[AMF] Implicit Network-initiated Deregistration
Two timers are introduced (both with duration of T3512 + 4 min):
-MOBILE_REACHABLE
-IMPLICIT_DEREGISTRATION
MOBILE_REACHABLE is set when NAS connection for the UE is released.
IMPLICIT_DEREGISTRATION is set when MOBILE_REACHABLE expires.
On MOBILE_REACHABLE expiry Paging is ignored.
On IMPLICIT_DEREGISTRATION expiry:
-UE's RM_State is set to DEREGISTERED
-UE is Nudm_SDM_Unsubscribed
-UE is Nudm_UECM_Deregistered
-PDU sessions are released
-AM policies are deleted
Existing flag amf_ue->network_initiated_de_reg is used.
Two timers are introduced (both with duration of T3512 + 4 min):
-MOBILE_REACHABLE
-IMPLICIT_DEREGISTRATION
MOBILE_REACHABLE is set when NAS connection for the UE is released.
IMPLICIT_DEREGISTRATION is set when MOBILE_REACHABLE expires.
On MOBILE_REACHABLE expiry Paging is ignored.
On IMPLICIT_DEREGISTRATION expiry:
-UE's RM_State is set to DEREGISTERED
-UE is Nudm_SDM_Unsubscribed
-UE is Nudm_UECM_Deregistered
-PDU sessions are released
-AM policies are deleted
Existing flag amf_ue->network_initiated_de_reg is used.
o Generate the private key as below.
$ openssl genpkey -algorithm X25519 -out /etc/open5gs/hnet/curve25519-1.key
$ openssl ecparam -name prime256v1 -genkey -conv_form compressed -out /etc/open5gs/hnet/secp256r1-2.key
o The private and public keys can be viewed with the command.
The public key is used when creating the SIM.
$ openssl pkey -in /etc/open5gs/hnet/curve25519-1.key -text
$ openssl ec -in /etc/open5gs/hnet/secp256r1-2.key -conv_form compressed -text
In ausf/udm.yaml
hnet:
o Home network public key identifier(PKI) value : 1
Protection scheme identifier : ECIES scheme profile A
- id: 1
scheme: 1
key: /etc/open5gs/hnet/curve25519-1.key
o Home network public key identifier(PKI) value : 2
Protection scheme identifier : ECIES scheme profile B
- id: 2
scheme: 2
key: /etc/open5gs/hnet/secp256r1-2.key
o Home network public key identifier(PKI) value : 3
Protection scheme identifier : ECIES scheme profile A
- id: 3
scheme: 1
key: /etc/open5gs/hnet/curve25519-1.key
o Home network public key identifier(PKI) value : 4
Protection scheme identifier : ECIES scheme profile B
- id: 4
scheme: 2
key: /etc/open5gs/hnet/secp256r1-2.key
Related to #1779
The current load percentage of the NF Service Consumer is provided
in the payload body of the PATCH request when periodically
contacting the NRF (heart-beat).
AMF: ratio between currently connected ran_ue and maximum number of them
SMF: ratio between current PDU sessions and maximum available
PCF: ratio between current AM+SM policy associations and maximum available
or ratio between currently connected UEs and maximum number of them
(the load which is higher)
AUSF, UDM: ratio between currently connected UE and maximum number of them
BSF: ratio between current sessions and maximum available
NSSF: ratio between currently used NSIs and maximum number of them
NRF currently doesn't determine that the NF Profile has changed.
Expose RM metrics with labels according to ETSI TS 128 552 V16.13.0 in
AMF by using hash.
The metrics are named respecting the rule:
<generation>_<measurement_object_class>_<measurement_family_name>_<metric_name_as_in_TS_128_552>
Since slice itself is not unique, the plmnid label is exposed in
addition to snssai.
RegInitFail is exposed as an alternative to RegInitReq and RegInitSucc
counters so cause label can be provided. It counts rejected registrations
and rejected authentications.
Rejected authentications are counted under label cause="0".
Exposed metrics example:
-standard gauge:
fivegs_amffunction_rm_registeredsubnbr{plmnid="00101",snssai="1000009"} 1
-nonstandard counter:
fivegs_amffunction_rm_reginitfail{cause="3"} 4
Even if the configured log level for the application was set to "error",
the first "info" message of the metrics library was output to the log.
Reorder the initialization of the metrics library.
AMF does not crash anymore when a new UE registration request arrives,
and there is no available space left in UE context pool. Now it just
rejects the request with an error.
Each UE context has 'current' and 'next' TMSI values. AMF first
allocates the 'next' value, before confirming it and releasing the
'previous'. This means that we potentially need pool size of 2x the
amount of maximum configured UE.
Without this change, AMF would crash in case that there are 'x'
configured maximum amount of UE, and there are already 'x' registered
UE.
[gmm] INFO: Registration request (../src/amf/gmm-sm.c:135)
[gmm] INFO: [suci-0-001-01-1234-0-1-1000000000] SUCI (../src/amf/gmm-handler.c:149)
[gmm] DEBUG: OLD TSC[UE:0,AMF:0] KSI[UE:7,AMF:0] (../src/amf/gmm-handler.c:179)
[gmm] DEBUG: NEW TSC[UE:0,AMF:0] KSI[UE:7,AMF:0] (../src/amf/gmm-handler.c:186)
[amf] FATAL: amf_m_tmsi_alloc: Assertion `m_tmsi' failed. (../src/amf/context.c:2160)
[core] FATAL: backtrace() returned 13 addresses (../lib/core/ogs-abort.c:37)
AMF subscribes to UDM for each registered UE.
At the moment, UDM does not send callback to AMF when any of the UE's
properties in the database changes.
At the moment, AMF does properly parse the ModificationNotification, but
does not do anything useful.
Without this change, using metrics with core setup configurations
(configs/vonr.yaml for example) would not be possible. Having one
metrics section for whole config file causes every NF to start metrics
server on same port causing an abort.
In case that APN name sent from UE does not case-match with the one
configured in the database, AMF would reject the registration with the
message:
[gmm] WARNING: [imsi-xxx] DNN Not Supported OR Not Subscribed in the
Slice (../src/amf/gmm-handler.c:1051)
Add additional check when receiving Deregistration Notification from
UDM. UE should already be in registered state before accepting the
request and deregistering the UE.
Also add additional check that PCF association policy exists before
sending a delete request to PCF.
== Known limitation ==
Placing npcf-smpolicycontrol and pcf-policyauthorization
in different NFs is not supported. Both npcf-smpolicycontrol
and pcf-policyauthorization should be placed in the same NF.
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.
TS24.501
8.2.11 DL NAS transport
8.2.11.4 5GMM cause
The AMF shall include this IE when the Payload container IE
contains an uplink payload which was not forwarded and
the Payload container type IE is not set to "Multiple payloads".
-0-
As such, this function 'nas_5gs_send_gsm_reject()' must be used
only when an N1 SM message has been forwarded to the SMF.
Confirmation for non-cleartext IE should only be applied
to the initial NAS message. Registration requests and Service requests
with UplinkNASTransport do not have to.
All process will be forcely exited if it failed to encode the S1AP/NGAP/GTP/PFCP message. It is to make sure there was no problem with the encoding of open5gs.
1. DownlinkNASTransport
If AMF has not sent it previously, UE-AMBR is included in Registration
accept.
2. InitialContextSetupRequest
If PDUSessionResourceSetup is available, UE-AMBR is included
3. PDUSessionResourceSetupRequest
If AMF has not sent it previously, UE-AMBR is included
4. HandoverRequest
If PDUSessionResourceSetup is available, UE-AMBR is included
1. If UE does not use a NAS container for Non-cleartext IEs,
Open5GS AMF will send Registration reject message.
2. If UE sends Non-cleartext IEs without Integrity-protected,
Open5GS AMF will send Registration reject message.
3. If UE does not send NAS container in Security mode complete message,
Open5GS AMF will send Registration reject message.
The AMF shall assign a new 5G-GUTI for a particular UE:
a) during a successful initial registration procedure;
b) during a successful registration procedure
for mobility registration update; and
c) after a successful service request procedure invoked as a response
to a paging request from the network and before the release
of the N1 NAS signalling connection as specified in subclause 5.4.4.1.
The AMF should assign a new 5G-GUTI for a particular UE
during a successful registration procedure
for periodic registration update. The AMF may assign a new 5G-GUTI
at any time for a particular UE by performing
the generic UE configuration update procedure.
1. UE sends PDU session establishment request to the AMF.
2. AMF initiates Release Due to Duplicate Session ID.
3. SMF cannot find the session by SM-Context-Ref.
For the above condition, AMF sends NGAP ErrorIndication to the UE.
If parameter.ignore_requsted_nssai is true,
AMF will ignore the UE Requested NSSAI and create an allowed-NSSAI
based on the Default S-NSSAI in the Subscription DB.
AMF checks whether it can serve all the S-NSSAI(s) from
the Requested NSSAI present in the Subscribed S-NSSAIs
(potentially using configuration for mapping S-NSSAI values
between HPLMN and Serving PLMN), or all the S-NSSAI(s) marked
as default in the Subscribed S-NSSAIs in the case that
no Requested NSSAI was provided or none of the S-NSSAIs
in the Requested NSSAI are permitted,
i.e. do not match any of the Subscribed S-NSSAIs or not available
at the current UE's Tracking Area (see clause 5.15.3).
If both Delete-Session-Request/Response and
UEContextReleaseCommand/UEContextReleaseComplete are failed at the same time,
UE cannot attach to the EPC infinitely.
So, I've add the protection code
if timer expires when MME does not receive Delete-Session-Response.
Sukchan Lee
ridzafauzi
Gaber Stare
mitmitmitm
Miguel Borges de Freitas
Lester
Bostjan Meglic
Bostjan Meglic
Carlos Giraldo
endika
Pau Espin
Kenny Barlee