icm/max_conn 

This parameter determines the maximum number of (simultaneous) open connections in the ICM or in the SAP Web dispatcher.
The parameter value can be greater than icm/max_threads, as inactive connections require no thread in the ICM.

Value Range	Unit	Default value
10 - 32000	integer	500

Dependencies

The maximum number of sockets that one process can open is restricted by the parameter icm/max_sockets and ultimately by the operating system. This also restricts the value of icm/max_conn.

Each open ICM connection needs at least one socket. The SAP Web Dispatcher needs two sockets for one connection.