Category: Info

Copper Cabling Review

Those of you who have been following my blog know that I love to write about what I classify as the soft sciences. By that I mean protocols, call flows, software, security, and other technologies that are for the most part, hardware and infrastructure independent. Does it make much difference if I run a SIP stack on a PC, virtual server, or smart phone? Not really. SIP acts like SIP no matter what platform is sending or receiving it.

So, it may come as a surprise that today I am writing about something that has little to do with source code or security certificates. I want to espouse on Ethernet cables.

Honestly, I didn’t give cabling a lot of thought until last week when I was speaking at an Avaya Users’ Group meeting in Tampa, Florida. After the president discussed old and new business, he opened the floor to the members to ask questions of their fellow Avaya users.

The questions were good. I took notes on several and chimed in where I felt I had something to add. However, the one that I found most interesting was this, “We are in the process of redoing our building’s LAN cables and I was wondering if people are installing Cat-5 or Cat-6.”

The answers varied quite a bit. Some folks already made the switch, a few decided not to, and some fell into the not-sure-what-we-will-do category.

For those of you who don’t have a plan (and I will assume that many of you are in that camp), allow me to spend some time introducing you to the Cat-5, Cat-5e, Cat-6, and Cat-6a Ethernet cables.

But first, this handy-dandy comparison table.

 

Length (meters) 10 Mb/s 100 Mb/s 1 Gb/s 10 Gb/s Power Over Ethernet Frequency in Mhz
Cat-5 100  Yes  Yes  Yes 100
Cat-5e 100  Yes  Yes  Yes  Yes 100
Cat-6 100 (55m for 10Gb/s)  Yes  Yes  Yes  Yes  Yes 250
Cat-6a 100  Yes  Yes  Yes  Yes  Yes 500

 

The Differences

As the class of cable goes up, so does the speed and frequency of the wire. The biggest difference between Cat-5/5e and Cat-6/6a is the speed. Cat-5/5e tops out at 1 Gb/s and Cat-6/6a allows speeds up to 10 Gb/s.

The difference between Cat-6 and Cat-6a is that Cat-6 is only guaranteed for a distance of 55 meters at 10 Gb/s. Cat-6a can run at that same speed for up to 100 meters.

Physically, Cat-5/5e and Cat-6/6a differ in a number of ways. First, there are more twists per centimeter of wire in Cat-6/6a. Cat-5 and Cat-5e typically uses 1.5 to 2 twists per centimeter and Cat-6 and Cat-6a uses 2+ twists per centimeter. Twisting reduces interference between internal and external wires.

Second, Cat-6/6a use a thicker outside sheath than Cat-5/5e. This sheath protects against near end and alien crosstalk. Crosstalk is more likely as the frequency (Mhz) increases. Cat-6 and Cat-6a support higher frequency ranges so they have the thickest sheaths.

Lastly, a nylon spline (a longitudinal separator in the wiring) can also be used to reduce crosstalk. Cat-5e always has a spline, Cat-5 sometimes has a spline, and depending upon the manufacturer, Cat-6/6a may also have a spline. Since Cat-5e requires a spline and Cat-5 does not, Cat-5 has a thicker outside sheath than Cat-5e.

Cost-wise, Cat-6 and Cat-6a are about 10 to 20 percent more expensive than Cat-5/5e. So, cost is not a big issue considering the fact that you can obtain speeds ten times faster when you go to Cat-6/6a.

It’s important to know that Cat-6 and Cat-6a are backwards compatible and can be used with older Cat-5, Cat-5e, and even Cat-3 equipment.

Should You or Shouldn’t You?

If it were me, every new installation would use Cat-6a wiring. Running cable through a building is an expensive proposition and since most cable will stay in place for up to 10 years, I would future-proof my company by adding the fastest option available whether I was ready to rollout 10 Gb/s or not.  Running cable twice in a short amount of time would be very foolish

However, I would not pull out perfectly good Cat-5e cable if I wasn’t ready to move to a higher speed. Wait until you need it before spending the money. Besides, by that time, there may be something even better that you can run.

Mischief Managed

This is an important topic that may not jump out at you as you look at upgrading your network switches and routers. However, as you saw, cable choice can make the difference between lightening fast and yesterday’s speeds.

Notice that I didn’t mention Cat-7 cables. For some folks, Cat-6a is ancient history. However, that wasn’t the original question and I need to leave myself something for a future blog article. Stay tuned.

first article from andrew

TIA/EIA Structured Cabling Standards

Key cabling infrastructure standards

TIA

TIA

IEEE

IEEE

ISO

ISO

eia

EIA

IEC

ANSI

SA

BICSI

The TIA/EIA structured cabling standards define how to design, build, and manage a cabling system that is structured, meaning that the system is designed in blocks that have very specific performance characteristics. The blocks are integrated in a hierarchical manner to create a unified communication system. For example, workgroup LANs represent a block with lower-performance requirements than the backbone network block, which requires high-performance fiber-optic cable in most cases. The standard defines the use of fiber-optic cable (single and multimode), STP (shielded twisted pair) cable, and UTP (unshielded twisted pair) cable.

The initial TIA/EIA 568 document was followed by several updates and addendums as outlined below. A major standard update was released in 2000 that incorporates previous changes.

TIA/EIA-568-A-1995 (Commercial Building Telecommunications Wiring Standards)    Defines a standard for building cable system for commercial buildings that support data networks, voice, and video. It also defines the technical and performance criteria for cabling.

TIA/EIA-568-A updates (1998-1999)    The TIA/EIA-568 was updated several times through this time period. Update A1 outlined propagation delay and delay skew parameters. Update A2 specified miscellaneous changes. Update A3 specified requirements for bundled and hybrid cables. Update A4 defined NEXT and return loss requirements for patch cables. Finally, update A5 defined performance requirements for Enhanced Category 5 (Category 5E).

TIA 568-B.1-2000 (Commercial Building Telecommunications Wiring Standard)    The year 2000 update packages all the previous addendums and service updates into a new release and, most important, specifies that Category 5E cable is the preferred cable type that can provide minimum acceptable performance levels. Several addendums were also released that specify technical information for 100-ohm twisted-pair cable, shielded twisted-pair cable, and optical fiber cable.

TIA/EIA-569-A-1995 (Commercial Building Standard for Telecommunications Pathways and Spaces)    This standard defines how to build the pathways and spaces for telecommunication media.

TIA 570-A-1998 (Residential and Light Commercial Telecommunications Wiring Standard)    This standard specifies residential cabling.

TIA/EIA-606-1994 (Building Infrastructure Administration Standard)    This standard defines the design guidelines for managing a telecommunications infrastructure.

TIA/EIA-607-1995 (Grounding and Bonding Requirements)    This standard defines grounding and bonding requirements for telecommunications cabling and equipment.

The current trend is to evolve the standards to support high-speed networking such as Gigabit Ethernet and define advanced cable types and connectors such as four-pair Category 6 and Category 7 cable. Category 6 is rated for channel performance up to 200 MHz, while Category 7 is rated up to 600 MHz.

Why you need to get Structured Cabling Contractor?

The market now are very competitive even in this structured cabling market, I believe every one can pull and install the cable but are they install in the correct manner?

Electrical contractors that do install structured cabling without a solid knowledge of the process may be putting both the home’s network and their own professional reputation at risk. However, refusing to take part in the structured cabling market may not be the best move for an electrical contractor either.

There are some important differences between pulling electrical wires and pulling structured cabling that electrical contractors need to be aware of to provide quality work and earn a good reputation in this growing field. One of the biggest differences between electrical wiring and structured cabling is the fragility of the latter. “In the installation of structured cabling, you can easily destroy the performance of the cables if they’re not handled right.”

For example, the maximum pulling tension for low-voltage cable is much less than that used for electrical cables. Each manufacturer has its own standard, but less than 25 pounds is typically recommended. What will happen if more force is used? “One improper tug at a wire, and you can pull out the twist that is so carefully put in by the manufacturer, degrading performance.

It is also important to note that the low-voltage cable, such as fiber optic cable, cannot bend at a 90 angle, so it must form a loop in order to turn in a different direction. The radius of this loop also depends on manufacturer specifications. If there is too sharp of a bend in the cabling, some of the cable fibers could break or kink and also degrade the signal.

You must install low-voltage cables at least 12 inches away from electrical wires, and run them parallel to one another. They must not be closer than this for more than 6 feet. If electrical wires and low-voltage cables cross, they must do so at a 90° angle.

Keeping up with the competition

Though many builders seem willing to give their structured cabling work to electrical contractors, some are still not sure they will perform at the level of electronic systems contractors, alarm system installers, and even home entertainment installers — all specifically trained in low-voltage installations.

“I think the electrical contractors have a ways to go to prove that they know what they’re doing in this area [structured cabling]”, “Their background and experience is on the electrical side, which is totally different than on the communications side.”

Data Center Physical Infrastructure (Enterprise Networks)

Data Center Infrastructure Structured Cabling

Data Center Infrastructure Structured Cabling – Facilities

When designing a data center, several factors should be taken into consideration, including standards compliance.  When implementing a structured cabling solution, the standard recommends a star topology architecture to achieve maximum network flexibility.  TIA-942 outlines additional factors crucial to data center design, including recognized media, cable types, recommended distances, pathway and space considerations and redundancy. In addition to standards compliance, the need for infrastructure flexibility to accommodate future moves, adds and changes due to growth, new applications, data rates and technology advancements in system equipment must be considered.

Data Center Needs

As data centers face the continued need to expand and grow, the fundamental concerns are constant. Data center infrastructures must provide reliability, flexibility and scalability in order to meet the ever-changing data center network.

Reliability: Data center cabling infrastructures must provide security and enable 24 x 365 x 7 uptime. Tier 4 data centers have uptime requirements of 99.995 percent, less than one-half hour per year.

Flexibility: With the constant in data centers being change, the cabling infrastructure must be modular to accommodate changing requirements and easy to manage and adjust for minimal downtime during moves, adds and changes.

Scalability: Cabling infrastructures must support data center growth, both in addition of system electronics and increasing data rates to accommodate the need for more bandwidth. The infrastructure must be able to support existing serial duplex transmission and provide a clear migration path to future parallel optic transmission. In general, the infrastructure should be designed to meet the challenges of the data center over a 15- to 20-year service life.

TIA-942 includes four tiers relating to various levels of redundancy (Annex G)

Tier I – No Redundancy – 99.671% available

Tier II – Redundant component, but 1 path – 99.741% available

Tier III – Multiple paths, components, but 1 active path – 99.982% available

Tier IV – Multiple paths, components, all active – 99.995% available – < 1/2 hour downtime/year

Low Smoke Zero Halogen Cable (LSZH)

What are Halogens?
When grouped together, the elements fluorine, chlorine, bromine, iodine and astatine make up a chemical family known as the Halogens. You may not have been aware of it, but halogens have many uses, and most of us come into contact with them on a daily basis. Just think about it: the fluoride in your toothpaste, the chlorine in your pool, the iodine in your medicine cabinet…they’re all halogens!

 

Halogens as Flame Retardants
Pool maintenance, first aid and dental hygiene aside, halogens are also widely used as flame retardants in a variety of plastics, including the PVC (polyvinyl chloride) that makes up many cable jackets and electronics-related products. Unfortunately, when it comes to the health of both humans and the environment, halogen-based flame retardants can be a double-edged sword.
Ironically, while these halogen compounds keep plastics from catching fire and spreading flames, they can also release hazardous gases if the plastic actually ignites. Carcinogenic substances like Polychlorinated Biphenyls (PCBs), Polycyclic Aromatic Hydrocarbons (PAHs), Nitro Polycyclic Aromatic Hydrocarbons and dioxins are all by-products produced when halogenated plastics burn. These gaseous compounds pose a double threat…not only are they dangerous in vapor form, but they can also condense into caustic acids (such as hydrochloric acid) when they come into contact with water.

 

Low Smoke Zero Halogen Materials: a Safer Alternative
It’s all in the name… “Low Smoke Zero Halogen” sums everything up: these materials (such as polypropylene) contain absolutely no halogens, but still have excellent flame resistance and produce very little smoke when burned.
LSZH cabling is the safest choice for plenum use and any other applications in which smoke is likely to both build up and come into contact with people, since no harmful toxins are actually released.

LSZH Structured Cabling

The Hidden Hero Structured Cabling System

Cabling is one of the most important elements within any IT network and is one of the biggest IT investments that companies make. Selecting the right cabling system can have a tangible impact on a range of issues, including network performance, the speed at which data can pass through the network. Therefore, making the right choice of cabling system is too important an issue to be ignored.

Understandably, since cabling is an occasional rather than a regular purchase, most IT managers cannot be expected to be experts in this area, but this does mean that they often need to rely on advice from contractors, consultants, installers and suppliers. This can be dangerous, depending on the quality of the information being distributed. Poor-quality or inadequate cabling systems can bring a network to a standstill.

There have even been occasions where it has been necessary to rip out large sections of structured cabling, due to faults that need to be located and repaired, costing the companies involved vast amounts of money, as well as lost time. These faults may not be immediately obvious, potentially causing the user company considerable disruption at a later date.

The good news is that with a basic understanding of the cabling market and installation issues, IT managers can make more informed choices. The first question is: structured or not? Direct cabling is cheaper, but it is essentially a blind network, without any means to manage or configure it easily. This is particularly important when changes need to be made, for instance switching around connections to end-users, should there be a reorganisation in an office.

When correctly labelled, the patch panel of a structured cabling system makes it easy to see at a glance every connection, so changes can be quickly and easily made, usually without requiring a specialist visit from a third party. Moreover, efficient installation means that any potential EMI or crosstalk options can be minimised, for instance by ensuring specified distances between cables, minimising bend radius and using techniques, such as dual-pathing with diverse routing of cables. Given how often most companies will need to make changes to their cabling systems, however small, structured cabling is these days the sensible option.