[Issue] no periodic registration with open5gs

[deux9745]

Dear

I test ueransim with open5gs for periodic registration (t3512), even though t3512 is expired there is no periodic registration from ueransim, is it issue ?

from cli of ueransim, I can see timer is soon expired since I set the timer to 30 sec.

$ timers
T3346: .
T3396: .
T3444: .
T3445: .
T3502: .
T3510: .
T3511: .
T3512: rem[0] int[30]
T3516: .
T3517: .
T3519: .
T3520: .
T3521: .
T3525: .
T3540: .
T3584: .
T3585: .

However there is no action for periodic registration.

UERANSIM v3.2.6
[2022-07-13 16:00:14.419] [nas] [info] UE switches to state [MM-DEREGISTERED/PLMN-SEARCH]
UERANSIM v3.2.6
[2022-07-13 16:00:14.432] [sctp] [info] Trying to establish SCTP connection... (192.168.56.104:38412)
[2022-07-13 16:00:14.436] [sctp] [info] SCTP connection established (192.168.56.104:38412)
[2022-07-13 16:00:14.436] [sctp] [debug] SCTP association setup ascId[29]
[2022-07-13 16:00:14.436] [ngap] [debug] Sending NG Setup Request
[2022-07-13 16:00:14.438] [ngap] [debug] NG Setup Response received
[2022-07-13 16:00:14.438] [ngap] [info] NG Setup procedure is successful
[2022-07-13 16:00:15.421] [rrc] [debug] UE[1] new signal detected
[2022-07-13 16:00:15.421] [rrc] [debug] New signal detected for cell[1], total [1] cells in coverage
[2022-07-13 16:00:15.422] [nas] [info] Selected plmn[901/70]
[2022-07-13 16:00:15.422] [rrc] [info] Selected cell plmn[901/70] tac[1] category[SUITABLE]
[2022-07-13 16:00:15.422] [nas] [info] UE switches to state [MM-DEREGISTERED/PS]
[2022-07-13 16:00:15.422] [nas] [info] UE switches to state [MM-DEREGISTERED/NORMAL-SERVICE]
[2022-07-13 16:00:15.422] [nas] [debug] Initial registration required due to [MM-DEREG-NORMAL-SERVICE]
[2022-07-13 16:00:15.423] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2022-07-13 16:00:15.423] [nas] [debug] Sending Initial Registration
[2022-07-13 16:00:15.423] [nas] [info] UE switches to state [MM-REGISTER-INITIATED]
[2022-07-13 16:00:15.423] [rrc] [debug] Sending RRC Setup Request
[2022-07-13 16:00:15.423] [rrc] [info] RRC Setup for UE[1]
[2022-07-13 16:00:15.424] [rrc] [info] RRC connection established
[2022-07-13 16:00:15.424] [rrc] [info] UE switches to state [RRC-CONNECTED]
[2022-07-13 16:00:15.424] [nas] [info] UE switches to state [CM-CONNECTED]
[2022-07-13 16:00:15.424] [ngap] [debug] Initial NAS message received from UE[1]
[2022-07-13 16:00:15.455] [nas] [debug] Authentication Request received
[2022-07-13 16:00:15.469] [nas] [debug] Security Mode Command received
[2022-07-13 16:00:15.469] [nas] [debug] Selected integrity[2] ciphering[0]
[2022-07-13 16:00:15.509] [ngap] [debug] Initial Context Setup Request received
[2022-07-13 16:00:15.510] [nas] [debug] Registration accept received
[2022-07-13 16:00:15.510] [nas] [info] UE switches to state [MM-REGISTERED/NORMAL-SERVICE]
[2022-07-13 16:00:15.510] [nas] [debug] Sending Registration Complete
[2022-07-13 16:00:15.510] [nas] [info] Initial Registration is successful
[2022-07-13 16:00:15.510] [nas] [debug] Sending PDU Session Establishment Request
[2022-07-13 16:00:15.510] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2022-07-13 16:00:15.715] [nas] [debug] Configuration Update Command received
[2022-07-13 16:00:15.798] [nas] [debug] PDU Session Establishment Accept received
[2022-07-13 16:00:15.799] [ngap] [info] PDU session resource(s) setup for UE[1] count[1]
[2022-07-13 16:00:15.800] [nas] [info] PDU Session establishment is successful PSI[1]
[2022-07-13 16:00:15.825] [app] [info] Connection setup for PDU session[1] is successful, TUN interface[uesimtun0, 10.45.0.2] is up.

[madankumar9676]

If PDU session is active,UE won't initiate the Periodic registration.even though if t3512 timer expiry

[mrmohitrathod]

I have similar issue and I think open5gs is not supporting this feature yet.

After sending UE Context Release Complete, I have service request immediately with ngap.RRCEstablishmentCause: mps-PriorityAccess, all the time.

[gstaa]

Hi, @mrmohitrathod,

I face similar issue, but my cause is ngap.RRCEstablishmentCause: mo-Data.

I don't think this scenario is caused by an open5gs issue. AMF provides T3512 in Registration Accept and confirms UE Context Release. It is up to UERANSIM to send/not send Service request.

I have made some progress comparing to your scenario:

If I put UE in IDLE again (and again, if it sends Service request again...), than usually UE sends Registration update.

Reducing T3512 makes better chance to get Registration update.

Any luck with this?

[mrmohitrathod]

@gstaa thanks for the update. generally my inactivity timer was 5 minutes only and I was using the commercial UE with complete background removal for any data activity and also power save mode was on. I did tried it for more than 15 minutes and I wasn't able to see Registration update at all. I will try with the latest open5gs image and will share the latest results.

[gstaa]

Thanks, @mrmohitrathod.

But what open5gs feature, you think, is unsupported?

I use recent open5gs. I reduced T3512 to 4 s and even got Registration update without preceding Service request (4 s after UEContextReleaseComplete).
See attached trace in #725.
Packet no. 21 - registration with type: periodic registration updating.