Multiple gNBs on ZMQ set up

[christsaks]

Hi to all,
I am trying to run 2 gnBs using the ZMQ set up but I am facing some issues. I know there is much discussion on multi-UE support and that is possible with GNU radio and i have successfully set up this but with multi gnb i am facing some challenges. Are there changes needed to the open5gs side to support this? Is there some tutorial for this set up? I have observed that using a different GTPU_PORT in the second gnb instance makes it connect to the open5gs but problems come later when i try to connect a UE to that gnB. Maybe some change is needed in the conf files of the open5gs?
Thanks in advance for any help

[pgawlowicz]

To connect the 2nd gNB to the same Open5gs running in docker, one need to add a second IP address to the bridge interface connecting to the Open5gs docker container.

1. Get the name of the Open5gs docker bridge:

ip -o addr show | grep "10.53.1.1"

2. Add a second IP address to the bridge:

sudo ip addr add 10.53.1.3/24 dev BRIDGE_NAME

3. Use the IP=10.53.1.3 as amf.bind_addr in the 2nd gNB config.

4. Remember to use different ZMQ ports for the gNB-UE pairs. Also, the UE has to have different IMSI, that need to be added to the Open5gs database.

You can take the Open5gs subscriber database and the UE configs from our tutorial. Remember to adapt ZMQ ports!

[christsaks]

Thank you! Following you instructions i was able to connect 2 gnbs and ping to their UEs!