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Cat5e for High Speed Networks

Bandwidth precedes data rates just as highways come before traffic. Doubling the bandwidth is like adding twice the number of lanes on a highway. The trends of the past and the predictions for the future indicate that data rates have been doubling every 18 months. As streaming media applications such as video and multi-media become commonplace, the demands for faster data rates will increase and spawn new applications that will benefit from the higher bandwidth offered by category 5e.

Cat5 enhanced (Cat5e), supports short-run Gigabit Ethernet (1000 Mbps) networking by utilizing all four wire pairs and is backward-compatible with ordinary CAT5. Currently defined in TIA/EIA-568-B, Cat 5e provides performance of up to 100 MHz, and is frequently used for both 100 Mbit/s and gigabit Ethernet networks. Cat5e cable is an enhanced version of Cat 5 that adds specifications for far end crosstalk. Although 1000BASE-T was designed for use with Cat 5 cable, the tighter specifications associated with Cat 5e cable and connectors make it an excellent choice for use with 1000BASE-T.

The Gigaplus range of Cat5e products offer customers a Gigabit Ethernet solution. The Gigaplus system offers a guaranteed performance that not only meets the requirement of the relevant standard, but offers the comfort of substantial headroom. In the current market GigaPlus represents a sound investment for general office horizontal cabling and residential cabling for networks running Gigabit Ethernet applications.

Some of the Cat5e systems like Belden IBDN System 1200 have been developed to support high-speed network applications such as Gigabit Ethernet and provide clear bandwidth up to 160 MHz; an increase of 60% over Cat5e standard of 100 MHz.

These cables incorporate a patented design which provides complete quality control during the manufacturing process. This provides high quality cables that consistently offer improved channel performance and large cabling systems for all new cabling installations.

 For more information on Cat5e cables, please log onto www.mayflex.com

Cat5e for High Speed Networks / Mike Nicholson

Mike Nicholson

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Working the Third Shift: Tips to Avoid Counterfeits When Buying and Selling Used Cisco

San Francisco, California January 17th, 2006: If you’ve ever strolled down the streets of New York, you’re familiar with the enterprising street vendors offering imitation Gucci handbags and fake Rolex watches at a fraction the price of retail. Don’t be surprised if you’re offered a Cisco router on your next stroll down Canal Street. While clear statistics specific to the network hardware market are not available, according to a white paper by AGMA and consulting company, KPMG, counterfeit products account for nearly 10% of the overall IT products market. So whether it’s luxury goods or high-end data networking, illicit manufacturers have seized the opportunity to flood the market with fake merchandise.

Third-Shift

Recently, there has been an explosion of counterfeit hardware that has hit the market. While these items can be poorly made knock-offs, in some cases are actually made by companies licensed by Cisco and other companies to manufacture their hardware. Only the discerning eye of an experienced reseller can hope to detect the physical subtleties between the Cisco original and fake. Companies in China, for example, already have the experience, manufacturing capacity, and technical know-how to produce Cisco’s products. And sometimes they run extra shifts or a “third shift” to produce a surplus of product, which they distribute illegally on the black market. The result has been a surge in the level of counterfeit products available on the US market. Often, these products can be traded unknowingly to either the buyer or seller. That is until a problem arises.

These counterfeit products have a dramatically higher failure rate due to lax manufacturing controls. Buyers often find out they’ve been duped when exercising a warranty. Naturally, Cisco will refuse to honor a warranty on counterfeit product hence the end user is stuck with a lemon. Sometimes users will find out an item is counterfeit when they attempt to register a serial number, only to discover that what they have is a duplicated number, which has already been assigned to another buyer.

Gray-Market Deals

While savvy buyers will sometimes be wary of fire sale pricing on new Cisco hardware, counterfeiters have become increasingly smarter and have started marketing these products as “used” and leaking these products to the secondary market. Following the dot-com bust, buyers became accustomed to buying new out-of-box equipment at liquidation prices. This created a new channel for counterfeit sellers to slip their wares into the gray market with less scrutiny. By selling a new “counterfeit” item, as used, deeply discounted prices are less likely to raise a red flag for buyers.

Safe Tips

Most buyers don’t realize they have counterfeit Cisco hardware until it’s installed and begins to have issues. Excessive network outages and failures are often a signal that something in your network is a fake. This begs the question of how to protect yourself from buying counterfeit equipment.

1. Be wary of anything being sold from China. Sometimes Chinese sellers will even use fictitious names and pose as an American company. Typically English language skills can be a tip-off. If it sounds like an ad or email was written by Borat, don’t buy.

2. Develop relationships with trusted vendors. Companies that have a long-standing reputation and extensive client base will most likely only buy from trusted sources. By working with someone you know and trust, you are less likely to encounter issues with fake gear.

3. Make sure your vendor checks serial numbers in the vendor database for EVERY piece they purchase.

4. Use your eyes, and look for anything unusual. Inspect the item carefully for irregularities in logo size, packaging materials, holograms and chip sets.

Working the Third Shift: Tips to Avoid Counterfeits When Buying and Selling Used Cisco / Razvan Jr

Peter Gilberd has a collective 10 years experience in IT sales. He is currently the President for Townsend Assets Group (TAG), a leading reseller of pre-owned data networking and telecom equipment. For more comprehensive information on the process of selling used hardware, refer to TAG’s Buy-Sell Used Cisco page.

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Ntp Server Static GPS Antenna Systems

The Global positioning System (GPS) is often used by computer equipment, such as NTP Server systems, to provide an accurate timing reference for time critical applications. This article provides an overview of GPS for timing applications and describes the equipment used to install a GPS antenna in a static location.

Overview – Using GPS for Accurate Time

The Global Positioning System is a US military system for worldwide navigation. The system consists of 24 orbiting satellites, each satellite has a highly accurate atomic clock on-board synchronised to UTC time. The satellites continuously broadcast time and position information. The time and position information can be obtained worldwide with a GPS receiver and antenna. GPS works continuously in any whether conditions, anywhere in the world. Additionally, there is no set up fee or subscription charges to utilise the GPS systems. Many computer timing systems and NTP Server systems utilise GPS as an accurate external timing reference.

The Accuracy of GPS Timing Systems

GPS receivers provide highly accurate position and timing information. Typically, a GPS receiver can provide positioning information to an accuracy of 15m. NTP Server systems can obtain timing information from GPS to a resolution of a few nanoseconds.

The GPS Signal

The transmitted GPS signal is very weak low-power radio signal, designated L1 and L2. L1 is the civilian GPS frequency transmitted at 1575.42 MHz. The signals travel by line of sight and can pass through clouds, glass and plastics but are blocked by objects such as metal and brickwork. Therefore, the ideal location for a GPS antenna is on rooftop with a full 360-degree view of the sky. However, often installation on the side of a building or in a window can provide adequate results. As a rule of thumb, the better the view of the sky, the greater the likelihood of a good consistent signal lock.

GPS Timing Antenna Types

The GPS antenna acts as an amplifier to boost the GPS signal for transmission along a cable, usually coax, to the GPS receiver. GPS Timing antenna’s provided with NTP server systems utilise a pole-mounting system. The antenna screws to a threaded pole for installation on rooftops. This arrangement provides the GPS antenna with a rigid mount easily able to withstand high winds without damage. Typically the GPS antenna is fairly small in size, measuring less than 90cm in diameter. Low-cost patch type antennas are also available, but these are generally better suited to vehicle applications.

GPS Antenna Cable Types and Cabling Distances

The cable distance that can be utilised by a GPS antenna depends mainly on the amplification of the GPS antenna and the quality of coax used in the installation. A typical GPS timing antenna may have a gain of 35 db. Relatively low-quality coax such as RG58 has an attenuation of 0.64 db/m at 1575 MHz. Therefore, a cable run of 55m can be obtained using RG58 cable. With very high quality coax cable, such as LMR400, an unaided cable run of 200m can be achieved. However, very high quality coax can be expensive. A good price-performance compromise is LMR200 cable, which can be run unaided to 80m.

Extending Cabling Distance with In-Line GPS Amplifiers

In-line GPS amplifiers provide further amplification of the GPS signal to increase the cable distance between the GPS antenna and receiver. GPS amplifiers are fitted in-line with the antenna cable and obtain power from the receiver via the coax cable. No external power-supplies are required. Typically, a GPS amplifier may add a further 20 dB of gain, adding 30m of low-quality RG58 coax, 40m of LMR200 coax or 100m of high quality LMR400 coax. Additionally, multiple in-line amplifiers may be utilised to further increase cable distance.

Sharing a Single Antenna Between Multiple Receivers – GPS Splitters

GPS splitters allow a single GPS antenna to be utilised by two or more NTP server systems. The GPS splitter splits the signal received from the GPS antenna into multiple outputs for synchronizing multiple NTP servers. GPS splitters are generally available with 2, 4 or 8 outputs.

Protecting GPS Systems – GPS Surge Suppressors

Surge suppressors protect expensive NTP server equipment from electro-static discharges, such as lightning, that may be picked up by an externally mounted GPS antenna. Surge suppressors are installed in-line on the coax cable between the antenna and receiver, ideally where the cable enters the building. Surge suppressors require a low-impedance ground, to discharge any received surge. The surge suppressor requires no power-supply or additional cabling.

Ntp Server Static GPS Antenna Systems / David Evans

Dave Evans develops atomic clock time synchronisation systems to ensure accurate time on PC networks. Click here to find out more about GPS NTP Server systems.

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