Regardless what I set my exec-timeout to be, my telnet session

times out after 4 to 5 minutes.  This is the config now.

line vty 0 4
exec-timeout 60 0
privilege level 15
password 7 15140A00077A27743A
transport input telnet

I also presently have service tcp-keepalives-in running.

How can I change my inactivity timer to something longer than 4 to 5 minutes.  Thanks.