7.8 IM CN subsystem timers
24.2293GPPIP multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP)Release 18Stage 3TS
Table 7.8.1 shows recommended values for timers specific to the IM CN subsystem.
Table 7.8.1: IM CN subsystem
|
Timer |
Value to be applied at the UE |
Value to be applied at the P-CSCF |
Value to be applied at the S-CSCF |
Meaning |
|
reg-await-auth |
not applicable |
not applicable |
4 minutes |
The timer is used by the S-CSCF during the authentication procedure of the UE for registration. For detailed usage of the timer see subclause 5.4.1.2. The authentication procedure may take in the worst case as long as 2 times Timer F. The IM CN subsystem value for Timer F is 128 seconds. |
|
request-await-auth |
not applicable |
not applicable |
4 minutes |
The timer is used by the S-CSCF during the authentication procedure of the UE for requests different than REGISTER. For detailed usage of the timer see subclause 5.4.3.6.1. The authentication procedure may take in the worst case as long as 2 times Timer F. The IM CN subsystem value for Timer F is 128 seconds. |
|
emerg-reg |
Configurable value between 8 seconds and 20 seconds |
not applicable |
not applicable |
The timer is used by the UE to supervise the time from deciding that an emergency service is to be established via the IM CN subsystem until completion of the emergency registration procedure, including any required IP-CAN procedures. For detailed usage of the timer see subclause 5.1.6.1. |
|
emerg-request |
Configurable value between 5 seconds and 15 seconds |
not applicable |
not applicable |
The timer is used by the UE during initial request for emergency service. For detailed usage of the timer see subclause 5.1.6.8.1. |
|
NoVoPS-dereg |
Configurable value between 0 seconds and 65535 seconds |
not applicable |
not applicable |
The timer is used by the UE when the UE receives a VoPS not supported indication from the lower layers and indicates the time the UE needs to wait before the UE deregisters from IMS if the UE is configured with a policy to deregister, see subclause B.3.1.0a, L.3.1.0a, U.3.1.0a and W.3.1.0a |
|
emerg-non3gpp |
Configurable value between 5 seconds and 20 seconds |
not applicable |
not applicable |
The timer is used by the UE to supervise the time for searching usable 3GPP access to setup an emergency call before attempting the emergency call via non-3GPP access. For detailed usage of the timer see subclauses R.2.2.6.1 and W.2.2.6.1. |
NOTE: The UE and the P-CSCF use the value of the reg-await-auth timer to set the SIP level lifetime of the temporary set of security associations.