Stuart Clark wrote:


BBC iPlayer streams use a bit rate of 550 kbps, and there's 400 hours of it
per week, and the iPlayer saves a week's worth. That works out to be about
90 MB, so on a say 1 GB hard drive there's lots of space for other content,
and they might as well install more than one hard disk if they're going to
install equipment.

At the end of the day, the cache shouldn't be just for the BBC's stuff, the
optimal use would be for the cache to hold content that accounts for the
most bandwidth, which could include popular YouTube videos and all sorts.
Once installed, the hard drives are still increasing at faster than Moore's
Law at the moment, so if they changed things so that these caches could
serve files to users from the exchanges, that would have a dramatic impact
on bandwidth.

The main problem is BT though, because if Ofcom just lets BT do whatever it
wants it'll block these caches being installed because BT would lose out in
terms of bandwidth. Ofcom really needs to actually do something that's in
the best interests of both the ISPs and broadband users but which isn't
going to help BT.



A cache inside exchanges could dramatically improve the situation, IMO. At
the end of the day, bandwidth is expensive for the ISPs, so stopping some of
the bandwidth travelling over the backhaul would obviously be of benefit.


--
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

On Sun, 13 Apr 2008 00:02:09 +0100, Cork Soaker wrote:

No I didn't but you seem to have missed my point which is that the
proposal could only ever work if there was no ISP other than BT able to
offer service over their monopoly network.

As others have pointed out ADSL is not just Internet delivery. BT don't
actually "see" the IP layer as such as it's encapsulated in a tunnel back
to the ISP who are the first point where traffic may legitimately be
differentiated by which stage the cost elements have already been
attracted so it's pointless to interfere.

Arguable BT could do as has been suggested for their own connections
however that would give them an unfair advantage which OFCOM would block
for good reason.

On Sun, 13 Apr 2008 00:01:33 +0100, Cork Soaker wrote:

Yes. Why should we need OFCOM approval? On what basis could OFCOM
legitimately give or refuse approval if there were such a scheme other
than on a revenue raising on for the govt?

: That would help for P2P, but nothing else,

Like the BBC iPlayer? The whole point of discussion?

: and even that would probably
: be quite marginal. How many people are likely to be downloading the same
: torrent (or whatever other P2P system equivalent) at the same exchange

You mean over multicast, say? Like, something from the BBC IP network?

"Jason Clifford" <jason@ukfsn.org> wrote in message
news:ftt3la$m7m$1@localhost.localdomain...
: On Sun, 13 Apr 2008 00:02:09 +0100, Cork Soaker wrote:
:
: > You missed the point about adding routing equipment at the exchange
: > didn't you?
:
: No I didn't but you seem to have missed my point which is that the
: proposal could only ever work if there was no ISP other than BT able to
: offer service over their monopoly network.
:
: As others have pointed out ADSL is not just Internet delivery. BT don't
: actually "see" the IP layer as such as it's encapsulated in a tunnel back
: to the ISP who are the first point where traffic may legitimately be
: differentiated by which stage the cost elements have already been
: attracted so it's pointless to interfere.

Routing equipment is easily able to route multiple ISP streams. If ten
users on ten different ISPs request the same content, then obviously this
means ten streams. If more users from the same ISPs request the same
content then it's just ten streams.

:
: Arguable BT could do as has been suggested for their own connections
: however that would give them an unfair advantage which OFCOM would block
: for good reason.
:

: At the end of the day, the cache shouldn't be just for the BBC's stuff,
the
: optimal use would be for the cache to hold content that accounts for the
: most bandwidth, which could include popular YouTube videos and all sorts.

Indeed.
Some ISPs do you use caching, but it's all at their core datacentre. It
still saves them a fortune.
Freeserve used to do it, but it relied on users adding their proxy to the
PCs config, so it was opt-in.

"The Natural Philosopher" <a@b.c> wrote in message
news:1208080312.22308.2@proxy00.news.clara.net...
: Cork Soaker wrote:
: > "Jason Clifford" <jason@ukfsn.org> wrote in message
: > news:ftrdjp$1uf$2@localhost.localdomain...
: > : On Sat, 12 Apr 2008 17:17:41 +0100, Cork Soaker wrote:
: > :
: > : > : Why should they be free to do all that without paying the costs of
: > : > doing : so and why should the ISPs or anyone else be required to pay
for
: > : > their : doing so?
: > : >
: > : > Because that's what they signed up for when asking for the license
to do
: > : > so.
: > :
: > : I've never seen anything to back up such a claim. No ISP "asked for a
: > : license" to run under those terms - I certainly didn't (not that there
is
: > : such a thing as a license to run an ISP)
: >
: > So you just startup and don't need OFCOM approval?
: >
: >
: Definitely. We never got OFCOM approval when we started doing it.

Probably because you're a reseller.

Stuart Clark <stuart.clark@Jahingo.com> writes:

By the RTT of packets between the two users.

"Graham Murray" <newspost@gmurray.org.uk> wrote in message
news:87bq4ditmo.fsf@newton.gmurray.org.uk...
: Stuart Clark <stuart.clark@Jahingo.com> writes:
:
: > and is the P2P software going to choose a nearby user anyway (how does
: > it know it is nearby for starters).
:
: By the RTT of packets between the two users.

I've already said that DNA by BitTorrent does this, but....

This is not new in P2P networks either. Kazaa did this (to a very limited
amount) by prioritising connections to IPs on the same WAN subnet. I have
no idea if this still happens, I don't use it anymore. I know, it's not
based on RTT or ping, but it did help with speeds (and therefore bandwidth).

: The main advantage of that though is the system is much simpler and
: cheaper. Imaging having hundreds of cross country routes, meaning miles
: and miles more track. How much extra is all that going to cost to
: maintain, and how much more complex is planning a route between two
: locations. The wider Internet is already seeing some pain at the growth
: of the routing table, with many routers now being unable to cope, and
: this is with just 250k routes - how's BT's system going to work with
: millions of routes (one per ADSL user).

IPv6. This is what it was designed to achieve.

On Sun, 13 Apr 2008 16:29:07 +0100, Cork Soaker wrote:

And to do that BT would have to inspect the content of all of your
communications - in breach of RIPA.

Given their inlawful co-operation with Phorm to do this to their own
customers already do you really want BT able to do the same to everyone?

"Jason Clifford" <jason@ukfsn.org> wrote in message
news:fttfrc$rp1$1@localhost.localdomain...
: On Sun, 13 Apr 2008 16:29:07 +0100, Cork Soaker wrote:
:
: > Routing equipment is easily able to route multiple ISP streams. If ten
: > users on ten different ISPs request the same content, then obviously
: > this means ten streams. If more users from the same ISPs request the
: > same content then it's just ten streams.
:
: And to do that BT would have to inspect the content of all of your
: communications - in breach of RIPA.

No they don't. How do you think they route traffic in the first place?

:
: Given their inlawful co-operation with Phorm to do this to their own
: customers already do you really want BT able to do the same to everyone?

On Sun, 13 Apr 2008 20:18:22 +0100, Cork Soaker wrote:

So how to *you* suggest BT (or anyone else) should be able to
discriminate as to which traffic to interfere with and which to allow to
pass on to the ISP in the normal manner or are you agreeing that the only
way such a system could work would be to abolish all ISPs other than BT
and hand control over them?

"Cork Soaker" <ISawYourMotherLast@Night.invalid> wrote in message
news:fttel8$ggl$1@registered.motzarella.org...
no.

IPv6 solves the issue of number of addresses (although that isnt relevant to
this anyway).

but a different (related) problem is how to build a router which can cope
with say 100 times the current Internet routing table (not far off 1,000,000
routes for a router that doesnt use defaults to ignore chunks of the total
routes around).

the fix so far has been address aggregation, where a router only needs
detailed info about "local" routes, and less and less about more distant
routes.

"distance" in this case usually means crossing the boundary to another
address management domain - in this context that is a different ISP.

and so yes - building an arbitary partial mesh between all the ISPs at an
exchange and their interfaces and exchanging routes in a meaningful way to
handle "short circuiting" local traffic is another can of worms.

Oh - and did i mention all those ISPs get charged for backhaul - so they are
going to want to make sure other ISPs dont dump "their" traffic out of the
exchange onto them and avoid BT use charges.........

Ironically BT have been talking about doing more or less this for multicast
on 21CN (to support real time streaming) - 21CN is their new replacement for
voice and broadband on 1 network, and it gives them a chance to tinker with
design.
Regards

stephen_hope@xyzworld.com - replace xyz with ntl

"stephen" <stephen_hope@xyzworld.com> wrote in message
news:RRtMj.7398$B83.1601@newsfe3-gui.ntli.net...
: "Cork Soaker" <ISawYourMotherLast@Night.invalid> wrote in message
: news:fttel8$ggl$1@registered.motzarella.org...
: >
: >
: > : The main advantage of that though is the system is much simpler and
: > : cheaper. Imaging having hundreds of cross country routes, meaning
miles
: > : and miles more track. How much extra is all that going to cost to
: > : maintain, and how much more complex is planning a route between two
: > : locations. The wider Internet is already seeing some pain at the
growth
: > : of the routing table, with many routers now being unable to cope, and
: > : this is with just 250k routes - how's BT's system going to work with
: > : millions of routes (one per ADSL user).
: >
: > IPv6. This is what it was designed to achieve.
:
: no.
:
: IPv6 solves the issue of number of addresses (although that isnt relevant
to
: this anyway).

It also solves routing problems as IPv6 address are heirarchical - the way
IPv4 was supposed to be, but it failed because registries were just throwing
IPs anywhere to make up for the shortfall.

This is why one node on a network has several different IPv6 addresses, for
each network.

:
: but a different (related) problem is how to build a router which can cope
: with say 100 times the current Internet routing table (not far off
1,000,000
: routes for a router that doesnt use defaults to ignore chunks of the total
: routes around).

IPv6, being heirarchical only needs to know where the network is, not every
IP within the network or internetwork.
The next router knows the next part of the network, and the next router
knows the next part. This is part of the IPv6 standard and was designed to
alleviated the problem of table overflow. Not cure it though, obviously.

:
: the fix so far has been address aggregation, where a router only needs
: detailed info about "local" routes, and less and less about more distant
: routes.
:
: "distance" in this case usually means crossing the boundary to another
: address management domain - in this context that is a different ISP.
:
: and so yes - building an arbitary partial mesh between all the ISPs at an
: exchange and their interfaces and exchanging routes in a meaningful way
to
: handle "short circuiting" local traffic is another can of worms.
:
: Oh - and did i mention all those ISPs get charged for backhaul - so they
are
: going to want to make sure other ISPs dont dump "their" traffic out of the
: exchange onto them and avoid BT use charges.........

That's up to the routing table and encapsulation - this already happens on
many networks.

:
: Ironically BT have been talking about doing more or less this for
multicast
: on 21CN (to support real time streaming) - 21CN is their new replacement
for
: voice and broadband on 1 network, and it gives them a chance to tinker
with
: design.

We'll see how well they do it, and how long it takes them!

"Jason Clifford" <jason@ukfsn.org> wrote in message
news:fttnt7$9sb$1@localhost.localdomain...
: On Sun, 13 Apr 2008 20:18:22 +0100, Cork Soaker wrote:
:
: > : And to do that BT would have to inspect the content of all of your :
: > communications - in breach of RIPA.
: >
: > No they don't. How do you think they route traffic in the first place?
:
: So how to *you* suggest BT (or anyone else) should be able to
: discriminate as to which traffic to interfere with and which to allow to
: pass on to the ISP in the normal manner or are you agreeing that the only
: way such a system could work would be to abolish all ISPs other than BT
: and hand control over them?

They're called routing tables. Do you know how the internet works?

On Sun, 13 Apr 2008 23:29:12 +0100, Cork Soaker wrote:

I certainly do. That's why I asked my question as it seems some people
here (who are suggesting that BT should setup some form of localised
routing or caching at exchanges for p2p) do not.

DAB sounds worse than FM wrote:

Hmm, I think you're a factor of a 1000 out...

stephen wrote:
That happens on international circuits anyway. If two ISPS have peering
points at two places they ALWAYS dump their packets onto the other at
the earliest opportunity.

Knowing it will be done to them anyway on the reverse route.

Asymmetrical routing is standard in this case.

Cork Soaker wrote: