1. HandoverRequired
2. HandoverRequest
3. HandoverFailure
4. UEContextReleaseCommand
5. HandoverPreparationFailure
If UEContextReleaseComplete is not received,
the Source-UE will have the Target-UE.
6. HandoverRequired
There may be cases where the Source UE has a Target UE
from a previous HandoverRequired process. In this case,
it is recommended to force the deletion of the Target UE information
when receiving a new HandoverRequired.
7. HandoverRequest
8. HandoverFailure
9. UEContextReleaseCommand
10. UEContextReleaseComplete
11. HandoverPreparationFailure
... Crashed ...
While they were continuing their fuzzy testing and developing PacketRusher, an unusual issue with the AMF was observed. The problem arises when a single Ethernet frame containing three bundled SCTP chunks is sent. This behavior is reproduced with PacketRusher when attempting to concurrently register two UEs with the same MSIN.
The expected behavior is that the PDU Session Establishment Accept is sent inside a DownlinkNASTransport to RAN UE NGAP ID 1. However, it is actually sent inside an InitialContextSetupRequest to RAN UE NGAP ID 2. The MAC of this NAS message is invalid for the Security Context of RAN UE NGAP ID 2 (probably valid for RAN UE NGAP ID 1)
Based on the standard document below, when the UE is in the IDLE state,
we checked the implicit timer and tried to send a message to the UE,
but it doesn't work properly.
So, first of all, I deleted the related code.
- TS 24.301 Ch 5.3.7
If ISR is not activated, the network behaviour upon expiry of
the mobile reachable timer is network dependent, but typically
the network stops sending paging messages to the UE on the
first expiry, and may take other appropriate actions
- TS 24.501 Ch 5.3.7
The network behaviour upon expiry of the mobile reachable timer is network dependent,
but typically the network stops sending paging messages to the UE on the first expiry,
and may take other appropriate actions.
[ETSI TS 128 552 V16.9.0](https://www.etsi.org/deliver/etsi_ts/128500_128599/128552/16.09.00_60/ts_128552v160900p.pdf)
5.2.2 Registration procedure related measurements
SNSSAI labels are not provided.
- Number of registration requests received by the AMF is
exposed for each registration type.
```
fivegs_amffunction_rm_reginitreq 1
fivegs_amffunction_rm_regmobreq 0
fivegs_amffunction_rm_regperiodreq 0
fivegs_amffunction_rm_regemergreq 0
```
- Number of successful initial registrations at the AMF is
exposed for each registration type.
```
fivegs_amffunction_rm_reginitsucc 1
fivegs_amffunction_rm_regmobsucc 0
fivegs_amffunction_rm_regperiodsucc 0
fivegs_amffunction_rm_regemergsucc 0
```
- The existing counter of failed registrations at the AMF
is exposed separately for each registration type.
```
fivegs_amffunction_rm_reginitfail
fivegs_amffunction_rm_regmobfail
fivegs_amffunction_rm_regperiodfail
fivegs_amffunction_rm_regemergfail
```
5.2.5.2 Measurements for 5G paging
Number of 5G paging procedures initiated at the AMF:
```
fivegs_amffunction_mm_paging5greq 1
```
Number of successful 5G paging procedures initiated at the AMF:
```
fivegs_amffunction_mm_paging5gsucc 1
```
5.2.11 Authentication procedure related measurements
Number of authentication requests:
```
fivegs_amffunction_amf_authreq 2
```
Number of authentication rejections:
```
fivegs_amffunction_amf_authreject 1
```
Number of failed authentications due to parameter error:
```
fivegs_amffunction_amf_authfail{cause="21"} 1
```
5.2.8 UE Configuration Update procedure related measurements
Number of UE Configuration Update commands requested by the AMF:
```
fivegs_amffunction_mm_confupdate 2
```
Number of UE Configuration Update complete messages received by the AMF:
```
fivegs_amffunction_mm_confupdatesucc 1
```
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.
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
Most of the time, an application wants to perform some amount of data buffering
in addition to just responding to events. When we want to write data,
for example, the usual pattern runs something like:
1. Decide that we want to write some data to a connection;
put that data in a buffer.
2. Wait for the connection to become writable
3. Write as much of the data as we can
4. Remember how much we wrote, and if we still have more data to write,
wait for the connection to become writable again.
Now, Open5GS implements the above method by default when transmitting data
in a stream type socket.
- Set the number of UEs in units of AMF/MME instead of gNB/eNB.
- See default value as shown below
Number of UEs per AMF/MME : 4,096
Number of gNB/eNB per AMF/MME : 32
Sukchan Lee
Gaber Stare