session-timeout           : enable: specifies that the session-timeout attribute
of the APN is enabled. This parameter is optional.

disable: specifies that the
session-timeout attribute of the APN is disabled. This parameter is optional

timeout-length: specifies the
duration of the session-timeout attribute. This parameter is optional. It is an
integer ranging from 1 to 7200. The default value is 60. It is expressed in
minutes. This parameter is valid only when session-timeout is set to enable.