Sending GPRS commands only, no SMS

I am testing Teltonika FMM130 GPS trackers and want to send custom commands as part of the response from the server, only using GPRS. SMS responses are 25 cents each here, so I want to send all commands only via GPRS and never use SMS within Traccar.

I have attempted to send a custom command ("getinfo") which in HEX using Teltonika Codec 12 is as follows:
000000000000000F0C010500000007676574696E666F0100004312

I am using UDP connections from the Teltonika devices which are working fine for general tracking. The server always responds with a 7 byte data packet whose data content is 00050000013803. I assume that when I send a command, it is queued by Traccar and sent to the device at its next data transmission as part of the server reply.

Monitoring packets with Wireshark, I never see the command being sent to the GPS tracker, just the 7 byte response from Traccar for the regular updates from the GPS tracker.

I also note that nowhere in the Traccar web GUI is there any mention of "Connections" so I am unable to assign connections to groups or to devices. There is no "Connections" menu option for users either. I am running server and app version 6.5.

What changes are needed in my Config File to make this work? Currently I only have the defaults as per the Docker container setup (database.driver, database.url, database.user and database.password).

UDP doesn't have a connection concept and I'm not sure we support UDP commands for Teltonika. I recommend trying TCP.

That doesn't explain why I have no Connections options in the web GUI.

The UDP command send did seem to work after a time though:

2024-10-21 12:43:59  INFO: [U140ff72c: teltonika < 1.152.110.94] 005ccafe0124000f3XXXXXXXXXXXXXXXXX8e0100000192acbe07e00056949854e9501d400000000000000000000008000400ef0000f00000c80200450300030042330400430fec00440000000100100000edb10000000001
2024-10-21 12:43:59  INFO: [U140ff72c: teltonika > 1.152.110.94] 00050000012401
2024-10-21 12:43:59  INFO: Event id: XXXXXXXXXXXXX, time: 2024-10-21 12:43:59, type: deviceOnline, notifications: 0
2024-10-21 12:43:59  INFO: Event id: XXXXXXXXXXXXX, time: 2024-10-21 12:43:59, type: queuedCommandSent, notifications: 0
2024-10-21 12:43:59  INFO: [U140ff72c] id: XXXXXXXXXXXXX, command type: custom sent
2024-10-21 12:43:59  INFO: [U140ff72c: teltonika > 1.152.110.94] 00000000000000230c01050000001b000000000000000f0c010500000007676574696e666f0100004312010000312f
2024-10-21 12:43:59  INFO: [U140ff72c] id: XXXXXXXXXXXXX, time: 2024-10-21 12:43:08, lat: -XX.06256, lon: 1XX.25789, course: 0.0
2024-10-21 12:53:59  INFO: Event id: XXXXXXXXXXXXX, time: 2024-10-21 12:53:59, type: deviceUnknown, notifications: 0

By connection you mean the linking function. It's under Settings > Devices > Connections.

That's the problem. It doesn't exist.

This is all I have when I edit a device:

UDP command sending using the "Custom Commands" once-off command at least appears to be working. Traccar not knowing how to deal with the data sent back is fine; this was just a test and the command "getinfo" sent to a Teltonika sends back a bunch of Teltonika specific info which obviously Traccar doesn't know what to do with.

2024-10-21 14:04:10  INFO: [U140ff72c: teltonika < 1.152.106.139] 006dcafe0101000f3XXXXXXXXXXXXXXXXXXXXXXXXXX8e0100000192ad081cb8005694a098e9501e7d002300000d00000000000c000500ef0000f00000150400c800004501000500b5000c00b600080042377300430ffe00440000000200f10000c54500100000001d0000000001
2024-10-21 14:04:10  INFO: [U140ff72c: teltonika > 1.152.106.139] 00050000010101
2024-10-21 14:04:10  INFO: Event id: XXXXXXXXXXXXX, time: 2024-10-21 14:04:10, type: deviceOnline, notifications: 0
2024-10-21 14:04:10  INFO: Event id: XXXXXXXXXXXXX, time: 2024-10-21 14:04:10, type: queuedCommandSent, notifications: 0
2024-10-21 14:04:10  INFO: [U140ff72c] id: XXXXXXXXXXXXX, command type: custom sent
2024-10-21 14:04:10  INFO: [U140ff72c: teltonika > 1.152.106.139] 00000000000000660c01050000005e005ccafe01c1000f3XXXXXXXXXXXXXXXXXXXXXXXXXX631378e0100000192aca37b0000569498fae9501e190000000000000000000008000400ef0000f00000c8020045030003004231c100430ffd00440000000100100000e2a9000000000101000035ea
2024-10-21 14:04:10  INFO: [U140ff72c] id: XXXXXXXXXXXXX, time: 2024-10-21 14:04:03, lat: -X.06253, lon: X.25810, course: 0.0
2024-10-21 14:04:10  INFO: [U140ff72c: teltonika < 1.152.106.139] 00000000000000290c010600000021756e6b6e6f776e20636f6d6d616e64206f7220696e76616c696420666f726d61740100005ac0
2024-10-21 14:04:10  WARN: Unknown device -
                                            !unknown command or invalid format (1.152.106.139)

I still need to be able to configure saved commands though, which is the remaining issue to resolve.

This is all I have when I edit a device

I never said anything about editing a device.

OK, well I don't have anything in the GUI marked as "Connections". I really don't know where you're directing me to go. This is all I have:

Oh my GOD. You mean the LINK SYMBOL?

I've never used the link symbol in a website that way in 30 years. God damn.

Guess I learned something new today then.

Anyway, I also worked out that I was stupidly sending raw hex commands to my teltonika devices when Traccar already knew they were teltonika and I didn't need to do the hex encoding. Derp.

By the way, you are somewhat right about UDP. The queued commands stuff is no bueno when your device is using UDP and behind CGNAT with an unknown session timeout. Traccar might assume the device is online, fire off the command via UDP and assume everything worked.

TCP will likely resolve much of this (coupled with the Teltonika timeouts and keepalives). My issue is I was trying to keep data consumption extremely low but I think 1MB per month for any kind of actively moving device isn't enough, and with TCP overheads it definitely won't be enough. I'll pivot to slightly more expensive SIM plans.