[ih] reinventing the wheel, was Internet History Lives on the Internet?

[Grant Taylor]

On 02/26/2019 03:14 PM, Miles Fidelman wrote:
> One source, multiple destinations, without duplication of traffic.  
> Essentially combining what would otherwise be multiple, redundant flows 
> into a distribution tree.

True multicast is one source and one transmission of the data.

BitTorrent is inherently multiple transmissions of the data, all be it 
from different sources.

Reusing the simple scenario, CA wants to send to EU1 and EU2.

CA send the first half to EU1 and the second half to EU2 (likely at the 
same time.  Then EU1 sends the first half to EU2 and EU2 sends the 
second half to EU1.

CA sent one copy of the data, EU1 and EU2 also sent half of the data. 
Thus the same data was sent twice.

This is not multicast.

> That's what IP multicast does, bittorent does something similar as an 
> overlay to standard IP.

Nope.  Multicast sends the data one time and all receivers receive it at 
the same time.  (Where same time allows for network latency.)

There is one single transmission source.  The data is transmitted one 
single time.



-- 
Grant. . . .
unix || die