feat: add missing description for linking UERANSIM gNB and UE

[LaumiH]

Hi,

while setting up free5gc compose with an integrated UERANSIM gNB and UE, I noticed that the documentation was missing a small detail: Before adding the ue service to the compose yaml, actually the values of the linkIp in config/gnbcfg.yaml and gnbSearchList in config/uecfg.yaml need to be replaced. The have 127.0.0.1 as of now, and thus are unable to communicate.

I suggest adding this small detail to the documentation to make it easier for newbies to get a first end-to-end 5GC with a gNB and UE running!

Cheers, Laura

[abousselmi]

Thanks @LaumiH for spotting this.

The initial idea was to launch the UE from within the gNB container using docker exec. But if we are using a separate container for the UE, we should specify the gNB IP for the RLS communication, just like you said.

It would be nice if you can also add - gnb.free5gc.org to this list ?

https://github.com/free5gc/free5gc-compose/blob/488bad89172e8b29b1553006757b88c5cc553e21/config/uecfg.yaml#L22

[LaumiH]

I suppose there could as well be a short sentence in the documentation about starting a UE directly within the ueransim container using docker exec, as the UE config file (uecfg.yaml) is already being copied into the container. This would simplify starting multiple UEs, too.

[abousselmi]

Yes that would be great !