Legitimate Kazaa/Bittorrent for software updates etc?

[GregA]

Apple has the deals with Akamai to get high speed downloads anywhere in the world - which works great.

But what would happen if they used a Bittorrent/Kazaa/eDonkey style system to download things like OS updates, software downloads, developer builds, quicktime movies, and so on.

It's a legitimate use of the technology and would improve responsiveness etc. Is there a downside to it?

 

[Makosuke]

I don't personally see what any problems would be, although I suppose there could be one.

Security, maybe? Someone hacking their DL app to corrupt any data it sent out, that is. Of course, it seems like the most you could do is break a download or slow one down this way, since the chunks (or whole file) from the corrupted client wouldn't checksum.

It would seem that, since Apple would be seeding the download with as much bandwidth as necessary that there wouldn't even be an issue if not many people were downloading at a given time--Apple would just pick up the slack, and it'd still be cheaper for them than hosting the whole thing.

I've seen professional operations use Bittorrent downloads to handle huge spikes in load, so I'm guessing the real issue is one of corporate image--they don't want to look like they need help supplying the downloads. An Apple-branded client (maybe proprietary) would help that image, though.

 

[iJon]

because that means they would have to build bittorrent into the system and then there server would always be uploading which would be waste of bandwidth.

iJon

 

[Makosuke]

Originally posted by iJon
because that means they would have to build bittorrent into the system and then there server would always be uploading which would be waste of bandwidth.

I'm not an expert on file transfer, but I don't follow your logic.

So far as I understand it, Bittorrent lets one site seed a download. If 5 people want to download that file at the same time, the seed location starts giving each of those people a different chunk of the file. Once they've each got a chunk, then they start spreading those chunks to each other instead of the server having to send the file to every person. The end result, in theory, would be that all five people would get the file and the server would only have to spit out each chunk once.

Now, it never works quite that smoothly in real life, and if people have a much faster download than upload or something similar that'll also cause it not to work as well, and people (or ISPs) might eventually start complaining if there's too much client-to-client traffic. But, the absolute worst that can happen is that the server sends each person the file once, which is exactly what's happening with a modern server anyway.

How would a swarm downloading system make things worse?

 

[GregA]

Originally posted by Makosuke
<snip> If 5 people want to download that file at the same time, the seed location starts giving each of those people a different chunk of the file. Once they've each got a chunk, then they start spreading those chunks to each other instead of the server having to send the file to every person.

<snip> people (or ISPs) might eventually start complaining if there's too much client-to-client traffic. But, the absolute worst that can happen is that the server sends each person the file once, which is exactly what's happening with a modern server anyway.

I've looked up a few things since asking the question. You're right about the way it works with chunks of the file shared. [edit] It also only lets you download at the same rate you upload to someone else (which leads to a few issues with firewalls!).

iJon is right that when you are downloading using Bittorrent, you do upload some info at regular intervals to the 'server' ("tracker") which records your systems location (for sharing) and info on what you've downloaded. Still, it's a small amount of data in comparison to what you would otherwise download.

I guess people could complain if uploading slowed them down. But why would your ISP not like client-to-client traffic? In fact, if a sharing application (whatever technology) could identify which peers are close by or on your ISPs network, your speeds would increase and your ISP wouldn't be paying external download charges (with my ISP, it wouldn't count towards my GB limits).

 

[Nermal]

The problem I have with BitTorrent is that I never know where my downloads are coming from. I'm never sure whether I'm using up my international GB allowance or not. Actually, I think I'll email the people that make BitTorrent and see whether they can add a "limit to your country" feature.

Edit: I can't find an email address to send suggestions to