UE keeps on sending Registration Request after successful Registration Complete

Q/A
#1

Hi All,

I am trying to attach a Real UE on free5gc via GNB. Once Registration procedure is completed, UE keeps on sending new Register Request (Type: mobility registration updating). In Mobility Registration Request, UE is setting “NG-RAN-RCU” to 1.

AMF is sending Registration Accept (after sending release command for old NGAP-UE-ID) and getting Registration Complete. Then again it is receiving Register Request.

I am attaching the packet capture for the same.

Has anyone seen this issue? Re-Reg-From-UE.pcap (12.3 KB)

#2

Hi,
Can you provide more UE related settings, please?
and the logs of the core network, it seems that the problem is not visible from the pcap.
Also if you are using cellphone as UE you need to set the value of imsVoPS in free5gc/config/amfcfg.ymal to 1.

#3

Hi @tim1207

Enabling imsVoPS flag has helped. Thanks.

Now I see the UE is Registered and PDU session is established.

But now, I see the signal loss on UE after 1 min or so. This is happening after I get Release Request from GNB with cause “release-due-to-ngran-generated-reason”.

I am checking this with GNB vendor. Please let me know if you know the root cause for this UE behavior.

On the phone I see,

Screen Shot 2024-08-09 at 17.23.49
Screen Shot 2024-08-09 at 17.23.49764×1232 139 KB

#6

Hi @tim1207

Th problem is not solved.

The phone model is : Pixel7a (Model:G0DZQ)
GnodeB: Mosolabs 5G Model: SCE5164

#7

Hi @tim1207

Th problem is not solved.

The phone model is : Pixel7a (Model:G0DZQ)
GnodeB: Mosolabs 5G Model: SCE5164

#5

Hey,@aleemgsl
Please let me know if you solve the problem.
I think this problem should be caused by GNB.
Additionally, could you please provide the models of your UE and RAN?

#8

@aleemgsl
Could you please ask the RAN vendor to have a look. If they analyze and point out that it is our problem (core network), we will help you deal with it.