require application sharing, an average of 47 meetings and 188 users connect concurrently to each Front End Server for application sharing.
Tested a variety of meeting sizes (based our user model of up to 250 users in a shared pool) to ensure server scalability.