3 replies to this topic

[mohammad]

Hi all, My Netduino Plus is a Web server. When it receives any packet, it reads the the packet length from its header. Then, Netduino drops it. My question is how Netduino can receive the packets with length larger than its RAM capacity (28KB). I could send packets larger than 80KB and Netduino could read their headers. Any reply is appreciated. Thanks, Mohammad

[Chris Walker]

Hi Mohammad, Are you trying to send TCP packets of 80KB...or chunks of data that large? You can't send a single TCP packet that big to a Netduino--but if you sent it that much data you'll get a small chunk (say 1500 bytes) that you can read and process. And the rest of the data should be "held back" until your Netduino Plus has enough room in its buffers to receive it. Chris

[mohammad]

Hi Chris,

Thanks for your reply.
I sent chunks of data around 80KB. My assumption: chunks of data = TCP/IP packets. Am I wrong?
I know that MTU for Ethernet only allows 1.5KB of data to transfer. So, the TCP packets should be fragmented on router, then send to Netduino.

And the rest of the data should be "held back" until your Netduino Plus has enough room in its buffers to receive it.

My understanding from your reply is in this way:
- 80KB data are sent to Netduino. Netduino can read the header, but it cannot read the whole content. When it empties its memory, the pending contents can be loaded in Netduino. Yes?

Thanks again,
Mohammad

[Chris Walker]

My understanding from your reply is in this way:
- 80KB data are sent to Netduino. Netduino can read the header, but it cannot read the whole content. When it empty its memory, the pending contents can be loaded in Netduino. Yes?

Yes, that should work.

Chris