This question always comes up during the ADS. The problem is there isn't a magic bullet. Each customer will have a different user model that will dictate scale for their environment. The product team on development of OCS looked at core customer data to determine sizes of web conferences. Most conferences are quite small (4-6 participants). In fact in mining data from Live Meeting we found that over 80% of meetings had 20 or fewer participants. Beyond that we found that 99% of all meetings had under 100 participants. So that being said we looked at a model with 250 participants. This is not hard-coded and meetings can be more. In order to test and have a user model we used 250 users. How did we determine this? We too the total number of users (50,000) and multiply that by concurrency rate (5%). That gives us the total number of users we expect at any given time. This was 2500 users. If we have two Conferencing servers this 1250 users per server. One scenario we did with this was to use 6 participants per meetings and we could scale 610 meetings per server.
You will probably hear that 250 is the limit. It isn't. If I have a conference with 250 users and I add one more to the conference all is fine. The limitations of conferencing are your CPU and memory. When we tested we used dual proc/dual core systems with 4 gigs of memory.
You can have large amounts of web conferences in your OCS architecture and it can be scaled well beyond our tested architecture. Other limits to be aware of are things like IT resources. If you have large 1000 participant meetings do you have a helpdesk to support these request. So there is a lot more than just looking at server scale for this...
Take care till next time.
What about anonymous users, is the same limitation? I mean with one internal user how many anonymous users I am able to invite?
Thanks in advance.