Tidbits

CableWholesale, my favorite cable vendor, publishes monthly articles on tech hardware. This is one such article on ethernet cables, wonderfully written and illustrated. Enjoy!

Support • Technical Articles • Category Cable Cornucopia * Phone: 888-212-8295 * Fax: 925-455-0808

Dear Raoul,

As a service to our many customers, CableWholesale.com publishes a monthly series of informative technical articles, with each one focusing on a particular technology. Our goal is to help our customers get better aquainted with the often confusing cables, connectors, and standards to be encountered out there.

Tell us what you think of this article! We value your feedback. Reply back to articles@cablewholesale.com and give us your thoughts.

Category Cable Cornucopia

It's been awhile since we've done a technical article about networking, and as with most things in technology, times have changed a bit.

In this article, we are going to focus on the various "levels" of Category Cable (more commonly known as Ethernet cable or, broadly, networking cable), what defines these levels, and how they are most commonly used. We'll also debunk a few myths and marketing claims about Category Cable.

First, let's review the commonly used types of networking cable out there. The following networking cable types are defined by the Telecommunications Industry Association (TIA), the standards body most commonly recognized in the United States. These cable types are defined in the TIA/EIA-568-C standard, published in 2009 (superseding the "TIA/EIA-568-B" standard, which was published in 2001). Among many other things, the standard specifies certain electrical and performance properties at given frequencies for the various levels (categories) of cabling.

Category 3 Cable
You will not find this much in the context of networking these days. Category 3 cable can support frequencies of up to 16 MHz and is rated for a 10 megabit-per-second (mbps) connection, which is about the speed of a typical home DSL internet connection. Many network professionals think of category 3 cable as telephone cable, since in the real world that is about all it would be considered useful for, and no new networking installations would specify it. (As a matter of fact, it is still included as a recognized standard cabling type in the TIA/EIA-568-C standard for voice applications.) However, there are still plenty of buildings with older network installations using category 3 cable. Most of these are bei ng rewired.

Category 5 Cable
This was the first cable to offer 100 mbps speeds and was widely deployed in the late '90s and early 2000s. As recently as two years ago most new computers that had built-in network cards had 100 mbps network cards and existing Category 5 wiring was adequate. However it is no longer recognized in the latest TIA/EIA-568-C standard as a valid cabling type; thus no new network installations should use Category 5 cable. For historical reasons the standard does mention the performance requirements for Category 5 cable up to 100 MHz frequencies.

Category 5E Cable
Category 5E cable is now the minimum recognized cable for data networking applications, as defined by the current standard. Like Category 5 cable, it also is rated for up to 100 MHz frequencies. Additional performance standards enable it to support transmission speeds of up to 1000 mbps ("gigabit Ethernet").

Category 6 Cable
Category 6 cable, the standard for which was defined in 2002, raises the bandwidth limit to 250 MHz; as a practical matter, Category 6 cable, like Category 5E, currently supports gigabit Ethernet (speeds of up to 1000 mbps). When the standard was released, Category 6 cable was described as "being able to support future applications." In practice there are few areas in traditional networking environments where Category 6 cable would be required (as opposed to Category 5E cable). Shorter runs of Category 6 cable can even support speeds of up to 10 gigabits per second (10,000 mbps), a speed that would otherwise require Category 6A wire. Category 6 cable is also often necessary for some non-traditional uses; fo r example, converters that can transform HDMI video signals for transmission over network wire often require the additional frequency support found in Category 6 cable.

Category 6A cable
This is the newest category standard recognized by the TIA (2008). Category 6A cable can support frequencies up to 500 MHz and speeds up to 10 gbps. Demand is still relatively low for Category 6A wire, as of this writing. This is, in part, due to fiber-optic cable already supporting 10 gigabit speed (often written as 10gE, for 10 gigabit Ethernet), rather than by twisted-pair copper cable.

Category 7 and 7A Cable
As mentioned at the beginning of this article, the TIA/EIA-568-C standard, as developed by the Telecommunications Industry Association, is the primary standard used in the United States. However, in Europe, Africa, and Asia, the ISO/IEC 11801 standard, as defined by the International Standards Organization, is followed. It has similar standards for cabling up through Category 6A (referred to as "Class EA"), but also specifies standards for "Class F" and "Class FA" cabling, with frequency ratings of 600 MHz and 1000 MHz, respectively.

Common Myths about Networking Cables

Now that we've presented the actual defined standards for networking cable, it is worth taking a few minutes to look at some common marketing claims, myths, and other oddball statements floating around out there.

The Mysterious Category 6E Cable
This is one of our favorites here at CableWholesale. Many manufacturers out there have taken to producing a "superior" Category 6 cable, which they refer to as Category 6E. Generally, this product claims to perform at up to 500 MHz, 550 MHz, or 600 MHz frequencies (the Category 6 standard is 250 MHz). Although it is often a high quality cable, the fact remains that there is no such cable in any defined standard. Clearly, in spite of the frequency claims, it is not a Category 6A cable, or else it would be so labeled (and priced accordingly; true Category 6A cable does not come cheap!). We at CableWholesale feel that marketing such a dubious product does nothing but confuse the marketplace, while not doing anything to improve your network. We have even heard of some vendors trying to distinguish between Category 6 "Big E" and Category 6 "little e " (as well as using similar designations on Category 5E cable). When in doubt, refer back to the standards.

"I need Cat 6 cable for my home!"
Many home users believe that they need Category 6 cable run in their homes to support their high-speed internet connection. In fact, even Category 5E is technically overkill for today's high-speed internet services. A "typical" high-speed internet service to the home is anywhere from 1 mbps to 10 mbps; a few lucky folk have been able to get 50 mbps to their homes. Category 5E cable can support gigabit Ethernet. That's 1000 mpbs. So, for the home, don't waste money on Category 6 cable (or components!).

"I need Category 6 cable for gigabit Ethernet!"
As we stated above, a properly installed Category 5E network will support gigabit Ethernet. We do have to emphasize "properly installed." It (hopefully) goes without saying that in order for any system (network or otherwise) to achieve its rated performance, it must be properly installed.

Network Cable Quality Traps

In recent years there have been a few trends in our industry that are putting the pinch on quality. One reason is rising raw materials costs. Networking cable is made from copper and some form of plastic insulation (typically PVC), which is made from oil. As both copper and oil prices have climbed so has the cost of properly manufactured network cable. At the same time there has been more and more pressure from customers at various levels to keep prices competitive. The result is that more and more lower-quality networking cable is being produced that does not actually perform as it should. The following are a few examples of quality issues that we've seen in the wild.

Copper-clad aluminum wiring
Network cable wires should be made out of pure copper wires. However some manufacturers, in order to shave costs, have been making network cable out of copper-coated aluminum wires. On the surface they look the same. However you can scrape away the copper coating with a sharp blade to expose the aluminum wire underneath, as shown in this picture:

Bare Copper

Copper Clad Aluminum

Incorrect Safety Rating on Jackets
Network cable generally needs to adhere to certain electric code or fire code safety ratings. Broadly speaking, in the United States, these are defined by the National Electric Code and certified by 3rd party labs such as Underwriters Laboratories (UL) or Intertek. Unfortunately there has been a trend to label network cable jackets as meeting certain flame ratings when they do not. The certification labs do not test every single unit; they test a sample, give the manufacturer a certificate, and then trust the manufacturer to keep producing the same product as the sample. Recently Underwriters Laboratories has been stepping up enforcement efforts to prevent unscrupulous manufacturers from supplying non-conforming product, but "caveat emptor" is still the word of the day. It is often difficult for the end consumer of a product to know the difference.

So how should you guard yourself against this product? One way is to always have a qualified installer to help manage your network install. Ask them to provide a performance test result that certifies the rated performance of a network run. Testing tools such as Fluke Networks DTX series and Agilent's WireScope series are excellent performance testers.

Click image to view PDF

Also ensure the wire that is used comes from a reputable source that stands behind their product.

Glossary of Common Networking Terms

UTP - Unshielded twisted pair, which refers to network wire that does not contain any inner shielding. Most network cable fits into this category.

STP - Shielded Twisted Pair, refers to network cable that has inner shields. In the USA, this tends to be a generic designation for any shielding present in network cable; true STP cable refers to a product with individual aluminum foil shields around each of the four pairs of wire. Most cable marketing in the USA as STP cable should properly be called FTP, "Foil Twisted Pair" or ScTP, "Screened Twisted Pair" which refers to a single foil shield around all eight wires.

Twisted Pair - All modern network cable is made from eight color-coded wires that are twisted in pairs. (show image

) The term twisted pair refers to this construction. Wires are twisted to help eliminate crosstalk (the "bleeding" of signal from one wire to another), thus improving data transmission performance.

CM - One of many cable jacket fire safety ratings as defined in the National Electric Code. It refers to a jacket type that is rated for in wall use for multi-story residential buildings or single-story commercial buildings. For more information check out "Jowling about Jackets" a previous technical article"?

CMR - One of many cable jacket fire safety ratings as defined in the National Electric Code. It refers to a "riser" rated cable; meaning, one that can be installed between floors of a multistory commercial building.

CMP - One of many cable jacket fire safety ratings as defined in the National Electric Code. It refers to a cable that is suitable for installation within a plenum space.

Plenum - A space in buildings that is used for air circulation / air return from HVAC (heating and air-conditioning) units. Because air from plenum spaces circulates rapidly through a building, it is important that any cable laid in this protected area be constructed in such a way that it will minimize toxic smoke.

Sincerely yours,
Your CableWholesale.com Technical Support Team
articles@cablewholesale.com

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The Tudor Pattern Book

Tue, 13 Sep 2011 14:27:03 -0700

The Tudor Pattern Book

via HOW TO BE A RETRONAUT by Amanda on 9/13/11

…

Thank you to the Bodleian Library

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Laugh-Out-Loud Cats #1779

Wed, 31 Aug 2011 08:18:00 -0700

via flickr.com

Awesome.

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Why Iceland Should Be in the News, But Is Not

Mon, 29 Aug 2011 04:16:53 -0700

Wonderful article detailing Iceland's social revolution, which re-affirmed its sovereignty and made it a true democracy.

Why Iceland Should Be in the News, But Is Not

By Deena Stryker

Date posted: 15 August 2011
View this article online here: http://sacsis.org.za/site/article/728.1

An Italian radio program's story about Iceland’s on-going revolution is a stunning example of how little our media tells us about the rest of the world. Americans may remember that at the start of the 2008 financial crisis, Iceland literally went bankrupt. The reasons were mentioned only in passing, and since then, this little-known member of the European Union fell back into oblivion.

As one European country after another fails or risks failing, imperiling the Euro, with repercussions for the entire world, the last thing the powers that be want is for Iceland to become an example. Here's why:

Five years of a pure neo-liberal regime had made Iceland, (population 320 thousand, no army), one of the richest countries in the world. In 2003 all the country’s banks were privatized, and in an effort to attract foreign investors, they offered on-line banking whose minimal costs allowed them to offer relatively high rates of return. The accounts, called IceSave, attracted many English and Dutch small investors. But as investments grew, so did the banks’ foreign debt. In 2003 Iceland’s debt was equal to 200 times its GNP, but in 2007, it was 900 percent. The 2008 world financial crisis was the coup de grace. The three main Icelandic banks, Landbanki, Kapthing and Glitnir, went belly up and were nationalized, while the Kroner lost 85% of its value with respect to the Euro. At the end of the year Iceland declared bankruptcy.

Contrary to what could be expected, the crisis resulted in Icelanders recovering their sovereign rights, through a process of direct participatory democracy that eventually led to a new Constitution. But only after much pain.

Geir Haarde, the Prime Minister of a Social Democratic coalition government, negotiated a two million one hundred thousand dollar loan, to which the Nordic countries added another two and a half million. But the foreign financial community pressured Iceland to impose drastic measures. The FMI and the European Union wanted to take over its debt, claiming this was the only way for the country to pay back Holland and Great Britain, who had promised to reimburse their citizens.

Protests and riots continued, eventually forcing the government to resign. Elections were brought forward to April 2009, resulting in a left-wing coalition which condemned the neoliberal economic system, but immediately gave in to its demands that Iceland pay off a total of three and a half million Euros. This required each Icelandic citizen to pay 100 Euros a month (or about $130) for fifteen years, at 5.5% interest, to pay off a debt incurred by private parties vis a vis other private parties. It was the straw that broke the reindeer’s back.

What happened next was extraordinary. The belief that citizens had to pay for the mistakes of a financial monopoly, that an entire nation must be taxed to pay off private debts was shattered, transforming the relationship between citizens and their political institutions and eventually driving Iceland’s leaders to the side of their constituents. The Head of State, Olafur Ragnar Grimsson, refused to ratify the law that would have made Iceland’s citizens responsible for its bankers’ debts, and accepted calls for a referendum.

Of course the international community only increased the pressure on Iceland. Great Britain and Holland threatened dire reprisals that would isolate the country. As Icelanders went to vote, foreign bankers threatened to block any aid from the IMF. The British government threatened to freeze Icelander savings and checking accounts. As Grimsson said: “We were told that if we refused the international community’s conditions, we would become the Cuba of the North. But if we had accepted, we would have become the Haiti of the North.” (How many times have I written that when Cubans see the dire state of their neighbor, Haiti, they count themselves lucky.)

In the March 2010 referendum, 93% voted against repayment of the debt. The IMF immediately froze its loan. But the revolution (though not televised in the United States), would not be intimidated. With the support of a furious citizenry, the government launched civil and penal investigations into those responsible for the financial crisis. Interpol put out an international arrest warrant for the ex-president of Kaupthing, Sigurdur Einarsson, as the other bankers implicated in the crash fled the country.

But Icelanders didn't stop there: they decided to draft a new constitution that would free the country from the exaggerated power of international finance and virtual money. (The one in use had been written when Iceland gained its independence from Denmark, in 1918, the only difference with the Danish constitution being that the word ‘president’ replaced the word ‘king’.)

To write the new constitution, the people of Iceland elected twenty-five citizens from among 522 adults not belonging to any political party but recommended by at least thirty citizens. This document was not the work of a handful of politicians, but was written on the internet. The constituent’s meetings are streamed on-line, and citizens can send their comments and suggestions, witnessing the document as it takes shape. The constitution that eventually emerges from this participatory democratic process will be submitted to parliament for approval after the next elections.

Some readers will remember that Iceland’s ninth century agrarian collapse was featured in Jared Diamond’s book by the same name. Today, that country is recovering from its financial collapse in ways just the opposite of those generally considered unavoidable, as confirmed yesterday by the new head of the IMF, Christine Lagarde to Fareed Zakaria. The people of Greece have been told that the privatization of their public sector is the only solution. And those of Italy, Spain and Portugal are facing the same threat.

They should look to Iceland. Refusing to bow to foreign interests, that small country stated loud and clear that the people are sovereign.

That’s why it is not in the news anymore.

via sacsis.org.za

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The Campus Pot Connection

Wed, 24 Aug 2011 23:01:00 -0700

via onlinecolleges.net

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The arrogance of authority

Tue, 02 Aug 2011 02:40:00 -0700

Got this via email from Tom L. What a wonderful story! Thanks Tom!

A DEA officer stopped at a ranch in Texas , and talked with an old rancher. He told the rancher, "I need to inspect your ranch for illegally grown drugs." The rancher said, "Okay , but don't go in that field over there.....", as he pointed out the location.

The DEA officer verbally exploded saying, " Mister, I have the authority of the Federal Government with me!" Reaching into his rear pants pocket, he removed his badge and proudly displayed it to the rancher. "See this badge?! This badge means I am allowed to go wherever I wish.... On any land!! No questions asked or answers given!! Have I made myself clear... do you understand?!!"

The rancher nodded politely, apologized, and went about his chores.

A short time later, the old rancher heard loud screams, looked up, and saw the DEA officer running for his life, being chased by the rancher's big Santa Gertrudis bull...

With every step the bull was gaining ground on the officer, and it seemed likely that he'd sure enough get gored before he reached safety. The officer was clearly terrified. The rancher threw down his tools, ran to the fence and yelled at the top of his lungs...

"Your badge, show him your BADGE!!!"

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The U.S. Debt Owed by Each American Throughout History

Mon, 04 Jul 2011 15:21:00 -0700

via feedproxy.google.com

The debt amounts are adjusted for inflation, so that's the real debt increase per person since 1918 till 2010.

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The emergence of vaccine-induced diseases

Sat, 18 Jun 2011 02:31:47 -0700

The Emergence of Vaccine Induced Diseases.pdf Download this file

This is an article from Mercola.com, in PDF format, which contains important information about vaccines, their benefits and -- more importantly -- the problems they create. Please read this before blindly vaccinating your children, particularly your newborn babies. You have a choice.

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The Green Thing

Thu, 16 Jun 2011 00:11:56 -0700

Got this by email and couldn't resist sharing it. Author is unknown.

In the line at the supermarket, the cashier told the older woman that she should bring her own grocery bag because plastic bags weren't good for the environment. The woman apologised to her and explained, "We didn't have the green thing back in my day."

The clerk responded, "That's our problem today. The former generation did not care enough to save our environment."

She was right, that generation didn't have the green thing in its day.

Back then, they returned their milk bottles, soft drink bottles and beer bottles to the shop. The shop sent them back to the factory to be washed and sterilized and refilled, so it could use the same bottles over and over. They were recycled.

But they didn't have the green thing back in that customer's day.

In her day, they walked up stairs, because they didn't have an escalator in every store and office building. They walked to the grocery store and didn't climb into a 300-horsepower machine every time they had to go two blocks.

But she was right. They didn't have the green thing in her day.

Back then, they washed the baby's nappies because they didn't have the throw-away kind. They dried clothes on a line, not in a 220 volt energy gobbling machine - wind and solar power really did dry the clothes. Kids got hand-me-down clothes from their brothers or sisters, not always brand-new clothing.

But that old lady is right; they didn't have the green thing back in her day.

Back then, they had one TV, or radio, in the house - not a TV in every room. And the TV had a small screen the size of a handkerchief, not a screen the size of a cricket pitch. In the kitchen, they blended and stirred by hand because they didn't have electric machines to do everything for you. When they packaged a fragile item to send in the mail, they used a wadded up old newspaper to cushion it, not Styrofoam or plastic bubble wrap. They didn't have air conditioning or electric stoves with self cleaning ovens. They didn't have battery operated toys, computers, or telephones.

Back then, they didn't fire up an engine and burn fuel just to cut the lawn. They used a push mower that ran on human power. They used hand operated clippers to trim the shrubs. They exercised by working so they didn't need to go to a health club to run on treadmills that operate on electricity.

But she's right; they didn't have the green thing back then.

They drank from a glass filled from the tap when they were thirsty instead of using a plastic bottle every time they had a drink of water. They refilled their writing pens with ink instead of buying a new pen, and they replaced the razor blades in a razor instead of throwing away the whole razor just because the blade got dull.

But they didn't have the green thing back then.

Back then, people walked or took the bus and kids rode their bikes to school or rode the school bus instead of turning their mums into a 24-hour taxi service. They had one electrical outlet in a room, not an entire bank of sockets to power a dozen appliances. And they didn't need a computerized gadget to receive a signal beamed from satellites 2,000 miles out in space in order to find the nearest pizza joint.

But isn't it sad the current generation laments how wasteful the old folks were just because they didn't have the green thing back then?

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Honey may be effective at killing bacteria, aiding antibiotic resistance - Pri-Med Online

Sun, 01 May 2011 00:09:00 -0700

"Holistic and alternative medicine doctors have long known that honey has antimicrobial properties. Now, researchers at the University of Wales Institute Cardiff have discovered how a certain variety from New Zealand may have some significant medical uses."

Read the full article.

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