OpenAirInterface 5G Core Network Function Topology for Nephio

[[TOC]]

1. Introduction

This repository contains Kpt packages and package variants for OAI operators and network functions. Designed for Nephio release 2.

NOTICE

All the files are published under BSD 3-Clause License and the yaml definations provided by nephio.

Git repository for OAI Operators --> https://gitlab.eurecom.fr/development/oai-operators

Repository structure is below

.
├── database
├── docs
│   └── images
├── oai-amf
├── oai-ausf
├── oai-nrf
├── oai-nr-ue
│   └── nrue
├── oai-cp-operators
│   ├── crds
│   └── operator
├── oai-up-operators
│   ├── crds
│   └── operator
├── oai-repository
├── oai-rfsim-gnb
│   └── gnb
├── oai-smf
├── oai-udm
├── oai-udr
├── oai-upf-edge
├── package-variant
└── package-variant	Package variant for all nfs, database and operator

The package-variants are designed to deploy Nephio R2 deployment.

2. How to deploy the toplogy on Nephio

Step 0: Prerequisite

1. Make sure that you have a running core, core and edge cluster topology as defined in nephio exercise.

git clone https://github.com/OPENAIRINTERFACE/oai-packages.git
# IF NEEDED
git checkout <branch>
cd oai-packages

Step 1 (Optional): Adding oai-packages repository in nephio repo list

kpt live init oai-repository
kpt live apply oai-repository

The output is similar to:

installing inventory ResourceGroup CRD.
inventory update started
inventory update finished
apply phase started
repository.config.porch.kpt.dev/oai-packages apply successful
apply phase finished
reconcile phase started
repository.config.porch.kpt.dev/oai-packages reconcile pending
repository.config.porch.kpt.dev/oai-packages reconcile successful
reconcile phase finished
inventory update started
inventory update finished
apply result: 1 attempted, 1 successful, 0 skipped, 0 failed
reconcile result: 1 attempted, 1 successful, 0 skipped, 0 failed, 0 timed out

To verify the repository is on-boarded

kubectl get repositories | grep oai-packages

The output is similar to:

NAME                      TYPE   CONTENT   DEPLOYMENT   READY   ADDRESS
oai-packages              git    Package   false        True    https://github.com/OPENAIRINTERFACE/oai-packages

Step 2: Deploy core network functions package variant

Now start deploying the core network function package variant starting with database.

1. UDR requires that the database is running
2. All AMF, SMF, UDR, UDM, AUSF will wait for NRF container to be healthy

kubectl apply -f package-variant/database.yaml

The output is similar to:

packagevariantset.config.porch.kpt.dev/core-oai-database created

After couple of seconds you will see database pod in core cluster in oai-core namespace

kubectl get pods -n oai-core --context core-admin@core

The output is similar to:

NAME                     READY   STATUS    RESTARTS   AGE
mysql-5c6cb749bc-nsdsp   1/1     Running   0          47s

Step 2.1 Deploy operators on the core and edge cluster

kubectl apply -f package-variant/operators-cp.yaml
kubectl apply -f package-variant/operators-up.yaml

The output is similar to:

packagevariant.config.porch.kpt.dev/oai-cp-operators created
packagevariant.config.porch.kpt.dev/oai-up-operators created

After couple of mins oai-operator package will be in main branch of gitea Core and Edge repository. Core network control plane operators will be in Core cluster and user plane in Edge cluster.

kubectl get pods -n oai-cn-operators --context core-admin@core
kubectl get pods -n oai-cn-operators --context edge-admin@edge

The output is similar to:

## control plane
NAME                                   READY   STATUS    RESTARTS   AGE
oai-amf-controller-55dfbf8c4-9qdl4     1/1     Running   0          2m24s
oai-ausf-controller-769d64999f-28ntm   1/1     Running   0          2m24s
oai-nrf-controller-67f556bf75-8svd5    1/1     Running   0          2m24s
oai-smf-controller-5b6db9f5cb-klfsw    1/1     Running   0          2m24s
oai-udm-controller-867847d4cb-qdrzl    1/1     Running   0          2m24s
oai-udr-controller-764f4bfdb9-zw622    1/1     Running   0          2m24s
## user plane
NAME                                  READY   STATUS    RESTARTS   AGE
oai-upf-controller-75cbc869cb-zchjl   1/1     Running   0          11s

Step 2.3 Deploy Control Plane and User Plane Functions

Deploy control plane network functions AMF, SMF, NRF, UDR, UDM, AUSF

kubectl apply -f package-variant/nrf.yaml
kubectl apply -f package-variant/udm.yaml
kubectl apply -f package-variant/udr.yaml
kubectl apply -f package-variant/ausf.yaml
kubectl apply -f package-variant/amf.yaml
kubectl apply -f package-variant/smf.yaml
kubectl apply -f package-variant/upf-edge.yaml

In around 6-7 mins you will see all the control plane NFs in oai-core namespace in core cluster.

kubectl get pods -n oai-core --context core-admin@core

The output is similar to:

NAME                             READY   STATUS    RESTARTS      AGE
amf-core-5667d55644-nkthg    1/1     Running   0             85s
ausf-core-77867547bb-vl92j   1/1     Running   0             85s
mysql-5c6cb749bc-hn26d       1/1     Running   0             15m
nrf-core-7c79d988f5-lszwk    1/1     Running   0             85s
smf-core-5966dfd454-fc484    1/1     Running   0             82s
udm-core-56f78c9c7c-44556    1/1     Running   0             85s
udr-core-6f685c97db-2vrb7    1/1     Running   0             85s

In few mins you will see upf instances in oai-core namespace in edge cluster respectively.

kubectl get pods -n oai-core --context edge-admin@edge

The output is similar to:

NAME                          READY   STATUS    RESTARTS   AGE
upf-edge-696976df64-gwn42   1/1     Running   0          42m

Step 3: Check if the PFCP session between UPF and SMF is established

It is really important that the PFCP session is established between SMF and UPF. If there is no PFCP session then there is no point in moving forward. To check the session you have to read the logs of SMF or UPF.

kubectl logs -n oai-core <edge-upf-pod-name> --context edge-admin@edge | grep 'Received SX HEARTBEAT REQUEST' | wc -l

The output is similar to (any value more than one means that the session is established successfully):

26

In case you don't see a session the mostly probably it is a networking issue in the setup and UPF is not able to reach the SMF n4 ip-address. To check this we suggest that you go inside the SMF pod and install tcpdump and ping n4 ip-address of UPF.

To deploy the RAN network functions you can follow the steps from the Nephio documentation.

Contribution requests

In a general way, anybody who is willing can contribute on any part of the code in any network component.

Contributions can be simple bugfixes, advices and remarks on the design, architecture, coding/implementation.