VoNR calls not completing properly

[Rashed97]

Hi,

First I wanted to thank you for the wonderful setup and guides. Using this, I've successfully set up a 5G SA network with a B210 radio. Using the experimental 5G IMS PyHSS branch, I've been able to get several Android UEs to register successfully with P-CSCF/S-CSCF. The UEs show a successful registration, and SMSoIP works fine. Calls however, do not complete; the devices never even get a dial tone. P-CSCF logs show that the N5 routes seem to be working fine, so I'm not really sure where to start with this.

A note on these UEs: when I start the B210 as an eNB instead of a gNB, they can register on the LTE network and VoLTE works fine. There appears to be an issue with video calling over IMS, but I have not looked at it enough to have any idea whether that's a UE issue or IMS issue.

Please let me know what logs you'd like me to provide and I can provide those in a follow up. I'm happy to help debug this however you'd like.

Thanks!

[herlesupreeth]

@Rashed97

I've successfully set up a 5G SA network with a B210 radio.

In general the VoNR is not working as expected mainly due to failure in setting up a dedicated bearer for the call. This is still largely work in progress. Will let you know once its ready to be tested again

A note on these UEs: when I start the B210 as an eNB instead of a gNB, they can register on the LTE network and VoLTE works fine. There appears to be an issue with video calling over IMS, but I have not looked at it enough to have any idea whether that's a UE issue or IMS issue.

Regarding issue with video calls, please attach a pcap taken for below scenario

1. Start pcap
2. Register two UEs
3. Attempt video call
4. Wait for it to fail
5. Stop pcap and attach here

[Rashed97]

@herlesupreeth Thanks for the clarification.

In general the VoNR is not working as expected mainly due to failure in setting up a dedicated bearer for the call. This is still largely work in progress. Will let you know once its ready to be tested again

Are there any workarounds for this right now, or is this pretty much entirely broken in srsRAN? I’ve seen some of the discussion threads around this, and it looks like it potentially works sometimes, or am I misunderstanding?

Regarding issue with video calls, please attach a pcap taken for below scenario

1. Start pcap
2. Register two UEs
3. Attempt video call
4. Wait for it to fail
5. Stop pcap and attach here

For this, should it just be a PCAP on the host machine with -i any ?

[herlesupreeth]

Are there any workarounds for this right now, or is this pretty much entirely broken in srsRAN? I’ve seen some of the discussion threads around this, and it looks like it potentially works sometimes, or am I misunderstanding?

So far we haven't had any luck making VoNR call work when tested between two devices (as per the main contributor it worked when calling a device from an application server). I dont think there is a workaround for it. I will try to see whether this issue can be fixed easily or not.

For this, should it just be a PCAP on the host machine with -i any ?

Yes, thats right

[Rashed97]

So far we haven't had any luck making VoNR call work when tested between two devices (as per the main contributor it worked when calling a device from an application server). I dont think there is a workaround for it. I will try to see whether this issue can be fixed easily or not.

OK, great thanks. Let me know if there's anything I can help with.

For this, should it just be a PCAP on the host machine with -i any ?

Yes, thats right

Great, appreciate it, thanks. I'll grab this at my first opportunity.