Part of the reason bit torrent works really well is that the file is downloaded in random order. It lets everyone cooperate, while still being robust to bad peers, bad network connections, churn etc.

If you want live high quality streaming, a lot of reasons bit torrent works so well goes away.

Latency matters. In bit torrent if the peer goes away, no big deal, just try again in 5 minutes with another peer, you are downloading in random order, who cares if one piecs is delayed 5 minutes. In a live stream your app is broken if it cuts out for 5 minutes.

In bit torrent, everyone can divide the work - clients try to download the part of the file the least number of people have, quickly rare parts of the file spread everywhere. In streaming everyone needs the same piece at the same time.

Bit torrent punishes people who dont contribute by deprioritizing sending stuff to peers that freeride. It can do this on the individual level. In a p2p streaming setup, you probably have some peers getting the feed, and then sending it to other peers. The relationship isnt reciperocal so its harder to punish freeriders as you can't at the local level know if the peer you are sending data to is pushing data to the other nodes it is supposed to or not.

I'm sure some of these have work arounds, but they are hard problems that aren't really satisfactorily solved

For a while, I was CTO of a company called Livestation [0], which as the Wikipedia article states, was "originally based on peer-to-peer technology acquired from Microsoft Research".

This P2P stack was meant to allow for mass scaling of lowish latency video streaming, even in parts of the World with limited peer bandwidth to original content source servers. The VC-1 format got into a legal quagmire, as most video streaming protocols do, and it speaks volumes that by the time I turned up in ~2012-ish, the entire stack was RTMP, RTSP, HDS and HLS with zero evidence of that P2P tech stack in production.

My main role was to get the ingest stack out of a DC and into cloud, while also dealing with a myriad of poor design decisions that led to issues (yes, that 2013 outage in the first paragraph of the wiki article was on my watch).

At no point did anybody suggest to me that what we really needed to fix our attention back to was P2P streaming, beyond the fact the company built a version of Periscope (Twitter's first live streaming product), and launched it weeks/months before they did, and were pivoting towards a social media platform, at which point I decided to go do other things.

The technical and legal problems are real, and covered elsewhere here. People want reliable delivery. Even Spotify, YouTube and others who have licensed content and could save a pile by moving to DRM-ified P2P don't go near it, and that should tell you something about the challenges.

I'd love more widespread adoption of P2P tech, but not convinced we'll ever see it in AV any time soon, unfortunately.

[0] https://en.wikipedia.org/wiki/LiveStation

Splitcast Technology built this in 2012. The company folded (couldn't find revenue, and had founder struggles ) but as far as I remember the tech worked. It still needed a lot of seeding nodes, but a significant chunk of the bandwidth was provided by the "viewer peers".

Key part of that tech was that it synchronized the playback between all peers. That was nice for stock market announcements and sport events for example.

https://web.archive.org/web/20131208173255/http://splitcast....

https://www.youtube.com/watch?v=R5UYu9jeQbY

https://www.crunchbase.com/organization/splitcast-technology

There is peertube and webtorrent, but they does not seem to catch the mainstream users.

In my opinion, NAT and the extensive tracking that has led users to distrust sharing their IP addresses are the reasons why it hasn't caught on.

Imagine YouTube using P2P technology, it would save lot of money spent on caching servers.

The real reason is that bandwidth is dirt cheap, if you know what are you are doing at scale.

For 'hobbyists' there is a lot of complexity with setting up your own streaming infrastructure compared to just using YouTube or Twitch.

Then for media companies who want to own it, they can just buy their own infra and networking which is outrageously cheap. HE.net advertises 40gbit/sec of transit for $2200/month. I'm oversimplifying this somewhat, you do have issues with cheap transit and probably need backups especially for certain regions. But there isn't much of a middleground between hobbyists and big media cos.

For piracy (live sports streams), I've read about https://en.wikipedia.org/wiki/Ace_Stream being used for this exact purposes FWIW. This was a while back but I know it had a lot of traction at one point.