Operating system name and version: Centos 6
Version of smsd: v3.1.15
Smsd installed from: package repository
Name and model of a modem / phone: Nokia 30 and iRZ MC55iT
Interface: both modems have serial and connected via usb2com adapters ATEN UC232A

For now, we have round robin configuration so no matter from what modem is used for sending.
But we found some problem, example:
Our monitoring system send 2 messages to smstools.
Smstools send sms about problem via first modem.
Then it sends second via second modem.

Problem in todays smartphones, those 2 sms from different numbers is not become available in one conversation.
Exept windows smartphones, sms from different numbers is always different conversations.
It's uncomfortable for users to search and etc.

How can i configure smstools remember, that if it sends first sms to user mobile via first gsm modem, so next sms to same user goes via same modem if it works.
Same with another user2 mobile, if it send him sms via second modem, so next sms to shis user2 goes via same modem.

Is it even possible to have something like roundrobin with memory on smstools?

You need to use queues. In the smsd.conf, define:



For the modems define like this:


With these definitions you can select the queue ( = modem) in the message file, using Queue: GSM1 header, for example. If no header is defined, the modem which first picks up the message, will send it, as they work now.

Your monitoring system could now choose the queue, and add the header. This exactly is not what you asked, but it's how queues can work.

If you want SMSTools to remember what queue was used for some destination, you could use the checkhandler for this. The script (which you have to write) could get the destination number, and check from SQL database if some specific queue should be used for that number. If queue is not found, the script could randomly select the queue and store it to the database. Write the selected or found queue to the message file, and proper modem will be used for sending.

This is external functionality for smsd, and I do not remember if here are any samples for it.

Thanks for idea.
We will look into it.