configure in isp domain view:
domain xxxx
authorization-attribute
idle-cut 30 10240 ---30 mins , 10240 bytes
authorization-attribute
session-timeout 360----360 mins ,6 hours
idle-cut minutes: Specifies an idle timeout period in minutes. The value range for the minutes argument is 1 to 129600. This option is applicable only to portal, wireless LAN, and PPP users.
session-timeout minutes: Specifies the session timeout timer for users, in minutes. The value range for the minutes argument is 1 to 4294967295. The device logs off a user when the user's session timeout timer expires. This option is applicable only to portal and LAN users.