Mqtt publish limitation in message length


Iam using Quectel EG21-G modem. Iam trying to send a 12 KB mqtt packet to cloud. But it seems like modem throwing an error when i specify any length greater than 10200 bytes.

when i send AT+QMTPUBEX command with specifying data length more than 10200, it throwing error instead of the prompt ‘>’ (this indicate that the modem is ready to receive).

So Could anybody please let me know whether there is any restriction in the size of maximum possible mqtt publish packet size .

Any help on this is highly appreciated