Network Cable Management Techniques
You must be familiar with all of the various types of cable to which a server and home network devices may be connected and the capabilities and shortcomings of these media types.
Copper Cable
Copper cabling uses electrical signals to represent the ones and zeroes in a transmission. The most common type of copper cabling in use is twisted pair cabling. There are two primary types of twisted pair cabling: shielded twisted pair (STP) and unshielded twisted pair (UTP). In both cases, the cabling consists of pairs of wires twisted around each other.
Twisted pair cabling is a type of wiring in which two conductors of a single circuit are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources; for instance, electromagnetic radiation from unshielded twisted pair (UTP) cables, and crosstalk between neighboring pairs. The UTP cable offers no shielding (hence the name) and is the network cabling type most prone to outside interference.
Crossover and Straight Through
While any twisted pair cable can be called a patch cable, there are actually three types of patch cables they are different in the way in which they are wired and in the situation in which they are required, and these cables come in specifications called categories used to describe their capabilities.
Two wiring standards are commonly used with twisted-pair cabling: T568A and T568B (sometimes referred to simply as 568A and 568B). These are telecommunications standards from TIA and EIA that specify the pin arrangements for the RJ-45 connectors on UTP or STP cables. The number 568 refers to the order in which the wires within the Category 5 cable are terminated and attached to the connector. The signal is identical for both. The cable color code is the 568B standard on each end of a straight-through 10/100BaseT cable. If a crossover cable is needed, use the 568A standard on one end and 568B on the other end. Use a straight thru cable assembly, 568B on both ends when connecting Hub to NIC Card. When connecting hub to hub or NIC to NIC, the wires must crossover at the opposite end of the cable assembly, use the 568B on one end, 568A on the other end.
Crossover cables are used to connect like devices, while straight-through cables are used to connect dissimilar devices. For example, to connect a router to another router or a switch to another switch, use a crossover cable. To connect a router to a switch or a computer to a switch, use a straight-through cable. Auto MDI-X ports on newer network interfaces detect if the connection would require a crossover, and automatically chooses the [shadow=blue][tooltip=A medium dependent interface describes the interface both physical and electrical in a computer network from a physical layer implementation to the physical medium used to carry the transmission. Ethernet over twisted pair also defines a medium dependent interface crossover MDI-X interface. ]medium dependent interface [/tooltip](MDI)[/shadow] or MDI-X configuration to properly match the other end of the link.
Rollover Cable
A rollover cable is a cable using a completely reversed wiring pattern. It is used to connect to a router, switch, or access point console port to manage the device using a HyperTerminal application.
Category 5 cable
Category 5 cable, commonly referred to as Cat 5, is a twisted pair cable for carrying signals. Category 5 cabling transmits data at speeds up to 100 Mbps and is used with Fast Ethernet (operating at 100 Mbps) with a transmission range of 100 meters. The cable standard provides performance of up to 100 MHz and is suitable for 10BASE-T, 100BASE-TX (Fast Ethernet), 1000BASE-T (Gigabit Ethernet), and 2.5GBASE-T. The specifications for 10BASE-T networking specify a 100-meter length between active devices. This allows for 90 meters of solid-core permanent wiring, two connectors and two stranded patch cables of 5 meters, one at each end. Although it had its share of popularity (it’s used primarily for 10/100 Ethernet networking), it is now an outdated standard. Newer implementations use the Cat 5e standard.
Category 5e cable
CAT5e cabling transmits data at speeds up to 1 Gbps (1000 Mbps). Category 5e cabling can be used up to 100 meters, depending on the implementation and standard used, and it provides a minimum of 100 MHz of bandwidth. It also contains four twisted pairs of copper wire, but they’re physically separated and contain more twists per foot than Category 5 to provide maximum interference protection.
Category 6 cable
Category 6 cable, commonly referred to as Cat 6, is a standardized twisted pair cable for Ethernet and other network physical layers that is backward compatible with the Category 5/5e and Category 3 cable standards. CAT6 cabling transmits data at speed up to 10 Gbps, has a minimum of 250 MHz of bandwidth, and specifies cable lengths up to 100 meters (using CAT6a). Whereas Category 6 cable has a reduced maximum length when used for 10GBASE-T, Category 6A cable (or Augmented Category 6) is characterized to 500 MHz and has improved alien crosstalk characteristics, allowing 10GBASE-T to be run for the same 100 meter distance as previous Ethernet variants. Category 6 cable typically consists of four twisted pairs of copper wire, but its capabilities far exceed those of other cable types. Category 6 twisted pair uses a longitudinal separator, which separates each of the four pairs of wires from each other and reduces the amount of crosstalk possible.
Fiber Optic Cable
An optical fiber cable is a cable containing one or more optical fibers that are used to carry light. An optical fiber (or optical fibre) is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Because fiber-based media use light transmissions instead of electronic pulses, such problems as EMI and crosstalk become nonissues. It is the most secure of all cable media. It does have distance limitations based on the mode in use and the cable type. Two types of fiber-optic cable are available: single-mode and multimode. As the name implies, single-mode uses a single direct beam of light, thus allowing for greater distances and increased transfer speeds. With multimode, a lot of light beams travel through the cable, bouncing off the cable walls; this weakens the signal, reducing the length that the data signal can travel.
Below table lists the speed and transmission limitations for the most common fiber-optic implementations.
Copper Cable
Copper cabling uses electrical signals to represent the ones and zeroes in a transmission. The most common type of copper cabling in use is twisted pair cabling. There are two primary types of twisted pair cabling: shielded twisted pair (STP) and unshielded twisted pair (UTP). In both cases, the cabling consists of pairs of wires twisted around each other.
Twisted pair cabling is a type of wiring in which two conductors of a single circuit are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources; for instance, electromagnetic radiation from unshielded twisted pair (UTP) cables, and crosstalk between neighboring pairs. The UTP cable offers no shielding (hence the name) and is the network cabling type most prone to outside interference.
Crossover and Straight Through
While any twisted pair cable can be called a patch cable, there are actually three types of patch cables they are different in the way in which they are wired and in the situation in which they are required, and these cables come in specifications called categories used to describe their capabilities.
Two wiring standards are commonly used with twisted-pair cabling: T568A and T568B (sometimes referred to simply as 568A and 568B). These are telecommunications standards from TIA and EIA that specify the pin arrangements for the RJ-45 connectors on UTP or STP cables. The number 568 refers to the order in which the wires within the Category 5 cable are terminated and attached to the connector. The signal is identical for both. The cable color code is the 568B standard on each end of a straight-through 10/100BaseT cable. If a crossover cable is needed, use the 568A standard on one end and 568B on the other end. Use a straight thru cable assembly, 568B on both ends when connecting Hub to NIC Card. When connecting hub to hub or NIC to NIC, the wires must crossover at the opposite end of the cable assembly, use the 568B on one end, 568A on the other end.
Crossover cables are used to connect like devices, while straight-through cables are used to connect dissimilar devices. For example, to connect a router to another router or a switch to another switch, use a crossover cable. To connect a router to a switch or a computer to a switch, use a straight-through cable. Auto MDI-X ports on newer network interfaces detect if the connection would require a crossover, and automatically chooses the [shadow=blue][tooltip=A medium dependent interface describes the interface both physical and electrical in a computer network from a physical layer implementation to the physical medium used to carry the transmission. Ethernet over twisted pair also defines a medium dependent interface crossover MDI-X interface. ]medium dependent interface [/tooltip](MDI)[/shadow] or MDI-X configuration to properly match the other end of the link.
Rollover Cable
A rollover cable is a cable using a completely reversed wiring pattern. It is used to connect to a router, switch, or access point console port to manage the device using a HyperTerminal application.
Category 5 cable
Category 5 cable, commonly referred to as Cat 5, is a twisted pair cable for carrying signals. Category 5 cabling transmits data at speeds up to 100 Mbps and is used with Fast Ethernet (operating at 100 Mbps) with a transmission range of 100 meters. The cable standard provides performance of up to 100 MHz and is suitable for 10BASE-T, 100BASE-TX (Fast Ethernet), 1000BASE-T (Gigabit Ethernet), and 2.5GBASE-T. The specifications for 10BASE-T networking specify a 100-meter length between active devices. This allows for 90 meters of solid-core permanent wiring, two connectors and two stranded patch cables of 5 meters, one at each end. Although it had its share of popularity (it’s used primarily for 10/100 Ethernet networking), it is now an outdated standard. Newer implementations use the Cat 5e standard.
Category 5e cable
CAT5e cabling transmits data at speeds up to 1 Gbps (1000 Mbps). Category 5e cabling can be used up to 100 meters, depending on the implementation and standard used, and it provides a minimum of 100 MHz of bandwidth. It also contains four twisted pairs of copper wire, but they’re physically separated and contain more twists per foot than Category 5 to provide maximum interference protection.
Category 6 cable
Category 6 cable, commonly referred to as Cat 6, is a standardized twisted pair cable for Ethernet and other network physical layers that is backward compatible with the Category 5/5e and Category 3 cable standards. CAT6 cabling transmits data at speed up to 10 Gbps, has a minimum of 250 MHz of bandwidth, and specifies cable lengths up to 100 meters (using CAT6a). Whereas Category 6 cable has a reduced maximum length when used for 10GBASE-T, Category 6A cable (or Augmented Category 6) is characterized to 500 MHz and has improved alien crosstalk characteristics, allowing 10GBASE-T to be run for the same 100 meter distance as previous Ethernet variants. Category 6 cable typically consists of four twisted pairs of copper wire, but its capabilities far exceed those of other cable types. Category 6 twisted pair uses a longitudinal separator, which separates each of the four pairs of wires from each other and reduces the amount of crosstalk possible.
Fiber Optic Cable
An optical fiber cable is a cable containing one or more optical fibers that are used to carry light. An optical fiber (or optical fibre) is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Because fiber-based media use light transmissions instead of electronic pulses, such problems as EMI and crosstalk become nonissues. It is the most secure of all cable media. It does have distance limitations based on the mode in use and the cable type. Two types of fiber-optic cable are available: single-mode and multimode. As the name implies, single-mode uses a single direct beam of light, thus allowing for greater distances and increased transfer speeds. With multimode, a lot of light beams travel through the cable, bouncing off the cable walls; this weakens the signal, reducing the length that the data signal can travel.
Below table lists the speed and transmission limitations for the most common fiber-optic implementations.
- The 100BaseFX speed is 100Mbps, distance (multimode) 412 meters and distance (single mode) 10,000 meters.
- The 1000BaseSX speed is 1000 Mbps, distance (multimode) 220 to 550 meters and distance (single mode) not used.
- The 1000BaseLX speed is 1000 Mbps, distance (multimode) 550 meters and distance (single mode) 5 km.
- The 10GBaseER speed is 10,000 Mbps, distance (multimode) not used and distance (single mode) 40 km.