Cork Soaker wrote:
Not the way that you thinjk: They are just routing frame relay packets
to your ISP.

NONE of the backhaul is done using IP routing whatsoever.

IP stops at your DSL modem, and reappears at YOUR ISP's frame relay
termination kit.

BT, in this case, is not acting as an ISP at all. It is acting as a
simple connectivity supplier, connecting their DSLAM (or if LLU the
ISP's DSLAM) to the ISPS port over a virtual circuit.

Cork Soaker wrote:

You haven't a clue really, have you?

Cork Soaker wrote:
reseller.

You haven't a clue really, have you?

"The Natural Philosopher" <a@b.c> wrote in message
news:1208168688.24758.0@proxy02.news.clara.net...
Another one that thinks he knows how its done.
Wrong as it happens. ;-)
The last time I looked the IP was encapsulated in IP, so no routing is done
on the contents of the packet but it is on the wrapper.

Frame relay is old hat.

dennis@home wrote:
I suggest you look again then. BT's backhaul is frame relay
So is BT.

Peter Watson wrote:

Indeed.


--
Steve - www.digitalradiotech.co.uk - Digital Radio News & Info

The adoption of DAB was the most incompetent technical
decision ever made in the history of UK broadcasting:
http://www.digitalradiotech.co.uk/da...ion_of_dab.htm

Not been paying much attention to this thread, sorry.
Can I ask a question?
Do people downloading from the BBC iplayer effect me and my speed?
If yes I'm worried as today I learnt my Wii console can, and Nintendo are
very shortly to extend the feature. If this iplayer does effect me when
others downloading in my telephone area then Wii owners might bring the use
of broadband to a halt.

--
Regards,
David

Please reply to News Group

Cork Soaker wrote:
Closeness by IP address isn't going to help much as for example a Zen
user will be on a completely different range than a Plusnet user, even
if they are on the same exchange. RTT might help, depending on how
different it is between two users on one exchange and two users on two
close by but different exchanges.

Cork Soaker wrote:
The Flash iPlayer, which is the one all the ISPs are complaining about,
doesn't use P2P.

Multicast is only useful for live streams, not video on demand or P2P.

Cork Soaker wrote:
It could work if IP addresses where allocated by BT rather than by a
particular ISP so they could be aggregated by exchange. But that then
reduces the ISP to basically a reseller of the BT ISP.

DAB sounds worse than FM wrote:
Basically you'd just install an Akamai box at each exchange (as they are
a popular CDN who use the lots of machines all over the place model).
This of course only helps with content suppliers who pay Akamai (or
whoever's CDN machine you do end up installing), so it could quite
easily miss big bandwidth users and not help the ISP as much as it could.

The installing these machines is the easy bit though. Any LLU provider
could do this today, but there probably isn't enough of a benefit to do so.

IPStream users are different though (and I'm sure the same might be true
of other wholesale products from other providers). As things currently
stand you'd have to make some big changes to how IPStream works (with
knock on big changes to ISPs and how they run) to let these caches be
accessible from a home ADSL connection.

David wrote:
Using iPlayer via your PC or Wii will affect your own connection.

If enough people used it who are connected to your exchange (or do
anything which uses a lot of bandwidth) it could max out the exchange's
connection - could happen for really tiny exchanges with slower backhaul
connections.

The core BT network is very unlikely to notice iPlayer, and if things do
slow down BT will upgrade bits as it is in their best interest to do so
(as they are paid based on its usage).

Your ISPs connection could be affected much more easily, especially if
they run their connections close to the limit (eg. the low cost
providers) or only have small connections (eg. the very small ISPs).

The biggest impact is likely to be that the cost to an ISP of keeping
their customers connected to the Internet will rise, which could result
in them having to raise prices.

Cork Soaker wrote:
OFCOM in general don't get involved with the average telecoms
company/ISP unless:

They have significant market power (eg. BT)
There are lots of complaints or similar problems
They need to be allocated a shared resource (eg. telephone numbers)

It isn't really in anyone's best interest to have to register with OFCOM
as they already have the legal tools needed to regulate and registration
would just increase cost to the industry.

"Stuart Clark" <stuart.clark@Jahingo.com> wrote in message
news:36hcd5-3si.ln1@stuart.Jahingo.com...
multicast can be used for file delivery - there have been several multicast
systems built for that and used in corporate networks. So if you had a
"choose and watch later" model for video on demand, then it might be useful.

you could schedule the multicast when you had lined up several recievers, or
you sent lots of bits of a file in any order.

Also there is no reason multicast cannot be used for P2P - it just isnt
common enough to make it worthwhile for the P2P systems "out there" to
bother implementing it.

Since most machines using P2P are on the end of ADSL or cable links where
the uplink is much slower than the downlink, using multicast where 1 stream
could get sent to multiple recievers would improve system performance.
--
Regards

stephen_hope@xyzworld.com - replace xyz with ntl

Stuart Clark wrote:

Velocix (previously called CacheLogic) is the company the BBC has apparently
been working with, and they're touting a new-style kind of CDN. See this
interview:

http://uk.youtube.com/watch?v=bLEW_enZEgE



Akamai's model doesn't suit the ISPs, and I think they'll end up being the
ones footing the bill, and although I don't know the details about Velocix's
solution, it sounds to me from what the chief exec is saying that their
model more closely fits what the ISPs need to be implemented.



I disagree. All it takes is for a CDN company to start using a different
model, where caches inside exchanges store the files that account for the
most bandwidth, and not for them to only store the content from certain
content providers, because that model wouldn't be of much benefit. There's a
gap in a lucrative marke here, so it's bound to be filled at some point.

A CDN with caches inside the exchanges is the only way to avoid all the
iPlayer and other video traffic from travelling over BT's and the ISPs'
networks, which is where the bandwith costs are incurred.

The iPlayer consists of 400 hours of TV programmes at the moment, which at
550 kbps works out to be about 90 GB of storage space for all of the iPlayer
TV programme files. 1 TB hard drives are only £150 at the moment, so just
one hard disk could store all the iPlayer TV programmes, all of the BBC's
Listen Again radio programmes, all of 4oD's programmes, the most popular
YouTube videos, thousands of the most popular web pages and so on. And when
1 TB hard drives only cost £150, if they're going to go to the expense of
installing one hard drive they may as well install more than that.
Installing content provider-oblivious caches inside the exchanges could
massively reduce the amount of bandwidth the ISPs need for the backhaul for
video, IMO, because hard disks could hold the large majority of video files
that people would view.

YouTube videos are only about 200 kbps, and they're only about 3 - 5 minutes
or whatever on average. Say the average were 4 minutes in length, that works
out as being 6 MB per YouTube video, or 167 YouTube videos per GB, or 16,667
YouTube videos per 100 GB. I'd bet that if you stored 100 GB of YouTube
videos you'd account for the vast majority of all YouTube traffic. And the
same applies to all the other video applications. And when things move to
using HD, hard drive capacities will have grown in size to cater for that.



Ofcom estimates that the bandwidth bill for the iPlayer over the next 5
years could be up to £831m, so although BT would be against such a CDN, teh
CDN plus the changes required to implement it would be far cheaper than
£831m.


--
Steve - www.digitalradiotech.co.uk - Digital Radio News & Info

The adoption of DAB was the most incompetent technical
decision ever made in the history of UK broadcasting:
http://www.digitalradiotech.co.uk/da...ion_of_dab.htm

DAB sounds worse than FM wrote:
How do you get that data onto the cache machines?

For static downloadable content using a HTTP proxy would work. You would
need a fairly quick set of servers in your exchange as basically all web
traffic would be passing through them. Lots of ISPs used to run proxies
so it's nothing new. They can be a pain to maintain - needs careful
attention to keep them caching the stuff that actually makes a difference.

That doesn't help for streaming though - so that is things like the
Flash iPlayer. To be able to "cache" those your server in the exchange
would have to run various types of streaming server (eg. Flash, Windows
Media, Quicktime, etc) and then BT/CDN owner would need to approach
content owners to obtain copies of all their media, as well as working
out a system of getting updates & distributing them to all the exchanges.

That is probably quite a lot of work in itself, getting the BBC,
YouTube, or whoever to allow a third-party to have access. They aren't
just going to let anyone take a copy of their data without some fairly
strict contract provisions. And of course the content providers could
just say no or charge for such access - you can't force them to let you,
particularly the non UK based ones.

Stuart Clark wrote:

Couldn't they just send data to it like if it were any normal computer?



Right.



The iPlayer streams are effectively still static files though.



The main issue here is the BBC iPlayer traffic, and the BBC definitely would
definitely allow the ISPs to store iPlayer programmes on such a CDN because
it would get the ISPs off their back.

YouTube and everything else would just be a bonus for the ISPs if they could
cache it in the exchanges, but the really big bandwidth issue is the
iPlayer - a 30 minute iPlayer programme is about 120 MB, whereas YouTube
videos tend to be about 5 MB in size.



The BBC would jump at this like a flash.



As I say, the main issue is the iPlayer, and the ISPs would have no problems
getting permission to store the iPlayer programmes.


--
Steve - www.digitalradiotech.co.uk - Digital Radio News & Info

The adoption of DAB was the most incompetent technical
decision ever made in the history of UK broadcasting:
http://www.digitalradiotech.co.uk/da...ion_of_dab.htm

DAB sounds worse than FM wrote:
Not for streams. Streams are real time (so a 30 minute programme takes
30 minutes with the ability to skip to any point within the program
without having to download the entire file up to that point. The other
thing about streaming protocols is that they are often designed to be
"unrecordable".

They are static files on the BBC's streaming server. Nobody can get to
those files though, only to a streamed version of them.

I can assure you there is a lot more out there than just iPlayer! The
only difference is that the BBC is very well known. Once the other
terrestrial TV channels come on board you increase the number a few
times, and then any VoD services which will likely come about once
people are used to waiting "TV over the Internet". Having a solution for
the iPlayer may help in the short term, but unless it can scale to other
providers it's going to quickly lose its benefit.

The BBC isn't going to let just anyone have access so it will only be
the ISPs who sign contracts with them and agree to some fairly stringent
safeguards who will be able to do this. Remember the BBC has agreements
that iPlayer only works for a week, and it isn't going to hold much
water if files leak because of some lax security on the part of the CDN/ISP.

Stuart Clark wrote:

The iPlayer TV streams are just video files that the BBC has encoded and
stuck no a streaming server.



I'm talking about pushing the static files that are currently on BBC's
streaming servers onto these caches - the BBC actually uses an Akamai CDN to
distribute the iPlayer at the moment, BTW.



I mentinoed 4oD and YouTube in the last but one post on this sub-thread, and
I know there's plenty of other video websites out there. All I'm saying is
that the current row is between the BBC and the ISPs over the BBC iPlayer
bandwidth costs, and Ofcom estimated that the bandwidth due to the iPlayer
alone could cost the ISPs up to £831m over the next five years, so due to
that alone it would be worthwhile investing in a CDN with caches inside the
exchanges, and anything else it can carry in addition to the iPlayer streams
would just be a bonus for the ISPs.



4oD and ITV.com have already launched though, and you don't hear much said
about them, probably because the 4oD software is crap and when I tried
ITV.com it didn't really work properly, plus teh content is crap. And Five
only sells TV programmes from its big US import series, so I doubt many
people download those. They might pull their finger out, but at the moment
the iPlayer is almost the only show in town regarding TV content from the
terrestrial channels.

There's Project Kangaroo that's going to launch this year, which is a
collaboration between the terrestrial TV broadcasters, but not a lot is
known about it yet. That would be another thing they'd want to put on the
CDN caches though.



If Ofcom's estimate of £831m turns out to be correct for how much the
bandwidth bill for the iPlayer will be over the next 5 years, it would be
extremely cheap to install a CDN instead of picking up that bill. Basically,
they'd be best off trying to get as many content providers on-board as
possible, because isntalling and/or replacing hard drives would work out a
lot cheaper than buying BT Centrals each time the bandwidth increases.



Yeah, they'd have to work together on this.


--
Steve - www.digitalradiotech.co.uk - Digital Radio News & Info

The adoption of DAB was the most incompetent technical
decision ever made in the history of UK broadcasting:
http://www.digitalradiotech.co.uk/da...ion_of_dab.htm

In news:ijthd5-nen.ln1@stuart.Jahingo.com,
Stuart Clark <stuart.clark@Jahingo.com> typed, for some strange,
unexplained reason:
: DAB sounds worse than FM wrote:
: > Stuart Clark wrote:
: >> How do you get that data onto the cache machines?
: >
: >
: > Couldn't they just send data to it like if it were any normal
: > computer?
: >
:
: Not for streams. Streams are real time (so a 30 minute programme takes
: 30 minutes with the ability to skip to any point within the program
: without having to download the entire file up to that point. The other
: thing about streaming protocols is that they are often designed to be
: "unrecordable".

Rather pointless really as there is plenty of software around that will
record anything that passes through your soundcard.

Ivor