Hello,
I am using the latest SMS Server Tools 3 with Debian 12 from Debians official packet repo.
I installed to use it with a LTE LAN Gateway, using Telnet/TCP to communicate.
Basic communication works with following configuration:



Problem is that I'd like in every scenario (network down/maintenance, LTE modems reset, something gets unplugged for a second) - SMS Server Tools 3 should be retrying to connect and sent the SMS for all eternity.

However, if I do following:
- Start SMS Server Tools 3
- we can also test send an SMS, everything will be fine here
- Then connect to the LTE modem via telnet myself and with that blocking connection from the smsd
- Putting a new SMS in
- If at this point, within some seconds I do not end the telnet session and "free it up", it will end up in this cycle:


2023-10-10 12:47:14,5, smsd: SMS To: xxxxxxx. Moved file /var/spool/sms/outgoing/Test-SMS15 to /var/spool/sms/checked 2023-10-10 12:47:14,3, GSM1: Couldn't connect socket @IP:PORT, error: Connection refused, waiting 5 sec. 2023-10-10 12:47:19,6, GSM1: Couldn't connect socket @IP:PORT, error: Connection refused, waiting 5 sec. 2023-10-10 12:47:24,6, GSM1: Couldn't connect socket @IP:PORT, error: Connection refused, waiting 5 sec. 2023-10-10 12:47:29,6, GSM1: Couldn't connect socket @IP:PORT, error: Connection refused, waiting 5 sec. 2023-10-10 12:47:34,6, GSM1: Couldn't connect socket @IP:PORT, error: Connection refused, waiting 5 sec. 2023-10-10 12:47:39,6, GSM1: Couldn't connect socket @IP:PORT, error: Connection refused, waiting 5 sec. 2023-10-10 12:47:44,6, GSM1: Couldn't connect socket @IP:PORT, error: Connection refused, waiting 5 sec. 2023-10-10 12:47:49,6, GSM1: Couldn't connect socket @IP:PORT, error: Connection refused, waiting 5 sec. 2023-10-10 12:47:54,6, GSM1: Couldn't connect socket @IP:PORT, error: Connection refused, waiting 5 sec. 2023-10-10 12:47:59,6, GSM1: Couldn't connect socket @IP:PORT, error: Connection refused, waiting 5 sec. 2023-10-10 12:48:04,6, GSM1: Couldn't connect socket @IP:PORT, error: Connection refused, waiting 5 sec. 2023-10-10 12:48:09,3, GSM1: Cannot open socket @IP:PORT, error: Connection refused 2023-10-10 12:48:09,2, GSM1: Modem handler 0 terminated. PID: 1661, was started 23-10-10 12:46:43, up 1 min. 2023-10-10 12:48:10,2, smsd: Modem handler 0 (GSM1) terminated while mainprocess is still running. Exited, status 127.

Note that, the service was configured to never give up, and retry again and again - however, after one minute it does disables the modem handler permanently and never recovers. Only if I restart the complete service it will send out the SMS. How can we fix that?

Thanks a lot

In this case, the naming of the smsd settings may not be as clear as possible. When the device is a socket, the settings that affect it are called socket_connection_alarm_after, socket_connection_errorsleeptime and socket_connection_retries. I don't remember why these were given their own names back in the day. But using these you may make the daemon try endlessly.

However, some possible errors are such that smsd cannot handle them. It would be a good idea to use the alarmhandler feature and monitor what kind of notifications smsd gives in different situations. A situation where smsd does not resolve itself can be solved in a suitable way and, for example, get smsd to restart if necessary.

Parameters of alarmhandler are documented here.

Excellent, thank you very much, with changes to the socket_connection parameters it works.
Sorry for my oversight!