| Today's bandwidth expectations mean that Category | | | | and may be difficult to attach to 8P8C connectors |
| 5 is strategically dead. The Category 5 Enhanced (5e) | | | | without a special modular piece and are technically |
| standards, which should have been ratified in August | | | | not standard compliant. If components of the various |
| and may be finalized at November's committee | | | | cable standards are intermixed, the performance of |
| meeting, specify new measurements that provide | | | | the signal path will be limited to that of the lowest |
| more margins for 100BaseTX and ATM-155 traffic. | | | | category. As with all cables defined by TIA |
| Critically, Category 5e standards make reliable Gigabit | | | | EIA-568-B, the maximum allowed length of a Cat-6 |
| Ethernet connections possible. But many structured | | | | horizontal cable is 90 meters (295 feet). A complete |
| cabling suppliers argue that Category 5e is only an | | | | channel (horizontal cable plus cords on either end) is |
| interim solution on the road to Category 6, which will | | | | allowed to be up to 100 meters in length, depending |
| support at least 200 MHz; in the interests of | | | | upon the ratio of cord length: horizontal cable length. |
| sufficient operating margin, the IEEE is requesting a | | | | The cable is terminated in either the T568A scheme |
| 250-MHz Category 6 specification. Despite the fact | | | | or the T568B scheme. It doesn't make any |
| that the Category 6 standards are only at draft | | | | difference which is used, as they are both straight |
| stage, manufacturers are offering a host of products | | | | through (pin 1 to 1, pin 2 to 2, etc). Mixed cable types |
| and claiming that these products comply with the | | | | should not be connected in serial, as the impedance |
| draft proposals. What is a category 6 cable? Out of | | | | per pair differs and would cause signal degradation. |
| the three cable categories (Cat-5, Cat-5e & Cat-6), | | | | To connect two Ethernet units of the same type |
| Category 6 is the most advanced and provides the | | | | (PC to PC, or hub to hub, for example) a cross over |
| best performance. Just like Cat 5 and Cat 5e, | | | | cable should be used, though some modern hardware |
| Category 6 cable is typically made up of four twisted | | | | can use either type of cable automatically. Return |
| pairs of copper wire, but its capabilities far exceed | | | | loss measures the ratio of reflected-to-transmitted |
| those of other cable types because of one particular | | | | signal strength and is the single most difficult test to |
| structural difference: a longitudinal separator. This | | | | repeat with consistent results; at Category 6 levels, |
| separator isolates each of the four pairs of twisted | | | | the difference between a pass and a fail can be the |
| wire from the others, which reduces crosstalk, allows | | | | amount of bend in a test cord. Return loss is also |
| for faster data transfer, and gives Category 6 cable | | | | causing headaches for connector manufacturers, |
| twice the bandwidth of Cat 5! Cat 6 cable is ideal for | | | | because the RJ-45 system isn't up to the job. The |
| supporting 10 Gigabit Ethernet, and is able to operate | | | | final stumbling block with Category 5e ratification |
| at up to 250 MHz. Since technology and standards | | | | concerns the RJ-45 hardware; Category 6 is |
| are constantly evolving, Cat 6 is the wisest choice of | | | | committed to RJ-45 for backward compatibility, but |
| cable when taking any possible future updates to | | | | the ISO's proposed Category 7 system will have a |
| your network into consideration. Not only is Category | | | | new and as-yet-unspecified connector to accompany |
| 6 cable future-safe, it is also backward-compatible | | | | its revised cabling. Today, the return loss problem |
| with any previously-existing Cat 5 and Cat 5e cabling | | | | explains why manufacturers of Category 6 hardware, |
| found in older installations. Category 6, (ANSI/TIA | | | | which is supposed to be interoperable, claim Category |
| EIA-568-B.2-1) is a cable standard for Gigabit Ethernet | | | | 6 performance only if you use the manufacturers' |
| and other network protocols that is backward | | | | matched parts throughout a channel link. The |
| compatible with the Category 5, category 5e and | | | | Telecommunications Industry Association (TIA) is |
| Category 3 cable standards. Cat-6 features more | | | | working to complete a new specification that will |
| stringent specifications for crosstalk and system | | | | define enhanced performance standards for |
| noise. The cable standard is suitable for 10BASE-T / | | | | unshielded twisted pair cable systems. Draft |
| 100BASE-TX and 1000BASE-T (Gigabit Ethernet) and | | | | specification ANSI/TIA/EIA-568-B.2-10 specifies cable |
| is expected to suit the 10000BASE-T (10Gigabit | | | | systems, called "Augmented Category 6" or more |
| Ethernet) standards. It provides performance of up | | | | frequently as "Category 6a", that operates at |
| to 250 MHz. The cable contains four twisted copper | | | | frequencies up to 500 MHz and will provide up to 10 |
| wire pairs, just like earlier copper cable standards. | | | | Gbit/s bandwidth. The new specification has limits on |
| Although Cat-6 is sometimes made with 23 gauge | | | | alien crosstalk in cabling systems. Augmented |
| wire, this is not a requirement; the ANSI | | | | Category 6 specifies cable operating at minimum |
| TIA-568-B.2-1 specification states the cable may be | | | | frequency of 500 MHz, for both shielded and |
| made with 22 to 24 AWG gauge wire, so long as the | | | | unshielded. It can support future 10 Gb/s applications |
| cable meets the specified testing standards. When | | | | up to the maximum distance of 100 meters on a |
| used as a patch cable, Cat-6 is normally terminated in | | | | 4-connector channel. |
| 8P8C often incorrectly referred to as "RJ-45" | | | | Information on hypoallergenic cat food can be found |
| electrical connectors. Some Cat-6 cables are too large | | | | at the Hypoallergenic Diet site. |