Can CDN caches go inside exchanges?

I was told by someone yesterday that you can't put a CDN cache (e.g. for the
iPlayer) inside BT's exchanges, and the reason why he said you can't do this
is because a user's data goes to their ISP via BT's network over a virtual
circuit.

But I also read last night that Tiscali TV uses one video server for every 3
exchanges, and I also read this:

http://blog.ipdev.net/2007/04/proble...route-packets/

which proposes to put caches inside exchanges as a way to ease the bandwidth
problem due to video.

So does it matter that data goes from a user to an ISP over a virtual
circuit over BT's network? Couldn't the ISP receive the request to stream an
iPlayer programme and then send a message back to the cache located in the
user's local exchange to play the required file?


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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:
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On Sat, 29 Mar 2008 11:35:47 GMT, DAB sounds worse than FM wrote:
> I was told by someone yesterday that you can't put a CDN cache (e.g. for the
> iPlayer) inside BT's exchanges, and the reason why he said you can't do this
> is because a user's data goes to their ISP via BT's network over a virtual
> circuit.

My understanding is that if the ISP has unbundled the exchange, then they
are free to install a CDN cache there. But with IPStream/Datastream the ISP
doesn't have any equipment inside the exchange and gets the traffic handed
over at some point of presence. See http://en.wikipedia.org/wiki/Datastream:

"BT still manages the DSL multiplexing equipment at the various local
exchanges, and hands off the aggregated traffic to the OLO at one or a
few points of presence. With IPStream, BT also provides the IP transport
services."


Christof

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Christof Meerwald wrote:
> On Sat, 29 Mar 2008 11:35:47 GMT, DAB sounds worse than FM wrote:
>> I was told by someone yesterday that you can't put a CDN cache (e.g.
>> for the iPlayer) inside BT's exchanges, and the reason why he said
>> you can't do this is because a user's data goes to their ISP via
>> BT's network over a virtual circuit.
>
> My understanding is that if the ISP has unbundled the exchange, then
> they are free to install a CDN cache there.


Okay, thanks. Coincidentally I've just stumbled across something more about
the BBC's plans here:

http://www.telegraph.co.uk/money/mai...3/cnbbc123.xml

Where do you think "a little further upstream" is referring to here:

"Instead of traffic for each video having to go all the way from a central
BBC server to the viewer's desktop, PCs will be able to fetch the videos
from a cache in the local telephone exchange or a little further upstream."

Do you think the ISPs would share the cost of isntalling these caches?
Surely it's in the ISPs' own interests to stump up cash for this to put
other video stuff on as well as BBC iPlayer material, because if they just
put iPlayer stuff on then there's all the other video that's still going to
consume massive amounts of bandwidth. I'd have thought the best thing to do
would be for the ISPs to buy the caches themselves so that they can store
whatever optimises their bandwidth, which wouldn't necessarily be iPlayer
files.


--
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:
> Christof Meerwald wrote:
>> On Sat, 29 Mar 2008 11:35:47 GMT, DAB sounds worse than FM wrote:
>>> I was told by someone yesterday that you can't put a CDN cache (e.g.
>>> for the iPlayer) inside BT's exchanges, and the reason why he said
>>> you can't do this is because a user's data goes to their ISP via
>>> BT's network over a virtual circuit.
>> My understanding is that if the ISP has unbundled the exchange, then
>> they are free to install a CDN cache there.
>
>
> Okay, thanks. Coincidentally I've just stumbled across something more about
> the BBC's plans here:
>
> http://www.telegraph.co.uk/money/mai...3/cnbbc123.xml
>
> Where do you think "a little further upstream" is referring to here:
>
> "Instead of traffic for each video having to go all the way from a central
> BBC server to the viewer's desktop, PCs will be able to fetch the videos
> from a cache in the local telephone exchange or a little further upstream."
>
> Do you think the ISPs would share the cost of isntalling these caches?
> Surely it's in the ISPs' own interests to stump up cash for this to put
> other video stuff on as well as BBC iPlayer material, because if they just
> put iPlayer stuff on then there's all the other video that's still going to
> consume massive amounts of bandwidth. I'd have thought the best thing to do
> would be for the ISPs to buy the caches themselves so that they can store
> whatever optimises their bandwidth, which wouldn't necessarily be iPlayer
> files.
>
>
BT makes their money partly from renting out the last mile of copper,
and partly from the traffic between exchange and ISP.

It has no financial incentive to provide kit at the exchange to reduce
the latter.

Whereas the ISP that uses unbundled local loop has every incentive to do so.


Go figure.

The Natural Philosopher wrote:
> DAB sounds worse than FM wrote:
>> Christof Meerwald wrote:
>>> On Sat, 29 Mar 2008 11:35:47 GMT, DAB sounds worse than FM wrote:
>>>> I was told by someone yesterday that you can't put a CDN cache
>>>> (e.g. for the iPlayer) inside BT's exchanges, and the reason why
>>>> he said you can't do this is because a user's data goes to their
>>>> ISP via BT's network over a virtual circuit.
>>> My understanding is that if the ISP has unbundled the exchange, then
>>> they are free to install a CDN cache there.
>>
>>
>> Okay, thanks. Coincidentally I've just stumbled across something
>> more about the BBC's plans here:
>>
>> http://www.telegraph.co.uk/money/mai...3/cnbbc123.xml
>>
>> Where do you think "a little further upstream" is referring to here:
>>
>> "Instead of traffic for each video having to go all the way from a
>> central BBC server to the viewer's desktop, PCs will be able to
>> fetch the videos from a cache in the local telephone exchange or a
>> little further upstream." Do you think the ISPs would share the cost of
>> isntalling these
>> caches? Surely it's in the ISPs' own interests to stump up cash for
>> this to put other video stuff on as well as BBC iPlayer material,
>> because if they just put iPlayer stuff on then there's all the other
>> video that's still going to consume massive amounts of bandwidth.
>> I'd have thought the best thing to do would be for the ISPs to buy
>> the caches themselves so that they can store whatever optimises
>> their bandwidth, which wouldn't necessarily be iPlayer files.
>>
>>
> BT makes their money partly from renting out the last mile of copper,
> and partly from the traffic between exchange and ISP.
>
> It has no financial incentive to provide kit at the exchange to reduce
> the latter.
>
> Whereas the ISP that uses unbundled local loop has every incentive to
> do so.
>
> Go figure.


I'd suggest that Ofcom should grow some balls and regulate to make sure that
it's possible to install the CDN caches wherever the BBC wants to put them,
because it's obviously in the best interests of everyone apart from BT, but
knowing that Ofcom is such a pathetically weak regulator from watching it
"regulate" digital radio, I'd imagine that they'd do bugger all and let BT
do whatever they want.


--
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, 30 Mar 2008 12:32:00 +0000, DAB sounds worse than FM wrote:

> I'd suggest that Ofcom should grow some balls and regulate to make sure
> that it's possible to install the CDN caches wherever the BBC wants to
> put them, because it's obviously in the best interests of everyone apart
> from BT,

What on earth are you wittering on about? Regulation is /not/ the answer
to this. By the time they'd consulted and re-drafted enough times to get
it right, we'll all be driving flying cars, eating meals in pill form and
taking our annual holidays on Mars.

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Convergence, n: The act of using separate DSL circuits for voice and data

alexd wrote:
> On Sun, 30 Mar 2008 12:32:00 +0000, DAB sounds worse than FM wrote:
>
>> I'd suggest that Ofcom should grow some balls and regulate to make
>> sure that it's possible to install the CDN caches wherever the BBC
>> wants to put them, because it's obviously in the best interests of
>> everyone apart from BT,
>
> What on earth are you wittering on about? Regulation is /not/ the
> answer to this. By the time they'd consulted and re-drafted enough
> times to get it right, we'll all be driving flying cars, eating meals
> in pill form and taking our annual holidays on Mars.


Assuming that caches can go in unbundled exchanges, regulation would only be
needed if BT refused to allow them in non-unbundled exchanges, so there
would be nothing to lose would there, so what on earth are you wittering on
about?


--
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