Multicast on 21CN

The first article on

http://www.samknows.com/broadband/

says at the bottom:

"The afternoon was wrapped up with a proof of concept demonstration of video
content distribution in the 21CN network. Using Assured Rate QoS, BT showed
how content could be distributed from the core, from one of their 20
aggregation points or from the MSANs themselves (which will be present in
all exchanges in the UK). Distribution at this level is made possible by
using multicast, which is not available on the current BT IPStream product
range."

Could someone say whether what BT is doing will fix the problem PlusNet
describes on its blog entry below (I think it does, because it says that
multicast can be distributed from the different levels of the 21CN, and
PlusNet says that they want it split further down the line):

http://community.plus.net/blog/2008/...t-of-ipstream/

"The same thing applies with multicast. Multicast can be used to more
efficiently distribute content. A number of customers wanted to watch the
same video stream then using multicast rather than there being one stream
per customer between the content provider and the end user, where the
network paths are the same there only needs to be one stream. At the moment
on IPStream that would mean that if you were watching a multicast stream
there would only need to be one stream between the content provider and the
ISP's network and it splits into multiple feeds at central pipes.

Which of course is the major problem with using multicast at the moment, the
only cost saving to the ISP is the transit and/or peering costs, which as we've
seen above may not represent any real savings or at best only a tiny
reduction because you still have one stream per customer going across the
central pipes.

For multicast to be successful in the UK the stream must be split further
down the line, preferably at the BT PoP but at the very least at the local
exchanges. This is something we might see as part of BT's 21st Century
Network upgrades which are taking place over the next few years."




--
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

On 16/03/2008 19:08, DAB sounds worse than FM wrote:

> Using Assured Rate QoS

Isn't that one of the aspects of 21CN that BT will require you to
*really* open your wallet wide for?

On Sun, 16 Mar 2008 19:08:40 GMT, "DAB sounds worse than FM"
<dab.is@dead> wrote:

>The first article on
>
>http://www.samknows.com/broadband/
>
>says at the bottom:
>
>"The afternoon was wrapped up with a proof of concept demonstration of video
>content distribution in the 21CN network. Using Assured Rate QoS, BT showed
>how content could be distributed from the core, from one of their 20
>aggregation points or from the MSANs themselves (which will be present in
>all exchanges in the UK). Distribution at this level is made possible by
>using multicast, which is not available on the current BT IPStream product
>range."
>
>Could someone say whether what BT is doing will fix the problem PlusNet
>describes on its blog entry below (I think it does, because it says that
>multicast can be distributed from the different levels of the 21CN, and
>PlusNet says that they want it split further down the line):
>
>http://community.plus.net/blog/2008/...t-of-ipstream/
>
>"The same thing applies with multicast. Multicast can be used to more
>efficiently distribute content. A number of customers wanted to watch the
>same video stream then using multicast rather than there being one stream
>per customer between the content provider and the end user, where the
>network paths are the same there only needs to be one stream. At the moment
>on IPStream that would mean that if you were watching a multicast stream
>there would only need to be one stream between the content provider and the
>ISP's network and it splits into multiple feeds at central pipes.
>
>Which of course is the major problem with using multicast at the moment, the
>only cost saving to the ISP is the transit and/or peering costs, which as we've
>seen above may not represent any real savings or at best only a tiny
>reduction because you still have one stream per customer going across the
>central pipes.
>
>For multicast to be successful in the UK the stream must be split further
>down the line, preferably at the BT PoP but at the very least at the local
>exchanges. This is something we might see as part of BT's 21st Century
>Network upgrades which are taking place over the next few years."

The way I read it, it doe fix the problem. Frankly it would be
pointless to build a NGN like 21CN that didn't.

Multicast has to work from head-end (wherever that is) through to the
user (a set-top box for example) in order to save aggregation network
bandwidth for applications like IPTV.

Mark wrote:
> On Sun, 16 Mar 2008 19:08:40 GMT, "DAB sounds worse than FM"
> <dab.is@dead> wrote:
>
>> The first article on
>>
>> http://www.samknows.com/broadband/
>>
>> says at the bottom:
>>
>> "The afternoon was wrapped up with a proof of concept demonstration
>> of video content distribution in the 21CN network. Using Assured
>> Rate QoS, BT showed how content could be distributed from the core,
>> from one of their 20 aggregation points or from the MSANs themselves
>> (which will be present in
>> all exchanges in the UK). Distribution at this level is made
>> possible by
>> using multicast, which is not available on the current BT IPStream
>> product range."
>>
>> Could someone say whether what BT is doing will fix the problem
>> PlusNet describes on its blog entry below (I think it does, because
>> it says that multicast can be distributed from the different levels
>> of the 21CN, and PlusNet says that they want it split further down
>> the line):
>>
>> http://community.plus.net/blog/2008/...t-of-ipstream/
>>
>> "The same thing applies with multicast. Multicast can be used to more
>> efficiently distribute content. A number of customers wanted to
>> watch the
>> same video stream then using multicast rather than there being one
>> stream
>> per customer between the content provider and the end user, where the
>> network paths are the same there only needs to be one stream. At the
>> moment
>> on IPStream that would mean that if you were watching a multicast
>> stream
>> there would only need to be one stream between the content provider
>> and the ISP's network and it splits into multiple feeds at central
>> pipes.
>>
>> Which of course is the major problem with using multicast at the
>> moment, the only cost saving to the ISP is the transit and/or
>> peering costs, which as we've seen above may not represent any real
>> savings or at best only a tiny
>> reduction because you still have one stream per customer going
>> across the central pipes.
>>
>> For multicast to be successful in the UK the stream must be split
>> further
>> down the line, preferably at the BT PoP but at the very least at the
>> local exchanges. This is something we might see as part of BT's 21st
>> Century
>> Network upgrades which are taking place over the next few years."
>
> The way I read it, it doe fix the problem. Frankly it would be
> pointless to build a NGN like 21CN that didn't.


I agree, but just on Friday I was searching for info on whether the 21CN
would support multicast and the only mention I could find anywhere was on a
Griffin Internet web page which said it was "on the roadmap", and PlusNet
didn't seem too sure on their blog either. Anyway, at least they've
demonstrated it.

How long do you reckon it might be before BT actually launches it?

Tiscali's chief exec says their network support multicast as well, BTW:

http://networks.silicon.com/broadban...118,00.htm?r=2


> Multicast has to work from head-end (wherever that is) through to the
> user (a set-top box for example) in order to save aggregation network
> bandwidth for applications like IPTV.


Yep. The BBC is launching its multicast radio streams as well:

http://www.bbc.co.uk/blogs/radiolabs...our_co_1.shtml

"Ashley Brown asks "Will BBC Radio be getting multicast and MP3 streams?" -
not only will we be getting multicast streams, we've actually had them for a
number of years"

I'd imagine the TV channels multicast streams will launch as well once the
fuss about the iPlayer bandwidth has died down a bit...


--
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" <dab.is@dead> wrote in message
news:YeeDj.21323$(E-Mail Removed)...
> The first article on
>
> http://www.samknows.com/broadband/
>
> says at the bottom:
>
> "The afternoon was wrapped up with a proof of concept demonstration of
> video content distribution in the 21CN network. Using Assured Rate QoS, BT
> showed how content could be distributed from the core, from one of their
> 20 aggregation points or from the MSANs themselves (which will be present
> in all exchanges in the UK). Distribution at this level is made possible
> by using multicast, which is not available on the current BT IPStream
> product range."

Demonstrated that to BT more than three years ago!

>
> Could someone say whether what BT is doing will fix the problem PlusNet
> describes on its blog entry below (I think it does, because it says that
> multicast can be distributed from the different levels of the 21CN, and
> PlusNet says that they want it split further down the line):

The system I demonstrated could split the multicast down to the DSLAM
level.. I see no reason why BT can't do that as their exist DSLAMS can with
little modification if any.

>
> http://community.plus.net/blog/2008/...t-of-ipstream/
>
> "The same thing applies with multicast. Multicast can be used to more
> efficiently distribute content. A number of customers wanted to watch the
> same video stream then using multicast rather than there being one stream
> per customer between the content provider and the end user, where the
> network paths are the same there only needs to be one stream. At the
> moment on IPStream that would mean that if you were watching a multicast
> stream there would only need to be one stream between the content provider
> and the ISP's network and it splits into multiple feeds at central pipes.
>
> Which of course is the major problem with using multicast at the moment,
> the only cost saving to the ISP is the transit and/or peering costs, which
> as we've seen above may not represent any real savings or at best only a
> tiny reduction because you still have one stream per customer going across
> the central pipes.
>
> For multicast to be successful in the UK the stream must be split further
> down the line, preferably at the BT PoP but at the very least at the local
> exchanges. This is something we might see as part of BT's 21st Century
> Network upgrades which are taking place over the next few years."

BT could do it now.. its a case of who is going to pay.
If BT do multicast in the DSLAM then the ISPs are getting something for
nothing.
I remember the time when BT left routing on so stuff on the BT network
didn't transit the ISPs at all.. what did the ISPs do.. setup VPNs and stuff
like that to avoid their pipes and hence the charges.. BT stopped this by
forcing all the data up the ISPs pipe by encapsulating it early on and
putting it in tunnels to the ISP.


One option talked about was adding storage in the DSLAM to buffer video
streams for interactive playback.. ATM you have to go back to the central
server which limits the number of customers per DSLAM that can have
interactive video.. buffering it takes advantage of the fact that many will
be watching the same football match or eastenders so you can get more
customers doing interactive.

"Mark" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...


>
> Multicast has to work from head-end (wherever that is) through to the
> user (a set-top box for example) in order to save aggregation network
> bandwidth for applications like IPTV.
>

Multicast assumes you are going to have lots of people watching the same
stream at the same time.. rather limiting for interactive services. Good for
broadcast TV but isn't that what the TV network's for?

dennis@home wrote:
> "Mark" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>
>
>>
>> Multicast has to work from head-end (wherever that is) through to
>> the user (a set-top box for example) in order to save aggregation
>> network bandwidth for applications like IPTV.
>>
>
> Multicast assumes you are going to have lots of people watching the
> same stream at the same time..


The percentage bandwidth saving for multicast compared to unicast is:

% bandwidth saving = 100 * (n - 1) / n

where n is the number of users. Just for 10 users you get 90% bandwidth
saving, for 100 you get 99%, for 1000 you get 99.9% and so on.


> rather limiting for interactive
> services. Good for broadcast TV but isn't that what the TV network's
> for?


Multicast allows you to watch TV on a computer where you don't have a TV
set, and it's going to provide higher audio quality than DAB does.


--
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

dennis@home wrote:
> "DAB sounds worse than FM" <dab.is@dead> wrote in message
> news:YeeDj.21323$(E-Mail Removed)...
>> The first article on
>>
>> http://www.samknows.com/broadband/
>>
>> says at the bottom:
>>
>> "The afternoon was wrapped up with a proof of concept demonstration
>> of video content distribution in the 21CN network. Using Assured
>> Rate QoS, BT showed how content could be distributed from the core,
>> from one of their 20 aggregation points or from the MSANs themselves
>> (which will be present in all exchanges in the UK). Distribution at
>> this level is made possible by using multicast, which is not
>> available on the current BT IPStream product range."
>
> Demonstrated that to BT more than three years ago!
>
>>
>> Could someone say whether what BT is doing will fix the problem
>> PlusNet describes on its blog entry below (I think it does, because
>> it says that multicast can be distributed from the different levels
>> of the 21CN, and PlusNet says that they want it split further down
>> the line):
>
> The system I demonstrated could split the multicast down to the DSLAM
> level.. I see no reason why BT can't do that as their exist DSLAMS
> can with little modification if any.
>
>>
>> http://community.plus.net/blog/2008/...t-of-ipstream/
>>
>> "The same thing applies with multicast. Multicast can be used to more
>> efficiently distribute content. A number of customers wanted to
>> watch the same video stream then using multicast rather than there
>> being one stream per customer between the content provider and the
>> end user, where the network paths are the same there only needs to
>> be one stream. At the moment on IPStream that would mean that if you
>> were watching a multicast stream there would only need to be one
>> stream between the content provider and the ISP's network and it
>> splits into multiple feeds at central pipes. Which of course is the major
>> problem with using multicast at the
>> moment, the only cost saving to the ISP is the transit and/or
>> peering costs, which as we've seen above may not represent any real
>> savings or at best only a tiny reduction because you still have one
>> stream per customer going across the central pipes.
>>
>> For multicast to be successful in the UK the stream must be split
>> further down the line, preferably at the BT PoP but at the very
>> least at the local exchanges. This is something we might see as part
>> of BT's 21st Century Network upgrades which are taking place over
>> the next few years."
>
> BT could do it now.. its a case of who is going to pay.
> If BT do multicast in the DSLAM then the ISPs are getting something
> for nothing.
> I remember the time when BT left routing on so stuff on the BT network
> didn't transit the ISPs at all.. what did the ISPs do.. setup VPNs
> and stuff like that to avoid their pipes and hence the charges.. BT
> stopped this by forcing all the data up the ISPs pipe by
> encapsulating it early on and putting it in tunnels to the ISP.
>
>
> One option talked about was adding storage in the DSLAM to buffer
> video streams for interactive playback.. ATM you have to go back to
> the central server which limits the number of customers per DSLAM
> that can have interactive video.. buffering it takes advantage of the
> fact that many will be watching the same football match or eastenders
> so you can get more customers doing interactive.


I don't think BT would have demonstrated video over multicast on the 21CN to
journalists last week if they weren't going to use it.

There's also the competition element, because Virgin Media will be adding
support for multicast at the same time as it launches its 50 Mbps broadband
package, and Tiscali's network is designed to support multicast. That's 2
out of the 4 biggest ISPs supporting it, and the other LLU ISPs could
support it as well if they wanted to.


--
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" <dab.is@dead> wrote in message
news:iMtDj.6675$(E-Mail Removed)...
> dennis@home wrote:
>> "Mark" <(E-Mail Removed)> wrote in message
>> news:(E-Mail Removed)...
>>
>>
>>>
>>> Multicast has to work from head-end (wherever that is) through to
>>> the user (a set-top box for example) in order to save aggregation
>>> network bandwidth for applications like IPTV.
>>>
>>
>> Multicast assumes you are going to have lots of people watching the
>> same stream at the same time..
>
>
> The percentage bandwidth saving for multicast compared to unicast is:
>
> % bandwidth saving = 100 * (n - 1) / n
>
> where n is the number of users. Just for 10 users you get 90% bandwidth
> saving, for 100 you get 99%, for 1000 you get 99.9% and so on.

So on a typical DSLAM with 600 users you need a program several of them want
to watch to do multicast at the DSLAM.

>
>
>> rather limiting for interactive
>> services. Good for broadcast TV but isn't that what the TV network's
>> for?
>
>
> Multicast allows you to watch TV on a computer where you don't have a TV
> set,

Really!?

> and it's going to provide higher audio quality than DAB does.

Why should it, everyone is happy with Dab quality. ;-)

dennis@home wrote:
> "DAB sounds worse than FM" <dab.is@dead> wrote in message
> news:iMtDj.6675$(E-Mail Removed)...
>> dennis@home wrote:
>>> "Mark" <(E-Mail Removed)> wrote in message
>>> news:(E-Mail Removed)...
>>>
>>>
>>>>
>>>> Multicast has to work from head-end (wherever that is) through to
>>>> the user (a set-top box for example) in order to save aggregation
>>>> network bandwidth for applications like IPTV.
>>>>
>>>
>>> Multicast assumes you are going to have lots of people watching the
>>> same stream at the same time..
>>
>>
>> The percentage bandwidth saving for multicast compared to unicast is:
>>
>> % bandwidth saving = 100 * (n - 1) / n
>>
>> where n is the number of users. Just for 10 users you get 90%
>> bandwidth saving, for 100 you get 99%, for 1000 you get 99.9% and so
>> on.
>
> So on a typical DSLAM with 600 users you need a program several of
> them want to watch to do multicast at the DSLAM.


What, so that's the only place where they can save bandwidth, is it?


>> and it's going to provide higher audio quality than DAB does.
>
> Why should it, everyone is happy with Dab quality. ;-)


Yeah, everyone's over the moon with DAB, that's why the sales are doing so
well despite the BBC advertising the bollocks off it on TV, and there
haven't been any national station closures recently, and GCap didn't call it
"not economically feasible" and GCap didn't say that they wanted to pull out
of DAB completely if it weren't for some draconian legislation that would
screw their entire business up if they did, and GCap didn't say that DAB
provided lower quality than FM, and it won't take about 30 years to switch
off FM - it's just so good in every imaginable way. In fact it's probably
been the biggest success story in the history of the world ever.

And as for whether multicast will provide higher quality than DAB:

http://support.bbc.co.uk/multicast/streams.html

BBC: 128 kbps AAC
commercial radio: 128 or 192 kbps WMA

DAB: 128 kbps with the 1980s-vintage ridiculously inefficient MP2 codec

I rest my case.


--
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