How can I send messages larger than 65535 bytes?

[zkldi]

Full disclosure, I know little to nothing about networks at this layer.

I'm using matchbox_socket to send data between peers. One of the messages I'd like to send is fairly large (~200kb-1mb). This fails to send due to this error:

2023-07-16T00:24:53.516938Z ERROR matchbox_socket::webrtc_socket::native: error sending to data channel: Data(Sctp(ErrOutboundPacketTooLarge))    

Looking into this more shows that it happens in webrtc-data, and some wikipedia sleuthing says that sctp is fundamentally limited to 65535 bytes.

I would love to be able to send a message larger than that -- do I have to implement my own chunking and ordering? This seems like the sort of thing that someone's solved before, so am I missing some config option or something?

[simbleau]

You'll need to implement your own chunking and ordering, I suppose, yes. To my knowledge there's no config for this in matchbox. Perhaps in the underlying webrtc crate we use.

[simbleau]

Do we want to handle this or expect the user to do this themselves? @johanhelsing