[BUG] Unable to create tunnel for UE with multi-ue option

[avrodriguezgrad]

Describe the bug
I'm trying to use the multi-ue option with only 2 UEs for testing. Only with multi-ue -n 2, I have the log message telling "Interface for UE X has not been created. Tunnel has been disabled" but, if I exec multi-ue -n 2 --tunnel-vrf, I have exactly the same message, like if it's ignoring the vrf option.

I don't know if I'm missing something in terms of configuration.

To Reproduce
Steps to reproduce the behavior:
Deploy PacketRusher with ./packetrusher --config config.yml multi-ue -n 1 --tunnel-vrf true

Expected behavior
VRF tunnel interfaces have to be created.

Screenshots
If applicable, add screenshots to help explain your problem.

Architecture (please complete the following information):

• OS: Ubuntu 20.04
• Platform: x86_64
• Kernel: 5.4.0-100-lowlatency

Log:

Pcap:

Additional context

[linouxis9]

Hi @avrodriguezgrad!

Glad to see you using PacketRusher, you may see #83 for more reference on how to use multi-ue. Basically, it seems you are missing the --tunnel option.

Cheers,
Valentin

[avrodriguezgrad]

Oh, I did not see in discussions to search about the bug, thank you!

Currently, is it impossible to use only 1 gNB for multiple UEs? Do you have in your roadmap this feature?

[linouxis9]

@avrodriguezgrad
Currently, you can use multiple UEs with a single gNodeB only when not using the --tunnel option, with it, you indeed need dedicated gNodeB per UE.
This is indeed on the roadmap, and the whole goal of this PR #47 is to support this feature, but this is still very WIP :-)

[avrodriguezgrad]

I see. This creates me another doubt. Without the tunnel option, I'm having the above message about interface's not being created. Can I create the interface manually? Or what do you recommend me to generate traffic from UEs?

[linouxis9]

Without the tunnel option, the interface is indeed not being created. As such, you cannot do user plane traffic. You are limited to doing control plane procedures (Xn/NGAP handover, Idling, Deregistration, Creation/Deletion of PDU Sessions...)
You could however indeed generate traffic manually from the UEs without the tunnels after PacketRusher has etablished the PDU Sessions, by using a tool like Cisco TRex which can generate raw GTP-U traffic. This is something I would like to investigate as well, but don't have the time to work on for now.

[avrodriguezgrad]

Okey, thanks for the explanation! If I have time the following weeks, I'll try to investigate this too.

Thanks again!
Álvaro