[ETSI TS 128 552 V16.9.0](https://www.etsi.org/deliver/etsi_ts/128500_128599/128552/16.09.00_60/ts_128552v160900p.pdf):
Registration type label is not provided.
A nonstandard PLMNID label is added to achieve uniqueness.
- 5.3.1.3 Number of PDU sessions requested to be created by the SMF
PLMNID and SNSSAI are defined during PDU session creation processing.
Some requests can be rejected during processing before label values are known.
Those requests are not counted under particular labels.
To count also such requests, the basic metric with empty labels is exposed too.
```
fivegs_smffunction_sm_pdusessioncreationreq{plmnid="",snssai=""} 1
fivegs_smffunction_sm_pdusessioncreationreq{plmnid="00101",snssai="1000009"} 1
```
- 5.3.1.4 Number of PDU sessions successfully created by the SMF
```
fivegs_smffunction_sm_pdusessioncreationsucc{plmnid="00101",snssai="1000009"} 1
```
- 5.3.1.5 Number of PDU sessions failed to be created by the SMF
```
fivegs_smffunction_sm_pdusessioncreationfail{cause="400"} 1
```
Example for one successful and one failed (during creation processing) PDU session creation:
```
fivegs_smffunction_sm_pdusessioncreationreq{plmnid="",snssai=""} 2
fivegs_smffunction_sm_pdusessioncreationreq{plmnid="00101",snssai="1000009"} 1
fivegs_smffunction_sm_pdusessioncreationsucc{plmnid="00101",snssai="1000009"} 1
fivegs_smffunction_sm_pdusessioncreationfail{cause="400"} 1
```
According to the following standards the response to the endpoint
/nudm-sdm/${supi}/sm-data should be an array of
SessionManagementSubscriptionData objects, instead of only one object.
TS 29.503 version 16.6.0
TS 29.505 version 16.4.0
UDR now responds to the request with only item in the array.
UDM copies all items as is.
SMF uses only the first item in the array, even if there are more
present.