The original poster wonders why there isn't a widely adopted peer-to-peer (P2P) protocol for live streaming similar to how BitTorrent works for file sharing. They envision a system where viewers contribute their bandwidth to distribute the stream, reducing the load on the original broadcaster and potentially improving stability and scalability, especially for events with large audiences. The existing solutions mentioned, like WebRTC, are acknowledged but considered inadequate for various reasons, primarily due to complexity, latency issues, or lack of true decentralization. Essentially, they're asking why the robust distribution model of torrents hasn't been effectively translated to live video.
The original poster on Hacker News, under the title "Ask HN: Why is there no P2P streaming protocol like BitTorrent?", poses the fundamental question of why a robust and widely adopted peer-to-peer protocol for streaming media, similar in functionality and success to BitTorrent for file sharing, does not currently exist. They acknowledge the existence of some attempts at P2P streaming solutions, specifically mentioning WebTorrent, but express confusion as to why none have achieved widespread adoption or managed to offer a compelling user experience that rivals traditional centralized streaming platforms. The author implies a desire for a decentralized streaming ecosystem where content creators could distribute their work directly to viewers without relying on intermediaries, potentially leading to benefits such as reduced costs, censorship resistance, and increased availability. They seem perplexed by the apparent technical hurdles preventing the successful implementation of such a protocol, despite the proven viability of P2P technology for large-scale file distribution as demonstrated by BitTorrent. The core of their inquiry revolves around understanding the underlying technological or logistical challenges that have hindered the development and popularization of a truly effective P2P streaming protocol. They are essentially seeking insight into the specific reasons why, despite the apparent demand and potential advantages, such a technology has not yet become a mainstream reality.
Summary of Comments ( 165 )
https://news.ycombinator.com/item?id=43684286
HN users discussed the challenges of real-time P2P streaming, citing issues with latency, the complexity of coordinating a swarm for live content, and the difficulty of achieving stable, high-quality streams compared to client-server models. Some pointed to existing projects like WebTorrent and Livepeer as partial solutions, though limitations around scalability and adoption were noted. The inherent trade-offs between latency, quality, and decentralization were a recurring theme, with several suggesting that the benefits of P2P might not outweigh the complexities for many streaming use cases. The lack of a widely adopted P2P streaming protocol seems to stem from these technical hurdles and the relative ease and effectiveness of centralized alternatives. Several commenters also highlighted the potential legal implications surrounding copyrighted material often associated with streaming.
The Hacker News post "Ask HN: Why is there no P2P streaming protocol like BitTorrent?" generated a robust discussion with a variety of perspectives on the challenges and existing solutions for P2P streaming.
Several commenters pointed out that P2P streaming protocols do exist, albeit with limitations that prevent widespread adoption. Examples cited include WebTorrent, Livepeer, and Tribler. Some argued that the question's premise was flawed, highlighting the existence of these protocols, while others elaborated on why these existing solutions haven't achieved mainstream success.
A recurring theme in the comments was the inherent difficulty of real-time streaming via P2P. Commenters explained that the strict timing requirements of streaming content differ significantly from downloading files, where order and completion are paramount, but timing is less critical. The unpredictable nature of P2P networks, with peers joining and leaving intermittently, makes it challenging to guarantee smooth, uninterrupted playback. Issues like latency, buffering, and ensuring data arrives in the correct sequence were frequently mentioned as obstacles.
Several technical challenges were discussed in detail. These included:
Some commenters suggested that centralized Content Delivery Networks (CDNs) offer a more reliable and efficient solution for streaming, at least for now. The infrastructure and optimization provided by CDNs address many of the challenges inherent in P2P streaming.
While acknowledging the difficulties, some expressed optimism about the future of P2P streaming. They pointed to advancements in technologies like WebRTC and distributed hash tables (DHTs) as potential solutions to some of the existing challenges. The potential for reduced infrastructure costs and increased resilience against censorship were cited as key motivators for continued development in this area.
One compelling comment thread delved into the complexities of live streaming versus on-demand streaming in a P2P context. Live streaming poses greater challenges due to the real-time nature of the content and the need for low latency. On-demand content, in contrast, allows for more flexibility in piece acquisition and can tolerate higher latency.
Another interesting discussion focused on the potential of blockchain technology to incentivize participation in P2P streaming networks. By rewarding seeders with cryptocurrency, it might be possible to create a more robust and sustainable ecosystem.
In summary, the comments offered a nuanced perspective on the state of P2P streaming. While acknowledging the existence of such protocols, they highlighted the significant technical hurdles that have prevented widespread adoption. The discussion covered various aspects, from the challenges of real-time data delivery to the potential of emerging technologies like WebRTC and blockchain. The overall sentiment reflected a cautious optimism, acknowledging the difficulties while recognizing the potential benefits of a decentralized streaming future.