When UE would send a request to release PDU session, AMF would
eventually send "PDU Session Resource Release Command" downlink to both
UE (N1) and gNB (N2). Each UE and gNB would then reply with "PDU Session
Resource Release Response" indicating they released their own resources.
Usually the first one to respond would be gNB. SMF made an assumption
that this would always be the case. And it would wait for signal that UE
resources were freed, before releasing session resources. But
occasionally the situation is that UE responds first, and SMF releases
resources prematurely.
This situation does not normally occur. But under high stress (100's of
UE PDU releases at the same time) this happens occasionally.
According to the standard, this situation is perfectly normal.
3GPP TS 23.502 Rel. 16
4.3.4.2 UE or network requested PDU Session Release for Non-Roaming and
Roaming with Local Breakout
...
Steps 8-10 may happen before steps 6-7.
...
* Introduce Cancel Location and Insert Subscriber Data features to HSS.
* HSS database will keep track of last known MME and Update Time
* Purged UE flag is established in HSS for future PUR handling
* HSS Thread will connect to database and watch change stream
mongoDB must be configured with a Replica Set to use this
* HSS will send IDR if subscription data changes
* HSS will send CLR to old MME if MME host or realm changes
* Function created to allow ULA and IDR to generate Subscription-Data AVP
* MME Hostname and Realm shown in WebUI
* Resolve freeDiameter errors
During a ULR, if database does not contain a last known MME, a CLR is being sent to a Null destination. This will ensure that a destination is available in the database before sending the CLR.
* Removed change streams. Added PUR handling.
* newline needed at end of file.
* Removed temp variable.
* * Change WebUI to 2x2 display
* Including UE Purged indicator
* Using pointers in ogs_subscription_data_t
* better memory mangement with pointers
* Tweak to Destination used by hss_s6a_send_idr to use last known MME
* Check for null mme_host and mme_realms
Do this before trying to compare the strings.
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.
* npcf-smpolicycontrol - enabled or disabled
* npcf-policyauthorization - enabled or disabled
Only one of npcf-smpolicycontrol and npcf-policyauthorization cannot be enabled. (../src/pcf/sbi-path.c:151)
They can be enabled or disabled together.
OpenAPI specification for sending NF discovery query with
"service-names" parameter is defined as folowing:
- name: service-names
...
style: form
explode: false
According to OpenAPI specification, this means array items
should be delimited with a comma character (example: /users?id=3,4,5).
== 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.
- Gy instead of Gx AVP was used.
- Use correct avp position and avp variables.
Fixes: 657eef9169 ("[SMF] send 3GPP-Charging-Characteristics on Gx if received on S5/8c")
The 3GPP-Charging-Characteristics is an operator specific AVP
(optional). The 3GPP-Charging-Characteristics can be filled by the HSS
and forwarded by the MME towards the SMF.
The 3GPP-Charging-Characteristics is an operator specific AVP
(optional). The 3GPP-Charging-Characteristics can be filled by the HSS
and pass through to the Gx interface.
See ETSI 29.212 5.4.0.1 for further details.
* Add Diameter Dictionary Elements
* Initial IDR Framework
* Resolve Compile Issues
* Moving Closer
* Compile error
* Somewhat Working stuffing Code
* Add Timestamp Changes
* Cleanup some of this code. mme_s6a_handle_idr in s6a-handler.c removed for now, since it will only come in handy when IDR flag is set to request current location, which would involve breaking out into paging. I think there's a few other things we can do just within fd-path first.
* further removal of mme_s6a_handle_idr
In case that SMF was configured to run without Diameter, it would crash
on application exit due to uninitialized variables/pointers.
ERROR pid:unnamed in fd_sess_handler_destroy@sessions.c:324: ERROR: Invalid parameter '(handler && ( ((*handler) != ((void *)0)) && ( ((struct session_handler *)(*handler))->eyec == 0x53554AD1) ))', 22
[smf] FATAL: smf_gx_final: Assertion `ret == 0' failed. (../src/smf/gx-path.c:1353)
The problem occurred in the following scenario:
1. VLR sent PAGING-REQUEST to the MME
2. MME sent S1-Paging to the UE
3. Paging failed
4. MME responded SERVICE-REQUEST to the VLR
5. VLR sent DOWNLINK-UNITDATA to the MME
6. Even though there is no S1 Context,
MME try to sent DownlinkNASTransport message to the UE.
7. So, the problem occurred.
I've changed the number 4 PAGING-REJECT instead of SERVICE-REQUEST.
* CLR while idle is broken after 7031856cd7
Cancel Location Request arriving while UE is idle will not proceed to paging due to this check for S1 connection. Using new flag "isAnswer" to bypass this check to allow paging to occur when we are not doing a AIA/ULA related procedure.
* No Context Setup is required when sending the detach request. If the paging was due to wanting to send a Detach Request to the UE, then we fast track to sending the detach request.
* emm-sm.c:
In the case of MME initiated detach while UE is idle, there is no initial conext setup. We go right from the service request after paging into sending the detach request. TS23.401
mme-path.c:
Using nas_eps.type in the case of MME Initiated Detach while UE is idle does not work. nas_eps.type would represent the service request.
mme-s11-handler.c:
After S11 action, no action should be taken. We want to wait for the detach accept from the UE before proceeding with the S1 release (detach).
* InitialContextSetup should occur for detach.
Sukchan Lee
neg2led
Bostjan Meglic
jmasterfunk84
Bostjan Meglic
EugeneBogush
mitmitmitm
Alexander Couzens