Connection TimeOut!!!

Hello: RH 9.0, freeRADIUS 1.4 I have been using freeRADIUS for the last 10 Months. Works great. I like to setup a maximum connection time of 120 minutes for each user. I am a complete newbie. Can somebody direct me to the file I need to set the timeout time? I also need to know the exact command, if possible. Thanks in Advance. Kirt