Lite reliable UDP library for .NET Standard 2.1 (Mono, .NET)

HighLevel API Part: LiteEntitySystem

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OLD BRANCH (and examples) for 1.x

Little Game Example on Unity

Documentation

( Warning! Master branch can be unstable! )

• Lightweight
  • Small CPU and RAM usage
  • Small packet size overhead ( 1 byte for unreliable, 4 bytes for reliable packets )
• Simple connection handling
• Peer to peer connections
• Helper classes for sending and reading messages
• Multiple data channels
• Different send mechanics
  • Reliable with order
  • Reliable without order
  • Reliable sequenced (reliable only last packet)
  • Ordered but unreliable with duplication prevention
  • Simple UDP packets without order and reliability
• Fast packet serializer (Usage manual)
• Automatic small packets merging
• Automatic fragmentation of reliable packets
• Automatic MTU detection
• Optional CRC32C checksums
• UDP NAT hole punching
• NTP time requests
• Packet loss and latency simulation
• IPv6 support (using separate socket for performance)
• Connection statistics
• Multicasting (for discovering hosts in local network)
• Unity support
• Support for .NET8 optimized socket calls (much less gc)
• Supported platforms:
  • Windows/Mac/Linux (.NET Framework, Mono, .NET Core, .NET Standard)
  • Lumin OS (Magic Leap)
  • MonoGame
  • Godot
  • Unity 2021.2 (Desktop platforms, Android, iOS, Switch)

• 

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• Minimal supported Unity is 2021.2. For older Unity versions use 1.x library versions
• Always use library sources or OpenUPM package instead of precompiled DLL files ( because there are platform specific #ifdefs and workarounds for unity bugs )

var listener = new EventBasedNetListener();
var client = new NetManager(listener);
client.Start();
client.Connect("localhost" /* host IP or name */, 9050 /* port */, "SomeConnectionKey" /* text key or NetDataWriter */);
listener.NetworkReceiveEvent += (fromPeer, dataReader, channel, deliveryMethod) =>
{
    Console.WriteLine("We got: {0}", dataReader.GetString(100 /* max length of string */));
    dataReader.Recycle();
};

while (!Console.KeyAvailable)
{
    client.PollEvents();
    Thread.Sleep(15);
}

client.Stop();

var listener = new EventBasedNetListener();
var server = new NetManager(listener);
server.Start(9050 /* port */);

listener.ConnectionRequestEvent += request =>
{
    if(server.ConnectedPeersCount < 10 /* max connections */)
        request.AcceptIfKey("SomeConnectionKey");
    else
        request.Reject();
};

listener.PeerConnectedEvent += peer =>
{
    Console.WriteLine("We got connection: {0}", peer);  // Show peer IP
    var writer = new NetDataWriter();         // Create writer class
    writer.Put("Hello client!");                        // Put some string
    peer.Send(writer, DeliveryMethod.ReliableOrdered);  // Send with reliability
};

while (!Console.KeyAvailable)
{
    server.PollEvents();
    Thread.Sleep(15);
}
server.Stop();

Set BroadcastReceiveEnabled on a manager that should receive broadcast packets. They are reported through OnNetworkReceiveUnconnected with UnconnectedMessageType.Broadcast. With multiple network interfaces, bind the manager to the local IPv4 address of the interface to use instead of calling Start(port):

using System.Net;
using LiteNetLib;

var listener = new EventBasedNetListener();
var manager = new NetManager(listener)
{
    BroadcastReceiveEnabled = true,
    IPv6Enabled = false
};

var localAddress = IPAddress.Parse("192.168.1.10"); // address assigned to the desired interface
manager.Start(localAddress, IPAddress.IPv6Any, 9050);

Use the same address-specific Start overload for a sender. To use multiple IPv4 interfaces, create a manager bound to each interface address.