Send json tcp request

Hello all,

I'm trying to get data from my 3d printer through tcp port 35. I was able to sniff the packages between my computer and the printer with wireshark, but I was not able to get data with node red. It seems that there is a communication with custom json. I've tried to inject the json data directly through the tcp request node but I got a connection error.

I've attached some pictures of the wireshark dump because I am not able to upload the dump as zip file.

There are 3 packages sent repeatedly:

  1. from the host to the printer with a length of 54 bytes
  2. from the host to the printer with a length of 183 bytes including the json data
  3. from the printer to the host with a length of 775 bytes with the result

Is there anyone who is familiar with wireshark who can help me here?

Thanks in advance

you need to check that you can connect to port 35 - quite often ports below 1024 are only available to root by default.

Yes, you are right. Thanks for pointing. I will check that.