Cable in which the center core, a glass cladding composed of varying layers of reflective glass, refracts light back into the core. Looks dramatically different from the twisted pair cable and coaxial cable described above. Maximum cable length is 25 kilometers and transmission rates are up to 2 Gbps. Fiber optic cable carries laser light encoded with digital signals, and is capable of reliably transmitting billions of bits of data per second, which compares very well with coaxial and twisted pair. It also offers greater security (much more difficult to tap), it emits no electromagnetic radiation, and is not affected by EM radiation. Fiber’s main disadvantage is its expense. The cable itself is more expensive to buy, more expensive to install, and since fiber optic techs command very high salaries, it is more expensive to maintain.
Click here to view an installation of fiber optic cable.
Click here to view a good close-up picture of fiber optic cable.
Here are other network cabling resources available on the web:
An
Excellent Gigabit Ethernet Page
Webopedia’s
list of cables and networking hardware
A
How-to Cable Web page
Ethernet
Cables and Accessories
This is a
commercial site with lots of great cable pictures
Very, very
good pictures of Ethernet cable and network implementation
A
Couple of Fiber Optic Tranceivers
And, uh, not to scare anyone – it’s not likely to turn up on the test –
but here’s a White
Paper on 10GB Ethernet and 10
Gigabit Ethernet Alliance Home Page
Stands for “Registered Jack-11.” This is a four-wire connector used mainly to connect telephone equipment in North America. An ordinary phone circuit uses two wires and the RJ-11 jack uses four. It’s easy to confuse the RJ-11 with the RJ-45 jack, which holds eight wires and is slightly larger. It's possible to find RJ-11 connectors linking network nodes in certain types of LANs, though RJ-45 connectors are far more common. However, the average modem uses an RJ-11 jack, so this connector does see use on a LAN.
Click here to view a photo of an RJ-11 connector (or unplug your telephone and have a close look).
RJ-45 connectors are used on 10base-T networks and are defined in IEEE 802.3. They are used to connect computers in LANs. If your computer is attached to a standard Ethernet network, pull out the cable and have a look. The RJ-45 is a single-line jack for digital transmission over ordinary phone wire, either untwisted or twisted. The interface has eight pins or positions. There are two varieties, keyed and unkeyed. The keyed type of plug has a small bump on its end and its proper receptacle has a matching slot. Both jack and plug must match.
Some RJ-45 connectors are vendor specific. For instance, Cisco products use the following three types of RJ-45 cables:
RJ-45 connectors also are popular outside of computer networking. They’re used in the type of digital phone systems you find in hotels and offices.
Click here to view a diagram of RJ-11 and RJ-45 interfaces.
Cisco’s
Cabling Guide for Console and Aux ports (RJ-45 mostly)
Cisco’s
Page of Cabling and Connectors
RJ-45
Pinouts
Awesome page with
RJ-45 Pinning Specifications
How to
Make a Patch Cable
How to Make Crossover Cable
How
to Crimp Your Own RJ-45 Cable
RJ-45
Connector Wire Colors