The per UE idle-timeout value can be provided in RADIUS access-accept or COA for a DSM UE in standard Idle-Timeout attribute. The minimum idle-timeout allowed is 150 seconds. The idle-timeout is enforced on the ISA for a DSM UE. If there is no data to/from a UE for up to idle-timeout value, the UE is removed and accounting-stop is sent. Subsequently, if a UE re-associates and connects to an open SSID on an AP, and has an IP address with a valid lease, then the first data packet from the UE triggers authentication. Successful authentication results in creation of DSM UE.
To improve idle-timeout behavior an optional SHCV check can be performed after the idle-timeout expires. This check verifies connectivity to all DHCP, DHCPv6 and /128 SLAAC addresses using ARP or NDP. While the check is performed for every address, the result is applied to the whole UE. The UE is only deleted when verification of all addresses fails. When at least one connectivity verification succeeds the UE and all of the allocated addresses are kept and the idle-timeout process is restarted.
The per UE session timeout value can be provided in RADIUS access-accept or COA in standard Session-Timeout attribute. The value is interpreted as an absolute value, and the UE is unconditionally deleted regardless of activity. The minimum allowed value for session-timeout is 300 seconds.