funsec mailing list archives
Re: "Network Neutrality" or "Open Internet"
From: "Fergie" <fergdawg () netzero net>
Date: Sun, 16 Apr 2006 13:54:17 GMT
-- "Dude VanWinkle" <dudevanwinkle () gmail com> wrote:
In general terms, remember that electrical or optical signalling is _clocked_ into 'the network'.
err, what?
Think of it this way: Your circuit 'size' is just timing, re: 1.536Mb/s. See? It's just electrical clocking. It's a matter of speed, not size. It does not have any other function. Routers, on the other hand, recieve and transmit data at their (electrical or optical) associated _speeds_ on various interfaces, but at the electrical level (go back and re-acquait yourself with the OSI 7-layer model, for example), but it has absolutely no effect on packet communications aside from clocking bits onto a wire. The router still has to look at the bits, determined header and encapsulation information, match them to destinations (remember that all forwarding in IP is done by destination), and put them back out on the appropriate interface, and then you are back at electrical (or optical) clocking (speed) again. Where this gets interesting is with overcommitment, as Valdis pointed out. You can't put ten pounds of shite in a five pound bag, so when there are times of day when the aggregate amount of traffic is graeter than the router is able to put on the wire at any given time, the queues start to fill up, and packets will be dropped. Now, dependent on the amount of packet drops is how the transport protocols behave during loss -- TCP has slow-start, UDP (by design, unfortunately) keeps spitting traffic into the network and relies on the application layer to detect and adjust to packet loss. When the amount of packet loss becomes arbitrarily large, then it becomes an exercise for the reader to determine how to 'manage' the packet loss -- normally by doing some creative packet drop based on what traffic you think is 'important' or who pays you more not to drop their traffic. Of course, there is also fanciful non-FIFO queuing schemes, but I won't go into that now. :-) - ferg p.s. SLA's are _almost_ always written for _availability_ -- not capacity or throughput -- THAT is handled by the circuit _speed_, which is always constant. ;-) Confused yet? ;-) -- "Fergie", a.k.a. Paul Ferguson Engineering Architecture for the Internet fergdawg () netzero net or fergdawg () sbcglobal net ferg's tech blog: http://fergdawg.blogspot.com/ _______________________________________________ Fun and Misc security discussion for OT posts. https://linuxbox.org/cgi-bin/mailman/listinfo/funsec Note: funsec is a public and open mailing list.
Current thread:
- Re: "Network Neutrality" or "Open Internet", (continued)
- Re: "Network Neutrality" or "Open Internet" Valdis . Kletnieks (Apr 15)
- Re: "Network Neutrality" or "Open Internet" Sean Donelan (Apr 16)
- Re: "Network Neutrality" or "Open Internet" and why it costs Kevin McAleavey (Apr 16)
- Re: "Network Neutrality" or "Open Internet" Fergie (Apr 15)
- Re: "Network Neutrality" or "Open Internet" Dude VanWinkle (Apr 15)
- Re: "Network Neutrality" or "Open Internet" Valdis . Kletnieks (Apr 16)
- Re: "Network Neutrality" or "Open Internet" Dude VanWinkle (Apr 16)
- RE: "Network Neutrality" or "Open Internet" StyleWar (Apr 16)
- Re: "Network Neutrality" or "Open Internet" Dude VanWinkle (Apr 15)
- Re: "Network Neutrality" or "Open Internet" Fergie (Apr 15)
- Re: "Network Neutrality" or "Open Internet" Fergie (Apr 15)
- Re: "Network Neutrality" or "Open Internet" Fergie (Apr 16)
- Re: "Network Neutrality" or "Open Internet" Fergie (Apr 16)
- Re: "Network Neutrality" or "Open Internet" Dude VanWinkle (Apr 16)