A friend in the community was trying to connect an SMF made by another
manufacturer with an SBI interface and found a big problem with Open5GS.
All of the code in the part that generates the Resource URI
from HTTP.location is invalid.
For example, suppose we create a Resource URI with SMContext as below.
{apiRoot}/nsmf-pdusession/<apiVersion>/sm-contexts/{smContextRef}
In this case, Open5GS extracted the {smContextRef} part of the HTTP.location
and appended it to the beginning
{apiRoot}/nsmf-pdusession/<apiVersion>/sm-contexts/.
This implementation may not work properly if the apiRoot changes.
Consider a different port number as shown below.
<HTTP.location>
127.0.0.4:9999/nsmf-pdusession/v1/sm-contexts/1
The SMF may send an apiRoot to the AMF with a changed port number,
in which case the AMF must honor it.
Therefore, instead of extracting only the smContextRef from HTTP.location,
we modified it to use the whole thing to create a Resource URI.
We modified all NFs that use HTTP.location in the same way, not just SMFs.
- have a more consistent naming among the NF's
- always have the same prefix (amf_/smf_/pcf_) depending on the NF
- function name is always the same, how the function calculates the load
is NF specific and internal to the function itself (but not the function
name).
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 metrics with labels according to ETSI TS 128 552 V16.13.0 in
PCF 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.
AM policy:
fivegs_pcffunction_pa_policyamassoreq and
fivegs_pcffunction_pa_policyamassosucc do not expose snssai label
since it is not available at the time of exposure.
plmnid is defined during AM policy processing, so not to lose the
difference to ...succ, the basic metric
fivegs_pcffunction_pa_policyamassoreq is preserved.
SM policy:
snssai is defined during SM policy processing, so not to lose the
difference to ...succ, the basic metric
fivegs_pcffunction_pa_policysmassoreq is preserved.
Those 2 basic metrics retain their position but are exposed with empty
labels.
Metrics with labels are called later, when the label values are known.
Exposed metrics example:
-standard counters:
fivegs_pcffunction_pa_policyamassoreq{plmnid=""} 3
fivegs_pcffunction_pa_policyamassoreq{plmnid="99970"} 3
fivegs_pcffunction_pa_policyamassosucc{plmnid="99970"} 3
fivegs_pcffunction_pa_policysmassoreq{plmnid="",snssai=""} 3
fivegs_pcffunction_pa_policysmassoreq{plmnid="99970",snssai="1000009"} 3
fivegs_pcffunction_pa_policysmassosucc{plmnid="99970",snssai="1000009"} 3
-nonstandard gauge (added for controlling purposes -
same metric as existing metric on AMF and SMF):
fivegs_pcffunction_pa_sessionnbr{plmnid="99970",snssai="1000009"} 0
Sukchan Lee
Bostjan Meglic
mitmitmitm
Gaber Stare
Daniele