Cabling and Connectors

Cabling and Connectors

• - Different types of Cabling have different types of connectors

Fiber Cabling Connectors

• Fiber Cabling uses a range of connectors:
• ST Connectors: A straight tip connector has a long, straight, ceramic tip and uses a bayonet style locking system - you push and turn to lock. This type of cable supports single mode and multimode fiber cable. It is less susceptible to contact damage during installation than angled type connectors.
• SC Connectors: An SC connector has a square molded plastic plug casing with a push/pull locking system. It supports single mode and multimode fiber cable and is commonly used for data communication within networks.
• LC Connectors: Sometimes called little connectors, have largely replaced SC connectors. These connectors resemble small SC connectors but are elongated and not as wide. They support single mode and multimode fiber and are used for high data interconnection.

UTP Cabling Connectors

• - Registered Jack-45 or RJ-45 is designed for use with twisted pair cabling.
• - Takes one of two forms - Male or Female - Each of which includes 8 conductors
• - RJ-45 are used mainly in Ethernet networks and look like larger versions of RJ-11 telephone connectors.
• - RJ-11 or Registered Jack 11 is a four or six wire connector used to connect telephone lines. In computing environments it is commonly used to connect analog modems to a telephone line.
• - The ANSI/TIA/EIA 568 Standard define two termination methods for the RJ-45 Ethernet Connectors - T568A and T568B. Each of these specifies a which wire pairs connect to which pins in the connector.
• - Each wire pair in the conductors of a 4 pair data cable have insulators that are color coded, blue, orange, green and brown.
• - The first conductor in a wire pair is coded with a colour stripe around a white insulator. A solid color is used on the second conductor.
• - The main difference between T568A and T568B terminations is that the green and orange wire pairs are swapped.
• - Although its unclear which termination is more popular, US Government and TIA use T568A - You should avoid swapping between the two whilst on a network.

Slide 4

• Different Ethernet Standards use the wire pair differently...
• Ethernet & Fast Ethernet: Ethernet & Fast Ethernet use one wire pair in a cable to transmit data and another wire pair to receive data. They are known as the Transmit or TX and Receive or RX pair.
• Gigabit & 10Gb Ethernet: Transmit and receive data at the same time using all four wire pairs. This is accomplished using improved methods of signal encoding.

Crossover -

• - If an intermediate device like switch or hub connects two devices, it has to perform a crossover internally to connect the transmit pair of one of the devices to the receive pair of the other device.
• - You can use crossover cables to connect the same types of network devices, such as two switches or two hubs. You can even connect to end hubs to assist with trouble shooting.

Crossover Cables

• - Crossove cables are made from standard UTP Cable but have the connectors wired oppositely.
• - This allows the transmit pair of one connector to connect to the receiving pair of the other connector, without the need for an intermediate system.
• - Cable connection types can be automatically detected and configured using Auto-medium dependent interface, or Auto-MDIX, Capabilities.
• - For this reason, cross over cables aren't usually needed in modern twisted-pair Ethernet networks.

Coaxial Cable Connectors

• - A great deal of work has been done by test equipment measurement companies to develop smaller connectors for reliable performance in the millimeter and GHz waave ranges.
• - Consequently there are a wide variety of connectors available for use with the coaxial cable and its various applications, including audio, video, microwave, digital or radio frequency.
• - F series connectors were originally designed for cable television use and used for VHF, antenna television applications. They're also commonly used with satellite systems and cable modems.
• - F connectors are relatively cheap, and are used at an impedence of 75ohms in the 250Mhz to 1 Ghz. They usually have a threaded coupling.
• - Although push on versions are available, they suffer from poor shielding against airborne electrical interference.

BNC Connector

• - Originally created for military applications, the BNC connector is a common connector for use with coaxial cable. Its uses range from test instruments, to radio and television applications.
• - The BNC connector is known by a number of different names:
• - Bayonet Navy Connector
• - Baby Neil Connector
• - Bayonet Neil-Concelman
• BNC Connectors typically have a slotted outer connector with a bayonet fitting, but other types are also available. Each gender connector is fitted with a plastic insulator.
• You can use a variety of adaptors, including terminators, barrel connectors, and T-Connectors with BNC Connectors.
• BNC Connectors come in versions for both 50 & 75 ohm cable impedance. They're commonly used in RF and video applications below 3 GHz.
• If used above 4GHz, signal loss if often experienced. So although BNC connectors are useful up to 10GHz, they're potentially unstable at these frequencies.