40 byte limit on UDP messages over NB-IoT R410/R412

Krolken 2018-10-01 09:35:02 UTC #1

I am seeing problem with sending larger UDP messages than 40 bytes. If I send smaller my server receives them but larger than 40 bytes nothing comes to the server.

Ex:

[2018-10-01 11:19:46,747] DEBUG: Sent: b'AT+USOST=0,"xxx.xx.xxx.xxx",9xxx,44,"3030303030303030303031303030303030303030313030303030303030303130303030303030303030303031"\r\n'
[2018-10-01 11:19:46,774] DEBUG: Processing URC: +USOST: 0,44
[2018-10-01 11:19:46,774] DEBUG: Unhandled urc: b'+USOST: 0,44'
[2018-10-01 11:19:46,774] DEBUG: Received: [b'+USOST: 0,44', b'OK']
[2018-10-01 11:19:46,774] DEBUG: AT Command response = []

Is there a way of finding out if it is a problem with the module or the network provider? I have tried with a N211 and the same operator and that works fine.

Jan 2018-10-01 11:12:50 UTC #2

The OK means that the module has a correct payload lenght.
If the payload would be incorrect size. The module will return an error.

Krolken 2018-10-01 12:22:19 UTC #3

Yes. So what could be the problem of the messages not arriving to the server.

When will packets be fragmented?