(This question is a re-post, I posted it on March 28 but did not get any responses. Hopefully this time possibly somebody who can answer the question will notice it.)
We're currently running an install of Kannel 1.4.3-0ubuntu2 (as installed from the Ubuntu respositories) with a Multi-Tech MTCBA-G-F4 (http://www.multitech.com/en_US/products/families/multimodemgprs/) running to deliver SMS messages. We've experienced twice so far over a few months (rarely) that the modem appears to lose connectivity to the GSM operator. This is what happens then (the SMS PDU has been redacted for confidentiality reasons) 2011-03-25 08:58:06 [14228] [8] DEBUG: boxc_receiver: sms received 2011-03-25 08:58:06 [14228] [8] DEBUG: send_msg: sending msg to box: <127.0.0.1> 2011-03-25 08:58:08 [14228] [6] DEBUG: AT2[multitech-modem-1]: TP-Validity-Period: 24.0 hours 2011-03-25 08:58:08 [14228] [6] DEBUG: AT2[multitech-modem-1]: --> AT+CMGS=50^M 2011-03-25 08:58:08 [14228] [6] DEBUG: AT2[multitech-modem-1]: <-- > 2011-03-25 08:58:08 [14228] [6] DEBUG: AT2[multitech-modem-1]: send command status: 1 2011-03-25 08:58:08 [14228] [6] DEBUG: AT2[multitech-modem-1]: --> [redacted] 2011-03-25 08:58:08 [14228] [6] DEBUG: AT2[multitech-modem-1]: --> ^Z 2011-03-25 08:58:09 [14228] [6] DEBUG: AT2[multitech-modem-1]: <-- > 2011-03-25 08:58:09 [14228] [6] DEBUG: AT2[multitech-modem-1]: <-- ERROR 2011-03-25 08:58:09 [14228] [6] ERROR: AT2[multitech-modem-1]: Generic error: ERROR 2011-03-25 08:58:09 [14228] [6] DEBUG: AT2[multitech-modem-1]: send command status: -1 At this point, a restart of Kannel is not sufficient to get SMS delivery working again. What I've had to do is to shut down Kannel, then use Minicom to send an "AT+CFUN=1" command to the modem. This command is used to perform a reset on the modem, as per the documentation available from Multitech at http://www.multitech.com/en_US/DOCUMENTS/Collateral/manuals/S000293J.pdf (page 16). Now, this is a pain to have to do manually, so ideally what I'd like to do is to make it so that Kannel will automatically restart the modem if it runs into any difficulty. Adding AT+CFUN=1 to the modem initialization string should mean that the modem is automatically restarted whenever Kannel is (I have not tested this...) but that only solves half the problem - the other half is to automatically re-initialize the modem whenever there's an ERROR like that. Is there any convenient way to do this, perhaps I'm running an antiquated version of Kannel and this functionality already exists in a later version? Or is the only way to change this behaviour to change the AT2 driver itself?
