[ale] Broadcasts on TCP/IP?

[Dave Brooks]

IP Multicast is still in the works, though, no?  Don't you have to purchase
special "Class D" IP addresses for this?

-Dave
dave at spork.deflux.org

-----Original Message-----
 From: Todd R. Palmer <t2palmer at avana.net>
To: ale at cc.gatech.edu <ale at cc.gatech.edu>
Date: Wednesday, July 01, 1998 10:16 PM
Subject: Re: [ale] Broadcasts on TCP/IP?


> Can broadcasts be used reasonable on TCP/IP given its connection
orientation?
>
> Any thoughts?

If you are looking for a protocol to do routable broadcasting, check
into IP Mulitcast.  It uses UDP/IP, but it routable (if the router
supports it), unlike UDP broadcast.

The idea of a TCP/IP broadcast defeats the purpose.  Each client
would have to respond and then open a connection to the server, and
the server would have to have a connection to each client.  Too much
overhead to maintain (what if you have 12,000 clients?).  IP Multicast
works by allowing you to join a "Mulitcast Group", which basically
tells your nic to listen on a "Multicast Group Address".  You can join
as many groups as you want.  The server then broadcasts on the
multicast group address, and it is received by anyone who is
listening.

Just my $0.02.

todd

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The 2 most common elements in the universe are hydrogen and stupidity.

Todd Palmer
Developer
t2palmer at avana.net
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