Cannot connect srsUE to gNB through ZMQ. Gets stuck on RRC Connected.

[fabio-patrizi]

Hi all,
I'm having troubles in connecting the srsUE to the gNB via ZMQ.

I've followed the steps in the tutorial. I have built open5gs, srsRAN_Project and srsRAN_4G from sources on Ubuntu 22.04.2 LTS (actually, I'm on a Mac M1 Max). Each of them seems to work fine and apparently the gNB and open5gs connect with each other. However, when the srsUE seems to fail in connecting. Details follow.

gNB commit is ce86e47
srsUE commit is 921f17484

(Expected behavior)
As per the tutorial, the srsUE output should end by something as follows:
...
RRC Connected
PDU Session Establishment successful. IP: 10.45.10.2
RRC NR reconfiguration successful.

(Observed behavior)
However, I get the following output:

Active RF plugins: libsrsran_rf_uhd.so libsrsran_rf_zmq.so
Inactive RF plugins:
Reading configuration file ./srsRAN_4G/build/ue_zmq.conf...

Built in Release mode using commit 921f17484 on branch master.

Opening 1 channels in RF device=zmq with args=tx_port=tcp://127.0.0.1:2001,rx_port=tcp://127.0.0.1:2000,base_srate=11.52e6
Supported RF device list: UHD zmq file
CHx base_srate=11.52e6
Current sample rate is 1.92 MHz with a base rate of 11.52 MHz (x6 decimation)
CH0 rx_port=tcp://127.0.0.1:2000
CH0 tx_port=tcp://127.0.0.1:2001
Current sample rate is 11.52 MHz with a base rate of 11.52 MHz (x1 decimation)
Current sample rate is 11.52 MHz with a base rate of 11.52 MHz (x1 decimation)
Waiting PHY to initialize ... done!
Attaching UE...
Random Access Transmission: prach_occasion=0, preamble_index=0, ra-rnti=0x39, tti=334
Random Access Complete. c-rnti=0x4601, ta=0
RRC Connected

In particular, I do not get the lines:

PDU Session Establishment successful. IP: 10.45.10.2
RRC NR reconfiguration successful.

which indicate successful connection (according to the tutorial).

When I test the connection with ping, it doesn't work.

gNB output is:
Lower PHY in executor blocking mode.

--== srsRAN gNB (commit ce86e47) ==--

Connecting to AMF on 127.0.0.5:38412
Available radio types: uhd and zmq.
Cell pci=1, bw=10 MHz, dl_arfcn=368500 (n3), dl_freq=1842.5 MHz, dl_ssb_arfcn=368410, ul_freq=1747.5 MHz

==== gNodeB started ===
Type to view trace

Configuration files are attached:
gnb_zmq.txt
ue_zmq.conf.txt

EDIT: forgot to attach open5gs config files
amf.yaml.txt
upf.yaml.txt

As an aside, the field rf_driver in gnb_zmq.txt does not seem to be correctly parsed. Indeed I get the following error when running the gNB:
INI was not able to parse rf_driver.++
Run with --help for more information.

EDIT:
Also using "ss_type: common" in gnb_zmq.txt does not work and produces the following error:
INI was not able to parse cell_cfg.ss_type
Run with --help for more information.

For this reason, after inspecting the config files provided with the release, I switched to ru_sdr. If I do so, it works fine. This is commented inline in the gNB configuration file.

To reproduce the issue, just run the open5gs, followed by the gNB, then by the srsUE. If needed, I can provide the specific command lines used, as well as the logs.

Thank you in advance for any help you can provide.
Best!

[oguztudo]

I encountered the same issue when i forgot to add ue1
Check with :
sudo ip netns list

if the list is empty try:
sudo ip netns add ue1

[SadeghKrmi]

@ismagom Sure, thanks for supporting, log for ue and gNB are as follows
ue.log
gnb.log

[herlesupreeth]

I see from your ue.log the following

2023-06-30T14:06:58.088603 [UE ] [I] Built in Release mode using commit 49f1edd6f on branch master.

But the latest commit in master branch of srsRAN_4G is fa56836b14dc6ad7ce0c3484a1944ebe2cdbe63b. Notice that they do not match.

[SadeghKrmi]

@herlesupreeth Hey, I used latest commit, but I am facing same issue, It got stuck at RRC Connected, without receiving IP. I am attaching new logs, I'd appreciate your opinion.

gnb.log

ue.log

[herlesupreeth]

I took a look at the logs but couldn't find anything that could give a hint about the issue. Can you please increase the log level to debug for following layers under log configuration for gNB and also enable ngap pcap and send both the logs and ngap pcap. Thanks

  phy_level: debug
  mac_level: debug
  rrc_level: debug

[SadeghKrmi]

Sure, please find the logs in below.

ue.log
gnb.log
gnb_ngap.zip

[herlesupreeth]

@SadeghKrmi I see that Core Network is rejecting your UE registration request so its a issue in your Core Network configuration. I would suggest to check whether you have correctly entered UE's SIM details in the Core Network and also check the MNC and MCC.

[SadeghKrmi]

@herlesupreeth thanks for the response, I installed Mongodb on ubuntu 22.04 earlier, but seems because I am using virtualization and CPU is not supporting features needed by Mongodb, it fails to startup the db, I switched to ubuntu 20.04 to be able to install Mongodb of version 4, then this issue is fixed, now I am receiving "PLMN not allowed" error which I am trying to solve.

[herlesupreeth]

Its the same error as before. I would suggest checking your UE details entered in mongo db / WebUI of open5gs

[SadeghKrmi]

@herlesupreeth thanks, now it is fixed, I inserted the wrong UE imsi.