UE-non3GPP

User Equipment for non-3GPP access via free5gc N3IWF V3.1.1

Recommended Environment

UE-non3GPP has been tested against the following environment:

• SO: Ubuntu 20.04 (LTS) x64
• Uname -r: 5.4.0-122-generic
• Memory: 1 GB
• Disk: 25 GB

Prerequisites

UE-non3GPP was built and tested with Go 1.14.4. You can check the Go version on your system with the following command:

go version

If another version of Go is installed, remove the existing version and install Go 1.14.4 with the following sequence of commands (assuming your current version of Go is in the default location):

sudo rm -rf /usr/local/go
wget https://dl.google.com/go/go1.14.4.linux-amd64.tar.gz
sudo tar -C /usr/local -zxvf go1.14.4.linux-amd64.tar.gz

However, if Go is not installed on your system you should run the following commands:

wget https://dl.google.com/go/go1.14.4.linux-amd64.tar.gz
sudo tar -C /usr/local -zxvf go1.14.4.linux-amd64.tar.gz
mkdir -p ~/go/{bin,pkg,src}
# The following commands 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

You can get more detailed information about installing golang from the official website of golang

Config UE-non3GPP

Clone the project with the following command:

git clone -b develop https://github.com/LABORA-INF-UFG/UE-non3GPP.git 

Open the conf/config.yaml file in your preferred text editor and change the configuration parameters as described in the following table:

Field Name	Description
authsubscription.permanentkeyvalue	This parameter must be set to the same value as the permanentKeyValue field of the subscriptionData.authenticationData.authenticationSubscription collection existing in the Free5GC MongoDB, which records the registration data of the UEs. In free5gc GUI (new subscriber) the attribute is represented by the K* field of the registration form.
authsubscription.opcvalue	This parameter must be set to the same value as the opcValue field of the subscriptionData.authenticationData.authenticationSubscription collection existing in the Free5GC MongoDB, which records the registration data of the UEs.
authsubscription.opvalue	This parameter must be set to the same value as the opValue field of the subscriptionData.authenticationData.authenticationSubscription collection existing in the Free5GC MongoDB, which records the registration data of the UEs. In free5gc GUI (new subscriber) the attribute is represented by the Operator Code Value* field of the registration form.
authsubscription.sequencenumber	This parameter must be set to the same value as the sequencenumber field of the subscriptionData.authenticationData.authenticationSubscription collection existing in the Free5GC MongoDB, which records the registration data of the UEs. In free5gc GUI (new subscriber) the attribute is represented by the SQN* field of the registration form. This field contains a hexadecimal value that is incremented in MongoDB by the N3IWF each time the same UE registers in the 5GC, therefore, for the correct functioning of UE-non3GPP, the hexadecimal value of the configuration parameter must be modified in order to be equivalent to the existing one in the mongoDB base.
msin	This parameter must be configured with the last N values of the ueId field of the subscriptionData.authenticationData.authenticationSubscription collection existing in Free5GC MongoDB, which records the registration data of the UEs. In the free5gc (new subscriber) GUI, the attribute is represented by the SUPI (IMSI)* field of the registration form. The value of the SUPI (IMSI)* field is made up of the mcc code (eg: 208), followed by the mnc code (eg: 93), followed by a numerical sequence that represents the value to be assigned to the msin parameter. For example, assuming that in the free5gc GUI (new subscriber) the SUPI (IMSI)* field has the value 208930000000001, then the value to assign to the parameter msin in UE-non3GPP config file is 0000000001
hplmn.mcc	This parameter makes up the first 3 digits of SUPI (IMSI)* field and represents the Mobile Country Code
hplmn.mnc	This parameter makes up digits 4 and 5 of SUPI (IMSI)* and represents the Mobile Network Code.
ranuengapid	TODO
amfuengapid	TODO
authenticationmanagementfield	TODO
localpublicipaddr	This parameter represents the IP address of the machine where UE-non3GPP is running. It will be used by N3IWF to maintain active communication
localpublicportudpconnection	This parameter represents the port that N3IWF will use to forward messages to UE-non3GPP
linkgre.name	This parameter will be used to create the network interface through which it will be possible to establish communication with the data network through the 5GC
ipsecinterfacename	This parameter will be used to create the network interface through which all control communication between N3IWF and UE-non3GPP will take place.
ipsecinterfacemark	This parameter represents an IPSec virtual interface tag (any value except 0, default value is 7 if not defined). It must be the same value assigned to the configuration file of the N3IWF to which UE-non3GPP will connect
snssai.sst	Single Network Slice Selection Assistance Information - Slice/Service Type (1 byte hex string, range: 0~F)
snssai.sd	Single Network Slice Selection Assistance Information - Slice Differentiator (3 bytes hex string, range: 000000~FFFFFF)
pdusessionid	TODO
dnnstring	TODO
n3iwfinfo.ikebindaddress	This parameter must be configured with the IP address of the N3IWF
n3iwfinfo.ikebindport	This parameter must be configured with the N3IWF IKE interface access port. Must contain the same value assigned to the N3IWF configuration file
n3iwfinfo.ipsecifaceprotocol	Protocol used in the communication process. UDP default value

Run UE-non3GPP

After adjusting all the configuration parameters, registering the UE in free5GC with the same parameters used in the configuration file and making sure that 5GC and N3IWF are running, execute the following command:

go run cmd/main.go ue

After execution, open another terminal on the same machine and check if a new network interface (eg gretun1) has been created.

Testing how UE-non3GPP works

To test the operation of UE-non3GPP run the command below:

ping -I gretun1 8.8.8.8

The above command triggers a connection (ping) to google. If everything is in perfect working order, the terminator must present a positive response to the request. This means that you can direct network traffic to the gretun1 interface and data network access via 5GC will perform satisfactorily.