nRF9160 MQTT - Receiving large (over 2kB) messages causing a disconnect

Question

Hi 
 
 MQTT large message receiving when trying to obtain certs from aws... 
 
 Setup 
 Modem: 1.3.3 
 nRF Connect: 2.3.0 
 
 I have seen posts 254191 & 303100 that relate to this this and discuss a number of work arounds. To replicate I have removed all custom code and running example code on the dk 
 
 Running serial_lte_modem example and implementing native_tls 
 testing against aws iot core (secure) , and hivemq (unsecure) 
 The data limit is in the low 2300's as the payload/topic combined. This points me away from the 2kB secure buffer as mentioned in 303100 
 Increased buffers in the native overlay 
 
 also found and increased the below in slm_defines.h this has little effect. 
 
 // #define SLM_AT_MAX_RSP_LEN 2100 
 #define SLM_AT_MAX_RSP_LEN 4096

// #define SLM_MAX_MESSAGE_SIZE NRF_SOCKET_TLS_MAX_MESSAGE_SIZE 
 #define SLM_MAX_MESSAGE_SIZE 4096

snap shot of log 
 #XMQTTEVT: 7,0 
 #XMQTTMSG: 21,10 
 nrf91/slm/mqtt/topic0 
 aaaasdfsad 
 
 #XMQTTEVT: 2,0 
 #XMQTTMSG: 21,10 
 nrf91/slm/mqtt/topic0 
 aaaasdfsad 
 
 #XMQTTEVT: 2,0 
 #XMQTTEVT: 1,-113 
 %CESQ: 68,3,17,2 
 %CESQ: 255,0,255,0 
 
 any help much appreciated 
 Trent

gotrentus · Accepted Answer

Hi Charlie, i got it to work, using the following commands to load certs AT#XCMNG=0,1111,0," AT#XCMNG=0,1111,1," AT#XCMNG=0,1111,2," the key is to not use LTE Link Monitor, as the issues is how the LF / CR LF's are handled. I was advised to use Teraterm, making sure to set the new line transmit value to CR+LF That way the LF within the Cert that AWS generates is replaced correctly. I had previously tried adding the CR manually to each line in notepad++ but it doesn't appear to have the same effect. if anyone gets stuck on this, please sing out. again Charlie, thanks heaps for your help , it's appreciated! cheers Trent

gotrentus · Answer

Hi Charlie, 
 my bad, the case was 299891 nRF9160, SLM Firmware behaves incorrectly after activating Native TLS (critical problems) 
 thanks, i will check that link out.

nRF9160 MQTT - Receiving large (over 2kB) messages causing a disconnect

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