✅ Purpose
Enable UDP Tracker Support in I2P
Traditionally, I2P did not support UDP-based BitTorrent trackers, which limited compatibility with many torrents.
Proposal 160 introduces a specification to allow UDP BitTorrent tracker announces over I2P, helping to bridge the gap with Clearnet standards.
Enhance BitTorrent Usability in I2P
This upgrade is aimed at making BitTorrent within I2P more efficient and standardized, improving performance and compatibility.
Lightweight Alternative to HTTP Trackers
UDP is a low-latency, connectionless protocol, suitable for fast, scalable tracking compared to HTTP-based solutions.
Improved Privacy and Anonymity
Ensures that UDP announces respect I2P's anonymity model, using existing datagram delivery methods like SSU2 and NTCP2 securely within I2P.
✅ Use Case
Users Sharing Torrents Anonymously
I2P users can now use UDP trackers (like opentracker.dg2.i2p, opentracker.simp.i2p and opentracker.skank.i2p) for torrent sharing with increased efficiency.
BitTorrent Clients within I2P (e.g., qBitTorrent, BiglyBT, I2PSnark)
Clients that implement the proposal can now announce to and scrape from UDP trackers, similar to Clearnet usage.
Tracker Operators
Can now deploy Opentracker with the updated zzzot code (v0.20.0-beta3) to support UDP announce endpoints securely within the I2P network.
✅ Extra Information
Security and Specification Details
UDP announces are tunnelled securely using existing I2P datagram transport.
The proposal allows both IPv4 and IPv6 address types, but mandates usage of I2P destination hashes (as opposed to IPs).
Backward Compatibility
Clients and trackers gracefully fall back to HTTP if UDP is not available, ensuring no breakage for older clients.
Current Status
The feature is reviewed, approved, and under active testing. Early signs show stable functioning of updated trackers and clients.
Tracker Implementation
The zzzot tracker software has been updated (0.20.0-beta3) to support this.
The Opentracker instances opentracker.dg2.i2p, opentracker.simp.i2p and opentracker.skank.i2p now run this version.
✅ Citations
Proposal 160 - UDP Trackers in I2P
🔗
https://geti2p.net/spec/proposals/160-udp-trackers
Specifies how to implement UDP BitTorrent announces over I2P.
I2P & BitTorrent Overview
🔗
https://geti2p.net/en/docs/applications/bittorrent
Explains usage of BitTorrent inside I2P and benefits of anonymous seeding.
UDP Announces Spec
🔗
https://geti2p.net/spec/udp-announces
Describes the wire protocol for UDP announces and their use in I2P.
Status Update - July 2025
📅 Approved, tested in dev builds 2.9.0-4/-5, zzzot v0.20.0-beta3 active
Live deployment of UDP trackers confirmed.
