Deprecated: The ministreaming library predates today’s streaming library. Modern applications must use the full streaming API or SAM v3. The information below is retained for developers reviewing legacy source code shipped in
ministreaming.jar.
Overview
Ministreaming sits on top of I2CP to provide reliable, in-order delivery across I2P’s message layer—much like TCP over IP. It was originally factored out of the early I2PTunnel application (BSD licensed) so alternative transports could evolve independently.
Key design constraints:
- Classic two-phase (SYN/ACK/FIN) connection setup borrowed from TCP
- Fixed window size of 1 packet
- No per-packet IDs or selective acknowledgements
These choices kept the implementation small but limit throughput—each packet usually waits almost two RTTs before the next is sent. For long-lived streams the penalty is acceptable, but short HTTP-style exchanges suffer noticeably.
Relationship to the Streaming Library
The current streaming library extends the same Java package (net.i2p.client.streaming). Deprecated classes and methods remain in the Javadocs, clearly annotated so developers can identify ministreaming-era APIs. When the streaming library superseded ministreaming it added:
- Smarter connection setup with fewer round trips
- Adaptive congestion windows and retransmission logic
- Better performance over lossy tunnels
When Was Ministreaming Useful?
Despite its limits, ministreaming delivered reliable transport in the earliest deployments. The API was intentionally small and future-proof so that alternate streaming engines could be swapped in without breaking callers. Java applications linked it directly; non-Java clients accessed the same functionality through SAM support for streaming sessions.
Today, treat ministreaming.jar as a compatibility layer only. New development should:
- Target the full streaming library (Java) or SAM v3 (
STREAMstyle) - Remove any lingering fixed-window assumptions when modernising code
- Prefer higher window sizes and optimised connect handshakes to improve latency-sensitive workloads
Reference
- Streaming Library documentation
- Streaming Javadoc – includes deprecated ministreaming classes
- SAM v3 specification – streaming support for non-Java applications
If you encounter code that still depends on ministreaming, plan to port it to the modern streaming API—the network and its tooling expect the newer behaviour.