Running Multiple gNB (over the air setup with usrp b200) scenario with Open5gs Core

[ethanlin355]

I am trying to run 2 gnBs with usrp b200 connected to 4 usrp b210 UEs, and i can connect first gnb to the core no problem but i encounter some issues with connecting second gnb

first gnb(gnb1) successful output:

--== srsRAN gNB (commit 2be82d8ea) ==--

Lower PHY in quad executor mode.
Available radio types: uhd and zmq.
[INFO] [UHD] linux; GNU C++ version 11.2.0; Boost_107400; UHD_4.1.0.5-3
[INFO] [LOGGING] Fastpath logging disabled at runtime.
Making USRP object with args 'type=b200'
[INFO] [B200] Detected Device: B200
[INFO] [B200] Operating over USB 3.
[INFO] [B200] Initialize CODEC control...
[INFO] [B200] Initialize Radio control...
[INFO] [B200] Performing register loopback test... 
[INFO] [B200] Register loopback test passed
[INFO] [B200] Setting master clock rate selection to 'automatic'.
[INFO] [B200] Asking for clock rate 16.000000 MHz... 
[INFO] [B200] Actually got clock rate 16.000000 MHz.
[INFO] [MULTI_USRP] Setting master clock rate selection to 'manual'.
[INFO] [B200] Asking for clock rate 23.040000 MHz... 
[INFO] [B200] Actually got clock rate 23.040000 MHz.
Cell pci=1, bw=20 MHz, 1T1R, dl_arfcn=368500 (n3), dl_freq=1842.5 MHz, dl_ssb_arfcn=368410, ul_freq=1747.5 MHz

N2: Connection to AMF on 10.53.1.2:38412 completed
E2AP: Connection to Near-RT-RIC on 10.0.2.10:36421 completed
==== gNB started ===
Type <h> to view help
Late: 0; Underflow: 1; Overflow: 0;
Late: 0; Underflow: 2; Overflow: 0;`

second gnb if i'm using same amf blind address (10.53.1.1) output:

Connecting to AMF on 10.53.1.2:38412
Failed to bind UDP socket to 10.53.1.1:2152. Address already in use

if i use different amf blind address(10.53.1.99) output:

srsran@srsran:~/srsRAN_Project/build/apps/gnb$ sudo ./gnb -c ./gnb2_uhd.yaml cu_cp  amf --bind_addr="10.53.1.99"   e2 --addr="10.0.2.10" --bind_addr="10.0.2.99"
 
--== srsRAN gNB (commit 2be82d8ea) ==--

Lower PHY in quad executor mode.
Failed to bind UDP socket to 10.53.1.99:2152. Cannot assign requested address
srsRAN ERROR: Unable to allocate the required NG-U network resources

here is my gnb yaml file:

gnb1:

cu_cp:
  amf:
    addr: 10.53.1.2
    port: 38412
    bind_addr: 10.53.1.1
    supported_tracking_areas:
      - tac: 7
        plmn_list:
          - plmn: "00101"
            tai_slice_support_list:
              - sst: 1

ru_sdr:
  device_driver: uhd
  device_args: type=b200
  clock: internal
  srate: 23.04
  tx_gain: 80
  rx_gain: 40

cell_cfg:
  dl_arfcn: 368500
  band: 3
  channel_bandwidth_MHz: 20
  common_scs: 15
  plmn: "00101"
  tac: 7
  pdcch:
    dedicated:
      ss2_type: common
      dci_format_0_1_and_1_1: false
    common:
      ss0_index: 0
      coreset0_index: 12
  prach:
    prach_config_index: 1
  pdsch:
    mcs_table: qam64
  pusch:
    mcs_table: qam64

log:
  filename: /tmp/gnb.log
  all_level: info

pcap:
  mac_enable: enable
  mac_filename: /tmp/gnb_mac.pcap
  ngap_enable: enable
  ngap_filename: /tmp/gnb_ngap.pcap

e2:
  enable_du_e2: true                # Enable DU E2 agent (one for each DU instance)
  e2sm_kpm_enabled: true            # Enable KPM service module
  e2sm_rc_enabled: true             # Enable RC service module
  addr: 127.0.0.1                   # RIC IP address
  #bind_addr: 127.0.0.100           # A local IP that the E2 agent binds to for traffic from the RIC. ONLY required if running the RIC on a separate machine. 
  port: 36421                       # RIC port

metrics: 
  rlc_report_period: 1000           # Set reporting period to 1s

gnb2:

cu_cp:
  amf:
    addr: 10.53.1.2
    port: 38412
    bind_addr: 10.53.1.1
    supported_tracking_areas:
      - tac: 7
        plmn_list:
          - plmn: "00101"
            tai_slice_support_list:
              - sst: 1

ru_sdr:
  device_driver: uhd
  device_args: type=b200
  clock: internal
  srate: 23.04
  tx_gain: 80
  rx_gain: 40

cell_cfg:
  dl_arfcn: 368500
  band: 3
  channel_bandwidth_MHz: 20
  common_scs: 15
  plmn: "00101"
  tac: 7
  pdcch:
    dedicated:
      ss2_type: common
      dci_format_0_1_and_1_1: false
    common:
      ss0_index: 0
      coreset0_index: 12
  prach:
    prach_config_index: 1
  pdsch:
    mcs_table: qam64
  pusch:
    mcs_table: qam64

log:
  filename: /tmp/gnb2.log
  all_level: info

pcap:
  mac_enable: enable
  mac_filename: /tmp/gnb2_mac.pcap
  ngap_enable: enable
  ngap_filename: /tmp/gnb2_ngap.pcap

[ethanlin355]

I Found solution similar to zmq setup #561