Ask HN: Why is there no P2P streaming protocol like BitTorrent?

Hacker News Discussion ↗

Existing P2P Streaming Solutions

  • Multiple commenters note that “P2P streaming” already exists in various forms: BitTorrent clients with sequential download, Popcorn Time, Stremio, WebTorrent, Tribler, AceStream, PeerTube, proprietary P2P CDNs, and older systems like Joost, PPLive, PeerCast, Livestation, BitTorrent Live, Splitcast, Octoshape.
  • PeerTube in particular is highlighted as doing P2P for both VOD and live streams, but typically scales to hundreds of viewers with ~10–30s delay, not Twitch‑scale.
  • Some paid TV and sports platforms reportedly use proprietary P2P under the hood, invisible to users.

Live Streaming vs Video-on-Demand

  • Many point out that BitTorrent already works fine for streaming static files (movies, episodes) if clients request pieces sequentially and buffer.
  • Live streaming is fundamentally different: everyone needs the same segment at the same time, and you can’t “seed” future parts of a file that don’t exist yet.
  • Techniques like HLS/DASH segmenting (2–10s chunks with a few segments buffered) can tolerate some delay, but ultra‑low latency “chat with streamer” scenarios are much harder.

Networking and Protocol Challenges

  • Major obstacles: latency, jitter, out‑of‑order delivery, peer churn, and NAT/CGNAT making direct P2P connections unreliable.
  • Residential links are asymmetrical and often capped; upload is too scarce to form deep P2P trees for mass events.
  • Browser-based P2P (WebRTC/WebTorrent) adds overhead and is constrained; many torrents have far fewer WebRTC peers than native ones.
  • Multicast could solve the one‑to‑many problem, but is effectively disabled on the public internet; overlay projects like Librecast aim to work around this.

User Incentives and Behavior

  • BitTorrent’s success relies on incentives (tit‑for‑tat, rarest‑piece selection) and tolerance for delay; live viewers are intolerant of buffering or multi‑minute gaps.
  • Many users wouldn’t want their paid connection used as an upstream CDN, especially with data caps or weak upload.
  • For piracy, downloading to watch later is often preferable to streaming; for legal platforms, users expect “it just works” Netflix‑like UX.

Business, Legal, and Industry Factors

  • Commenters argue CDNs and transit are now cheap enough that P2P’s complexity rarely pays off; development and operational cost dominate.
  • Centralized architectures give platforms control over quality, DRM, and monetization; P2P complicates licensing and enforcement.
  • As mainstream services (Netflix, YouTube, Spotify, Twitch) solved convenience and catalog issues, mass user demand for P2P faded to niche and illicit use cases.