Definitions for Cat5, Cat5e, Cat6 and Cat7 Patch Cables and Patch Cords

Cat5 Patch Cables (UTP)
(Unshielded Twisted Pair)

A multipair (usually 4 pair) high performance patch cable that consists of twisted pair conductors, used mainly for data transmission. Note: The twisting of the pairs gives the patch cable a certain amount of immunity from the infiltration of unwanted interference. cat5 UTP cabling systems are by far, the most common (compared to SCTP) in the United States. Basic cat 5 cable was designed for characteristics of up to 100 MHz. Cat5 cable is typically used for Ethernet networks running at 10 or 100 Mbps.

Cat5e Patch Cables (enhanced)

Same as Cat5, except that it is made to somewhat more stringent standards (see comparison chart below). The Cat5e standard is now officially part of the 568A standard. Minimum Cat5e cable is recommended for all new installations, patch cords and Ethernet cables.

Cat6

Same as Cat5e, except that it is made to a higher standard (see comparison chart below) . The Cat6 standard is now officially part of the 568A standard. Cat6 Ethernet cables and patch cords are available as both off-the-shelf and as custom made products.

Cat7

Same as Cat6 patch cords, except that are made to a higher standard (see comparison chart below). The Cat7 standard is still in the works (as of this writing) and is not yet part of the 568A standard. One major difference with cat7 patch cables and patch cords (as compared with cat 5, cat5e, and cat6 patch cables) is that all 4 pairs are individually shielded, and an overall shield enwraps all four pairs. Cat7 patch cords will use an entirely new connector (other than the familiar RJ-45 used for cat 5, cat 5e and cat 6 patch cords).

Cat5 Cable (SCTP)
(Screened Twisted Pair)

Same as cat5 patch cables described above, except that the twisted pairs are given additional protection from unwanted interference by an overall shield. There is some controversy concerning which is the better system (UTP or SCTP). Cat5 SCTP Ethernet cables and patch cords require all components to maintain the shield, and are used almost exclusively in European countries.

Cat5e, RJ45 jack
(Work Area Outlet)

An 8 conductor, compact, modular, female jack that is used to terminate cat5e patch cables at the user (or other) location. The jack is specifically engineered to maintain the performance of cat5E cabling.

Cat5e Patch Panel

A Cat5e Patch Panel is basically just a series of many cat5e jacks, condensed onto a single panel. Common panel configurations are 12, 24, 48, and 96 ports. Patch panels are typically used where all of the horizontal Ethernet cables meet, and are used to connect the segments to the Network Hub.

Cat5e Patch Cable

A Cat5e Patch Cable consists a length of cat5e cable with an RJ-45 male connector, crimped onto each end. The patch cable assembly is used to provide connectivity between any two cat5e female outlets (jacks). The two most common are from hub to patch panel, and work area outlet (jack) to the computer.

EIA/TIA 568A Standard

This standard was published in July of 1991. The purpose of EIA/TIA 568A, was to create a multiproduct, multivendor, standard for connectivity. Prior to the adoption of this standard, many "proprietary" cabling systems existed. This was very bad for the consumer. Among other things, the standard set the minimum requirements for cat5e cable, patch cables/patch cords and network hardware. The 568 "standard" is not to be confused with 568A or 568B wiring schemes, which are themselves, part of the "568A standard".

568A and 568B Wiring Schemes

When we refer to a jack or a patch panel's wiring connection, we refer to either the 568A, or 568B wiring scheme, which dictates the pin assignments to the pairs of cat5e cable. It is very important to note that there is no difference, whatsoever, between the two wiring schemes, in connectivity or performance when connected form one modular device to another (jack to Patch panel, RJ-45 to RJ-45, etc.), so long as they (the two devices) are wired for the same scheme (A or B). The only time when one scheme has an advantage over the other, is when one end of a segment is connected to a modular device, and the other end to a punch block. In which case, the 568A has the advantage of having a more natural progression of pairs at the punch block side.

Four Pairs

Pair 1: White / Blue

Pair 3: White / Green

Pair 2: White / Orange

Pair 4: White / Brown

Wiremap

This is the most basic test that can be performed on a cat5e segment. Wiremap tests for the basic continuity between the two devices. In 568A or B, all eight pins of each device should be wired straight through (1 to 1, 2 to 2, 3 to 3, etc.). A wiremap (continuity) test, should also test for absence of shorts, grounding, and external voltage.

Crosstalk

Crosstalk is the "bleeding" of signals carried by one pair of the patch cord, onto another pair through the electrical process of induction (wires need not make contact, signals transferred magnetically). This is an unwanted effect, that can cause slow transfer, or completely inhibit the transfer of data signals over the patch cable. The purpose of the wire twists, in cat5e cable is to significantly reduce the crosstalk, and it's effects. Two types are: NEXT (Near End Crosstalk), and FEXT (Far End Crosstalk). Fiber Optic cable is the only medium that is 100% immune to the effects of crosstalk.

Ambient Noise or
Electromagnetic Interference (EMI)

Similar to crosstalk, in that it is an unwanted signal that is induced into the network cables and patch cords. The difference is that ambient noise (or EMI) is typically induced from a source that is external to the network cable. This could be an electrical cable or device, or even an adjacent cat5E patch cable.

Attenuation

Attenuation is the loss of signal in a network cable segment due to the resistance of the wire plus other electrical factors that cause additional resistance (Impedance and Capacitance for example). A longer network cable length, poor connections, bad insulation, a high level of crosstalk, or ambient noise, will all increase the total level of attenuation. The 568A standard, specifies the maximum amount of attenuation that is acceptable in a cat5e cable segment or patch cord.