6 Ethernet Myths Revealed

July 17, 2014 at 10:00 AM

 

Let's challenge your Ethernet knowledge.

 

Did you know that Ethernet cabling is one of the most common cabling types? It's almost as common as electrical wiring! Ethernet is often run through walls, ceilings, under floors, and usually branches in a star topography from a central wiring closet.

 

Since it's so popular, we've put together some common assumptions about Ethernet cabling that are worth investigating.

 

See if you know the correct answers: 

 
 
 
 
 

 1. Myth or Fact:  The color of the cable jacket indicates what kind of signal the cable carries.

 

Myth! Ethernet is Ethernet, so there aren't different signal types. Although, there may be different speeds running in the same building. Usually, your IT department will use different colored cables to keep track of where the cable goes. This makes it a lot easier in the wiring closet to identify cables.

 
 
 
 

2. Myth or Fact:  If I run cables that are EIA/TIA 568 B standard, I cannot use any cables wired to the EIA/TIA 568 A standard on the same network.

 

Myth! The EIA/TIA 568 A and B standards are actually both straight-through pinned. They are pin to pin, 1 through 8. The difference is in the color code of the wires inside the jacket. These standards were originally set to improve network performance and consistency between manufacturers. 

 

For this reason, if you mix A and B standard cables in a network, the network will run perfectly fine. However, if someone has to cut a cable and re-punch it, you run the chance of punching to the wrong standard. Best practice is to have all cables that are permanently installed (behind walls, through the floor or ceiling, etc) wired to the same standard.

 
 
 
 
 

3. Myth or Fact: The distance between a workstation and a wiring closet can determine how fast the Internet runs on that person's computer.

 
 

This depends. The rule of thumb for Ethernet is that the distance between any two nodes should not be more than 100 meters (328 feet). Node to node may be understood as two items that get external power; patch panels, wall plates, and other components in the network typically don't count as nodes. If you run an Ethernet line exactly 328 feet from your wiring closet to a wall plate, when the user puts a short, 2 foot cable between the wall plate and the computer, they will actually be over the limit.

 
 

What happens if you go over the limit? Most often, users will experience very slow signal or no transmission. Your best bet is to always leave a little slack room between nodes. If you have to run cable beyond 100 meters, your best bet is to use a media converter to change the signal to fiber, then change it back to copper at the drop point.

 
 
 
 
 

4. Myth or Fact: In the wiring closet, Ethernet cables must be kept loose, not neatly tucked away, or else the internal wires could be damaged. This is why so many wiring closets are so messy.

 
 

Actually, this is partially true. The wires within Ethernet cables are twisted together, and this is important for the category rating that ensures the cable can handle the speed of the network. If the cable is bent, rotated, and flexed too much, those twists can come undone, throwing off the delay skew values. 

 

The rule of thumb is that Ethernet cables should never be stapled or tightly wound around something that would put a kink in the cable. Also, if you must make a tight 90 degree turn, you should make a 90 degree turn in the opposite direction nearby so the pressure on the twists is offset.

 

Of course, in your network closet you can easily use cable management equipment combined with angled connectors to keep the cables neatly under control. There's really no excuse for a messy wiring closet!

 
 
 
 
 

5. Myth or Fact: It doesn't matter whether you use solid conductor cables or stranded conductor cables, so long as you use a high enough category rating on the cables.

  

The difference between solid and stranded conductors is negligible, especially in short runs. So long as the category rating is high enough for the speed of your network, either should work.

 

However, that doesn't mean you can use solid and stranded cable interchangeably. Stranded conductor cables have the advantage of being much more flexible and able to take more abuse. For that reason, stranded cable is ideal for making patch cables, which may be moved and flexed as equipment moves. 

 

Solid conductor cables tend to fit better in 110 punches, and over long runs it performs slightly better. The standard suggestion is to use solid conductor in 90% of long cable runs and 10% or less of stranded conductor cable. This makes solid the preferred cable to use in permanent installations such as through the walls of a building between the wiring closet and the drop points.

 
 
 
 
 

6. Myth or Fact: If you want to dramatically improve the speed of your Ethernet network, you should use all shielded, plenum rated cables.

 

Myth! Neither shielding nor plenum rating will dramatically improve the speed of a network, though both shielding and plenum rating have their uses. The shielding on a cable helps to protect it from electromagnetic interference (EMI). In some applications, like radio stations, power stations and factories where high-power equipment may be running, EMI can be a big problem. 

 

In those situations, shielding doesn't merely help, it is essential (and yes, it does dramatically increase the speed in those situations, but only because the speed without shielding would be dramatically slower). In all other situations, shielding doesn't do anything but cost more money, and it may actually hurt a network if the shield isn't properly grounded at both ends.

 

As for plenum rating, this has to do with the material that the cable jacket is made out of. Plenum rated cables are specially designed to self-extinguish if there is a fire, thereby preventing the fire from "jumping floors" or burning through the air ducts where the cables are often run. This has nothing to do with how the cable performs. 

 

In some buildings, such as high-rise offices, schools, and hospitals, the local fire codes requires plenum rated cable because the occupants may not be able to escape as quickly in the event of a fire. But if your fire code doesn’t require this, you're better off seeking standard Ethernet cables.

 
 
 
 

Also, check our text and video tips on modular and networking products. L-com offers a plethora of Ethernet related cables and components, including panel mount couplers, patch panels, switches,  and other adapters.     

7 Deadly Counterfeit Cable Sins for You to Avoid

January 30, 2014 at 10:00 AM

 

 

What scares you more than a faulty, over-rated, counterfeit cable? If you’re like us and work with cables on a daily basis, then you know the answer: nothing.  

 

Shockingly, unscrupulous sellers have found many ways to cut costs on cables, drawing customers in for the low price. But what they don’t tell you is that it comes at a price- sacrificing safety, performance, and network stability.

 

So how do you identify them? Counterfeit cables are bulk cables or cable assemblies sold under false pretenses to undercut legitimate manufacturers.  Usually this means the cable specification does not match the actual product construction. Or it could be that the seller falsely implies that a cable meets a particular performance standard or flammability rating such as Category 5E or CMP/Plenum.  If you get a low bid for your next cable quote, check these factors to make sure you are getting what you are paying for:

 
 
1. Substituting steel or aluminum for pure copper: copper-clad-steel (CCS) or copper-clad-aluminum (CCA) are classic methods of saving on costly copper needed to make cables. Over the length of the cable, however, the signal integrity will drop below the noise and cross-talk levels. There's a good reason the EIA/TIA has not approved CCS or CCA cable for use in high-speed networks…

2. Deceiving Connector construction: This is a two-part deception. For "RJ-45" (8p x 8c) connectors, rejected molded plastic bodies can be re-ground back to pellets, added to new plastic, and then made in new bodies, which can lower the combustion rating for the overall connector. A good tip: check the connector body for foggy or yellowing plastic. Aside from the body, the metal contacts are first coated with nickel then with gold to ensure a good connection. Manufacturers have been skipping the nickel and skimping on the gold, sometimes called gold flash or selective plating. Contacts made this way will eventually corrode and fail to connect when mated.

3. Cable Jacket Material: For those applications that require CMP or CMR flammability rating, the requirement is critical. If it is specified that the cable meets CMP or CMR ratings (per the NEC code) and you get an unusually low bid, ask for proof of the jacket material. A legitimate business will offer a signed Certificate of Conformance (CoC) for the product they sell.

4. Selective Electrical Performance Testing: Some manufacturers will claim their cable or cable assemblies were "Fluke tested", but won't clarify that they only ran the channel test, not the full patch testing. Patch testing is difficult to pass and more expensive, but legitimate manufacturers will do it because it ensures the cable conforms to standards and is worth what they are charging.

5. Misleading Cable Markings: All cables sold in the United States will use a UL "E-file Number" or the manufacturer's name and model number that you can look up on UL's database. The problem is that the marking may conform to UL's standard, but the cable may not. Again, a signed CoC will protect against counterfeits so make sure you get one!

6. Wire Gauge Changes: Often 25 or 26 AWG cables can be mislabeled as 24 AWG. If you require 24 AWG, you should always request a sample cable, cut it open, strip the insulation off of the wires and measure them. Don't trust a manufacturer that claims something they aren't selling; if they are untruthful about the wire gage, what else could they be hiding?

7. The Golden Sample: While it is a good idea to get a sample up front, many manufacturers will make a "golden sample" to be perfect for what you need, sometimes at great expense. When it comes time to manufacture the rest, they scrimp and cheat all they can to deliver under cost. You should always set up a system whereby you QC some of the cables in each shipment-and without the manufacturer's prior knowledge.
 
 
This problem is much more common than you think!
 
L-com found counterfeit cables from both big and small manufacturers, and from both domestic and oversea sources. “Made in the USA” means nothing if the cable is made with poor components in order to offer a cheaper price. If price is your priority, someone can always make a cheaper cable. It doesn’t matter where a cable is made, but how the cable is made.
 
The key is to know that your seller or manufacturer (like us!) is checking cable assemblies, insisting on proving UL compliance, testing their cables, and always meeting standards. At L-com our Ethernet cables are made in our own factory versus in a sub-contractor’s, guaranteeing superior quality every time. 
 

Typical LAN Structured Cabling: The Basics

January 16, 2014 at 10:00 AM

Keeping it neat
 

Typical LAN Structured Cabling Setup

We know things can get messy in your commercial building when installing any sort of cabling system. Many cabling systems require a full wiring closet or server room including racks, panels, patch cords, lightning protectors, routers, switches, and media converters. All of which is supported by a staff of IT professionals. 

 

Phew. That’s a lot to manage. And having Internet access in a commercial building is no longer just an option. It is a must.

 

Even if you are doing most of your file sharing and other network activities in the cloud, you can't get by without the basic cabling linking your office to an ISP. 

 

So what’s the solution? A Structured Cabling System, which is the cabling, connectors and accessories that make up the Local Area Network (LAN) inside a building.  At a minimum, this consists of a modem, router/network switch and Ethernet cabling. 

 

 

Here's the trick


Often you need something more complex than just a computer connected to the Internet.  That means you'll need an Ethernet router to handle internal network addressing, securing resources and providing a connection to the Wide Area Network (WAN).  You will also most likely require Ethernet switches to distribute traffic to many computers and servers in your LAN. 
 

Typical Ethernet Cable with RJ45 ConnectorSince routers and switches can't work alone, you will require Ethernet cabling- possibly a lot of it.  And when you have a lot of cabling, things can get even messier. Try out these high-quality right-angle Ethernet patch cables along with cable management rack panels to keep your area neat and organized. 

 

With all the different cables going to different systems, its obvious things can get confusing. We suggest color coding your network too. Check out our wide range of colors for Ethernet cables, here. If you specify that a certain color cable carries a certain signal type (such as phone or network traffic), you ensure that everyone who works on your network wiring can visually identify critical connections before they are disconnected.

 

As your network grows, you also need your structured cabling system to be scalable.  One good way to do this is to employ a well organized rack layout and utilize good cable management practices. This will make future growth easier to manage within your server room. Plan for future expansion by also including blank filler panels between patching sections in a rack and between network switching/routing equipment.

 

Around the building, set up plenty of user access points by terminating a minimum of two network ports per office workspace.  Installing keystone jacks in aesthetically pleasing wall plates or surface mount boxes will give an office space a finished look.
 

Typical Enclosure Setup with power, lightning protection, and networking productsFor remote and secure locations, use enclosures to house both wired and wireless equipment. To power these products, install Power over Ethernet (PoE) injectors and splitters that will eliminate the need for complicated electrical re-wiring. If the location is too far for traditional Ethernet wiring (about 100 meters and further), consider setting up a fiber optic link using commercial or industrial grade media converters
 

Finally, never forget the importance of lightning protection.  Electrical surges can occur anywhere with devastating effects on expensive and critical equipment. Nearly anything that carries an electrical current is vulnerable. 

 

Need more tips? Click here for our Telecom/Modular (Premise Wiring) tutorial page. 

 

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