UFlow

UFlow is a Rust library and UDP networking protocol for realtime internet data transfer, with a focus on simplicity and robustness. Though it has been designed from the ground up, UFlow's interface and functionality are inspired by the venerable ENet library.

Features

• Packet-oriented data transfer between two hosts
• Automatic packet fragmentation and reassembly according to the internet MTU (1500 bytes)
• 3-way connection handshake for proper connection management
• Up to 64 independently sequenced packet streams
• 4 intuitive packet transfer modes: Time-Sensitive, Unreliable, Persistent, and Reliable
• TCP-friendly, streaming congestion control implemented according to RFC 5348
• Efficient frame encoding and transfer protocol with minimal packet overhead
• CRC validation for all transmitted frames (Polynomial: 0x132c00699)
• 100% packet throughput and an unaffected delivery order under ideal network conditions
• Water-tight sequence ID management for maximum dup-mitigation
• Application-configurable receiver memory limits (to prevent memory allocation attacks)
• Nonce-validated data acknowledgements (to prevent loss rate / bandwidth spoofing)
• Resilient to DDoS amplification (request-reply ratio ≈ 28:1)
• Meticulously designed and unit tested to ensure stall-free behavior
• Threadless, non-blocking implementation

Documentation

Documentation can be found at docs.rs.

Architecture

Although a previous version is described in the whitepaper, much has changed about the library in the meantime (including the name!). The current version has the following improvements:

• TCP-friendly congestion control implemented according to RFC 5348
• Receiver memory limits (for packet reassembly)
• No sentinel packets or frames
• An additional packet send mode which causes packets to be dropped if they cannot be sent immediately (Time-Sensitive)
• No iteration over the number of channels

The new design will soon™ be summarized in an updated whitepaper.