On 15/12/2008, at 6:56 PM, Nathan Ward wrote:
On 15/12/2008, at 6:11 PM, Jasper Bryant-Greene
I'm not sure IPv6 will make multicast any
more likely to actually
happen. If someone thought deployment of multicast to the consumer
useful, it would already be happening - multicast goes through NATs
in the UK, where I understand the BBC are testing delivery of content
using multicast, and I'm pretty sure Kiwi NATs aren't functionally
different from British NATs :)
The main difference is that in Britain the NAT functionality happens
I'm pretty sure there are ADSL CPE on the market which do all that is
neccessary for basic multicast - in that a machine behind the NAT can
use IGMP to register interest in a multicast group, and the CPE will
proxy that IGMP join to the ISP, who then proceed to send multicast
datagrams destined for that group to that port, and the CPE sends it
to the internal machine that joined that group. I think my Dynalink
blob can do it, anyway. Not sure if it was enabled by default, though.
If it is enabled by default on a good chunk of CPE, then we're in an
even better position than we are with IPv6 - the end users already
"support" multicast, and the ISPs just need to "turn it on". I say
"support" because the apps have got better, but they're not all that
user-friendly yet. This is probably why the BBC have their own client-
As for why it doesn't happen now, why would an ISP
for a customer of theirs (ie. a streaming media provider) when they
can leave it disabled and charge a much higher access fee?
Because the streaming media provider may decide to reduce their costs
by hooking up to the APE and doing multicast all by themselves. That's
basically what the BBC is doing.
For example, a television station could provide high-def content only
to customers of multicast-enabled ISPs that they reach over APE, and
standard-def to everyone else that they reach over [insert expensive
transit ISP here].
Eyeballs ISPs would have pressure from their users, who want the high-
def content, and probably from the television station too, who wants
to pay less for transit, to enable multicast. This is exactly what's
happened in the UK - a bunch of end-user ISPs now support multicast
after the BBC started offering content.
What applications are available for multicast? Can
Flash do multicast?
I think Quicktime and Windows media can, yeah?
No idea about Flash - I would imagine the platform supports it but it
would probably depend on the specific application.
Quicktime, Windows Media Player, VLC, and various Linux media players
all support multicast with varying degrees of user-friendlyness.
Network Engineer, Unleash
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