FalconUDP is an application level protocol for sending and receiving small messages (one to one thousand or more bytes) frequently (once a minute to hundreds of times a second) to and from one or many connected peers. It has been implemented on top of the Internet User Datagram protocol (UDP).

This is the official .NET implementation, implemented as a .NET 4.0 Class Library: FalconUDP.dll. Throughout this site "FalconUDP" is used interchangeably to refer to the protocol or this .NET implementation.

FalconUDP is being developed by Gnomic Studios for their multiplayer game Square Heroes: http://www.squareheroes.com/, check it out to see FalconUDP perform

For the latest source please use GitHub: http://github.com/markmnl/FalconUDP. Only "stable" releases will be pushed to CodePlex periodically.


  • Authentication and connection orientated. FalconUDP only communicates with previously authenticated peers.
  • Reliable and in-order messages. Messages can be sent in-order, reliably, both in-order and reliable, or without any reliable and in-order checking and controls. Duplicates are always detected and dropped.
  • Minimal overhead. FalconUDP adds minimal data to the user-application's data to be sent and received "on the wire" and includes support for "packing" additional user-application packets into existing outgoing messages.
  • Latency estimation. FalconUDP measures round-trip-times from sending reliable messages till receiving the corresponding ACKnowlodgment, providing one way latency estimation to each connected peer.
  • Any Topology. User-applications can use their own logical network topology such as Server-Client or Peer-to-Peer, since a "Falcon peer" can have one or more connected peers.
  • Discovery. FalconUDP peers can "discover" other FalconUDP peers on the same subnet (if a FalconUDP peer is set to accept discovery requests and optionally the request has a valid token).
  • NAT Traversal. Two FalconUDP peers behind NAT(s) can establish a connection with each other after connecting to third publically accessible server to negotiate the connection.
  • Minimal garbage. FalconUDP makes extensive use of memory management techniques to avoid creating garbage such as: pooling objects, segmenting buffers from large ones (to prevent heap memory fragmentation) and copying data directly into and out of buffers.
  • Statistics. Total bytes per second sent and received to/from all remote peers.
  • Simulate latency, jitter and packet loss options.


  • Currently only IPv4 supported.*
  • No Congestion Control. FalconUDP provides no in-built congestion control.†
  • No Encryption. FalconUDP has no in-built encryption.†

*IPv6 planned
User-applications can use their own implementation before sending and after receiving data using the library's API.

Last edited Nov 21, 2014 at 11:47 PM by MrkMnl, version 35