Maximum payload size for nrf9151 in HEX format

[Juan Martinez Rossi]

Short Summary:

• When setting AT#XSENDTO=0,1,0, maximum size for MO payload is 1401B (1429B with UDP-IPv4 headers)
• When setting AT#XSENDTO=0,0,0, maximum size for MO payload is 1472B (1500B with UDP-IPv4 headers)

Setup description:

Parameter	Value
Previous Machine State Status	Attach Accept (Registered)
Current Machine State Test Status	Standard MO sequence
Nordic FW version	ntn_1.0.0-1.alpha
Nordic Application	serial-LTE.hex
Trace DB	trace_db_external_77723163-4d1e-4a87-bdb9-6719fb216168.tar.gz
Nordic command used	Payload in HEX: AT#XSENDTO=0,1,0,"{UDP_IP}",{UDP_Port},”{payload_content}” Payload in ASCII: AT#XSENDTO=0,0,0,"{UDP_IP}",{UDP_Port},”{payload_content}”

Test Results:

Test #	payload_size (MO)	Payload format	Transport	UDP packet size	Result	Observation
1	1401 B	HEX	UDP/IP	1429 B	Passed	MO successfully visible in our UDP server.
2	1402 B	HEX	UDP/IP	1430 B	Failed	The UE application notifies an ERROR message.
3	1472 B	ASCII	UDP/IP	1500 B	Passed	MO successfully visible in our UDP server.
4	1473 B	ASCII	UDP/IP	1501 B	Failed	Failed as expected, since 1500B is the standard MTU limit. The UE application notifies an ERROR message.

Log files attached.
Our standard modem configuration is detailed in attach-accept-sequence.log.

Fullscreen attach-accept-sequence.log Download

[2026-04-22 11:11:51,4907] [INFO] Resuming with persisted status INIT (updated 2026-04-22T11:11:43.921984+00:00, reason: CEREG state 0 (not registered))
[2026-04-22 11:11:51,4984] [INFO] /************************/
[2026-04-22 11:11:51,4989] [INFO] /* Time Synchronization */
[2026-04-22 11:11:51,4991] [INFO] /************************/
[2026-04-22 11:11:51,5248] [INFO] System timezone already set to UTC.
[2026-04-22 11:11:51,5821] [INFO] Trace capture started on /dev/ttyACM1 at 1000000 baud.
[2026-04-22 11:11:51,5831] [INFO] /***********************************/
[2026-04-22 11:11:51,5847] [INFO] /* Pass window 260422-test_auto_01 */
[2026-04-22 11:11:51,5853] [INFO] /***********************************/
[2026-04-22 11:11:51,5863] [INFO] >>> AT+CEREG?
[2026-04-22 11:11:51,6112] [INFO] <<< +CEREG: 5,0
[2026-04-22 11:11:51,6277] [INFO] <<< OK
[2026-04-22 11:11:51,6370] [INFO] /*************************/
[2026-04-22 11:11:51,6377] [INFO] /* Initial Configuration */
[2026-04-22 11:11:51,6382] [INFO] /*************************/
[2026-04-22 11:11:51,6401] [INFO] >>> AT+CFUN=0
[2026-04-22 11:11:51,6861] [INFO] <<< OK
[2026-04-22 11:11:51,9916] [INFO] >>> AT+CEREG=5
[2026-04-22 11:11:52,0156] [INFO] <<< OK
[2026-04-22 11:11:52,3429] [INFO] >>> AT+CSCON=1
[2026-04-22 11:11:52,3670] [INFO] <<< OK
[2026-04-22 11:11:52,6944] [INFO] >>> AT%xbandlock=0
[2026-04-22 11:11:52,7195] [INFO] <<< OK
[2026-04-22 11:11:53,0458] [INFO] >>> AT%XSYSTEMMODE=0,0,0,0,1
[2026-04-22 11:11:53,0690] [INFO] <<< OK
[2026-04-22 11:11:53,3972] [INFO] >>> AT%XBANDLOCK=1,,"256"
[2026-04-22 11:11:53,4222] [INFO] <<< OK
[2026-04-22 11:11:53,7486] [INFO] >>> AT%CELLULARPRFL=2,0,2,0
[2026-04-22 11:11:53,7740] [INFO] <<< OK
[2026-04-22 11:11:54,1000] [INFO] >>> AT%CELLULARPRFL=2,1,4,0
[2026-04-22 11:11:54,1256] [INFO] <<< OK
[2026-04-22 11:11:54,4517] [INFO] >>> AT%LOCATION=2,"41.3627","2.136","20",0,0
[2026-04-22 11:11:54,4784] [INFO] <<< OK
[2026-04-22 11:11:54,8031] [INFO] >>> AT+COPS=1,2,"<CONFIDENTIAL>"
[2026-04-22 11:11:54,8279] [INFO] <<< OK
[2026-04-22 11:11:55,1543] [INFO] >>> AT%SIBCONFIG=32,0
[2026-04-22 11:11:55,1786] [INFO] <<< OK
[2026-04-22 11:11:55,5052] [INFO] Registration window active (2026-04-22T11:11:51.488477+00:00 to 2026-04-22T11:13:21.488477+00:00 UTC).
[2026-04-22 11:11:55,5061] [INFO] Enabling radio towards pass midpoint.
[2026-04-22 11:11:55,5074] [INFO] >>> AT+CFUN=1
[2026-04-22 11:11:55,5544] [INFO] <<< OK
[2026-04-22 11:12:00,2703] [INFO] <<< +CEREG: 2,"0001","00000001",14
[2026-04-22 11:12:00,2726] [INFO] STATUS change: INIT -> INIT (CEREG state 2 (not registered))
[2026-04-22 11:12:00,2921] [INFO] <<< %SIBCONFIG: 32,"00000001",1,4,1138389,1204387,2656341,3013001,13782,2570283934,23090,-3,134614,,11,11,,,
[2026-04-22 11:12:00,3040] [INFO] <<< %SIBCONFIG: 0
[2026-04-22 11:12:00,7934] [INFO] <<< +CSCON: 1
[2026-04-22 11:12:03,8494] [INFO] <<< +CEREG: 5,"0001","00000001",14,,,"11100000","11100000"
[2026-04-22 11:12:03,8520] [INFO] STATUS change: INIT -> ATTACH_ACCEPT (Attach accepted (mode 5))
[2026-04-22 11:12:03,8524] [INFO] Attach accepted for 260422-test_auto_01 (reason: Attach accepted (mode 5)). NPRACH count: 0.
[2026-04-22 11:12:04,2973] [INFO] <<< OK
[2026-04-22 11:12:30,2672] [INFO] <<< +CSCON: 0
[2026-04-22 11:12:30,9958] [INFO] <<< %SIBCONFIG: 32,"00000001",1,4,1138389,1204387,2656341,3013001,13782,2570283934,23090,-3,134614,,11,11,,,
[2026-04-22 11:12:31,0074] [INFO] <<< %SIBCONFIG: 0
[2026-04-22 11:12:51,5297] [INFO] Applying retain-context (CFUN=45).
[2026-04-22 11:12:51,5309] [INFO] >>> AT+CIMI
[2026-04-22 11:12:51,5559] [INFO] <<< <CONFIDENTIAL>
[2026-04-22 11:12:51,5673] [INFO] <<< OK
[2026-04-22 11:12:51,5819] [INFO] >>> AT#XCLOSE
[2026-04-22 11:12:51,6063] [INFO] <<< #XCLOSE: 0,0
[2026-04-22 11:12:51,6176] [INFO] <<< OK
[2026-04-22 11:12:51,6329] [INFO] >>> AT+CFUN=45
[2026-04-22 11:12:51,7840] [INFO] <<< OK
[2026-04-22 11:12:51,8359] [INFO] Exiting with CFUN=45 due to status ATTACH_ACCEPT.
[2026-04-22 11:12:51,8365] [INFO] Context already retained earlier; skipping additional CFUN=45.
[2026-04-22 11:12:51,8370] [INFO] /************/
[2026-04-22 11:12:51,8378] [INFO] /* Shutdown */
[2026-04-22 11:12:51,8385] [INFO] /************/
[2026-04-22 11:12:52,8089] [INFO] Trace capture stopped.

Fullscreen test#1.log Download

[2026-04-22 08:38:11,1837] [INFO] Resuming with persisted status ATTACH_ACCEPT (updated 2026-04-22T08:23:01.167835+00:00, reason: Context retained after 260422-test_auto_01 attached-pass MO cycle)
[2026-04-22 08:38:11,1881] [INFO] /************************/
[2026-04-22 08:38:11,1886] [INFO] /* Time Synchronization */
[2026-04-22 08:38:11,1888] [INFO] /************************/
[2026-04-22 08:38:11,4481] [INFO] System timezone already set to UTC.
[2026-04-22 08:38:11,5055] [INFO] Trace capture started on /dev/ttyACM1 at 1000000 baud.
[2026-04-22 08:38:11,5067] [INFO] /*****************************************************/
[2026-04-22 08:38:11,5073] [INFO] /* Pass window 2026-04-22-1000-Nordic-MOsize_auto_01 */
[2026-04-22 08:38:11,5078] [INFO] /*****************************************************/
[2026-04-22 08:38:11,5090] [INFO] >>> AT+CEREG?
[2026-04-22 08:38:11,5383] [INFO] <<< +CEREG: 5,5,"0001","00000001",14,,,"11100000","11100000"
[2026-04-22 08:38:11,5441] [INFO] STATUS change: ATTACH_ACCEPT -> ATTACH_ACCEPT (Attach accepted (mode 5))
[2026-04-22 08:38:11,5559] [INFO] <<< OK
[2026-04-22 08:38:11,5598] [INFO] Persisted status ATTACH_ACCEPT prior to 2026-04-22-1000-Nordic-MOsize_auto_01; skipping attach detection.
[2026-04-22 08:38:11,5609] [INFO] Registration window active (2026-04-22T08:38:11.181037+00:00 to 2026-04-22T08:39:41.181037+00:00 UTC).
[2026-04-22 08:38:11,5616] [INFO] /*****************************/
[2026-04-22 08:38:11,5623] [INFO] /* Context Reuse Preparation */
[2026-04-22 08:38:11,5630] [INFO] /*****************************/
[2026-04-22 08:38:11,5642] [INFO] >>> AT
[2026-04-22 08:38:11,5874] [INFO] <<< OK
[2026-04-22 08:38:11,9150] [INFO] Ensuring radio is enabled before MO transmission.
[2026-04-22 08:38:11,9163] [INFO] >>> AT+CFUN=1
[2026-04-22 08:38:11,9636] [INFO] <<< OK
[2026-04-22 08:38:13,9678] [INFO] >>> AT#XSOCKET=1,2,0,10
[2026-04-22 08:38:13,9859] [INFO] <<< #XSOCKET: 0,2,17
[2026-04-22 08:38:13,9973] [INFO] <<< OK
[2026-04-22 08:38:14,0182] [INFO] AT#XSOCKET=1,2,0,10 response: #XSOCKET: 0,2,17
[2026-04-22 08:38:14,0189] [INFO] AT#XSOCKET=1,2,0,10 response: OK
[2026-04-22 08:38:14,0203] [INFO] >>> AT#XAPOLL=0,1,1
[2026-04-22 08:38:14,0355] [INFO] <<< OK
[2026-04-22 08:38:14,0708] [INFO] AT#XAPOLL=0,1,1 response: OK
[2026-04-22 08:38:14,0721] [INFO] >>> AT#XBIND=0,<CONFIDENTIAL>
[2026-04-22 08:38:14,0890] [INFO] <<< OK
[2026-04-22 08:38:14,1226] [INFO] AT#XBIND=0,<CONFIDENTIAL> response: OK
[2026-04-22 08:38:14,1233] [INFO] Socket ready for 2026-04-22-1000-Nordic-MOsize_auto_01 attached-pass MO cycle.
[2026-04-22 08:38:14,1239] [INFO] 2026-04-22-1000-Nordic-MOsize_auto_01 attached-pass MO cycle: sending 1 MO payload(s) to <CONFIDENTIAL>:<CONFIDENTIAL> with random 1401-byte payloads.
[2026-04-22 08:38:14,1245] [INFO] CSCON not connected; sending first MO to trigger connection.
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
[2026-04-22 08:38:14,3224] [INFO] MO payload trigger 1/1 dispatched.
[2026-04-22 08:38:14,3980] [INFO] <<< #XSENDTO: 0,0,1401
[2026-04-22 08:38:14,4094] [INFO] <<< OK
[2026-04-22 08:38:15,1444] [INFO] <<< +CEREG: 5,"0001","00000001",14,,,"11100000","11100000"
[2026-04-22 08:38:15,5376] [INFO] <<< +CSCON: 1
[2026-04-22 08:38:15,5382] [INFO] MO burst complete; 1/1 payload(s) dispatched.
[2026-04-22 08:38:15,5393] [INFO] MT expectation: after feeder link for 2026-04-22-1000-Nordic-MOsize_auto_01 anticipate responses to 1 MO transmissions.
[2026-04-22 08:38:45,2962] [INFO] <<< +CSCON: 0
[2026-04-22 08:38:46,0235] [INFO] <<< %SIBCONFIG: 32,"00000001",1,4,1138389,1204387,2656341,3013001,13782,2570283934,23090,-3,134614,,11,11,,,
[2026-04-22 08:38:46,0351] [INFO] <<< %SIBCONFIG: 0
[2026-04-22 08:39:11,2132] [INFO] Applying retain-context (CFUN=45) after MO sequence.
[2026-04-22 08:39:11,2145] [INFO] >>> AT+CIMI
[2026-04-22 08:39:11,2396] [INFO] <<< <CONFIDENTIAL>
[2026-04-22 08:39:11,2509] [INFO] <<< OK
[2026-04-22 08:39:11,2654] [INFO] >>> AT#XCLOSE
[2026-04-22 08:39:11,2901] [INFO] <<< #XCLOSE: 0,0
[2026-04-22 08:39:11,3016] [INFO] <<< OK
[2026-04-22 08:39:11,3162] [INFO] >>> AT+CFUN=45
[2026-04-22 08:39:11,4245] [INFO] <<< OK
[2026-04-22 08:39:11,4690] [INFO] Exiting with CFUN=45 due to status ATTACH_ACCEPT.
[2026-04-22 08:39:11,4698] [INFO] Context already retained earlier; skipping additional CFUN=45.
[2026-04-22 08:39:11,4703] [INFO] /************/
[2026-04-22 08:39:11,4711] [INFO] /* Shutdown */
[2026-04-22 08:39:11,4718] [INFO] /************/
[2026-04-22 08:39:12,4496] [INFO] Trace capture stopped.

Fullscreen test#2.log Download

[2026-04-22 08:51:32,6870] [INFO] Resuming with persisted status ATTACH_ACCEPT (updated 2026-04-22T08:39:11.466801+00:00, reason: Context retained after 2026-04-22-1000-Nordic-MOsize_auto_01 attached-pass MO cycle)
[2026-04-22 08:51:32,6911] [INFO] /************************/
[2026-04-22 08:51:32,6915] [INFO] /* Time Synchronization */
[2026-04-22 08:51:32,6918] [INFO] /************************/
[2026-04-22 08:51:32,9558] [INFO] System timezone already set to UTC.
[2026-04-22 08:51:33,0145] [INFO] Trace capture started on /dev/ttyACM1 at 1000000 baud.
[2026-04-22 08:51:33,0162] [INFO] /*****************************************************/
[2026-04-22 08:51:33,0170] [INFO] /* Pass window 2026-04-22-1000-Nordic-MOsize_auto_01 */
[2026-04-22 08:51:33,0176] [INFO] /*****************************************************/
[2026-04-22 08:51:33,0188] [INFO] >>> AT+CEREG?
[2026-04-22 08:51:33,0473] [INFO] <<< +CEREG: 5,5,"0001","00000001",14,,,"11100000","11100000"
[2026-04-22 08:51:33,0519] [INFO] STATUS change: ATTACH_ACCEPT -> ATTACH_ACCEPT (Attach accepted (mode 5))
[2026-04-22 08:51:33,0632] [INFO] <<< OK
[2026-04-22 08:51:33,0696] [INFO] Persisted status ATTACH_ACCEPT prior to 2026-04-22-1000-Nordic-MOsize_auto_01; skipping attach detection.
[2026-04-22 08:51:33,0705] [INFO] Registration window active (2026-04-22T08:51:32.684791+00:00 to 2026-04-22T08:53:02.684791+00:00 UTC).
[2026-04-22 08:51:33,0712] [INFO] /*****************************/
[2026-04-22 08:51:33,0718] [INFO] /* Context Reuse Preparation */
[2026-04-22 08:51:33,0723] [INFO] /*****************************/
[2026-04-22 08:51:33,0738] [INFO] >>> AT
[2026-04-22 08:51:33,0968] [INFO] <<< OK
[2026-04-22 08:51:33,4247] [INFO] Ensuring radio is enabled before MO transmission.
[2026-04-22 08:51:33,4263] [INFO] >>> AT+CFUN=1
[2026-04-22 08:51:33,4727] [INFO] <<< OK
[2026-04-22 08:51:35,4796] [INFO] >>> AT#XSOCKET=1,2,0,10
[2026-04-22 08:51:35,4976] [INFO] <<< #XSOCKET: 0,2,17
[2026-04-22 08:51:35,5089] [INFO] <<< OK
[2026-04-22 08:51:35,5301] [INFO] AT#XSOCKET=1,2,0,10 response: #XSOCKET: 0,2,17
[2026-04-22 08:51:35,5307] [INFO] AT#XSOCKET=1,2,0,10 response: OK
[2026-04-22 08:51:35,5317] [INFO] >>> AT#XAPOLL=0,1,1
[2026-04-22 08:51:35,5477] [INFO] <<< OK
[2026-04-22 08:51:35,5822] [INFO] AT#XAPOLL=0,1,1 response: OK
[2026-04-22 08:51:35,5834] [INFO] >>> AT#XBIND=0,<CONFIDENTIAL>
[2026-04-22 08:51:35,6002] [INFO] <<< OK
[2026-04-22 08:51:35,6339] [INFO] AT#XBIND=0,<CONFIDENTIAL> response: OK
[2026-04-22 08:51:35,6346] [INFO] Socket ready for 2026-04-22-1000-Nordic-MOsize_auto_01 attached-pass MO cycle.
[2026-04-22 08:51:35,6352] [INFO] 2026-04-22-1000-Nordic-MOsize_auto_01 attached-pass MO cycle: sending 1 MO payload(s) to <CONFIDENTIAL>:<CONFIDENTIAL> with random 1402-byte payloads.
[2026-04-22 08:51:35,6368] [INFO] CSCON not connected; sending first MO to trigger connection.
[2026-04-22 08:51:35,8337] [INFO] >>> AT#XSENDTO=0,1,0,"<CONFIDENTIAL>",<CONFIDENTIAL>,"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"
[2026-04-22 08:51:35,8344] [INFO] MO payload trigger 1/1 dispatched.
[2026-04-22 08:51:35,9033] [INFO] <<< ERROR
[2026-04-22 08:51:37,0562] [INFO] <<< +CEREG: 5,"0001","00000001",14,,,"11100000","11100000"
[2026-04-22 08:51:37,2179] [INFO] <<< %SIBCONFIG: 32,"00000001",1,4,1138389,1204387,2656341,3013001,13782,2570283934,23090,-3,134614,,11,11,,,
[2026-04-22 08:51:37,2296] [INFO] <<< %SIBCONFIG: 0
[2026-04-22 08:51:43,8354] [INFO] CSCON=1 not observed after trigger MO; aborting remaining 0 payload(s).
[2026-04-22 08:51:43,8360] [INFO] No MO payloads were successfully dispatched during 2026-04-22-1000-Nordic-MOsize_auto_01 attached-pass MO cycle.
[2026-04-22 08:51:43,8365] [INFO] MT expectation: after feeder link for 2026-04-22-1000-Nordic-MOsize_auto_01 anticipate responses to 0 MO transmissions.
[2026-04-22 08:52:32,7338] [INFO] Applying retain-context (CFUN=45) after MO sequence.
[2026-04-22 08:52:32,7351] [INFO] >>> AT+CIMI
[2026-04-22 08:52:32,7599] [INFO] <<< <CONFIDENTIAL>
[2026-04-22 08:52:32,7712] [INFO] <<< OK
[2026-04-22 08:52:32,7862] [INFO] >>> AT#XCLOSE
[2026-04-22 08:52:32,8109] [INFO] <<< #XCLOSE: 0,0
[2026-04-22 08:52:32,8222] [INFO] <<< OK
[2026-04-22 08:52:32,8371] [INFO] >>> AT+CFUN=45
[2026-04-22 08:52:32,9453] [INFO] <<< OK
[2026-04-22 08:52:32,9899] [INFO] Exiting with CFUN=45 due to status ATTACH_ACCEPT.
[2026-04-22 08:52:32,9907] [INFO] Context already retained earlier; skipping additional CFUN=45.
[2026-04-22 08:52:32,9912] [INFO] /************/
[2026-04-22 08:52:32,9918] [INFO] /* Shutdown */
[2026-04-22 08:52:32,9926] [INFO] /************/
[2026-04-22 08:52:33,9730] [INFO] Trace capture stopped.

Fullscreen test#3.log Download

[2026-04-22 09:23:59,0066] [INFO] Resuming with persisted status ATTACH_ACCEPT (updated 2026-04-22T09:22:10.776363+00:00, reason: Flight mode entered (CFUN=45))
[2026-04-22 09:23:59,0097] [INFO] /************************/
[2026-04-22 09:23:59,0101] [INFO] /* Time Synchronization */
[2026-04-22 09:23:59,0104] [INFO] /************************/
[2026-04-22 09:23:59,2583] [INFO] System timezone already set to UTC.
[2026-04-22 09:23:59,3149] [INFO] Trace capture started on /dev/ttyACM1 at 1000000 baud.
[2026-04-22 09:23:59,3157] [INFO] /**************************************************************/
[2026-04-22 09:23:59,3171] [INFO] /* Pass window 2026-04-22-1000-Nordic-MOsize1472ascii_auto_01 */
[2026-04-22 09:23:59,3179] [INFO] /**************************************************************/
[2026-04-22 09:23:59,3195] [INFO] >>> AT+CEREG?
[2026-04-22 09:23:59,3442] [INFO] <<< +CEREG: 5,4
[2026-04-22 09:23:59,3603] [INFO] <<< OK
[2026-04-22 09:23:59,3707] [INFO] >>> AT+CGPADDR
[2026-04-22 09:23:59,3976] [INFO] <<< +CGPADDR: 10,"<CONFIDENTIAL>"
[2026-04-22 09:23:59,4089] [INFO] <<< OK
[2026-04-22 09:23:59,4228] [INFO] ATTACH_ACCEPT -> ATTACH_ACCEPT | IPv4 confirmed <CONFIDENTIAL> | metadata={'ip': '<CONFIDENTIAL>', 'source': 'CGPADDR'}
[2026-04-22 09:23:59,4257] [INFO] STATUS change: ATTACH_ACCEPT -> ATTACH_ACCEPT (IPv4 confirmed <CONFIDENTIAL>)
[2026-04-22 09:23:59,4368] [INFO] Persisted status ATTACH_ACCEPT prior to 2026-04-22-1000-Nordic-MOsize1472ascii_auto_01; skipping attach detection.
[2026-04-22 09:23:59,4374] [INFO] Registration window active (2026-04-22T09:23:59.004067+00:00 to 2026-04-22T09:25:29.004067+00:00 UTC).
[2026-04-22 09:23:59,4379] [INFO] /*****************************/
[2026-04-22 09:23:59,4382] [INFO] /* Context Reuse Preparation */
[2026-04-22 09:23:59,4385] [INFO] /*****************************/
[2026-04-22 09:23:59,4392] [INFO] >>> AT
[2026-04-22 09:23:59,4624] [INFO] <<< OK
[2026-04-22 09:23:59,7899] [INFO] Ensuring radio is enabled before MO transmission.
[2026-04-22 09:23:59,7913] [INFO] >>> AT+CFUN=1
[2026-04-22 09:23:59,8383] [INFO] <<< OK
[2026-04-22 09:24:01,8439] [INFO] >>> AT#XSOCKET=1,2,0,10
[2026-04-22 09:24:01,8619] [INFO] <<< #XSOCKET: 0,2,17
[2026-04-22 09:24:01,8732] [INFO] <<< OK
[2026-04-22 09:24:01,8943] [INFO] AT#XSOCKET=1,2,0,10 response: #XSOCKET: 0,2,17
[2026-04-22 09:24:01,8950] [INFO] AT#XSOCKET=1,2,0,10 response: OK
[2026-04-22 09:24:01,8963] [INFO] >>> AT#XAPOLL=0,1,1
[2026-04-22 09:24:01,9116] [INFO] <<< OK
[2026-04-22 09:24:01,9468] [INFO] AT#XAPOLL=0,1,1 response: OK
[2026-04-22 09:24:01,9480] [INFO] >>> AT#XBIND=0,<CONFIDENTIAL>
[2026-04-22 09:24:01,9648] [INFO] <<< OK
[2026-04-22 09:24:01,9985] [INFO] AT#XBIND=0,<CONFIDENTIAL> response: OK
[2026-04-22 09:24:01,9994] [INFO] Socket ready for 2026-04-22-1000-Nordic-MOsize1472ascii_auto_01 attached-pass MO cycle.
[2026-04-22 09:24:02,0000] [INFO] 2026-04-22-1000-Nordic-MOsize1472ascii_auto_01 attached-pass MO cycle: sending 1 MO payload(s) to 18.195.154.86:<CONFIDENTIAL> with random 736-byte payloads.
[2026-04-22 09:24:02,0009] [INFO] CSCON not connected; sending first MO to trigger connection.
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
[2026-04-22 09:24:02,0812] [INFO] MO payload trigger 1/1 dispatched.
[2026-04-22 09:24:02,1531] [INFO] <<< #XSENDTO: 0,0,1472
[2026-04-22 09:24:02,1647] [INFO] <<< OK
[2026-04-22 09:24:03,3156] [INFO] <<< +CEREG: 5,"0001","00000001",14,,,"11100000","11100000"
[2026-04-22 09:24:03,3184] [INFO] STATUS change: ATTACH_ACCEPT -> ATTACH_ACCEPT (Attach accepted (mode 5))
[2026-04-22 09:24:03,7074] [INFO] <<< +CSCON: 1
[2026-04-22 09:24:03,7082] [INFO] MO burst complete; 1/1 payload(s) dispatched.
[2026-04-22 09:24:03,7089] [INFO] MT expectation: after feeder link for 2026-04-22-1000-Nordic-MOsize1472ascii_auto_01 anticipate responses to 1 MO transmissions.
[2026-04-22 09:24:07,3315] [INFO] <<< #XAPOLL: 0,1
[2026-04-22 09:24:33,4666] [INFO] <<< +CSCON: 0
[2026-04-22 09:24:34,1939] [INFO] <<< %SIBCONFIG: 32,"00000001",1,4,1138389,1204387,2656341,3013001,13782,2570283934,23090,-3,134614,,11,11,,,
[2026-04-22 09:24:34,2054] [INFO] <<< %SIBCONFIG: 0
[2026-04-22 09:24:59,0550] [INFO] Applying retain-context (CFUN=45) after MO sequence.
[2026-04-22 09:24:59,0563] [INFO] >>> AT+CIMI
[2026-04-22 09:24:59,0811] [INFO] <<< <CONFIDENTIAL>
[2026-04-22 09:24:59,0927] [INFO] <<< OK
[2026-04-22 09:24:59,1074] [INFO] >>> AT#XCLOSE
[2026-04-22 09:24:59,1318] [INFO] <<< #XCLOSE: 0,0
[2026-04-22 09:24:59,1434] [INFO] <<< OK
[2026-04-22 09:24:59,1583] [INFO] >>> AT+CFUN=45
[2026-04-22 09:24:59,2668] [INFO] <<< OK
[2026-04-22 09:24:59,3111] [INFO] Exiting with CFUN=45 due to status ATTACH_ACCEPT.
[2026-04-22 09:24:59,3119] [INFO] Context already retained earlier; skipping additional CFUN=45.
[2026-04-22 09:24:59,3131] [INFO] /************/
[2026-04-22 09:24:59,3138] [INFO] /* Shutdown */
[2026-04-22 09:24:59,3143] [INFO] /************/
[2026-04-22 09:25:00,2921] [INFO] Trace capture stopped.

Fullscreen test#4.log Download

[2026-04-22 09:34:07,7765] [INFO] Resuming with persisted status ATTACH_ACCEPT (updated 2026-04-22T09:29:48.595449+00:00, reason: Flight mode entered (CFUN=45))
[2026-04-22 09:34:07,7796] [INFO] /************************/
[2026-04-22 09:34:07,7800] [INFO] /* Time Synchronization */
[2026-04-22 09:34:07,7803] [INFO] /************************/
[2026-04-22 09:34:08,0501] [INFO] System timezone already set to UTC.
[2026-04-22 09:34:08,1068] [INFO] Trace capture started on /dev/ttyACM1 at 1000000 baud.
[2026-04-22 09:34:08,1076] [INFO] /**************************************************************/
[2026-04-22 09:34:08,1087] [INFO] /* Pass window 2026-04-22-1000-Nordic-MOsize1473ascii_auto_01 */
[2026-04-22 09:34:08,1094] [INFO] /**************************************************************/
[2026-04-22 09:34:08,1112] [INFO] >>> AT+CEREG?
[2026-04-22 09:34:08,1402] [INFO] <<< +CEREG: 5,5,"0001","00000001",14,,,"11100000","11100000"
[2026-04-22 09:34:08,1466] [INFO] STATUS change: ATTACH_ACCEPT -> ATTACH_ACCEPT (Attach accepted (mode 5))
[2026-04-22 09:34:08,1585] [INFO] <<< OK
[2026-04-22 09:34:08,1620] [INFO] Persisted status ATTACH_ACCEPT prior to 2026-04-22-1000-Nordic-MOsize1473ascii_auto_01; skipping attach detection.
[2026-04-22 09:34:08,1629] [INFO] Registration window active (2026-04-22T09:34:07.774005+00:00 to 2026-04-22T09:35:37.774005+00:00 UTC).
[2026-04-22 09:34:08,1637] [INFO] /*****************************/
[2026-04-22 09:34:08,1648] [INFO] /* Context Reuse Preparation */
[2026-04-22 09:34:08,1654] [INFO] /*****************************/
[2026-04-22 09:34:08,1665] [INFO] >>> AT
[2026-04-22 09:34:08,1898] [INFO] <<< OK
[2026-04-22 09:34:08,5173] [INFO] Ensuring radio is enabled before MO transmission.
[2026-04-22 09:34:08,5186] [INFO] >>> AT+CFUN=1
[2026-04-22 09:34:08,5659] [INFO] <<< OK
[2026-04-22 09:34:10,5719] [INFO] >>> AT#XSOCKET=1,2,0,10
[2026-04-22 09:34:10,5902] [INFO] <<< #XSOCKET: 0,2,17
[2026-04-22 09:34:10,6015] [INFO] <<< OK
[2026-04-22 09:34:10,6224] [INFO] AT#XSOCKET=1,2,0,10 response: #XSOCKET: 0,2,17
[2026-04-22 09:34:10,6231] [INFO] AT#XSOCKET=1,2,0,10 response: OK
[2026-04-22 09:34:10,6242] [INFO] >>> AT#XAPOLL=0,1,1
[2026-04-22 09:34:10,6396] [INFO] <<< OK
[2026-04-22 09:34:10,6746] [INFO] AT#XAPOLL=0,1,1 response: OK
[2026-04-22 09:34:10,6758] [INFO] >>> AT#XBIND=0,<CONFIDENTIAL>
[2026-04-22 09:34:10,6923] [INFO] <<< OK
[2026-04-22 09:34:10,7263] [INFO] AT#XBIND=0,<CONFIDENTIAL> response: OK
[2026-04-22 09:34:10,7272] [INFO] Socket ready for 2026-04-22-1000-Nordic-MOsize1473ascii_auto_01 attached-pass MO cycle.
[2026-04-22 09:34:10,7279] [INFO] 2026-04-22-1000-Nordic-MOsize1473ascii_auto_01 attached-pass MO cycle: sending 1 MO payload(s) to 18.195.154.86:<CONFIDENTIAL> with random 737-byte payloads.
[2026-04-22 09:34:10,7286] [INFO] CSCON not connected; sending first MO to trigger connection.
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
[2026-04-22 09:34:10,8087] [INFO] MO payload trigger 1/1 dispatched.
[2026-04-22 09:34:10,8800] [INFO] <<< #XSENDTO: 0,0,0
[2026-04-22 09:34:10,8916] [INFO] <<< ERROR
[2026-04-22 09:34:11,9534] [INFO] <<< +CEREG: 5,"0001","00000001",14,,,"11100000","11100000"
[2026-04-22 09:34:12,1145] [INFO] <<< %SIBCONFIG: 32,"00000001",1,4,1138389,1204387,2656341,3013001,13782,2570283934,23090,-3,134614,,11,11,,,
[2026-04-22 09:34:12,1262] [INFO] <<< %SIBCONFIG: 0
[2026-04-22 09:34:18,8106] [INFO] CSCON=1 not observed after trigger MO; aborting remaining 0 payload(s).
[2026-04-22 09:34:18,8114] [INFO] No MO payloads were successfully dispatched during 2026-04-22-1000-Nordic-MOsize1473ascii_auto_01 attached-pass MO cycle.
[2026-04-22 09:34:18,8129] [INFO] MT expectation: after feeder link for 2026-04-22-1000-Nordic-MOsize1473ascii_auto_01 anticipate responses to 0 MO transmissions.
[2026-04-22 09:35:07,8069] [INFO] Applying retain-context (CFUN=45) after MO sequence.
[2026-04-22 09:35:07,8082] [INFO] >>> AT+CIMI
[2026-04-22 09:35:07,8329] [INFO] <<< <CONFIDENTIAL>
[2026-04-22 09:35:07,8442] [INFO] <<< OK
[2026-04-22 09:35:07,8591] [INFO] >>> AT#XCLOSE
[2026-04-22 09:35:07,8837] [INFO] <<< #XCLOSE: 0,0
[2026-04-22 09:35:07,8951] [INFO] <<< OK
[2026-04-22 09:35:07,9099] [INFO] >>> AT+CFUN=45
[2026-04-22 09:35:08,0182] [INFO] <<< OK
[2026-04-22 09:35:08,0627] [INFO] Exiting with CFUN=45 due to status ATTACH_ACCEPT.
[2026-04-22 09:35:08,0634] [INFO] Context already retained earlier; skipping additional CFUN=45.
[2026-04-22 09:35:08,0641] [INFO] /************/
[2026-04-22 09:35:08,0652] [INFO] /* Shutdown */
[2026-04-22 09:35:08,0661] [INFO] /************/
[2026-04-22 09:35:09,0460] [INFO] Trace capture stopped.

[Simon D-M]

Hi,

I'm not what your question is...

If you are wondering if your measured max sizes are correct, they are. The max sizes have been documented in the AT#XSENDTO documentation:

When setting AT#XSENDTO=0,1,0, maximum size for MO payload is 1401B (1429B with UDP-IPv4 headers)

The <data> parameter is required when <mode> is 0 (string mode) or 1 (hex string mode). For string mode (0), it is a string that contains the data to be sent. For hex string mode (1), it is a hexadecimal string representation of the data to be sent. The maximum payload size in hexadecimal string mode is up to 2800 characters (1400 bytes). For large packets, it is recommended to use data mode (2) since AT parser’s memory limits the maximum size of data that can be sent in string or hex string modes. This parameter is not used when <mode> is 2 (data mode).

When setting AT#XSENDTO=0,0,0, maximum size for MO payload is 1472B (1500B with UDP-IPv4 headers)

UDP packets that exceed the Maximum Transmission Unit (MTU) of any network segment along their path may be dropped or fragmented, increasing the risk of packet loss. Ethernet networks have an MTU of 1500 bytes, which allows a maximum UDP payload of 1472 bytes for IPv4 and 1452 bytes for IPv6. With DTLS sockets, the usable payload size is further reduced due to encryption overhead.

We recommend limiting UDP payloads to 1200 bytes. For bigger packet, we recommend using "data mode" (<mode> = 2) since AT parser’s memory limits the maximum size of data that can be sent in string or hex string modes.

Best regards,

Simon D-M