5G RAN Operators

Description

5G Ran Emulator is implemented as microk8s applications using Juju Charms and Microk8s Contains charm folder consisting of 2 k8s charm applications

• ue_app: ue pod is required for running User Equipment(UE) applications
• ran: Radio Access Network(RAN) generates gNodeB and UE

Usage

Prepare environment

A. Install Microk8s

a. Install Microk8s using the following commands,

sudo snap install microk8s --classic --channel 1.19/stable
sudo usermod -a -G microk8s `whoami`
newgrp microk8s
microk8s.status --wait-ready

The ouput "microk8s is running" signifies that Microk8s is successfully installed.

b. Enable the following required addons for Microk8s to deploy 5G Ran

microk8s.enable storage dns
microk8s.enable multus
microk8s.enable rbac
microk8s.enable metallb

NOTE: 5G RAN requires 2 loadbalancer IP addresses mandatorily. So allocate 2 IP addresses while enabling metallb.

B. Install Juju

a. Install Juju with the following commands,

sudo snap install juju --classic --channel 2.8/stable
juju bootstrap microk8s

Deploy

To deploy 5G RAN Emulator from Charmstore, follow the steps below,

a. Deploy ran applications

juju add-model ran
juju deploy cs:~tataelxsi-charmers/ran-5g

b. Configuring interface

For the deployment to get completed successfully, update master_interface field to your server's main interface name with the following command,

juju config ran master_interface="<interface_name>"

where interface_name stands for server's main interface name where ran is deployed

Deploy from local repository

To deploy 5G Ran from local repository, follow the steps below,

a. Clone the 5g-ran repository

git clone https://github.com/charmed-osm/5g-ran
cd 5g-ran/

b. Enable Microk8s registry for storing images

microk8s.enable registry

c. Build and push 5G Ran images to registry

./build_docker_images.sh
docker push localhost:32000/ran:1.0
docker push localhost:32000/ue:1.0

d. Execute the following script to build all the 5G Ran charms using Charmcraft,

./build_charms.sh

e. Create a model in Juju and deploy 5G Ran,

juju add-model ran
juju deploy ./bundle_local.yaml

f. Configuring interface

For the deployment to get completed successfully, update master_interface field to your server's main interface name with the following command,

juju config ran master_interface="<interface_name>"

where interface_name stands for server's main interface name where ran is deployed

Integration

5G Ran exposes its following services in order to facilitate control plane and data plane interactions with CORE,

• TCP Service - For Control Plane User Registration and Attach Scenario.
• UDP Service - For Data Transfer scneario

In order to achieve this, 5G Ran needs 2 Loadbalancer services to be exposed and published. This is done using,

microk8s.enable metallb

Juju Actions:

Note: Make sure 5G-Core(https://github.com/charmed-osm/5g-core) is deployed and 5G-core actions are done before performing the following actions in 5G-RAN,

a. Action "config-gnb" is used to configure the gNB with the operator specific parameters such as PLMN, Tracking area code, Global gNB Id, and the core interfacing parameters such as AMF IP, UPF IP etc.,

juju run-action ran/0 config-gnb amf-ip='<AMF_LB_IP>' upf-ip='<UPF_LB_IP>' --wait

where unit_id is the Unit number of the respective unit, AMF_LB_IP and UPF_LB_IP are the respective loadbalancer IP addresses of 5G-Core's AMF and UPF applications.

b. Action "connect-amf" is used to initiate a SCTP connection with the AMF. On a result of this action the core and RAN negotiate the parameters and NGAP connection is established between RAN and Core.,

juju run-action ran/0 connect-amf --wait

where unit_id is the Unit number of the respective unit,

c. Action "config-ue" which will be used to set UE’s context in RAN,

juju run-action ran/0 config-ue ue-mgmt-ip='<UE_eth0_IP>' ue-pdu-macaddress='<UE_eth1_mac>' --wait

where unit_id is the Unit number of the respective unit, UE_eth0_IP is the IP address of UE application's eth0 interface and UE_eth1_mac is the mac address of UE application's eth1 interface.

Check for the status of the action in the output which should be "completed".

Actions Verification:

"config-gnb", "connect-amf" and "config-ue" actions can be verified in RAN application pod in /var/log/free5gc.log file. The IP addresses of Core set, the SCTP connection successful message and the UE application's IP and MAC address set can be verified in this log file.

5G Scenarios

5G User Registration

After 5G-Core(https://github.com/charmed-osm/5g-core) and 5G-RAN are deployed and actions are completed, the user registration can be triggered through the following rest API call with POST method,

http://ran-loadbalancerip:8081/attachtrigger/1

Sample response for successful attach, Response Message: "Triggered Attach for the requested UE!" Response Code: 200 OK

Internet Traffic Flow

Once registration is successful, 5G-RAN's UE application would be enabled to access the data network. Test the following in UE application,

a. ICMP TRAFFIC

ping 8.8.8.8

b. TCP TRAFFIC

wget google.com

c. UDP TRAFFIC

nc -u <netcat server-ip> port

where netcat server-ip is the IP address of the server where netcat server is running. Note: for UDP traffic netcat server should be running in another server. To do that use the following commands in another server.

apt-get install netcat
nc -u -l -p <any unused port>

Voice Traffic Flow

Voice traffic flow can be tested once 5G-Core(https://github.com/charmed-osm/5g-core), 5G-RAN and 5G-IMS(https://github.com/charmed-osm/5g-ims) are deployed and actions are completed. To test voice traffic flows, a SIP client called PJSIP is already installed in the UE application. Follow the below steps,

a. Traverse to /pjproject directory in the UE pod.

b. alice.cfg is configured for an user named alice which is already available in IMS by default.

Note: The username, password and id can be changed to any user added from day-2 action of IMS as well.

c. Add the following content to /etc/hosts file,

<PCSCF_LB_IP> mnc001.mcc001.3gppnetwork.org <PCSCF-LB_IP> pcscf.mnc001.mcc001.3gppnetwork.org

Where <PCSCF-LB_IP> is the loadbalancer IP of PCSCF application and mnc001.mcc001.3gppnetwork.org is the domain added in coredns of IMS cluster.

d. Execute the following command to register the user alice with IMS,

pjsua --config-file alice.cfg --log-level=3

Note: Peform the above steps to register another user say bob with IMS so that SIP calls can be tested between the two users.

e. After registration of both users, press ‘m’ from UE application's alice and then press enter to initiate a SIP call.

f. Give bob’s id and then press enter. The message “Calling” can be observed in alice’s UE pod.

g. Then in bob’s server, the following message can be seen,

Press ‘a’ to answer or ‘h’ to hangup

h. Press a and then enter. Then the following message will be displayed,

Answer with code:

i. Type 200 and enter.

j. After this “Confirmed” message can be seen in both alice and bob indicating that the call between alice and bob is successful and that RTP packets are being sent between alice and bob. The same can be verified by capturing SIP packets using ngrep, tcpdump or wireshark.

k. Then to end/hangup the call, press h and then enter from alice. Verify the “Disconnected” message in both alice and bob.

Testing

Run Integration and Unit tests to test and verify the 5G Ran Charms.

Integration tests

Functional tests for 5G Ran were created using zaza.

Install tox

apt-get install tox

To run zaza integration test,

tox -e func_test

This command will create a model, deploy the charms, run tests and destroy the model.

Unit tests

Unit tests has to be executed in all the 5G Ran components/charms. The following commands show how to perform unit test in RAN,

cd charms/ran-operator
./run_tests

Similarly, unit tests can be run for all the other components/charms.

Get in touch

Found a bug?: https://github.com/charmed-osm/5g-ran/issues Email: [email protected]