Split 7.2 with FalconRX and Benetel: No messages from RU to DU

[cueltschey]

Overview

My lab and I have been trying to get an srsRAN split 7.2 working, with a benetel 550 RU and a Falcon RX switch. We are coming across the issue that the RU is not sending any messages back to the DU.

The Problem

We are getting some RX packets (although they are not on time), and no TX packets.

Here is our gNB log:

2025-01-27T22:07:37.330264 [OFH     ] [W] Sector#0: missed incoming User-Plane PRACH messages for slot '812.19' and sector#0
2025-01-27T22:07:37.340272 [OFH     ] [W] Sector#0: missed incoming User-Plane PRACH messages for slot '813.19' and sector#0
2025-01-27T22:07:37.350274 [OFH     ] [W] Sector#0: missed incoming User-Plane PRACH messages for slot '814.19' and sector#0
2025-01-27T22:07:37.360282 [OFH     ] [W] Sector#0: missed incoming User-Plane PRACH messages for slot '815.19' and sector#0
2025-01-27T22:07:37.370266 [OFH     ] [W] Sector#0: missed incoming User-Plane PRACH messages for slot '816.19' and sector#0
2025-01-27T22:07:37.380265 [OFH     ] [W] Sector#0: missed incoming User-Plane PRACH messages for slot '817.19' and sector#0
2025-01-27T22:07:37.390267 [OFH     ] [W] Sector#0: missed incoming User-Plane PRACH messages for slot '818.19' and sector#0
2025-01-27T22:07:37.400276 [OFH     ] [W] Sector#0: missed incoming User-Plane PRACH messages for slot '819.19' and sector#0
2025-01-27T22:07:37.410271 [OFH     ] [W] Sector#0: missed incoming User-Plane PRACH messages for slot '820.19' and sector#0
2025-01-27T22:07:37.420263 [OFH     ] [W] Sector#0: missed incoming User-Plane PRACH messages for slot '821.19' and sector#0

Falcon RX configuration

We configured the switch exactly according to this guide: FalconRX guide

PTP

As far as we can tell our PTP is synchronized

NIC

We are using an Intel E810 XXV card, as we heard it would be most effective for this setup

Benetel configuration

Here is our PTP log:
pcm4l.txt

Our eAxC configuration:
eaxc.txt

Our VLAN configuration:

=============================================
DU VLAN and MAC address configured in O-RU:
=============================================

DU VLAN Tag Control Information for downlink C-Plane Traffic (C0331)
Register 0xc0331, Value : 0x2

DU VLAN Tag Control Information for downlink U-Plane Traffic (C0330)
Register 0xc0330, Value : 0x2

DU VLAN Tag Control Information for uplink U-Plane Traffic (C0318)
Register 0xc0318, Value : 0xe002

 DU MAC Address for C-Plane Traffic (C0319/C031A)
Register 0xc0319, Value : 0x6f66ec28
Register 0xc031a, Value : 0x507c

DU MAC Address for U-Plane Traffic (C0315/C0316)
Register 0xc0315, Value : 0x6f66ec28
Register 0xc0316, Value : 0x507c

Here is our ru_config.cfg:
ru_config.txt

Here is a packet dump from eth0 on the RU:
eth0_tcpdump.pcap.txt

srsRAN gNB

Here is our gnb config:
gnb_ru_ran550_tdd_n78_20mhz_2x2.txt

Here is the output from our gNB:

sudo gnb -c ./gnb_ru_ran550_tdd_n78_20mhz_2x2.yml 

--== srsRAN gNB (commit cc2869f96) ==--

Warning: With the given prach_frequency_start=2, the PRACH opportunities overlap with the PUCCH resources/guardband in prbs=[0, 11). Some interference between PUCCH and PRACH interference should be expected
Initializing the Open Fronthaul Interface for sector#0: ul_compr=[BFP,9], dl_compr=[BFP,9], prach_compr=[BFP,9], prach_cp_enabled=true, downlink_broadcast=false
Cell pci=1, bw=20 MHz, 2T2R, dl_arfcn=640000 (n78), dl_freq=3600 MHz, dl_ssb_arfcn=639648, ul_freq=3600 MHz

N2: Connection to AMF on 10.53.1.2:38412 completed
==== gNB started ===
Type <h> to view help
t

Open5GS

for open5gs we are using docker compose from the srsRAN_Project repo

Some other relevant issues:

716
639

We are wondering where we most likely went wrong in the configuration process. If you could lead us in the right direction, it would be greatly appreciated.
Thanks, chase