Sx1301ar_conf_chan(0,0,0,..) failed: Maximum supported IF exceeded

Hi,
We’re trying to setup a Cisco Gateway with CPF. The gateway connects to ChirpStack gateway bridge port 3001, but when the software send the configuration it disconnects:

Aug 20 17:38:01 LABLAS331 chirpstack-gateway-bridge[26399]: time=“2021-08-20T17:38:01.43679316-03:00” level=debug msg=“sending message to gateway” gateway_id=fabcbdfffe9e0376 message=“{"msgtype":"router_config","NetID":null,"JoinEui":null,"region":"AU915","hwspec":"sx1301/2","freq_range":[915200000,918200000],"DRs":[[12,125,0],[11,125,0],[10,125,0],[9,125,0],[8,125,0],[7,125,0],[8,500,0],[-1,0,0],[12,500,1],[11,500,1],[10,500,1],[9,500,1],[8,500,0],[7,500,1],[-1,0,0],[-1,0,0]],"sx1301_conf":[{"radio_0":{"enable":true,"freq":915600000},"radio_1":{"enable":true,"freq":916600000},"chan_FSK":{"enable":false},"chan_Lora_std":{"enable":false,"radio":0,"if":0},"chan_multiSF_0":{"enable":true,"radio":0,"if":-400000},"chan_multiSF_1":{"enable":true,"radio":0,"if":-200000},"chan_multiSF_2":{"enable":true,"radio":0,"if":0},"chan_multiSF_3":{"enable":true,"radio":0,"if":200000},"chan_multiSF_4":{"enable":true,"radio":0,"if":400000},"chan_multiSF_5":{"enable":true,"radio":1,"if":-400000},"chan_multiSF_6":{"enable":true,"radio":1,"if":-200000},"chan_multiSF_7":{"enable":true,"radio":1,"if":0}},{"radio_0":{"enable":true,"freq":917200000},"radio_1":{"enable":true,"freq":918200000},"chan_FSK":{"enable":false},"chan_Lora_std":{"enable":false,"radio":0,"if":0},"chan_multiSF_0":{"enable":true,"radio":0,"if":-400000},"chan_multiSF_1":{"enable":true,"radio":0,"if":-200000},"chan_multiSF_2":{"enable":true,"radio":0,"if":0},"chan_multiSF_3":{"enable":true,"radio":0,"if":200000},"chan_multiSF_4":{"enable":true,"radio":0,"if":400000},"chan_multiSF_5":{"enable":true,"radio":1,"if":-400000},"chan_multiSF_6":{"enable":true,"radio":1,"if":-200000},"chan_multiSF_7":{"enable":true,"radio":1,"if":0}}]}”
Aug 20 17:38:01 LABLAS331 chirpstack-gateway-bridge[26399]: time=“2021-08-20T17:38:01.437790994-03:00” level=info msg=“backend/basicstation: router-config message sent to gateway” gateway_id=fabcbdfffe9e0376
Aug 20 17:38:01 LABLAS331 chirpstack-gateway-bridge[26399]: time=“2021-08-20T17:38:01.444615206-03:00” level=info msg=“backend/basicstation: gateway disconnected” gateway_id=d4adbdfffe9e0398 remote_addr=“10.1.124.201:40488”

Region is AU915.
The Cisco gateway does not show much info, but this trace seems to point an issue:

2021-08-20 20:28:39.644 [RAL:WARN] Ignoring unsupported/unknown field: gps_conf
2021-08-20 20:28:39.650 [RAL:ERRO] sx1301ar_conf_chan(0,0,0,…) failed: Maximum supported IF exceeded
2021-08-20 20:28:39.650 [any:ERRO] Closing connection to muxs - error in s2e_onMsg

Any inputs will be appreciated.
Thank you,
LC.

Could you share your chirpstack-gateway-bridge.toml configuration? From the error it looks like you are trying to configure more channels than supported by the gateway.

Thank you brocaar. I suspected that too. The Cisco gateway is pretty poor in terms of debugging info, but I managed to find a command that showed me the contents of station.conf:

show common-packet-forwarder log name config 250

This in turn showed me that the gateway was sitting on the central frequency for US902, even tough I have the commands for country, region, and a GPS antenna:

common-packet-forwarder profile
ipaddr 10.218.254.202 port 3001
gps enable
antenna 1 omni gain 5 loss 1
antenna 2 omni gain 5 loss 1
gatewayid FABCBDFFFE9E0376
auth-mode none
country Argentina
region-cp AU915
cpf enable

But station.conf was showing:

station.conf{
“radio_conf”:[
{
“pps”: false,
“board_type”: “MASTER”,
“board_rx_freq”: 908600000, /* radio RX central frequency in Hz /
“board_rx_bw”: 13000000, /
radio RX bandwidth in Hz */
[snip]

So I added the board-freq command to my config, and it solved the issue:

common-packet-forwarder profile
 ipaddr 10.218.254.202 port 3001
 gps enable
 antenna 1 omni gain 5 loss 1
 antenna 2 omni gain 5 loss 1
 gatewayid FABCBDFFFE9E0376
 auth-mode none
 country Argentina
 region-cp AU915
 board-freq 921500000
 cpf enable

So I’m scratching my head thinking if the gateway ignore these things:

  • Location as read from GPS.
  • Region as entered with region-cp
  • Country as entered with country command

But so far this issue is solved for me. We have new issues, but that’s good, at least we’re progressing in our POC.

Thanks.