free5GC disconnection with RAN

Q/A
1

Hi free5GC Team,

We’ve encountered the problem that free5GC disconnected with RAN while we were performing throughput test. After checking free5gc/SMF/UPF log, we think the reason might be due to UPF couldn’t handle the PFCP request. Therefore, the N4 PFCP failed, and consequently the disconnection with RAN.
We would like to know if it is the UPF or any other NF’s issue and the solution for it?
Thank you guys.

free5gc_log
free5gc_log1843×748 500 KB
smf_log
smf_log1816×944 632 KB
upf_log
upf_log1812×986 989 KB
free5gc.txt (3.8 MB) smf.txt (701.8 KB) upf.txt (193.3 KB)

2

@tuanthieu

Please provide more info and attach the free5gc full log including packet log (pcap) to analyze it.

  1. What kind of throughput test did you perform? Is data throughput test?
  2. What UE/RAN did you use?
  3. Did UE do registration and pdu session establishment successfully?
  4. Please describe your test steps in detail.
3

Hi,
Please find below details information fyr.

[Precondition]
Compal 5G UE
Compal 5G SA Small Cell

[Issue Scenario]

  1. 5G UE completed Registration and PDU Session procedure to camp on Compal Small Cell.
    → 5G UE got IP address 60.60.0.15

  2. We executed iperf command to perform throughput test between 5G UE and iperf server at 192.168.45.1

[Actual Result]
5GUE lost connection and free5GC need to restart.

[Expected Result]
5G UE behavior is normal to keep camping on 5G small cell

[Logs attached]
Packet log is attached (due to big file size, we only select ngap packets)
(free5gc/smf/upf logs have been attached in previous post)
20210902_free5gc_log.pcapng (27.0 KB)
Thanks!

4

@tuanthieu

Please follow https://github.com/free5gc/free5gc/wiki/Installation to get the the latest nightly version.

cd ~/free5gc
git checkout main
git submodule sync
git submodule update --init --jobs `nproc`
git submodule foreach git checkout main
git submodule foreach git pull --jobs `nproc`

Also get the latest gtp5g to install:

git clone https://github.com/free5gc/gtp5g.git
cd gtp5g
make
sudo make install

Build all NF binaries:

cd ~/free5gc
make all

Modify related config files with your network IP setting and execute ./run.sh to run free5gc again.

Run tcpdump before free5gc starts:

sudo tcpdump -i any -w free5gc.pcap

If there are still errors happened, please attach log/free5gc.log and free5gc.pcap.

5

Could you explain a little bit about the difference between the nightly build version and the official one?
Thank you!

6

The nightly build includes hotfixes.

7

We greatly appreciate your support! We will try to update and test the performance based on your solution.