Maximum number of users in multi-user mode?

There is no limit for simultaneous (different) users on our multi-user server. The multi-user server is not handling the traffic simultaneously; it handles all of the traffic in a queue and processes the information based on queuing order. If there are many users, the traffic may slow down, but there's no limitation for concurrent users as long as they are different users.
Same user can be logged into a multi-user model a maximum of nine times.