A major part of creating a viable network involves the installation of a cabling system. A solid cabling system is a good investment that will not only meet your current networking needs, but will last through your next-generation network as well.
No, it’s not ET calling home. “Alien Crosstalk” is defined as “unwanted signal coupling from one balanced twisted-pair component, channel, or permanent link to another”.
Alien crosstalk is not generally affected by common noise from motors, transformers, or florescent lighting fixtures. Alien crosstalk is specified as “a parameter for cabling to approximate the energy present when all cabling pairs are energized”.
It was once thought that copper cabling would never support speeds above 1 Gig, but Augmented Category 6, or Cat6a - has proven that wrong. Copper still lives and copper cabling may still be around at 40 Gig.
There has been much debate about which is the better option for supporting 10 Gig: Cat6a Unshielded Twisted Pair (UTP) or Cat6a Shielded Twisted Pair (STP)? Both solutions have their uses, and some key information can help installers make informed decisions.
The IEEE released the 802.3an 10GBASE-T standard in June of 2006, which specifies 10Gbs data transmission over four-pair copper cabling. The Telecommunications Industry Association (TIA) then began work on transmission performance specifications for the cabling. They published TIA Standard 568-B.2-10: Transmission Performance Specifications for 4-Pair 100 Ohm Augmented Category 6 Cabling in February 2008.
The new Cat6a standard extends the frequency of Cat6a cables to 500 MHz with specifications for a new performance parameter called Alien Crosstalk (ANEXT). Cat6a cables are fully backward compatible with all previous categories, including Cat6 and 5e. NEXT is crosstalk that occurs between adjacent cables and connecting hardware. The higher frequency signals of Cat6a makes ANEXT the limiting noise source for Cat6 and Cat5e systems.
Due to its ease of installation and familiarity among installers, Cat 6A UTP is today’s cabling of choice as it can support future bandwidth needs and 10Gb/s performance. In addition, the shield n the STP cable helps prevents electromagnetic and radiofrequency interference (EMI/RFI) on twisted pairs, helping eliminate the effects of noise from sources like machinery, generators, or medical imaging equipment, making STP systems the choice for industrial and healthcare facilities.
As most residential systems are not faced with EMI/RFI challenges, so UTP is still the recommended cabling type for home installations.
What is Cat6? Cat6 components are interoperable between different vendors and are fully backward compatible. Cat6 has the same nominal Impedance of 100 Ohms as Cat5 and 5e components, but with tighter tolerance on Impedance variations. Transmission parameters are specified to 250 MHz, compared to 100 MHz for Cat 5/5e.
Do Cat6 components behave differently? The diameters of Cat6 cables range between 0.21 to 0.25 inch (5.3 - 5.8 mm) compared to Cat5/5e’s range of 0.19 to 0.22 inch (4.8 – 5.5 mm). Cat6 also has a tighter twist length to reduce crosstalk interference.
What about installation? Cat6 cables and components are installed similar to Cat5/5e. There are design and installation issues that contractors and installers must pay greater attention to; including cable terminations and the pathway fill.
Will Cat6 supersede Cat5/5e? Yes. The only question is when. The installed cost for Cat6 cabling can be about 20 % higher than Cat5e, but prices will decrease as usage increases.
Will Cat6 deliver what is promised? Yes. There are no technical obstacles. Test parameters and procedures to qualify Cat6 components to ensure interoperability between different vendor’s products are in place and detailed.
What about the installed performance compared with Cat5/5e? The biggest benefit is much-improved Signal-to-Noise Ratio at the Receiver: Cat6 provides about 16 times better Signal-to-Noise Ratio compared to Cat5/5e over a wide frequency range.
Why do we need Cat6? The real question is “is Cat5e good enough for today and in the foreseeable future?” The answer is “Yes, but…”. Network switch ports are often at the “marginally compliant” limits of the IEEE standard and susceptible to cabling and temperature variations. Cat6 provides fewer bit errors than Category 5e for 100BASE-TX and 1000BASE-T applications.
Cabling is an evolutionary process. New challenges require new capabilities, and based on past trends and future projections, data rates will double about every 18 months. Running applications at 1 Gb/s pushes the limits of category 5e cabling, so doubling the bandwidth is like adding two or more lanes on a highway – you get faster and more efficient data “traffic flow”.
Streaming media applications such as video and multi-media are now commonplace, so the demand for faster data rates are increasing. These new applications will require the higher bandwidth of category 6 cabling.
Always study and document the required cabling layout and the distances between the equipment to be cabled before starting a Cat6 cable installation.
I met with the General Manager of a Holiday Inn in Northern Virginia. She manages a 200-unit building in Arlington, Virginia, an affluent suburb of Washington, DC. Her property provides rooms and facilities to handle meetings and conferences for vacationers and business travelers. She told me that she is trying to get wireless access installed into her building because she is losing business and wasting money.
She said that her hotel is providing free Internet access but her competition is providing free wireless access. Clients and management prefer wireless because it is much easier to manage and access. Clients don't like having to plug in a cable and having to make changes to their network settings to enable network access. Management does not like having to deal with multiple failure points in managing the hundreds of routers spread throughout the building. There is one in each room.
So, they have a lot of complaints about Internet access. It is not convenient. Sometimes clients don't even have a patch cable. So, the problems are overwhelming for both sides. Additionally, they have Meeting and Conference Rooms that are not hard-wired. So, every time they schedule a Conference for a business client they also have to pay their Internet Service Provider (ISP) to extend a bundle of network cables into the Meeting and Conference Rooms. As you can imagine, this is a hassle and a large financial expense. It cuts into their profit margins. And it is also a major inconvenience for both the staff and the customers.
We have presented a proposal to install network cabling and I expect to get approval in the coming weeks. It will save them time, money and reduce their efforts in providing reliable and fast Internet to their clients. I will update this posting as things progress.