Packet size in MQTT

TCP/IP Chip W5500
1

Hello
I’m using IoLibrary and I have this problem.
I’m using w5500 as my chip and I’m a mqtt client who is using iolibrary.
Until packet size is less than my socket dedicated volume everything is ok . I can subscribe and get message successfully .
But when packet size is more than socket dedicated volume, I receive nothing despite of subscribing this special topic.
Maximum socket dedicated volume is 16kb in w5500 chip, but my desired data size is more than 16kb its about 40kb .

Please help me solve this problem . what should I do ?
Thank you.

2

Anything over 40kb per packet is not available on our chip.

But if you want to send them sequentially, there is no problem with the code you are currently providing.

3

Thanks for your support.

what is the exact maximum size that your chip support and where this information has been set in your chip?

how can i set maximum size in your chip?

how can i send and receive big packet message sequentially?

4

In case of TCP mode, it can send up to 1460byte per packet.
image

Our chips not supports the fragmentation of TCP.
Therefore, in order to transmit a lot of data, it is necessary to control the memory.
For this part, we recommend that you check the send() / recv() function in the iolibrary that we provide.

5

hello irina thanks for your help.
I’m using mqtt protocol . do you have any solution for me ?
I will appreciate if you provide me piece of code for receiving a lot of data in mqtt using iolibrary?

6

We can support the MQTT example but I don’t know if that code can receive and transmit large amounts of data.
This code simply supports MQTT.

7

thanks, but this cant help us.
I have questions about details of ioLibrary.
would you please connect me with the developer of ioLibrary .

8

Ask your questions here.

9

we have sent and received large data with w5500 chip successfully by using its registers without iolibrary , but now we are using iolibrary and facing with problem, the issue is we cant receive large data . please provide me the process sequence of receiving large data using iolibrary. unfortunately the GitHub source code you mentioned didn’t help me .
please help me overcome this obstacle.