[25350] in North American Network Operators' Group

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Re: Real Media and M-Bone feeds

daemon@ATHENA.MIT.EDU (Jeff Mcadams)
Tue Oct 5 22:28:27 1999

Date: Tue, 5 Oct 1999 22:24:23 -0400
From: Jeff Mcadams <jeffm@iglou.com>
To: nanog@merit.edu
Message-ID: <19991005222423.B777@iglou.com>
Mime-Version: 1.0
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In-Reply-To: <199910052112.OAA01052@kitty.kotovnik.com>
Errors-To: owner-nanog-outgoing@merit.edu


Thus spake Vadim Antonov
>Fredrik Nyman <fredrik@swip.net> wrote:
>> How are you going to handle 100000 realvideo streams? If all those 100000
>> sources are in the US and all recievers are in Europe, there would be no
>> difference in the amount of bandwidth required across the ocean with
>> multicast compared to realvideo.

>Easily.  It is called cacheing.  Multicasting provides exactly the
>same bandwidth savings as cacheing with cache retention time set to zero.

With the constraint that if you want to provide exactly the same
bandwidth savings, you have to have a cache at every hop.  Without a
cache at every hop, there still can be significant savings, but not
quite equal to the bandwidth savings of multicast at every hop.
(Though, admittedly, multicast capable routers aren't available at every
hop either).
-- 
Jeff McAdams                            Email: jeffm@iglou.com
Head Network Administrator              Voice: (502) 966-3848
IgLou Internet Services                        (800) 436-4456


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