Thanks for the info Dave, this was very helpful. I actually meant Category 6 not Category 5e in my last email for GigE purposes.
> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Dave Watkins > Sent: Friday, June 10, 2005 10:39 AM > To: 'CLUG General' > Subject: RE: [clug-talk] voice & data on cat5 ( LONG) > > Hi Kin, > > Here are a few tidbits I have found. BTW, nobody mentioned Cat6 which if > Gigabit capable (as is Cat5e - but maxed out) > > > ............................................ > > Personally; unless you are required to have cabling that will last more > than > 7 years or so, I'd go Cat5e. > > As others have mentioned, Cat6 is basically better quality and will > hopefully support future enhancements better than Cat5e. However, at this > point in time, there is no practical difference; both support 1000Base-T > (Gigabit) up to 100M max (using all four pairs remember). > > Yes, you should definitely use PoE. Remember, not using PoE can also be > costly - you'll need lots more power sockets at desks. More importantly, > how > would you provide battery backup in times of power failure for all those > sockets? (people still expect phones to work during power failures and > this > is probably more critical in a school.) Much easier to put a UPS in the > wiring closet... > > If you have recent edge switches then add mid-span power units to them. > Otherwise, buy new PoE switches that support the 802.3af standard. Check > that your IP handsets will be compatible. Check the power budget on each > switch as some handsets consume more power than others and most switches > do > not have PSUs capable of handling the highest power devices on all ports. > > ......................................... > > > > If you are looking for a long term solution, install everything CAT-6. > If you plan to reconfigure work areas frequently, and need to save a few > bucks, install everything CAT-5e. > If you want a long term cabling solution, but still need to save a few > bucks, mix it up a bit. You could install CAT-6 cabling and CAT-5e > components (outlets, patch panels, patch cords, etc) You will save money > now > by installing cheaper components which can be replaced in the future when > the need arises. When the time does come to upgrade to CAT-6 it will be > much > more cost effective (from a labor standpoint)to replace jacks and patch > panels and test than it would be to remove all of the old cabling, install > all new cabling, jack, terminate and test. Besides, if you check around > and > chose your cable wisely, you may find that CAT-6 cable is not much more > expensive than CAT-5e > > ..................... > > > Cat5e and Cat6 Comparison > Category 6 Cabling System and Application > > > Why do I need all the bandwidth of category 6? As far as I know, there is > no > application today that requires 200 MHz of bandwidth. > > 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. Current applications running at > 1 > Gb/s are really pushing the limits of category 5e cabling. 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 6. This is > exactly what happened in the early 90's when the higher bandwidth of > category 5 cabling compared to category 3 caused most LAN applications to > choose the better media to allow simpler, cost effective, higher speed LAN > applications, such as 100BASE-TX. Note: Bandwidth is defined as the > highest > frequency up to which positive power sum ACR (Attenuation to Crosstalk > Ratio) is greater than zero. > > What is the general difference between category 5e and category 6? > > The general difference between category 5e and category 6 is in the > transmission performance, and extension of the available bandwidth from > 100 > MHz for category 5e to 200 MHz for category 6. This includes better > insertion loss, near end crosstalk (NEXT), return loss, and equal level > far > end crosstalk (ELFEXT). These improvements provide a higher signal-to- > noise > ratio, allowing higher reliability for current applications and higher > data > rates for future applications. > > Will category 6 supersede category 5e? > > Yes, analyst predictions and independent polls indicate that 80 to 90 > percent of all new installations will be cabled with category 6. The fact > that category 6 link and channel requirements are backward compatible to > category 5e makes it very easy for customers to choose category 6 and > supersede category 5e in their networks. Applications that worked over > category 5e will work over category 6. > > What does category 6 do for my current network vs. category 5e? > > Because of its improved transmission performance and superior immunity > from > external noise, systems operating over category 6 cabling will have fewer > errors vs. category 5e for current applications. This means fewer > re-transmissions of lost or corrupted data packets under certain > conditions, > which translates into higher reliability for category 6 networks compared > to > category 5e networks. > > When should I recommend or install category 6 vs. category 5e? > > >From a future proofing perspective, it is always better to install the > best > cabling available. This is because it is so difficult to replace cabling > inside walls, in ducts under floors and other difficult places to access. > The rationale is that cabling will last at least 10 years and will support > at least four to five generations of equipment during that time. If future > equipment running at much higher data rates requires better cabling, it > will > be very expensive to pull out category 5e cabling at a later time to > install > category 6 cabling. So why not do it for a premium of about 20 percent > over > category 5e on an installed basis? > > What is the shortest link that the standard will allow? > > There is no short length limit. The standard is intended to work for all > lengths up to 100 meters. There is a guideline in ANSI/TIA/EIA-568-B.1 > that > says the consolidation point should be located at least 15 meters away > from > the telecommunications room to reduce the effect of connectors in close > proximity. This recommendation is based upon worst-case performance > calculations for short links with four mated connections in the channel. > > What is a "tuned" system between cable and hardware? Is this really needed > if product meets the standard? > > The word "tuned" has been used by several manufacturers to describe > products > that deliver headroom to the category 6 standard. This is outside the > scope > of the category 6 standard. The component requirements of the standard > have > been carefully designed and analyzed to assure channel compliance and > electrical/ mechanical interoperability. > > What is impedance matching between cable and hardware? Is this really > needed > if product meets the standard? > > The standard has no impedance matching requirements. These are addressed > by > having return loss requirements for cables, connectors, and patch cords. > > Is there a use for category 6 in the residential market? > > Yes, category 6 will be very effective in the residential market to > support > higher Internet access speeds while facilitating the more stringent Class > B > EMC requirements (see also the entire FCC Rules and Regulations, Title 47, > Part 15). The better balance of category 6 will make it easier to meet the > residential EMC requirements compared to category 5e cabling. Also, the > growth of streaming media applications to the home will increase the need > for higher data rates which are supported more easily and efficiently by > category 6 cabling. > > Why wouldn't I skip category 6 and go straight to optical fiber? > > You can certainly do that but will find that a fiber system is still very > expensive. Ultimately, economics drive customer decisions, and today > optical > fiber together with optical transceivers is about twice as expensive as an > equivalent system built using category 6 and associated copper > electronics. > Installation of copper cabling is more craft-friendly and can be > accomplished with simple tools and techniques. Additionally, copper > cabling > supports the emerging Data Terminal Equipment (DTE) power standard under > development by IEEE (802.3af). > > What is meant by the term "Electrically Balanced"? > > A simple open wire circuit consisting of two wires is considered to be a > uniform, balanced transmission line. A uniform transmission line is one > which has substantially identical electrical properties throughout its > length, while a balanced transmission line is one whose two conductors are > electrically alike and symmetrical with respect to ground and other nearby > conductors.* "Electrically balanced" relates to the physical geometry and > the dielectric properties of a twisted pair of conductors. If two > insulated > conductors are physically identical to one another in diameter, > concentricity, dielectric material and are uniformly twisted with equal > length of conductor, then the pair is electrically balanced with respect > to > its surroundings. The degree of electrical balance depends on the design > and > manufacturing process. Category 6 cable requires a greater degree of > precision in the manufacturing process. Likewise, a category 6 connector > requires a more balanced circuit design. For balanced transmission, an > equal > voltage of opposite polarity is applied on each conductor of a pair. The > electromagnetic fields created by one conductor cancel out the > electromagnetic fields created by its "balanced" companion conductor, > leading to very little radiation from the balanced twisted pair > transmission > line. The same concept applies to external noise that is induced on each > conductor of a twisted pair. A noise signal from an external source, such > as > radiation from a radio transmitter antenna generates an equal voltage of > the > same polarity, or "common mode voltage," on each conductor of a pair. The > difference in voltage between conductors of a pair from this radiated > signal, the "differential voltage," is effectively zero. Since the desired > signal on the pair is the differential signal, the interference does not > affect balanced transmission. The degree of electrical balance is > determined > by measuring the "differential voltage" and comparing it to the "common > mode > voltage" expressed in decibels (dB). This measurement is called > Longitudinal > Conversion Loss "LCL" in the Category 6 standard. * The ABC's of the > telephone Vol. 7 > Category 6 Cable Questions > What is the difference between enhanced category 5e cable rated for 400 > MHz > and category 6 cable rated for 250 MHz? > > Category 5e requirements are specified up to 100 MHz. Cables can be tested > up to any frequency that is supported by the test equipment, but such > measurements are meaningless without the context of applications and > cabling > standards. The category 6 standard sets minimum requirements up to 250 MHz > for cables, connecting hardware, patch cords, channels and permanent > links, > and therefore guarantees reasonable performance that can be utilized by > applications. > > Why did all category 6 cable used to have a spline, and now is offered > without one? > > Some category 6 cable designs have a spline to increase the separation > between pairs and also to maintain the pair geometry. This additional > separation improves NEXT performance and allows category 6 compliance to > be > achieved. With advances in technology, manufacturers have found other ways > of meeting category 6 requirements. The bottom line is the internal > construction of the cable does not matter, so long as it meets all the > transmission and physical requirements of category 6. The standard does > not > dictate any particular method of cable construction. > > Is there a limitation on the size of bundles one can have with category 6? > Can you have 200-300 and still pass category 6? > > There is no limit imposed by the standards on the maximum number of > category > 6 cables in a bundle. This is a matter for the market and the industry to > determine based on practical considerations. It should be pointed out that > after six or eight cables, the performance in any cable will not change > significantly since the cables will be too far away to add any additional > external (or alien) NEXT. > Category 6 Patch Cord Questions > Will contractors be able to make their own patch cords? > > Category 6 patch cords are precision products, just like the cables and > the > connectors. They are best manufactured and tested in a controlled > environment to ensure consistent, reliable performance. This will ensure > interoperability and backward compatibility. All this supports patch cords > as a factory-assembled product rather than a field-assembled product. > > Do you have to use the manufacturer's patch cords to get category 6 > performance? > > The category 6 standard has specifications for patch cords and connectors > that are intended to assure interoperable category 6 performance. If > manufacturers can demonstrate that each component meets the requirements > in > the standard, minimum category 6 performance will be achieved. However, > manufacturers may also design their products to perform better than the > minimum category 6 requirements, and in these cases compatible patch cords > and connectors may lead to performance above the minimum category 6 > requirements. > > Category 6 Testing Questions Why do field tester manufacturers offer many > different link adapters if everyone meets the standard? > > This was an interim solution while the standard was still being developed > and the interoperability requirements were not yet established. It is > likely > that soon one or more adapters will work for testing of cabling from all > vendors. > > Would you get passing test results if you used a link adapter not > recommended by a manufacturer? > > You should expect to get passing results if both the link adapter > interface > and the mating jack that is part of the link are both compliant to > category > 6 requirements. > Category 6 Connecting Hardware Questions > Are the connectors for category 5e and category 6 different? Why are they > more expensive? > > Although category 6 and category 5e connectors may look alike, category 6 > connectors have much better transmission performance. For example, at 100 > MHz, NEXT of a category 5e connector is 43 decibels (dB), while NEXT of a > category 6 connector is 54 dB. This means that a cat6 connector couples > about 1/12 of the power that a cat5e connector couples from one pair to > another pair. Conversely, one can say that a category 6 connector is 12 > times less "noisy" compared to a category 5e connector. This vast > improvement in performance was achieved with new technology, new > processes, > better materials and significant R&D resources, leading to higher costs > for > manufacturers. > > What will happen if I mix and match different manufacturers' hardware > together? > > If the components are category 6 compliant, then you will be assured of > category 6 performance. _______________________________________________ clug-talk mailing list [email protected] http://clug.ca/mailman/listinfo/clug-talk_clug.ca Mailing List Guidelines (http://clug.ca/ml_guidelines.php) **Please remove these lines when replying
