gNBSim Usage

Description

The gNBSim tool simulates gNodeB and UE by generating and processing NAS and NGAP messages for the configured UEs and call flows. The tool currently supports simulation profiles for the following procedures,

  • Registration

  • UE Initiated PDU Session Establishment

  • UE Initiated De-registration.

  • AN Release

  • Ue Initiated Service Request Procedure

  • NW triggered de-registration

  • UE Requested PDU Session Release

  • NW triggered PDU Session Release

It is also capable to generate and send user data packets (ICMP echo request) and process down-link user data (ICMP echo response) over the established data plane path (N3 Tunnel).

gNBSim Code References

Configure gNBSim

  • The sample config file for gNBSim can be found here

    Note: The configuration has following major fields (Read the comments in the config file for more details)

    • gnbs:

      List of gNB’s to be simulated. Each item in the list holds configuration specific to a gNB.

    • profiles:

      List of test/simulation profiles. Each item in the list holds configuration specific to a profile.

    • customProfiles:

      List of custom profiles. Each item in the list holds configuration specific to a customProfile.

  • Enable or disable a specific profile using the enable field within profile block.

    Note: Currently following profiles are supported

Run gNBSim

  • To quickly launch and test AiaB with 5G SD-CORE using gNBSim:

    $ make 5g-test

    (refer AiaB documentation Aether In a Box - 5G)

  • Alternatively, you can do following

    running:

    $ make 5g-core

  • Once all PODs are up then you can enter into the gNBSim pod by running

    $ kubectl exec -it gnbsim-0 -n omec bash

  • Then run following command to launch gNBSim profiles:

    $ ./gnbsim

    Note: By default, the gNB Sim reads the configuration from /gnbsim/config/gnb.conf file. To provide a different configuration file, use the below command

    $ ./gnbsim --cfg <config file path>

Build gNBSim

  • If you find a need to change gNBSim code and use the updated image in the AIAB setup then follow below steps.

  • To modify gNBSim and build a new docker image:

    $ git clone https://github.com/omec-project/gnbsim.git
$ cd gnbsim
$ make docker-build  #requires golang installed on the machine

  • To use newly created image in the AiaB cluster:

Update ~/aether-in-box/sd-core-5g-values.yaml to point to the newly built image, then run:

$ cd ~/aether-in-a-box/
$ make reset-5g-test

$ make 5g-test

(refer AiaB documentation Aether In a Box - 5G)

gNBSim System level features

  • Logging summary result

  • HTTP API to create new profile. Below configuration enables http server in gNBSim. Example to use gNBSim can be found script

    config:
  gnbsim:
    httpServer:
      enable: true #enable httpServer in gnbsim
      port: 6000

  • Gnbsim can generate and send user data packets (ICMP echo request) and process downlink user data (ICMP echo response) over the established data plane path (N3 Tunnel). Configure number of data packets to be sent. Configure AS (Application Server) address. This is used to send data packets.

    - profileType: nwtriggeruedereg # profile type
  profileName: profile6 # uniqely identifies a profile within application
  enable: false # Set true to execute the profile, false otherwise.
  gnbName: gnb1 # gNB to be used for this profile
  startImsi: 208930100007497 # First IMSI. Subsequent values will be used if ueCount is more than 1
  ueCount: 1 # Number of UEs for for which the profile will be executed
  defaultAs: "192.168.250.1" #default icmp pkt destination
  perUserTimeout: 10 #if no expected event received in this time then treat it as failure

  • Executing all enabled profiles in parallel or in sequential order.

    config:
  gnbsim:
    yamlCfgFiles:
      gnb.conf:
        configuration:
            execInParallel: false #run all profiles in parallel

Note

There is execInParallel option under each profile as well. execInParallel under profile means that all the subscribers in the profile are run in parallel

  • Timeout for each call flow within profile

    - profileType: nwtriggeruedereg # profile type
  profileName: profile6 # uniqely identifies a profile within application
  perUserTimeout: 10 #if no expected event received in this time then treat it as failure

  • Getting gNBSim golang profile

    config:
  gnbsim:
    goProfile:
      enable: true #enable/disable golang profile in gnbsim
      port: 5000

  • Run gNBSim with single Interface or multi interface

    config:
  gnbsim:
    yamlCfgFiles:
      gnb.conf:
        configuration:
            singleInterface: false #default false i.e. multiInterface. Works well for AIAB

  • Support of Custom Profiles: User can now define your own profile. New profile can be created by using existing baseline procedure. Example of custom profile can be found here. Check customProfiles in gNBSim config <https://github.com/omec-project/gnbsim/blob/main/config/gnbsim.yaml>_

    customProfiles:
  customProfiles1:
    profileType: custom # profile type
    profileName: custom1 # uniqely identifies a profile within application
    enable: false # Set true to execute the profile, false otherwise.
    execInParallel: false #run all subscribers in parallel
    stepTrigger: true #wait for trigger to move to next step
    gnbName: gnb1 # gNB to be used for this profile
    startImsi: 208930100007487
    ueCount: 5
    defaultAs: "192.168.250.1" #default icmp pkt destination
    opc: "981d464c7c52eb6e5036234984ad0bcf"
    key: "5122250214c33e723a5dd523fc145fc0"
    sequenceNumber: "16f3b3f70fc2"
    plmnId: # Public Land Mobile Network ID, <PLMN ID> = <MCC><MNC>
      mcc: 208 # Mobile Country Code (3 digits string, digit: 0~9)
      mnc: 93 # Mobile Network Code (2 or 3 digits string, digit: 0~9)
    startiteration: iteration1
    iterations:
      #at max 7 actions
      - "name": "iteration1"
        "1": "REGISTRATION-PROCEDURE 5"
        "2": "PDU-SESSION-ESTABLISHMENT-PROCEDURE 5"  #5 second delay after this procedure
        "3": "USER-DATA-PACKET-GENERATION-PROCEDURE 10"
        "next":  "iteration2"
      - "name": "iteration2"
        "1": "AN-RELEASE-PROCEDURE 100"
        "2": "UE-TRIGGERED-SERVICE-REQUEST-PROCEDURE 10"
        "repeat": 5
        "next":  "iteration3"
      - "name": "iteration3"
        "1": "UE-INITIATED-DEREGISTRATION-PROCEDURE 10"
        #"repeat": 0 #default value 0 . i.e execute once
        #"next":  "quit" #default value quit. i.e. no further iteration to run

  • Delay between Procedures can be added using customProfiles.