nRF9160 MQTT message payload over 2302 bytes results in Socket error: POLLERR and dropped connection

[devincmurphy7]

Setup:

Modem firmware: mfw_nrf9160_1.3.2

nRF Connect SDK v2.1.2

nRF Connect for VS Code v2023.1.44

Windows 11

We are connecting to AWS over MQTT and subscribing to 1 message topic. If we publish to that topic from another device with a payload larger than 2302 bytes, the nRF9160 device gets Socket error: POLLERR and the AWS connection is dropped. There are not any other errors that appear in my log.

I found another forum post ("nRF9160 issue in receiving MQTT publish messages larger than 2048 bytes over TLS" Case ID: 254191) which seems to be the exact same problem. There were some workarounds mentioned that involved reducing the size of the MQTT message, but I am wondering if there is now any way to get around this without reducing the size of the MQTT message? Also is there going to be a "fix" to this problem at any point?

Fullscreen FailureLog.txt Download

[2023-02-16 15:04:24.337] [74636725] <dbg> net_mqtt_sock_tls: (0x2000e310): Created socket 0
[2023-02-16 15:04:34.258] [74970250] <dbg> net_mqtt_sock_tls: (0x2000e310): Connect completed
[2023-02-16 15:04:34.258] [74970267] <dbg> net_mqtt_enc: Encoding Protocol Description.
[2023-02-16 15:04:34.258]                                4d 51 54 54                                      |MQTT             
[2023-02-16 15:04:34.258] [74970268] <dbg> net_mqtt_enc: (0x2000e310): >> str_size:00000006 cur:0x20026645, end:0x20027840
[2023-02-16 15:04:34.258] [74970269] <dbg> net_mqtt_enc: (0x2000e310): >> val:0004 cur:0x20026645, end:0x20027840
[2023-02-16 15:04:34.258] [74970272] <dbg> net_mqtt_enc: (0x2000e310): Encoding Protocol Version 04.
[2023-02-16 15:04:34.258] [74970273] <dbg> net_mqtt_enc: (0x2000e310): >> val:04 cur:0x2002664b, end:0x20027840
[2023-02-16 15:04:34.258] [74970273] <dbg> net_mqtt_enc: (0x2000e310): >> val:00 cur:0x2002664c, end:0x20027840
[2023-02-16 15:04:34.258] [74970274] <dbg> net_mqtt_enc: (0x2000e310): Encoding Keep Alive Time 0384.
[2023-02-16 15:04:34.258] [74970275] <dbg> net_mqtt_enc: (0x2000e310): >> val:0384 cur:0x2002664d, end:0x20027840
[2023-02-16 15:04:34.258] [74970275] <dbg> net_mqtt_enc: Encoding Client Id.
[2023-02-16 15:04:34.258]                                64 65 76 69 6e 2d 63 65  6c 6c 2d 74 65 73 74    |devin-ce ll-test 
[2023-02-16 15:04:34.260] [74970276] <dbg> net_mqtt_enc: (0x2000e310): >> str_size:00000011 cur:0x2002664f, end:0x20027840
[2023-02-16 15:04:34.260] [74970277] <dbg> net_mqtt_enc: (0x2000e310): >> val:000f cur:0x2002664f, end:0x20027840
[2023-02-16 15:04:34.260] [74970278] <dbg> net_mqtt_enc: Encoding Will Topic.
[2023-02-16 15:04:34.260]                                6c 61 73 74 77 69 6c 6c  74 6f 70 69 63          |lastwill topic   
[2023-02-16 15:04:34.260] [74970278] <dbg> net_mqtt_enc: (0x2000e310): >> str_size:0000000f cur:0x20026660, end:0x20027840
[2023-02-16 15:04:34.260] [74970279] <dbg> net_mqtt_enc: (0x2000e310): >> val:000d cur:0x20026660, end:0x20027840
[2023-02-16 15:04:34.260] [74970280] <dbg> net_mqtt_enc: Encoding Will Message.
[2023-02-16 15:04:34.260]                                7b 22 6c 61 73 74 77 69  6c 6c 22 3a 20 22 6f 66 |{"lastwi ll": "of
[2023-02-16 15:04:34.260]                                66 6c 69 6e 65 22 7d                             |fline"}          
[2023-02-16 15:04:34.260] [74970281] <dbg> net_mqtt_enc: (0x2000e310): >> str_size:00000019 cur:0x2002666f, end:0x20027840
[2023-02-16 15:04:34.260] [74970281] <dbg> net_mqtt_enc: (0x2000e310): >> val:0017 cur:0x2002666f, end:0x20027840
[2023-02-16 15:04:34.262] [74970282] <dbg> net_mqtt_enc: (0x2000e310): << msg type:0x10 length:0x00000043
[2023-02-16 15:04:34.262] [74970283] <dbg> net_mqtt_enc: (0x2000e310): >> length:0x00000043 cur:(nil), end:(nil)
[2023-02-16 15:04:34.262] [74970285] <dbg> net_mqtt_enc: (0x2000e310): Fixed header length = 02
[2023-02-16 15:04:34.262] [74970286] <dbg> net_mqtt_enc: (0x2000e310): >> val:10 cur:0x20026643, end:0x20027840
[2023-02-16 15:04:34.262] [74970287] <dbg> net_mqtt_enc: (0x2000e310): >> length:0x00000043 cur:0x20026644, end:0x20027840
[2023-02-16 15:04:34.262] [74977889] <inf> net_mqtt: Connect completed
[2023-02-16 15:04:34.262] [74977903] <dbg> loggers: 2023-02-16 21:04:32 debug aws_iot.c:545: Using send socket timeout of 60 seconds
[2023-02-16 15:04:34.262] [74977915] <dbg> loggers: 2023-02-16 21:04:32 debug aws_iot.c:800: AWS IoT broker connection request sent
[2023-02-16 15:04:34.450] [74985373] <dbg> loggers: 2023-02-16 21:04:32 debug aws_iot.c:592: mqtt_input call
[2023-02-16 15:04:34.720] [74985374] <dbg> net_mqtt: (0x2000e310): state:0x00000002
[2023-02-16 15:04:34.720] [74985375] <dbg> net_mqtt_dec: (0x2000e310): >> cur:0x20025440, end:0x20025442
[2023-02-16 15:04:34.720] [74985378] <dbg> net_mqtt_dec: (0x2000e310): << val:20
[2023-02-16 15:04:34.720] [74985379] <dbg> net_mqtt_dec: (0x2000e310): length:0x00000002
[2023-02-16 15:04:34.720] [74985382] <dbg> net_mqtt_rx: (0x2000e310): [CID 0x20010610]: Received MQTT_PKT_TYPE_CONNACK!
[2023-02-16 15:04:34.720] [74985383] <dbg> net_mqtt_dec: (0x2000e310): >> cur:0x20025442, end:0x20025444
[2023-02-16 15:04:34.720] [74985384] <dbg> net_mqtt_dec: (0x2000e310): << val:00
[2023-02-16 15:04:34.720] [74985384] <dbg> net_mqtt_dec: (0x2000e310): >> cur:0x20025443, end:0x20025444
[2023-02-16 15:04:34.720] [74985385] <dbg> net_mqtt_dec: (0x2000e310): << val:00
[2023-02-16 15:04:34.720] [74985385] <dbg> net_mqtt_dec: (0x2000e310): [CID 0x20010610]: session_present_flag: 0
[2023-02-16 15:04:34.720] [74985386] <dbg> net_mqtt_rx: (0x2000e310): [CID 0x20010610]: return_code: 0
[2023-02-16 15:04:34.720] [74985398] <dbg> loggers: 2023-02-16 21:04:32 debug aws_iot.c:219: MQTT client connected!
[2023-02-16 15:04:34.722] [74989038] <dbg> loggers: 2023-02-16 21:04:32 debug aws_iot.c:229: Subscribing to topics
[2023-02-16 15:04:34.722] [74989052] <dbg> loggers: 2023-02-16 21:04:32 debug aws_iot.c:132: Subscribing to application topic: curb/messages/devin-cell-test
[2023-02-16 15:04:34.722] [74989053] <dbg> net_mqtt: (0x2000e310): [CID 0x20010610]:[State 0x06]: >> message id 0x3def topic count 0x0001
[2023-02-16 15:04:34.722] [74989070] <dbg> net_mqtt_enc: (0x2000e310): >> val:3def cur:0x20026645, end:0x20027840
[2023-02-16 15:04:34.722] [74989070] <dbg> net_mqtt_enc: (0x2000e310): >> str_size:0000001f cur:0x20026647, end:0x20027840
[2023-02-16 15:04:34.724] [74989071] <dbg> net_mqtt_enc: (0x2000e310): >> val:001d cur:0x20026647, end:0x20027840
[2023-02-16 15:04:34.724] [74989074] <dbg> net_mqtt_enc: (0x2000e310): >> val:01 cur:0x20026666, end:0x20027840
[2023-02-16 15:04:34.724] [74989074] <dbg> net_mqtt_enc: (0x2000e310): << msg type:0x82 length:0x00000022
[2023-02-16 15:04:34.724] [74989075] <dbg> net_mqtt_enc: (0x2000e310): >> length:0x00000022 cur:(nil), end:(nil)
[2023-02-16 15:04:34.724] [74989076] <dbg> net_mqtt_enc: (0x2000e310): Fixed header length = 02
[2023-02-16 15:04:34.724] [74989076] <dbg> net_mqtt_enc: (0x2000e310): >> val:82 cur:0x20026643, end:0x20027840
[2023-02-16 15:04:34.724] [74989077] <dbg> net_mqtt_enc: (0x2000e310): >> length:0x00000022 cur:0x20026644, end:0x20027840
[2023-02-16 15:04:34.724] [74989078] <dbg> net_mqtt: (0x2000e310): [0x20010610]: Transport writing 36 bytes.
[2023-02-16 15:04:35.232] [74994021] <dbg> net_mqtt: (0x2000e310): [0x20010610]: Transport write complete.
[2023-02-16 15:04:35.232] [74994022] <dbg> net_mqtt: (0x2000e310): [CID 0x20010610]:[State 0x06]: << result 0x00000000
[2023-02-16 15:04:35.232] [75004213] <dbg> loggers: 2023-02-16 21:04:33 debug aws_iot.c:592: mqtt_input call
[2023-02-16 15:04:35.232] [75004215] <dbg> net_mqtt: (0x2000e310): state:0x00000006
[2023-02-16 15:04:35.232] [75004217] <dbg> net_mqtt_dec: (0x2000e310): >> cur:0x20025440, end:0x20025442
[2023-02-16 15:04:35.232] [75004217] <dbg> net_mqtt_dec: (0x2000e310): << val:90
[2023-02-16 15:04:35.232] [75004218] <dbg> net_mqtt_dec: (0x2000e310): length:0x00000003
[2023-02-16 15:04:35.232] [75004223] <dbg> net_mqtt_rx: (0x2000e310): [CID 0x20010610]: Received MQTT_PKT_TYPE_SUBACK!
[2023-02-16 15:04:35.232] [75004223] <dbg> net_mqtt_dec: (0x2000e310): >> cur:0x20025442, end:0x20025445
[2023-02-16 15:04:35.232] [75004224] <dbg> net_mqtt_dec: (0x2000e310): << val:3def
[2023-02-16 15:04:35.232] [75004225] <dbg> net_mqtt_dec: (0x2000e310): >> cur:0x20025444, end:0x20025445
[2023-02-16 15:04:35.232] [75004225] <dbg> net_mqtt_dec: (0x2000e310): << bin len:00000001
[2023-02-16 15:04:46.896] [75390083] <dbg> loggers: 2023-02-16 21:04:44 debug aws_iot.c:880: Socket error: POLLERR
[2023-02-16 15:04:46.897] [75390096] <dbg> loggers: 2023-02-16 21:04:44 debug aws_iot.c:881: Cloud connection was unexpectedly closed.
[2023-02-16 15:04:46.897] [75390108] <dbg> loggers: 2023-02-16 21:04:44 debug aws_iot.c:894: Forcing disconnect

Fullscreen SuccessLog.txt Download

[2023-02-16 15:03:24.294] [72669313] <dbg> net_mqtt_sock_tls: (0x2000e310): Created socket 0
[2023-02-16 15:03:35.375] [73040727] <dbg> net_mqtt_sock_tls: (0x2000e310): Connect completed
[2023-02-16 15:03:35.375] [73040745] <dbg> net_mqtt_enc: Encoding Protocol Description.
[2023-02-16 15:03:35.375]                                4d 51 54 54                                      |MQTT             
[2023-02-16 15:03:35.375] [73040745] <dbg> net_mqtt_enc: (0x2000e310): >> str_size:00000006 cur:0x20026645, end:0x20027840
[2023-02-16 15:03:35.375] [73040747] <dbg> net_mqtt_enc: (0x2000e310): >> val:0004 cur:0x20026645, end:0x20027840
[2023-02-16 15:03:35.375] [73040747] <dbg> net_mqtt_enc: (0x2000e310): Encoding Protocol Version 04.
[2023-02-16 15:03:35.375] [73040748] <dbg> net_mqtt_enc: (0x2000e310): >> val:04 cur:0x2002664b, end:0x20027840
[2023-02-16 15:03:35.375] [73040749] <dbg> net_mqtt_enc: (0x2000e310): >> val:00 cur:0x2002664c, end:0x20027840
[2023-02-16 15:03:35.375] [73040749] <dbg> net_mqtt_enc: (0x2000e310): Encoding Keep Alive Time 0384.
[2023-02-16 15:03:35.375] [73040750] <dbg> net_mqtt_enc: (0x2000e310): >> val:0384 cur:0x2002664d, end:0x20027840
[2023-02-16 15:03:35.375] [73040753] <dbg> net_mqtt_enc: Encoding Client Id.
[2023-02-16 15:03:35.375]                                64 65 76 69 6e 2d 63 65  6c 6c 2d 74 65 73 74    |devin-ce ll-test 
[2023-02-16 15:03:35.378] [73040753] <dbg> net_mqtt_enc: (0x2000e310): >> str_size:00000011 cur:0x2002664f, end:0x20027840
[2023-02-16 15:03:35.378] [73040754] <dbg> net_mqtt_enc: (0x2000e310): >> val:000f cur:0x2002664f, end:0x20027840
[2023-02-16 15:03:35.378] [73040755] <dbg> net_mqtt_enc: Encoding Will Topic.
[2023-02-16 15:03:35.378]                                6c 61 73 74 77 69 6c 6c  74 6f 70 69 63          |lastwill topic   
[2023-02-16 15:03:35.378] [73040756] <dbg> net_mqtt_enc: (0x2000e310): >> str_size:0000000f cur:0x20026660, end:0x20027840
[2023-02-16 15:03:35.378] [73040756] <dbg> net_mqtt_enc: (0x2000e310): >> val:000d cur:0x20026660, end:0x20027840
[2023-02-16 15:03:35.378] [73040757] <dbg> net_mqtt_enc: Encoding Will Message.
[2023-02-16 15:03:35.378]                                7b 22 6c 61 73 74 77 69  6c 6c 22 3a 20 22 6f 66 |{"lastwi ll": "of
[2023-02-16 15:03:35.378]                                66 6c 69 6e 65 22 7d                             |fline"}          
[2023-02-16 15:03:35.378] [73040758] <dbg> net_mqtt_enc: (0x2000e310): >> str_size:00000019 cur:0x2002666f, end:0x20027840
[2023-02-16 15:03:35.378] [73040759] <dbg> net_mqtt_enc: (0x2000e310): >> val:0017 cur:0x2002666f, end:0x20027840
[2023-02-16 15:03:35.379] [73040760] <dbg> net_mqtt_enc: (0x2000e310): << msg type:0x10 length:0x00000043
[2023-02-16 15:03:35.379] [73040760] <dbg> net_mqtt_enc: (0x2000e310): >> length:0x00000043 cur:(nil), end:(nil)
[2023-02-16 15:03:35.379] [73040761] <dbg> net_mqtt_enc: (0x2000e310): Fixed header length = 02
[2023-02-16 15:03:35.379] [73040761] <dbg> net_mqtt_enc: (0x2000e310): >> val:10 cur:0x20026643, end:0x20027840
[2023-02-16 15:03:35.379] [73040762] <dbg> net_mqtt_enc: (0x2000e310): >> length:0x00000043 cur:0x20026644, end:0x20027840
[2023-02-16 15:03:35.379] [73048374] <inf> net_mqtt: Connect completed
[2023-02-16 15:03:35.379] [73048388] <dbg> loggers: 2023-02-16 21:03:33 debug aws_iot.c:545: Using send socket timeout of 60 seconds
[2023-02-16 15:03:35.379] [73048400] <dbg> loggers: 2023-02-16 21:03:33 debug aws_iot.c:800: AWS IoT broker connection request sent
[2023-02-16 15:03:35.503] [73053797] <dbg> loggers: 2023-02-16 21:03:33 debug aws_iot.c:592: mqtt_input call
[2023-02-16 15:03:35.779] [73053798] <dbg> net_mqtt: (0x2000e310): state:0x00000002
[2023-02-16 15:03:35.779] [73053802] <dbg> net_mqtt_dec: (0x2000e310): >> cur:0x20025440, end:0x20025442
[2023-02-16 15:03:35.779] [73053803] <dbg> net_mqtt_dec: (0x2000e310): << val:20
[2023-02-16 15:03:35.779] [73053803] <dbg> net_mqtt_dec: (0x2000e310): length:0x00000002
[2023-02-16 15:03:35.779] [73053806] <dbg> net_mqtt_rx: (0x2000e310): [CID 0x20010610]: Received MQTT_PKT_TYPE_CONNACK!
[2023-02-16 15:03:35.779] [73053807] <dbg> net_mqtt_dec: (0x2000e310): >> cur:0x20025442, end:0x20025444
[2023-02-16 15:03:35.779] [73053808] <dbg> net_mqtt_dec: (0x2000e310): << val:00
[2023-02-16 15:03:35.779] [73053809] <dbg> net_mqtt_dec: (0x2000e310): >> cur:0x20025443, end:0x20025444
[2023-02-16 15:03:35.779] [73053809] <dbg> net_mqtt_dec: (0x2000e310): << val:00
[2023-02-16 15:03:35.779] [73053810] <dbg> net_mqtt_dec: (0x2000e310): [CID 0x20010610]: session_present_flag: 0
[2023-02-16 15:03:35.779] [73053810] <dbg> net_mqtt_rx: (0x2000e310): [CID 0x20010610]: return_code: 0
[2023-02-16 15:03:35.779] [73053823] <dbg> loggers: 2023-02-16 21:03:33 debug aws_iot.c:219: MQTT client connected!
[2023-02-16 15:03:35.781] [73057472] <dbg> loggers: 2023-02-16 21:03:33 debug aws_iot.c:229: Subscribing to topics
[2023-02-16 15:03:35.781] [73057486] <dbg> loggers: 2023-02-16 21:03:33 debug aws_iot.c:132: Subscribing to application topic: curb/messages/devin-cell-test
[2023-02-16 15:03:35.781] [73057487] <dbg> net_mqtt: (0x2000e310): [CID 0x20010610]:[State 0x06]: >> message id 0xc4c1 topic count 0x0001
[2023-02-16 15:03:35.781] [73057504] <dbg> net_mqtt_enc: (0x2000e310): >> val:c4c1 cur:0x20026645, end:0x20027840
[2023-02-16 15:03:35.781] [73057504] <dbg> net_mqtt_enc: (0x2000e310): >> str_size:0000001f cur:0x20026647, end:0x20027840
[2023-02-16 15:03:35.782] [73057505] <dbg> net_mqtt_enc: (0x2000e310): >> val:001d cur:0x20026647, end:0x20027840
[2023-02-16 15:03:35.782] [73057506] <dbg> net_mqtt_enc: (0x2000e310): >> val:01 cur:0x20026666, end:0x20027840
[2023-02-16 15:03:35.782] [73057506] <dbg> net_mqtt_enc: (0x2000e310): << msg type:0x82 length:0x00000022
[2023-02-16 15:03:35.782] [73057507] <dbg> net_mqtt_enc: (0x2000e310): >> length:0x00000022 cur:(nil), end:(nil)
[2023-02-16 15:03:35.782] [73057508] <dbg> net_mqtt_enc: (0x2000e310): Fixed header length = 02
[2023-02-16 15:03:35.782] [73057508] <dbg> net_mqtt_enc: (0x2000e310): >> val:82 cur:0x20026643, end:0x20027840
[2023-02-16 15:03:35.782] [73057511] <dbg> net_mqtt_enc: (0x2000e310): >> length:0x00000022 cur:0x20026644, end:0x20027840
[2023-02-16 15:03:35.782] [73057512] <dbg> net_mqtt: (0x2000e310): [0x20010610]: Transport writing 36 bytes.
[2023-02-16 15:03:36.307] [73062468] <dbg> net_mqtt: (0x2000e310): [0x20010610]: Transport write complete.
[2023-02-16 15:03:36.307] [73062470] <dbg> net_mqtt: (0x2000e310): [CID 0x20010610]:[State 0x06]: << result 0x00000000
[2023-02-16 15:03:36.307] [73073331] <dbg> loggers: 2023-02-16 21:03:34 debug aws_iot.c:592: mqtt_input call
[2023-02-16 15:03:36.307] [73073333] <dbg> net_mqtt: (0x2000e310): state:0x00000006
[2023-02-16 15:03:36.307] [73073335] <dbg> net_mqtt_dec: (0x2000e310): >> cur:0x20025440, end:0x20025442
[2023-02-16 15:03:36.307] [73073335] <dbg> net_mqtt_dec: (0x2000e310): << val:90
[2023-02-16 15:03:36.307] [73073336] <dbg> net_mqtt_dec: (0x2000e310): length:0x00000003
[2023-02-16 15:03:36.307] [73073339] <dbg> net_mqtt_rx: (0x2000e310): [CID 0x20010610]: Received MQTT_PKT_TYPE_SUBACK!
[2023-02-16 15:03:36.307] [73073340] <dbg> net_mqtt_dec: (0x2000e310): >> cur:0x20025442, end:0x20025445
[2023-02-16 15:03:36.307] [73073340] <dbg> net_mqtt_dec: (0x2000e310): << val:c4c1
[2023-02-16 15:03:36.307] [73073341] <dbg> net_mqtt_dec: (0x2000e310): >> cur:0x20025444, end:0x20025445
[2023-02-16 15:03:36.307] [73073342] <dbg> net_mqtt_dec: (0x2000e310): << bin len:00000001
[2023-02-16 15:03:48.497] [73478768] <dbg> loggers: 2023-02-16 21:03:46 debug aws_iot.c:592: mqtt_input call
[2023-02-16 15:03:48.855] [73478769] <dbg> net_mqtt: (0x2000e310): state:0x00000006
[2023-02-16 15:03:48.855] [73478773] <dbg> net_mqtt_dec: (0x2000e310): >> cur:0x20025440, end:0x20025442
[2023-02-16 15:03:48.855] [73478774] <dbg> net_mqtt_dec: (0x2000e310): << val:30
[2023-02-16 15:03:48.855] [73478776] <dbg> net_mqtt_dec: (0x2000e310): >> cur:0x20025440, end:0x20025443
[2023-02-16 15:03:48.855] [73478776] <dbg> net_mqtt_dec: (0x2000e310): << val:30
[2023-02-16 15:03:48.855] [73478777] <dbg> net_mqtt_dec: (0x2000e310): length:0x0000091d
[2023-02-16 15:03:48.855] [73478780] <dbg> net_mqtt_rx: (0x2000e310): [CID 0x20010610]: Received MQTT_PKT_TYPE_PUBLISH
[2023-02-16 15:03:48.855] [73478780] <dbg> net_mqtt_dec: (0x2000e310): >> cur:0x20025443, end:0x20025462
[2023-02-16 15:03:48.855] [73478781] <dbg> net_mqtt_dec: (0x2000e310): >> cur:0x20025443, end:0x20025462
[2023-02-16 15:03:48.855] [73478782] <dbg> net_mqtt_dec: (0x2000e310): << val:001d
[2023-02-16 15:03:48.855] [73478782] <dbg> net_mqtt_dec: (0x2000e310): << str_size:0000001f
[2023-02-16 15:03:48.855] [73478783] <dbg> net_mqtt_rx: (0x2000e310): PUB QoS:00, message len 000008fe, topic len 0000001d

[Håkon Alseth]

Hi,

 

The modem can handle packet sizes up to 2k buffer size on secure sockets, as stated in the modem release notes (under limitations):

2kB secure socket buffer size.

 

The simplest workaround is to split the packet into two chunks.

The other option, which I do not recommend for your use-case, is to run the TLS stack (mbedtls) in the application, which will require alot of flash/ram usage.

 

Kind regards,

Håkon

[devincmurphy7]

Thank you for the response Hakon.

Yes I saw that limitation note. Is that a hardware limitation or is that a modem firmware limitation and are there plans to increase the size of that buffer?

Is there a notification my application can subscribe to from the modem to be notified when this problem has been encountered? Right now the connection just drops without any real indication of why.

Can you outline the changes required to run the TLS stack in our application, if we want to investigate that option? Or point me to another forum post, document, or example?

Clearly regardless of what we do buffer space on the 9160 is not unlimited, so at some point our server will have to split the messages into smaller pieces. We were just hoping we could get those chunks a bit larger...

[Håkon Alseth]

Hi,

 

devincmurphy7 said:

Can you outline the changes required to run the TLS stack in our application, if we want to investigate that option? Or point me to another forum post, document, or example?

This is the overlay used for using mbedtls in the application core:

https://github.com/nrfconnect/sdk-nrf/blob/main/samples/nrf9160/https_client/overlay-tfm_mbedtls.conf

 

Please note that your certificates will also be placed in the application core.

devincmurphy7 said:

Is there a notification my application can subscribe to from the modem to be notified when this problem has been encountered? Right now the connection just drops without any real indication of why.

No, unfortunately; there is no specific way to detect this in the application.

devincmurphy7 said:

Yes I saw that limitation note. Is that a hardware limitation or is that a modem firmware limitation and are there plans to increase the size of that buffer?

This is due to memory constraints, and will not change for the nrf9160.

 

Kind regards,

Håkon

[devincmurphy7]

Thanks again for your reply Hakon, I believe this answers all my questions.

[Håkon Alseth]

Glad to hear! Let me know if any issues pops up, or you have any questions. Hope you have a wonderful day!

 

Cheers,

Håkon