When a UE that requests slices tries to connect and there are no slices configured, the reject message is:
5GMM cause = 0x7 (5GS Services not allowed)
however it should be:
5GMM cause = 0x3e (No network slices available)
All 5GMM cause value in reject message is reviewed in this commit
UDM may send a Deregistration Notification to AMF, to deregister
specific UE from the network - Network-Initiated Deregistration.
Deregistration procedure includes sending Deregistration Request to UE,
starting a timer T3522, releasing PDU sessions from SMF, releasing PCF
policies from PCF, and waiting for Deregistration Accept from UE.
Not yet implemented is:
- to prevent deregistration of UE in case it has any emergency sessions,
- page UE when UE is in IDLE mode.
According to TS 23.502, 4.2.2.2.2, AMF sends Registration event to UDM
in the following cases:
- If the AMF has changed since the last Registration procedure, or
- if the UE provides a SUPI which doesn't refer to a valid context in
the AMF,
- or if the UE registers to the same AMF it has already registered
to a non- 3GPP access (i.e. the UE is registered over a non-3GPP access
and initiates this Registration procedure to add a 3GPP access).
In case that UE re-registers to the network with a GUTI, it bypasses
authentication check to the AUSF. In this case, AMF does not send
Registration event to UDM.
Consequently, when UE deregisters again, AMF would send a Deregistration
Event to a UDM, which does not have a context for it.
3GPP standard does not say when AMF sends Deregistration Event to UDM,
only that it is optional.
These (De-)Registration events are for (de-)registering AMF to the UDM
for serving the UE. And not for (de-)registering UE itself for purpose
of tracking when UE is registered on the network.
This partially reverts commit 7be7029ac4
* [SBI] Fix converting PatchItem to JSON
* [UDR] Add support for endpoint for patching subscription data
Add support for PATCH HTTP method for the following endpoint:
/subscription-data/{ueId}/context-data/amf-3gpp-access
Currently does not change any data in the database.
* [UDM] Add support for endpoint for patching subscription data
Add support for the following endpoint, HTTP PATCH method:
/nudm-uecm/v1/{ueId}/registrations/amf-3gpp-access
The endpoint is used when UE deregisters from the core, and AMF
sends a subscription modification request with "purgeFlag" set.
* [UDM] Add check for same GUAMI when patching subscription data
* [AMF] Send deregistration event to UDM
When UE sends deregistration request, AMF needs to send a
Nudm_UECM_Deregistration request to UDM.
The order of requests is now the following:
- send PDU session release to SMF
- send deregistration event to UDM
- send AM policy control release to PCF
For null protection scheme the SUCI needs to be BCD encoded. Whereas for
protection scheme profiles A and B the SUCI needs to be converted from
hexadecimal to ASCII.
This still needs the support for protection schemes A and B in UDM to
work.
1. UE registered and PDU established.
2. PCF does not receive Heartbeat.
- PCF De-registered state.
- Since PDU is established, SMF should not remove NF instance
3. PCF re-registered.
- HERE, WE NEED TO INCREASE NF REFERENCE COUNT.
Otherwise, NF instance will be removed if PCF is de-registered state
4. UE sends PDU release request.
5. Because SMF knows PCF NF instance, SMF can send PCF delete
3GPP TS 24.501 version 16.6.0 Release 16
4.4 NAS security
4.4.6 Protection of initial NAS signalling messages
1) the UE needs to send non-cleartext IEs in a REGISTRATION REQUEST
or SERVICE REQUEST message, the UE includes the entire REGISTRATION
REQUEST or SERVICE REQUEST message (i.e. containing both cleartext IEs
and non-cleartext IEs) in the NAS message container IE and shall cipher
the value part of the NAS message container IE. The UE shall then send
a REGISTRATION REQUEST or SERVICE REQUEST message containing
the cleartext IEs and the NAS message container IE;
During PDU Session Establishment,
if gNB sends PDUSessionResourceReleaseResponse,
AMF was crashed.
In this case, AMF/SMF remove Session Context and sends ErrorIndication.
An assert occurs when a NAS message retransmission occurs.
Because there is no `enb_ue` context.
Therefore, before removing enb_ue, all Timers must be stopped
to prevent retransmission of NAS messages.
Sukchan Lee
Bostjan Meglic
Bostjan Meglic
Carlos Giraldo
endika
Pau Espin