Start free-ran-ue

Caution

Do not start the UE on the same machine as free5GC, as this will cause data plane forwarding failures.

There are two options for deployment:

Use two separate machine.
Use namespace separation. For details, please refer to Quick Start.

A. Prerequisites

Golang:

free-ran-ue is built, tested and run with go1.24.5 linux/amd64

If Golang is not installed on your system, please execute the following commands:

Install Golang:

wget https://dl.google.com/go/go1.24.5.linux-amd64.tar.gz
sudo tar -C /usr/local -zxvf go1.24.5.linux-amd64.tar.gz
mkdir -p ~/go/{bin,pkg,src}
# The following assume that your shell is bash:
echo 'export GOPATH=$HOME/go' >> ~/.bashrc
echo 'export GOROOT=/usr/local/go' >> ~/.bashrc
echo 'export PATH=$PATH:$GOPATH/bin:$GOROOT/bin' >> ~/.bashrc
echo 'export GO111MODULE=auto' >> ~/.bashrc
source ~/.bashrc

Check Installation. You should see the version information:
```
go version
```

If another version of Golang is installed, please execute the following commands to replace it:

sudo rm -rf /usr/local/go
wget https://dl.google.com/go/go1.24.5.linux-amd64.tar.gz
sudo tar -C /usr/local -zxvf go1.24.5.linux-amd64.tar.gz
source $HOME/.bashrc
go version

B. Clone and Build free-ran-ue

Clone

git clone https://github.com/Alonza0314/free-ran-ue.git

Build
```
cd free-rna-ue
make
```
After building, a binary executable file will be generated in the build folder.

C. Start gNB

Modify the configuration file for gNB:

The configuration YAML file template is located at free-ran-ue/config/gnb.yaml.

Ensure that the information matches your core network settings. For core network settings, please refer to: Start free5GC
Start gNB:

After configuring the YAML file, execute the binary in the build folder to start gNB with the specified configuration file:
```
./build/free-ran-ue gnb -c config/gnb.yaml
```

D. Start UE

Modify the configuration file for UE:

The configuration YAML file template is located at free-ran-ue/config/ue.yaml.

Ensure that the information matches your web console settings, especially the authenticationSubscription section. For web console settings, please refer to: Create Subscriber via Webconsole

Pay attention to the ueTunnelDevice field, as this will be the name of the network interface created later.
Start UE:

After configuring the YAML file,execute the binary in the build folder to start UE with the specified configuration file:
```
./build/free-ran-ue ue -c config/ue.yaml
```

E. ICMP Test

After UE has started, a network interface will be available. Use ifconfig to check it:

ifconfig

Expected output included:

ueTun0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1500
        inet 10.60.0.1  netmask 255.255.255.255  destination 10.60.0.1
        inet6 fe80::b1e9:2933:3c64:b981  prefixlen 64  scopeid 0x20<link>
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 500  (UNSPEC)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 3  bytes 144 (144.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

ICMP test with ueTun0:

ping -I uetun0 8.8.8.8 -c 5

Expected successful output:

PING 8.8.8.8 (8.8.8.8) from 10.60.0.1 ueTun0: 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=116 time=3.99 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=116 time=3.90 ms
64 bytes from 8.8.8.8: icmp_seq=3 ttl=116 time=3.84 ms
64 bytes from 8.8.8.8: icmp_seq=4 ttl=116 time=4.07 ms
64 bytes from 8.8.8.8: icmp_seq=5 ttl=116 time=3.62 ms

--- 8.8.8.8 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4007ms
rtt min/avg/max/mdev = 3.618/3.881/4.067/0.152 ms

Now, both gNB and UE are running seccussfully.