To clarify my first response, 2 things I was referring to are bit different. Global properties is to re-authenticate every so often and second one is disconnect after being idle for so long.
Andy
1 -> https://community.checkpoint.com/t5/Remote-Access-VPN/Increase-VPN-Re-authentication-Timeout/td-p/83...
2 ->
To configure tunnel idleness:
1. Connect to the Security Management Server with GuiDBedit.
2. Open the Global Properties > properties > firewall_properties object.
3. Find disconnect_on_idle and these parameters:
• do_not_check_idleness_on_icmp_packets
• do_not_check_idleness_on_these_services - Enter the port numbers for the services that you want to ignore when idleness is checked.
• enable_disconnect_on_idle - to enable the feature
• idle_timeout_in_minutes
4. Save and install the policy.