Introduction

This repository is part of the SD-Core project. It provides a tool to simulate gNodeB and UE by generating NAS and NGAP messages for the configured UEs and call flows.

gNodeB Simulator Block Diagram

Reach out to us

1. Please refer to the official SD-Core documentation for more details.
2. #sdcore-dev channel in ONF Community Slack
3. Raise Github issues

Supported 3gpp procedures

1. UE Registration
2. UE Initiated PDU Session Establishment
3. UE Initiated De-registration 
4. AN Release
5. UE Initiated Service Request 
6. N/W triggered PDU Session Release
7. UE Requested PDU Session Release
8. N/W triggered UE Deregistration

Supported System level features

1. 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).
2. Executing all enabled profiles in parallel or in sequential order.
3. Timeout for each call flow within profile
4. Logging summary result
5. HTTP API to execute profile
6. Configure number of data packets to be sent and time interval between consecutive packets
7. Configure AS (Application Server) address. This is used to send data packets
8. Run gNBSim with single Interface or multi interface
9. Support of Custom Profiles
10. Delay between Procedures
11. Timeout for every profile

Using gNBSim

Step 1: Build gNBSim

1. Build gNBSim

    $ go build

2.  Build a docker image for gNBSim
    
    $ make docker-build

Step 2: Configure gNBSim

1. The config file for gNBSim can be found at <repo dir>/config/gnbsim.yaml
    
    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. Each profile executes   
            required set of systems procedures for the configured set of 
            IMSI's 
    
2. Enable or disable a specific profile using the "enable" field. 
    
    Currently following profiles are supported :
        - register: 
            Registration procedure
        - pdusessest (Default configured): 
            Registration + UE initiated PDU Session Establishment + User Data
             packets
        - deregister:
            Registration + UE initiated PDU Session Establishment + User Data
            packets + Deregister
        - anrelease:
            Registration + UE initiated PDU Session Establishment + User Data
            packets + AN Release
        - uetriggservicereq:
            Registration + UE initiated PDU Session Establishment + User Data
            packets + AN Release + UE Initiated Service Request

Step 3: Run gNBSim

If you want to run gNBSim as a standalone tool then deploy gNBSim using helm charts. If you want to run gNBSim along with 
other SD-Core Network Functions then use AIAB to deploy all network functions including gNBSim. 

1. Clone AIAB
2. Run "make 5g-core"
3. Trigger call flow testing using following commands


Enter gnbsim pod using kubectl exec command and run following commands, 

$ ./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/gnbsim.yaml

All these steps are explained in detail on AIAB documentation

Step 4: Optionally launching profiles through HTTP APIs

gNBSim can process HTTP Requests to launch profiles. For example running the
below curl command will launch a profile in gNBSim

$ curl -i -X POST 127.0.0.1:6000/gnbsim/v1/executeProfile -H 'Content-Type: application/json' -d '{"profileType":"nwreqpdusessrelease","profileName":"profile8","enable":true,"gnbName":"gnb1","startImsi":"208930100007497","ueCount":1,"opc":"981d464c7c52eb6e5036234984ad0bcf","key":"5122250214c33e723a5dd523fc145fc0","sequenceNumber":"16f3b3f70fc2","defaultAs":"192.168.250.1","plmnId":{"mcc":"208","mnc":"93"}}'

Pending Feature List

1. Common features for gNodeB Simulator

- Controlling Profiles - Adding support for aborting profile
- Controlling Profiles - Suspend/Pause profiles
- Controlling Profiles - Resume Profile
- Adding support for configurable rate of events

2. Data Testing Features

- Triggering downlink data from gNB Sim (CI/CD feature as well) 
- Provision data interface to gNBSim POD for data traffic testing

3. CI/CD features

- Advanced logging - Logic to calculate latency per transaction/ operation
- Reporting profile errors from all levels
- HTTP APIs to fetch subscriber/profile status from gNBSim

4. Negative Testing features

- Dropping incoming messages based on configuration
- Sending negative responses to request/command type messages based on configuration
- Handling security mode failure message

5. 3gpp features for gNodeB Simulator

- GUTI based registration
- Adding support for Resynchronization Profile
- Adding Support for N2 handover profile
- Adding Support for Xn Handover profile
- Adding support for handling end marker packet
- Generating GTPU echo request and handling incoming GTPU Request
- Support to send Error indication Message
- Support to handle Paging Request

6. gNBSim Deployment Features

- Support deployment of gNBSim as standalone container