Multicasting (bandwidth)

Hello,

If there is a server which is multicasting to the Internet, does it use
separate bandwidth for each connection? i.e. if one stream is taking
say, 5k, will a 1000 streams take 5000k, and therefore use all the
bandwidth I have from my provider?
Or, does ONE packet leave my host and then split across every router
necessary to get to all the hosts requesting a connection? This is what
my understanding of "multicast" was.


Thanks very much.

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(E-Mail Removed) tried to express the following opinion:

> If there is a server which is multicasting to the Internet, does it use
> separate bandwidth for each connection? i.e. if one stream is taking
> say, 5k, will a 1000 streams take 5000k, and therefore use all the
> bandwidth I have from my provider?

No, that is called unicast.

> Or, does ONE packet leave my host and then split across every router
> necessary to get to all the hosts requesting a connection? This is what
> my understanding of "multicast" was.

That is multicast.

- --
Solbu - http://www.solbu.net
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Solbu wrote:

> > Or, does ONE packet leave my host and then split across every router
> > necessary to get to all the hosts requesting a connection? This is what
> > my understanding of "multicast" was.
>
> That is multicast.

So what are some Linux server softwares for doing it? Can I use
icecast?

What software will be needed to actually play the stream - will
Winamp/XMMS and Windows Media Player/Mplayer do?

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(E-Mail Removed) tried to express the following opinion:

> Solbu wrote:
>> That is multicast.
>
> So what are some Linux server softwares for doing it? Can I use
> icecast?

In order to have multicast on a server your ISP must support it.
Most ISPs do not.

Unicast however is no problem. Just make sure you limit
the number of users to simultaneously llisten to the stream
down to a number your awailable bandwith can handle.

> What software will be needed to actually play the stream - will
> Winamp/XMMS and Windows Media Player/Mplayer do?

Yes.

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Solbu - http://www.solbu.net
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Hi,

On 2005-05-31, (E-Mail Removed) <(E-Mail Removed)> wrote:
>
> Solbu wrote:
>
>> > Or, does ONE packet leave my host and then split across every router
>> > necessary to get to all the hosts requesting a connection? This is what
>> > my understanding of "multicast" was.
>>
>> That is multicast.
>
> So what are some Linux server softwares for doing it? Can I use
> icecast?
>
This really is all on Google an Icecast's website...you really should be
using Google.

> What software will be needed to actually play the stream - will
> Winamp/XMMS and Windows Media Player/Mplayer do?
>
For Windoze users, the best thing to do is install VLC (realplayer will do it
but I would not trust it), under UNIX (including Linux) you have a number of
options:

1) mplayer
2) VLC
3) Xine
4) realplayer (ewwwwwww)
5) <insert four-zillion hits from google and the Multicast HOWTO>

You should not really be asking about the client software, multicasting is
just a transport medium really handled by the OS and various network hardware
between point A and B. You need to make sure there is a multicast enabled
route available between A and B (most ISPs seem not to support multicasting,
here in the UK that is true) and that you know how to configure routers under
your control to forward multicasted traffic between subnets.

Do read the HOWTO has a good starting point:

http://www.tldp.org/HOWTO/Multicast-HOWTO.html
http://jukie.net/~bart/multicast/Lin...MiniHOWTO.html
http://www.cschill.de/smcroute/ (better than mrouted for 'static' setups)

Cheers

Alex