© 2015 Falls Connect. Web Design by Proving Strike.

330.289.5635

Network Cable Types

 

There are three primary types of network cabling. They are Twisted Pair, Coaxial, and Fiber Optic. Each type is suited to specific applications and network topologies.

 

 

Twisted Pair


Twisted pair has become the most popular network cabling media today. Twisted pair cabling is used in a star or star tree topology for Ethernet networks. Maximum number of network devices is 1,024, with a maximum cable length of 100 meters for individual devices and a total distance of 500 meters of cabling between the furthest two devices, including links between data closets. The signal from a network hub can be repeated three times, giving you a maximum of four data closets. The distance between closets can be extended by switching to a star bus topology and using fiber optic cable for links between closets.

 

 

Category 3


In the beginning of twisted pair technology, some networks were set up utilizing spare pairs on existing phone systems or cabled with Category 3. These networks are only capable of 10 BASE T (10 megabits per second) data transfer, and most of them set up on spare pairs of existing phone wiring ran far slower than that. These networks have been obsolete for some time and cannot match the network speeds of today. New Category 3 should only be installed for phone systems.

 

 

Category 5


The predominant type of twisted pair installed in the majority of commercial buildings is unshielded Category 5. It is most commonly used for 100 BASE T Ethernet networks, giving data transfer rates of 100 megabits per second. In addition, the IEEE has approved a network standard for 1000 BASE T Ethernet networks (data transfer of 1,000 megabits per second) which can utilize most existing Category 5 cabling when it has been properly installed and certified. In addition to unshielded Category 5, there is also a shielded version, which provides some protection against electromagnetic interference. A typical application might be for a heavy manufacturing plant where interference from large electric motors could present a problem. For the vast majority of existing offices and most small industrial plants, unshielded Category 5 is the most commonly found cable.

 

 

Category 5e


Over the last several years, Category 5e has become the replacement for Category 5. There are two main types, known as “Little e” and “Big E”, capable of 155 and 350 megabit transmission respectively.  Although there are no network standards to support these speeds, the increased bandwidth does enhance this cable’s ability to run gigabit Ethernet. With the price drop of Category 5e over the last few years, it has become the most common choice for new network installation. 

 

 

Category 6


With the ever increasing speed of networks today, Category 6 is becoming more common in new office installations that demand reliable gigabit network speed. Although Category 6 will cost about $20 per run more on average, it is a viable choice today for a new network installation in a commercial space where the tenants plan to stay for an extended length of time. In addition, gigabit switches and network cards are also beginning to drop in price, so the cost of the hardware necessary to set up a true gigabit network is becoming less expensive as well.

 

Advantages

  • Reasonable cost

  • High Speed

  • Easy to add additional network devices

  • Supports large number of network devices

 

Disadvantages

  • High attenuation (signal loss) limits individual runs to 100 meters

  • Susceptible to EMI/RFI (except shielded type)

 

 

Coaxial Cable


Coaxial cable is gradually becoming obsolete due to speed limitations of 10 megabits per second. However, it is still a reliable media for small 10 BASE T networks, in addition to having some unique characteristics that make it a good choice for a few special circumstances.


The most common type of coaxial data cable in use today is RG-58 Thin Net. It is used in a bus topology for 10 BASE T Ethernet networks. There can be a maximum of five segments, each segment can support up to twenty devices and cannot exceed 608 feet in length. In addition, only three of the segments can support devices. The other two segments must be linking segments, with repeaters used to boost the signal between segments. Due to the greater length possible with RG-58 segments, it is sometimes used in a star bus topology to link closets where trying to use twisted pair for a link would exceed the distance limitation of 328 feet. The braided shielding of RG-58 also makes it a decent choice where EMI/RFI is a problem. RG-58 can (and should) be grounded at one end, which makes it a somewhat better choice for linking buildings than twisted pair, although not nearly as good as fiber optic.

 

Advantages

  • Low cost due to less total footage of cable, hubs not needed

  • Lower attenuation than twisted pair

  • Good immunity to EMI/RFI

 

Disadvantages

  • Limited in network speed

  • Limited in size of network

  • One bad connector can take down entire network

 

 

Fiber Optic


Data transmission over optical fiber has greatly increased over the last few years, although fiber to the desktop has not really caught on as expected. However, fiber optic plays an important role in many networks. In addition, it has some outstanding advantages over copper cabling for certain applications. There are a number of network topologies and standards based on fiber optic, such as 10 BASE FL and FDDI, which apply mainly to the backbone cabling of very large facilities and campus environments. The discussion will be limited here to the uses of fiber optic in star bus Ethernet network topologies.

 

When used as a link in a star bus topology, multi-mode fiber optic cable can transmit a maximum distance of 2,000 meters between all data closets, using a less expensive LED light source. While single mode fiber can transmit up to 3,000 meters, it requires a more expensive laser light source. By using fiber optic to link closets, it is possible to greatly extend the distance limitations in Ethernet networks using twisted pair only. Fiber optic is an outstanding choice for linking buildings together. In addition to the much greater distances possible, it is completely immune to over currents from lightning strikes and to ground potential problems. There is literally nothing metallic in a fiber optic cable to conduct current. It is an excellent choice for heavy manufacturing environments, such as a foundry, due to its immunity to EMI/RFI. Finally, it is the best choice where data of a highly sensitive nature is being transmitted. All copper cabling radiates a signal to a certain degree, making it at least possible for someone with sophisticated enough equipment to electronically eavesdrop. Fiber optic cable radiates no electrical signal at all, and the cable would be down for quite some time if someone tried to splice into it.

 

Advantages

  • Very high speed

  • Very low attenuation

  • Completely immune to EMI/RFI, over current, lightning strike

  • Cannot electronically eavesdrop

 

Disadvantages

  • Most expensive type of cable

  • Most difficult type of cable to install

  • Network hardware more expensive

 

 

Choosing the correct type of cabling depends on what type of network you have or intend to have, the number of network devices used, expected future growth, the speed requirements of your applications and the physical layout of your facility. Make this decision with the assistance of a professional, licensed and insured network cabling company and a good information technology consultant.