What is parameter for total number of user sessions for entire SAP system

Is there a profile parameter that limits total number of SAP user connections to that system. Im not talking about rdsip/max_alt_modes that limits number of sessions for particular user but a parameter that limits user connections to total number of users logging into particular system. I heard tht there is parameter that has default value 90, i want to change it but dont know whats the paramter name..plzz help me in this regard to proceed further.

Thank you