Implement Registration of UE’s with the Core Network

Step 1: Initialize the Service-Based Architecture (SBA) Dashboard

1. Open the SBA Simulator Dashboard

Launch the SBA Simulator Dashboard. This is the main interface for visualizing and managing all 5G Core Network Functions (NFs).

2. Verify Dashboard Initialization

Once the dashboard loads, verify the following:

NF List Panel – Displays all available NFs (left or top section).
Configuration Panel – Allows configuring each NF upon selection (right side).
Logs Section – Displays real-time NF logs (bottom section).
Command Terminal – Available per NF for debugging commands such as ping.

Ensure:

The UI is responsive.
No errors appear during initialization.

Fig: Service-Based Architecture (SBA) Dashboard

Step 2: Deploy Core Network Using Terminal

This method allows you to deploy all Network Functions and gNB services using Docker Compose from the terminal.

Step 2.1: Launch the Core Network

Click on the Terminal button to open the terminal, then from the project root directory, execute:

docker compose -f docker-compose.yml up -d

Executes Docker Compose to deploy core 5G network components (AMF, SMF, UPF, NRF, and others) in detached mode. Detached mode runs containers in the background, releasing the terminal session.

Fig: Core Network Deployment

Fig: Core Network Deployed

Step 2.2: Launch the gNB Services

Once the core network is up and running, deploy the gNB services:

docker compose -f docker-compose-gnb.yml up -d

Deploys the gNB (next-generation NodeB), the 5G radio access point. Upon startup, the gNB automatically registers with the core network, establishing connectivity for UE traffic.

Fig: gNB Deployment and Core Integration

Fig: gNB Deployed and Core Integrated

Step 2.3: Monitor Container Status

To continuously monitor the status of the core network containers, use:

watch docker compose -f docker-compose.yml ps -a

Provides a continuously refreshing view of core network container status. The -a flag displays all containers, including stopped ones. Used for monitoring stabilization and detecting unexpected exits.

Fig: Live container status monitoring with watch command

Step 2.4: Verify Network and IP Assignment (Optional)

To verify the Docker network and IP assignments:

docker network inspect oaiworkshop

Fig: Docker network inspection showing container IP assignments

It shows you the full details of the oaiworkshop Docker network — which containers are connected, what IP addresses they've been assigned, and how the network is configured. If you ever need to verify that a specific NF got the right IP or that all containers are on the same network, this is the command to run.

Step 2.6: Stop All Services

When you're done with testing or need to reset the environment:

docker compose -f docker-compose.yml down

Fig: Stopping all services and removing containers with docker compose down

This command stops and removes all containers, networks, and associated resources.

Step 3: Configure and Start Network Functions (NFs)

After deployment, configure individual Network Functions from the dashboard to establish proper service operation.

Step 3.1: Select an NF to Configure

From the NF List on the dashboard, click on the NF you want to deploy.

Examples include:

AMF (Access and Mobility Management Function)
SMF (Session Management Function)
UPF (User Plane Function)
NRF (Network Repository Function)
AUSF (Authentication Server Function)
UDM (Unified Data Management)
PCF (Policy Control Function)

Clicking an NF opens its Configuration Panel on the right.

Fig: Select NF and Open Configuration Panel

Step 3.2: Enter NF Configuration Details

In the configuration panel, enter the required fields:

IP Address:

Provide a valid IPv4 address (e.g., 192.168.1.10)
This is the address the NF will bind to for service communication

Port Number:

Set the port on which the NF will run (e.g., 8080, 9090, etc.)
Each NF should have a unique port to avoid conflicts

Protocol:

Select either HTTP/1 or HTTP/2 depending on the NF behavior
Some NFs may auto-select based on internal configuration

Parameter	Example	Description
IP Address	192.168.1.10	IPv4 address for NF binding
Port Number	8080	Service listening port
Protocol	HTTP/2	Communication protocol

Step 3.3: Start the NF

Click the Start NF button. The NF will begin starting up.

Step 3.4: Wait for NF Stabilization

Once initiated:

The NF takes around 4–5 seconds to stabilize
During this time, it registers itself and establishes basic service readiness
The NF attempts to connect to other available NFs
Once stabilized, it becomes fully operational

Fig: NF Stabilizing Process

Step 3.5: Verify NF Startup Logs

Scroll down to the Logs Section:

Successful startup messages include:

"NF started successfully" – Process/container started without errors
"Service registration complete" – NF registered with NRF
"NF ready to accept connections" – NF is live and operational

Example log output:

[AMF] 2024-01-15 10:32:45 - NF started successfully
          [AMF] 2024-01-15 10:32:47 - Connecting to NRF at 192.168.1.11:8000
          [AMF] 2024-01-15 10:32:48 - Service registration complete
          [AMF] 2024-01-15 10:32:49 - NF ready to accept connections

This indicates the function is live and communicating (if any peer NFs are up).

Step 3.6: Repeat for All Remaining NFs

Follow the same steps (3.1–3.5) for each NF in the 5G Core:

NRF (Network Repository Function) – Deploy first
UDM (Unified Data Management) – Deploy second
AUSF (Authentication Server Function) – Deploy third
SMF (Session Management Function) – Deploy fourth
UPF (User Plane Function) – Deploy fifth
AMF (Access and Mobility Management Function) – Deploy sixth
PCF (Policy Control Function) – Deploy last (optional)

For each NF, ensure:

Starts correctly without errors
Stabilizes within 4–5 seconds
Appears in the logs as active
Shows successful service registration

Once all NFs are deployed, configured, and stabilized, your 5G core setup becomes fully active and interconnected, ready for gNB and UE attachment.

Fig: All NF deployed

Step 4: Start the gNB (Radio Access Node)

Once the core network is stabilized, configure and start the gNB (base station).

Step 4.1: Select and Configure the gNB

From the NF List Panel on the dashboard:

Locate and click on the gNB tile
The gNB Configuration Panel appears on the right
Enter the following configuration details:

Parameter	Example	Description
IP Address	192.168.1.21	IPv4 address for gNB binding
Port Number	8089	SCTP/UDP listening port (GTP-U port)
PLMN ID	20801	Public Land Mobile Network ID
gNB ID	1	Unique base station identifier

Fig: Configure & Start gNB

Step 4.2: Click Start gNB

Click the Start gNB button to launch the radio access node.

Step 4.3: Wait for gNB Stabilization

Within 5 seconds, the gNB will become stable. During this initialization:

The gNB starts up and initializes radio resources
SCTP association is established with the core network
Internal service readiness checks are performed
The gNB becomes available for UE connections

Fig: gNB deployed & Stablized

Step 4.4: Verify gNB Connections

The gNB will establish the following connections:

1. NGAP Connection with AMF (N2 Interface)

Protocol: SCTP (Stream Control Transmission Protocol)
Purpose: Access and Mobility Management
Expected log: "NGAP association established with AMF"

2. GTP-U Tunnel with UPF (N3 Interface)

Protocol: GTP-U (GPRS Tunneling Protocol – User Plane)
Purpose: User data forwarding
Expected log: "GTP-U tunnel created with UPF at 192.168.1.13:2152"

3. Service Registration with NRF

All gNB services are registered in the Network Repository
Expected log: "gNB registered successfully in NRF"

Step 4.5: Verify gNB Logs

Scroll to the Logs Section and confirm these messages:

[gNB] 2024-01-15 10:35:00 - gNB started successfully
          [gNB] 2024-01-15 10:35:02 - Initializing radio resources
          [gNB] 2024-01-15 10:35:03 - SCTP association with core network established
          [gNB] 2024-01-15 10:35:04 - NGAP association established with AMF
          [gNB] 2024-01-15 10:35:05 - GTP-U tunnel created with UPF
          [gNB] 2024-01-15 10:35:05 - gNB ready to accept UE connections

All messages indicate successful gNB startup and core integration.

Step 5: UE Configuration and Registration

Once the gNB is up and connected to the core network, you can configure and register User Equipment (UE).

Step 5.1: Configure the UE

From the dashboard, select the UE tile and enter the following in the UE Configuration Panel:

Parameter	Example Value	Description
IMSI	001010000000101	15-digit subscriber identifier
Key (K)	fec86ba6eb707ed08905757b1bb44b8f	128-bit authentication key
OPc	C42449363BBAD02B66D16BC975D77CC1	Operator variant key
DNN	5G-Lab	Data Network Name
NSSAI SST	1	Slice Type (1=eMBB, 2=URLLC, 3=MIoT)

Fig: UE Configuration Panel

Step 5.2: Match Subscriber Profile

Ensure the UE configuration matches the profile stored in the UDR (Unified Data Repository).

This ensures successful authentication during the registration process.

Step 5.3: Start the UE

Click Start UE.

Within approximately 5 seconds, the UE:

Stabilizes
Sends registration messages to the core network
Initiates authentication with the core

Step 5.4: UE-to-Core Connection Sequence

The following sequence occurs after starting the UE:

N1 Connection Established – UE ↔ AMF connectivity established
NAS Signaling Activated – Non-Access Stratum messages exchanged
Authentication and Security Handshake Completed – UE is authenticated
PDU Session Established – Data path created from UE through UPF
IP Address Assignment – UE receives IP address on tun_0 (e.g., 192.168.100.2)

Fig: UE Registration and NAS Signaling

Step 6: Validate Connectivity

Once the UE is registered and assigned an IP address, validate end-to-end connectivity through the 5G network.

Step 6.1: Test Network Path Using Ping

From the UE terminal, test basic network connectivity:

ping -I oaitun_ue1 8.8.8.8 -c4

Expected result:

Reply messages received from the destination
0% packet loss indicating stable connectivity

Example successful ping output:

PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
          64 bytes from 8.8.8.8: icmp_seq=1 ttl=119 time=25.3 ms
          64 bytes from 8.8.8.8: icmp_seq=2 ttl=119 time=24.8 ms
          64 bytes from 8.8.8.8: icmp_seq=3 ttl=119 time=25.1 ms
          --- 8.8.8.8 statistics ---
          3 packets transmitted, 3 received, 0% packet loss, time 6ms

Fig: Successful Ping Test Through 5G Core

Example IP Mappings in Your Environment:

192.168.1.11 – AMF (Access and Mobility Management Function)
192.168.1.13 – UPF (User Plane Function)
192.168.1.16 – External Data Network (External DN)

Step 6.2: Measure Throughput Using iPerf

Step 6.2.1: Start iPerf Server on External Data Network

Click on ext-dn-1, open its terminal, and run the following command to start the iPerf server:

iperf3 -s

Fig: Starting iPerf Server on ext-dn-1

Step 6.2.2: Run iPerf Client from UE

To measure the throughput between the UE and external data network, use iPerf3:

Click on UE, open its terminal, and run the following command:

Throughput Test:

iperf3 -B <tun_ue_ip> -c <ext-dn_ip>

Replace:

<UE_ip> with the UE's assigned IP (e.g., 10.0.0.3)
<ext-dn_ip> with the external data network IP (e.g., 192.168.1.15)

Example:

iperf3 -B 10.0.0.3 -c 192.168.1.15

Expected output shows:

Transfer amount – Data transferred in MB/GB
Bandwidth – Throughput in Mbps or Gbps
Jitter – Variation in packet timing (lower is better)

Fig: Throughput Measurement with iPerf

Step 6.3: Measure Round-Trip Time (RTT) Using iPerf

To measure RTT (latency) in the reverse direction:

RTT Test:

iperf3 -B <tun_ue_ip> -c <ext-dn_ip> -R

The -R flag reverses the test direction, measuring reverse throughput and RTT.

Example:

iperf3 -B 10.0.0.3 -c 192.168.1.15 -R

This measures the latency and throughput from the external network back to the UE through the 5G core network.

Fig: RTT Measurement with iPerf

Step 6.4: Verify Connectivity Success Criteria

Your 5G Core Network simulation is functioning correctly if:

All NFs Start Successfully – No errors during core network startup
gNB Connects to AMF and UPF – Base station registered with core network
UE Registers Successfully – User equipment attached to the network
UE Receives an IP Address – IP assigned on the TUN interface
Ping Shows 0% Packet Loss – Network path is stable
iPerf Shows Measurable Throughput – Data transmission is functional

If all criteria are met, your 5G network is ready for further testing and validation.