This setting has two numbers:
Number of connections in keep-alive mode
Maximum number of connections allowed in keep-alive mode simultaneously
You can tune the maximum number of sessions that the server allows to wait at one time before closing the oldest connection by:
Setting or changing the MaxKeepAliveConnections value in the Magnus Editor of the Server Manager
The number of connections specified by MaxKeepAliveConnections is divided equally among the keep-alive threads. If MaxKeeepAliveConnections is not equally divisible by KeepAliveThreads, the server may allow slightly more than MaxKeepAliveConnections simultaneous keep-alive connections.