What is Digg?Sponsored by AVG
Not All Free Anti-Virus Software Is Created Equal view!
free.avg.com - 2.4 million people a week get AVG Anti-Virus Free, for the best protection against web threats.
40 Comments
- gankige, on 10/02/2009, -0/+53This is a great article.
I'm not sure if you are familiar with the paper or author, but Claude Shannon wrote this paper at Bell Labs back in the 40's. It was one of the first works in what we now call "information theory", and was where we got the term "bit" to denote a unit of information. This guy has had a huge impact in the electrical engineering world. His master's thesis at MIT is a big part of why digital computers that are so ubiquitous now. He proved that a network of switches (relays at the time, transistors now) can be designed to solve any boolean algebra problem, something we take for granted now.
It amazes me how many of his ideas still make an impact today. 60 years and 32000 citations later, and students in electrical engineering programs still learn about his name and ideas... - chadsmith729, on 10/02/2009, -2/+30http://farm3.static.flickr.com/2551/3951382520_b75 ...
That picture made my day. Hilarious. Great guide! - RagManX, on 10/02/2009, -0/+28"A message of N bytes is chopped into ceil(N / 1460) packets [1] which are then sent willy-nilly."
That description makes me laugh.
Good guide. Likes. - utahband, on 10/02/2009, -2/+25Digg's user base is full of wanna-be Engineers who are really just IT dudes.
- Addp009, on 10/02/2009, -1/+19This is a web-dev's guide to bandwidth. An engineer's guide to bandwidth would involve Shannon's information theory...
- RachelJTM, on 10/02/2009, -0/+17great guide
- bjornredtail, on 10/02/2009, -3/+16Bandwidth? Is he sure that he doesn't mean throughput? Bandwidth is a physical characteristic of the network medium that you are using. It describes the range of frequencies that the network can, or is allowed to carry. Throughput on the other hand describes the amount of data you can put through any given network connection.
- Subduction, on 10/02/2009, -0/+9That only matters if you had a need to.
- gigitrix, on 10/03/2009, -0/+7"IPv6, which has been coming any day now since the Clinton administration"
:)
These guys write good articles! - d03boy, on 10/02/2009, -0/+7An engineer's guide would involve some more calculus.
- MaxxusFlamus, on 10/02/2009, -0/+7http://farm3.static.flickr.com/2461/3950605017_2fe ...
as you can see- response time drop significantly where t= tea time! - 350Zed, on 10/03/2009, -1/+8Engineers who only consider classical engineering concepts to be legit (e.g., electrical, civil) make me laugh. We're already two centuries past the 19th, amigo.
- vil33, on 10/03/2009, -2/+8No, You are confusing the two different terms for bandwidth (analog and digital). The author was referring to the digital term in this case.
http://en.wikipedia.org/wiki/Bandwidth
"Bandwidth (computing) or digital bandwidth: a rate of data transfer, throughput or bit rate, measured in bits per second (kbps)" - drdepoy, on 10/03/2009, -2/+6Came in here to say the same thing. As a communications engineer it makes me stabby when people talk about symbol/bit rate as "bandwidth." I was sorely disappointed when I read this alleged "engineers" guide to "bandwidth" that did not correct this misconception in the first paragraph.
- Acksull, on 10/03/2009, -0/+4Spy sappin' my TCP connections and DNS lookups!
- desertDenizen, on 10/03/2009, -0/+4Whatever. I invented mac & cheese.
- Joshislong, on 10/03/2009, -0/+3Awesome post. I love reading about the people who laid the foundations of modern science and technology.
- jmcneilly, on 10/03/2009, -0/+3Cretins... Tea in a microwave...
- baldick, on 10/03/2009, -1/+4One of the best bandwidth guides I've read; very accurate and K.I.S.S.
- Armor1901, on 10/03/2009, -0/+3It may be biased (no *****...it IS called the CISCO Certified Network Associate after all...), but there is a TOOOOOOON of networking concepts and theory you learn that are universal. Also, hate to break it to you, Cisco pretty much runs things in the network world. You'd be wise to study their stuff.
- 350Zed, on 10/03/2009, -1/+3Throughput != Bandwidth
Wikipedia's definition is wrong.
Bandwidth represents local potential (e.g., on an interface or link), but throughput measures end-to-end actual performance (i.e., taking into account protocol inefficiencies, latency, loss, etc.). - 350Zed, on 10/03/2009, -0/+2Except for the fact that CCNA is _extremely_ biased toward Cisco's proprietary technology, so I wouldn't recommend it for the average aspiring network guru.
A better idea would be to get a few network architecture books, like this one:
http://www.amazon.com/Networking-Beginners-Fourth- ... - 350Zed, on 10/03/2009, -1/+3Overall, this is not a bad guide, however...
...assuming all packets are equal, and are all 1460 bytes in size, is just plain wrong.
One example of where this claim breaks down is when VoIP is in use, and packet sizes are much smaller than the MTU (Maximum Transmission Unit) allowed across the network--e.g., 100 byte packets.
That said, this is a good Bandwidth 101 guide, and I'd recommend that the author bring the next step into the 21st century with Bandwidth 201: Multimedia and QoS. - bradleyland, on 10/03/2009, -1/+3Yeah, well, it bugs the hell out of me when people refer to an 8P8C modular connector terminated EIA/TIA-568A/B as "RJ45", but the rest of the world doesn't give two ***** about abuse of technical terminology, so eventually I just shut up about it.
- Armor1901, on 10/03/2009, -2/+4Finally, an article I 100% understand and enjoy for once!! I'm a network engineer, and I actually build these networks and manage the routers and switches, and it's this stuff that I breathe all day long. You think this is complicated? HA! This is ***** networking 101, friends. If you want to get started in this stuff, study for the CCNA (ICND1 and ICND2) and you'll begin to learn. It's cool that for once it isn't another damn article about how to photoshop or program, etc...dugg!!
- 350Zed, on 10/03/2009, -0/+2True, but I've met more than a few CCIE's who take everything they know from the Book of Cisco, and who tend to miss both basic concepts of telecommunications and alternate perspectives.
- stxza, on 10/03/2009, -0/+2you tool.
- metrenome, on 10/03/2009, -0/+2that was so awful, i just had to digg you
- ThreeDee912, on 10/03/2009, -0/+2"Claude Shannon wrote this paper at Bell Labs back in the 40's"
Well, maybe not this specific paper... - MAGZine, on 10/03/2009, -0/+1Might be biased - it's certainly no all bad, considering many (tons) of big-name players use Cisco as their networking product supplier.
- kaelyiesta, on 10/14/2009, -0/+1Ah, wikipedia. Where the consensus of the masses turns the inaccurate vernacular into fact.
- kolbyjack, on 10/03/2009, -0/+1http://freedominterface.org/docs/iptables.pdf really helped me understand iptables. I have a printed copy in my drawer right now.
- MAGZine, on 10/03/2009, -1/+2I thought the information he presented was very 21st century. With more and more media devices with crappy net connections, this information becomes extremely handy when optimizing your site for mobile purposes - optimizing the packet use of your website can save a ton of time.
- equinoxChild, on 10/10/2009, -0/+1oooooh burn =P
- Jooshbro, on 10/02/2009, -0/+1Great article. I'd like to try out bandwidth shaping on my ubuntu box, but I can't find ipfw anywhere in the repos =[ Does anybody know where/if I can get it?
- Rethread, on 10/03/2009, -0/+1Cisco Certified Internetwork Expert (CCIE®) is the highest level of technical networking certification offered by Cisco. FTW
- dremspider, on 10/02/2009, -0/+1IPFW is a BSD thing (though it may exist in some port somewhere, who knows), IPtables does bandwidth shaping for Linux. I found these two documents:
http://linux-ip.net/articles/Traffic-Control-HOWTO ...
http://blog.edseek.com/~jasonb/articles/traffic_sh ...
If you are looking into getting into traffic shaping, then I would recommend learning the basics of IPtables first. This book is great for learning Linux firewalls.:
http://www.amazon.com/Linux-Firewalls-Detection-Re ...
\ - jo21, on 10/03/2009, -0/+1calc? are you first year?
and engineering one would ask you investigate the topic yourself. you have to do an printed word, a ppt and you have a test about it next week. - VanishingLex, on 10/03/2009, -3/+1perhaps my audience thinks individual people are more important than ideas. How narrow minded if thats the case.
My comment above was to illustrate that ideas are more important than who came up with them, which is ultimately of little consequence. - VanishingLex, on 10/03/2009, -8/+1Indeed, but if you went back in time and assassinated him, the same idea would have emerged from someone else anyway within a few more years probably given the usefulness of communications networks and therefore the number of people thinking about them.
© Digg Inc. 2009
— Content created and posted by Digg users is 
