srsDU will always fail to connect srsCU in multiple cell scenario

[IbrahimBabiker87]

iavf_configure_queues(): request RXDID[22] in Queue[0]
Initializing the Open Fronthaul Interface for sector#0: ul_compr=[BFP,9], dl_compr=[BFP,9], prach_compr=[BFP,9], prach_cp_enabled=false, downlink_broadcast=false
iavf_configure_queues(): request RXDID[22] in Queue[0]
Initializing the Open Fronthaul Interface for sector#1: ul_compr=[BFP,9], dl_compr=[BFP,9], prach_compr=[BFP,9], prach_cp_enabled=false, downlink_broadcast=false
F1-C: Connection to CU-CP on 10.0.135.21:38472 completed
Warning: Configured PRACH occasion collides with PUCCH RBs ([0..1) intersects [0..3)). Some interference between PUCCH and PRACH is expected.
Warning: Configured PRACH occasion collides with PUCCH RBs ([0..1) intersects [0..3)). Some interference between PUCCH and PRACH is expected.
srsRAN ERROR: Failed to connect DU to CU-CP

log:

2024-08-06T10:42:56.018949 [DU-F1   ] [I] F1 Setup: Sending F1 Setup Request to CU-CP...
2024-08-06T10:42:56.018951 [DU-F1   ] [I] Tx PDU du=0 tid=0: F1SetupRequest
2024-08-06T10:42:56.019291 [DU-F1   ] [I] Rx PDU du=0 tid=0: F1SetupResponse
2024-08-06T10:42:56.019295 [DU-F1   ] [I] F1 Setup: Procedure completed successfully.
2024-08-06T10:42:56.028623 [DU-MNG  ] [I] DU manager started successfully.
2024-08-06T10:42:56.028624 [DU      ] [I] DU-High started successfully
2024-08-06T10:42:56.028626 [DU      ] [I] DU started successfully
2024-08-06T10:42:56.028626 [DU      ] [I] Starting DU...
2024-08-06T10:42:56.028627 [DU      ] [I] Starting DU-High...
2024-08-06T10:42:56.028627 [DU-MNG  ] [I] DU manager starting...
2024-08-06T10:42:56.028751 [SCTP-GW ] [E] F1-C: Connection to 10.0.135.21:38472 failed. Cause: Connection is already in progress
2024-08-06T10:42:56.028752 [DU-F1   ] [E] Failed to establish F1-C TNL connection to CU-CP on 10.0.135.21:38472.

Error:

F1-C: Connection to 10.0.135.21:38472 failed. Cause: Connection is already in progress

is there any way to pass different IP for f1ap and f1u per each cell, otherwise above error will result ??

[improperaffo]

Hi @IbrahimBabiker87 you can set a different IP for the F1-U by adding the following section in the cu yaml file:

cu_up:
  nru:
    bind_addr: 10.42.0.132

[IbrahimBabiker87]

@improperaffo

the issue is not about different F1u and F1ap IPs, The issue is that for multiple cells in srsDU we will need multiple ips for f1ap otherwise I will have above error : Connection to 10.0.135.21:38472 failed. Cause: Connection is already in progress cause the IP is already taken by the first cell.

I have two cells configured in srsDU:

srsDU config :

f1ap:
  cu_cp_addr: 10.0.135.21
  bind_addr: 10.0.135.150


nru:
  queue_size: 2048
  bind_addr: 10.0.135.150

srsCU:

cu_cp:
  f1ap: 
    bind_addr: 10.0.135.21                    
    procedure_timeout: 1000               

cu_up: 
  nru:                                 
    bind_addr: 10.0.135.21               
    udp_max_rx_msgs: 256                 

[IbrahimBabiker87]

@improperaffo

the suggested HO config is using full gnb { directly connected to AMF} , not split srsDU/ srsCU
This issue is related to split DU/CU sraRAN version

suggested HO config "copied":

gnb_id: 411
gnb_id_bit_length: 32

amf:
  addr: 10.53.1.2                  # The address of the AMF. Check Open5GS config -> amf -> ngap -> addr
  bind_addr: 10.53.1.1             # A local IP that the gNB binds to for traffic from the AMF.

ru_sdr:
  device_driver: uhd
  device_args: type=x300
  tx_gain: 20
  rx_gain: 15
  srate: 92.16
  lo_offset: 45
  clock: internal
  sync: internal
  time_alignment_calibration: 0

[ismagom]

Hi @IbrahimBabiker87, srsDU does not currently support multiple cells.