On gw/smsc/smsc_smpp.c is defined smpp_status_to_smscconn_failure_reason that defines the retry policy in base of submit_sm_resp response.
As far as i can see SMPP_ESME_RTHROTTLED (throttling error) is marked as SMSCCONN_FAILED_TEMPORARILY so it should generate retry attempts. Enable debug log on bearerbox and check for "SMSC returned error code" lines. Regards, Vangelis static long smpp_status_to_smscconn_failure_reason(long status) { switch(status) { case SMPP_ESME_RMSGQFUL: case SMPP_ESME_RTHROTTLED: case SMPP_ESME_RX_T_APPN: case SMPP_ESME_RSYSERR: return SMSCCONN_FAILED_TEMPORARILY; break; default: return SMSCCONN_FAILED_REJECTED; } } From: Fajar<mailto:bebas...@yahoo.com> Sent: Saturday, October 22, 2016 4:58 AM To: Giulio Giovannini<mailto:giulio.giovann...@mobyt.it>; users@kannel.org<mailto:users@kannel.org> Subject: Re: SMS REJECTED due to throttling you'll need to reduce, by setting throughput. document doesn't say about temporary condition, it will discard it, but if you put delivery report url, it will call back with spesific status, in my setting, it is set as 16. my application will hit the message again, to queue in kannel... ________________________________ From: Giulio Giovannini <giulio.giovann...@mobyt.it> To: users@kannel.org Sent: Friday, 21 October 2016, 23:22 Subject: SMS REJECTED due to throttling Hi all, I have recently moved some UCP connections from kannel 1.4 to kannel 1.5. I am pretty sure that when kannel 1.4 received a NACK 04 (throttling) it considered it as temporary error and retried. Version 1.5 seems to consider it a permanent error and discards the SMS. Have a look at this log sequence from bearer-access.log: 2016-10-21 09:31:25 REJECTED Send SMS [SMSC:FO_HQS] [SVC:C00127_001] [ACT:433f083f-209f-4f62-979f-ae82b5742c90] [BINF:] [FID:8609681] [META:] [from:J.UNIVERSE] [to:+33682412951] [flags:-1:0:-1:-1:11] [msg:159:xxx] [udh:0:] 2016-10-21 09:31:25 Receive DLR [SMSC:FO_HQS] [SVC:C00127_001] [ACT:] [BINF:] [FID:8609681] [META:?orig_msg?dlr_mask=11&] [from:J.UNIVERSE] [to:+33682412951] [flags:-1:-1:-1:-1:16] [msg:24:NACK/04-Throttling error] [udh:0:] Should I set something in the conf to tell kannel that that error is temporary? Thanks, Giulio Giovannini