Network Cables
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- Category: Network Technology
- Published on Friday, 26 September 2008 13:19
- Written by Administrator
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Types Of Network Cables
Category 1 cable (Cat 1) a.k.a. voice-grade copper is a misnomer, probably adopted by those who assumed that TIA set up "Categories" for all types of cables originally defined by Anixter, the distributor, under the grades called "Levels." TIA-568 only recognized cables of Category 3 ratings or above. Anixter "Level 1" was a grade of unshielded twisted pair cabling designed for telephone communications, and was the most common on-premises wiring.
Category 2 cable, or simply Cat 2, is a misnomer, probably adopted by those who assumed that TIA set up "Categories" for all types of cables originally defined by Anixter, the distributor, under the grades called "Levels." TIA-568 only recognized cables of Category 3 ratings or above. Anixter "Level 2" was a grade of UTP cable capable of transmitting data at up to 4 Mbit/s. Cat 2 cable was frequently used on ARC net and 4 Mbit/s token ring networks, but it is no longer commonly used.
Category 3 cable, commonly known as Cat 3, is an unshielded twisted pair (UTP) cable designed to reliably carry data up to 10 Mbit/s, with a possible bandwidth of 16 MHz. It is part of a family of copper cabling standards defined jointly by the Electronic Industries Alliance and the Telecommunications Industry Association.
Category 3 was a popular cabling format among computer network administrators in the early 1990s, but fell out of popularity in favor of the very similar, but higher performing, Cat 5 standard. Presently, most new structured cable installations are built with Cat 5e or Cat 6 cable. Cat 3 is currently still in use in two-line telephone systems, and can easily be adapted to run VoIP (as long as you create a dedicated LAN for your VoIP telephone sets). While Cat 5 or higher is often recommended for VoIP, the reality is that the 10 Mbit/s bandwidth a cat 3 network can provide is far more than the 0.08 Mbit/s a VoIP phone needs at full load, and Cat 3 is even compatible with 802.3af PoE.
Note that unlike Cat 1, 2, 4, and 5 cables, Cat 3 is still recognized by TIA/EIA-568-B, its defining standard.
The newer 100BASE-T4 standard, which achieves speeds of 100 Mbit/s by using all 4 pairs of wires, allowed older Cat 3 based infrastructures to achieve a much higher bandwidth.
Category 5 cable, commonly known as Cat 5 or "Cable and Telephone", is a twisted pair cable type designed for high signal integrity. Many such cables are unshielded but some are shielded. Category 5 has been superseded by the Category 5e specification. This type of cable is often used in structured cabling for computer networks such as Ethernet, and is also used to carry many other signals such as basic voice services, token ring, and ATM (at up to 155 Mbit/s, over short distances
The Cat 5 cables are commonly used as Patch Cables ;
Patch cable or patch cord (sometimes patch cable or patch cord) is an electrical or optical cable, used to connect ("patch-in") one electronic or optical device to another for signal routing. Devices of different types (i.e.: a switch connected to a computer, or switch to router) are connected with patch cords. Patch cords are usually produced in many different colors so as to be easily distinguishable, and are relatively short, perhaps no longer than two meters. Types of patch cords include microphone cables, headphone extension cables, XLR connector, RCA connector and ¼" TRS connector cables (as well as modular Ethernet cables), and thicker, hose-like cords (snake cable) used to carry video or amplified signals. However, patch cords typically only refer to those short ones used with patch panels.
Patch cords can be as short as 3 inches or 8 cm, to connect stacked components, or route signals through a patch bay, or as much as twenty feet or 6 m or more in length for snake cables. As length increases, cables are usually thicker, and/or made with more shielding, to prevent signal loss (attenuation) and the introduction of unwanted radio frequencies and hum (electromagnetic interference).
Patch cords are often made of coaxial cables, with a positive or "hot" signal carried through a shielded core, and the negative electrical ground or earthed return connection carried through a wire mesh surrounding the core. Each end of the cable is attached to a connector, so the cord may be plugged in. Types of connectors may vary widely, particularly with adapting cables.
Patch cords may be:single-conductor wires using, for example, banana connectors coaxial cables using BNC connectors Ethernet Cat5, Cat5e, or Cat6 cables using "RJ-45" connectors with TIA/EIA-568-A or TIA/EIA-568-B wiring Optical fiber cables .
Category 5
The specification for category 5 cable was defined in ANSI/TIA/EIA-568-A, with clarification in TSB-95. These documents specified performance characteristics and test requirements for frequencies of up to 100 MHz.
Category 5 cable includes four twisted pairs in a single cable jacket. This use of balanced lines helps preserve a high signal-to-noise ratio despite interference from both external sources and other pairs (this latter form of interference is called crosstalk). It is most commonly used for 100 Mbit/s networks, such as 100BASE-TX Ethernet, although IEEE 802.3ab defines standards for 1000BASE-T - Gigabit Ethernet over category 5 cable. Cat 5 cable typically has three twists per inch of each twisted pair of 24 gauge copper wires within the cable.
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