Network Data Limitations on NetworkTransport.Send()

Questions & Answers
1

Hi, so I have some questions about sending relatively large amounts of data compared to a usual RPC you may send in a game. First of all, some background information: I am working on a small tank game where the networking structure is that a player is a host and they host from their computer for other players (allows unity relay, nat punchthrough, and lan play). I am worrying about how much data I can send because I want to allow users to create their own maps. They will most likely be sent as a serializable class or an ascii string. Note that while the maps wont be super complex, I basically just need an array of point A to point B. Here is what a map looks like:
map

A quick look at the NetworkTransport.Send() method doesnt give me an insight as to of how much data I can send in a single call. Unity - Scripting API: Networking.NetworkTransport.Send . Is there a limit to how much data I can send? In some of the demo code by Unity they always use a byte array set to a length of 1024. Is this my limitation? Thanks.

2

You need to use fragmented channel ids when using the NetworkTransport.Send method.

Fragmented Channel: “Maximum packet length is fixed, but sometimes you will probably want to send “big” messages. This channel type will disassemble your message to fragments before sending, and assemble it back before receiving.” (Source: All about the Unity networking transport layer | Unity Blog)

I also recommend using Message Pack to serialise your information, as it has built in LZ4 Compression, you can find out more about it here: GitHub - neuecc/MessagePack-CSharp: Extremely Fast MessagePack Serializer for C#(.NET, .NET Core, Unity, Xamarin). / msgpack.org[C#]