/gnbsim

gnbsim is a 5G SA gNB/UE simulator for testing 5G System.

Primary LanguageGoMIT LicenseMIT

gnbsim

gnbsim is a 5G SA gNB/UE (Rel. 16) simulator for testing 5G System. The project is aimed to understand 5GC more efficiently than just reading 3GPP standard documents.

Getting Started

Prerequisites

  • Golang environment on a Linux server to run gnbsim.

    • The project is tested on Raspbian GNU/Linux 10 (buster)

  • free5gc is running somewhere.

    • free5gc/free5gc v3.0.5 is used for testing the project.
    • Tested subscriber(s) have been provisioned by the free5gc web console.
    • change the free5gc configurations.

      • free5gc/config/amfcfg.conf

        ngapIpList:
  - 192.168.1.17        # external IP address for N2 address.
  # - 127.0.0.1

      • free5gc/config/smfcfg.conf

        interfaces:
  - interfaceType:
    endpoints:
      - 192.168.1.18 # external IP address for GTP-U (N3) address.
      # - 127.0.0.8

      • free5gc/src/upf/build/config/upfcfg.yaml

        gtpu:
  - addr: 192.168.1.18  # external IP address for GTP-U (N3) address.
  # - addr: 127.0.0.8

Installing and testing

  • Download the related files.

    $ git clone https://github.com/hhorai/gnbsim.git
$ cd gnbsim

  • Build the example binary.

    $ make test		# (optional) unit test for each libary.
$ make

  • Edit the configuration file (example.json).

    • SUPI(IMSI) is formed by mcc + mnc + msin. (e.g. 208930123456789)
    • NGAPPeerAddr indicates the IP address for N2 used by the AMF side.
    • GTPuIFname indicates the interface name for GTP-U used by gnbsim.
    • GTPuLocalAddr indicates the IP address for GTP-U used by gnbsim.
    • url indicates the destined URL for testing U-plane directly accessed by UEs.
    • wiki page might be helpful to understand the environment.
    $ cd example
$ vi example.json

  • Run gnbsim

    • root privilege is required to set an IP address which is dynamically assigned by the SMF.
    $ sudo ./example
    • Then you can find the following line in the debug message. In this case, your configuration for OPc and K are both correct.
    ***** Integrity check passed
    • And you could also find your UEs in 'subscriber' page in the free5gc web console.