Verily I say unto thee, that Mark Kent spake thusly:
> Another issue which has not been discussed here is the p2p nature of
> the iPlayer. It uses a similar approach to bittorrent, or skype,
> where your own PC becomes a server for other clients. My
> understanding is that there is no way of controlling this flow, and
> it has a habit of bringing the user's ADSL lines to a standstill. A
> friend who tried it found this out by accident, when trying to work
> out why his ADSL line seemed to have been reduced to a crawl. He
> fixed it by... killing the iPlayer.
I haven't used iPlayer (I did try the Flash streams though), but I've
read enough of the technical details to know that its P2P system is the
same as Sky's service ... i.e. "Kontiki", which I *do* use.
Kontiki is a proprietary P2P system in the usual client/server model.
The client is called "KHost.exe", and starts automatically with whatever
GUI front-end hooks into it (Sky Anytime, iPlayer, etc.). The server is
called KService.exe, and runs as a Windows service. As such it can be
started and stopped using the Windows "Services" MMC control interface,
or with the "net [start|stop] <service>" command.
For those, like me, using a router; in order to allow port forwarding,
for Kontiki, one must open inbound connections over TCP and UDP on ports
8080 and 1948 respectively. One does not strictly need to be a peer to
others for the system to work, but personally I prefer to not operate a
P2P system in leech mode.
There are a couple of problems for those not used to running P2P
software however. One is that closing down the application (iPlayer or
whatever) does not stop the service, so one's connection continues to
get hammered even when the application is not running. This tends to
perplex some people new to the whole file-sharing thing, especially
Windows users who, in the main, don't always seem to grasp the idea of
background services.
The other problem is the Kontiki package itself is *not* uninstalled
when the application is uninstalled, and indeed does not even *have* an
uninstaller (no entry in the "Add/Remove programs" applet). This is
extremely bad practice (thou shalt push what thee pop), and is IMHO
tantamount to Malware. Sky does offer a "cleaner" called KClean.exe,
which in itself only serves to support the Malware stigma.
The disgusting practise of covert and irremovable installs is far too
prevalent under Windows; many coming directly from Microsoft themselves
(see last year's "stealth updates" scandal), which is yet another reason
I intensely dislike the whole Windows paradigm, and much prefer an Open
and transparent system like Linux.
There are other issues not specific to Kontiki that make running P2P on
Windows a pain. One is the "half-open connections" limit, which IIRC is
limited to just *10* on Windows. This severely limits the scope of P2P,
essentially limiting the number of nodes that can provide packets for
your requests. There is a hack, naturally, which can be found here:
http://www.lvllord.de/?lang=en&url=downloads
Although it should be pointed out that allowing too many half-open
connections leaves one's system vulnerable to SYN flood attacks.
Another issue is that Windows networking is extremely inept, and
struggles greatly under load, especially WRT P2P. I find that more than
two or three simultaneous downloads, using Kontiki, brings the whole OS
to its knees, and that's on even a fairly beefy 2GHz system, but YMMV.
By comparison, I can run 20 or so concurrent BitTorrent downloads on my
533Mhz Fedora server, and rarely see the CPU utilisation exceed 20%, but
again, YMMV.
> There was no discussion with ISPs on this issue, in spite of the BBC
> and Microsoft's intention of using ISP bandwidth as a kind of
> broadcast medium.
Yes, I've read quite a few threads on the issue over at ADSLGuide
forums, and most of the ISP spokesmen are bloody furious with both Sky
and the MSBBC for flooding their networks. I'm undecided on the issue,
personally, since I think broadband users should get what they pay for,
but since the theoretical caps don't match the practical limits, then
once the majority start maxing out their connections, the centrals will
quickly be flooded. That's what you get for over-subscription, I guess.
Part of me wants to scream "Net Neutrality", but OTOH I think it's only
fair that Sky and the MSBBC should contribute something to the Network
costs, since they are contributing a huge volume of traffic.
--
K.
http://slated.org
.----
| "[Microsoft] are willing to lose money for years and years just to
| make sure that you don't make any money, either." - Bob Cringely.
| - http://blog.businessofsoftware.org/2007/07/cringely-the-un.html
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Fedora release 8 (Werewolf) on sky, running kernel 2.6.23.8-63.fc8
10:48:50 up 27 days, 8:24, 2 users, load average: 0.02, 0.24, 0.24
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