Hello, I'm using Kannel since few years as a core for gateway based on GSM modems (AT). Since few days I've got a problem with DLRs. I'm receiving only DLRs for some messages (before DLRs for all SMS were delivered correctly). No configuration changes were made from that time on my side. I've looked into logs and have seen that when receiving DLRs sometimes all is ok and sometimes there is "could not decode PDU to a message" message.
2012-08-28 09:22:01 [3626] [42] DEBUG: AT2[modem_032]: <-- +CDSI: "SM",0 2012-08-28 09:22:01 [3626] [42] DEBUG: AT2[modem_032]: +CMTI incoming SMS indication: +CDSI: "SM",0 2012-08-28 09:22:01 [3626] [42] DEBUG: AT2[modem_032]: <-- ^MODE:3,3 2012-08-28 09:22:02 [3626] [42] DEBUG: AT2[modem_032]: --> AT+CMGR=0^M 2012-08-28 09:22:02 [3626] [42] DEBUG: AT2[modem_032]: <-- +CMGR: 0,,25 2012-08-28 09:22:02 [3626] [42] DEBUG: AT2[modem_032]: <-- 07918405210077F79EC00B918405566182F6218082900332802180829003828000 2012-08-28 09:22:02 [3626] [42] DEBUG: AT2[modem_032]: received message from SMSC: +48501200777 2012-08-28 09:22:02 [3626] [42] ERROR: AT2[modem_032]: could not decode PDU to a message. 2012-08-28 09:22:02 [3626] [42] DEBUG: AT2[modem_032]: <-- OK ...but some DLRs are processed correctly: 2012-08-28 08:48:54 [3626] [42] DEBUG: AT2[modem_032]: <-- +CDSI: "SM",0 2012-08-28 08:48:54 [3626] [42] DEBUG: AT2[modem_032]: +CMTI incoming SMS indication: +CDSI: "SM",0 2012-08-28 08:48:54 [3626] [42] DEBUG: AT2[modem_032]: <-- ^MODE:3,3 2012-08-28 08:48:56 [3626] [42] DEBUG: AT2[modem_032]: --> AT+CMGR=0^M 2012-08-28 08:48:56 [3626] [42] DEBUG: AT2[modem_032]: <-- +CMGR: 0,,25 2012-08-28 08:48:56 [3626] [42] DEBUG: AT2[modem_032]: <-- 07918405210077F706B90B918405693009F2218082807541802180828075918000 2012-08-28 08:48:56 [3626] [42] DEBUG: AT2[modem_032]: received message from SMSC: +48501200777 2012-08-28 08:48:56 [3626] [42] DEBUG: AT2[modem_032]: got STATUS-REPORT for message <185>: 2012-08-28 08:48:56 [3626] [42] DEBUG: AT2[modem_032]: Numeric receiver (international) <+48509603XXX> I've decoded both PDUs using a tool from http://www.diafaan.com/sms-tutorials/gsm-modem-tutorial/online-sms-pdu-decoder/ and both could be decoded properly (as SMS-STATUS-REPORT). The one difference between those PDUs is that 07918405210077F706B90B918405693009F2218082807541802180828075918000 has PDU header: 06 and 07918405210077F79EC00B918405566182F6218082900332802180829003828000 has PDU header: 9E. I've made more tests and have seen that all DLRs with PDU header: 06 are decoded by kannel and processed correctly, but when PDU header: 9E than DLR isn't decoded properly and in logs there is "could not decode PDU to a message" message. Probably my GSM operator made some modifications and it delivers DLRs with 9E and 06 headers. I've looked into kannel source code but I can't find a place where to make modifications to have kannel decode PDU with 9E header correctly. Could you help me? Tomasz
