Cisco ICND1 Flashcard: Cables and Fiber, Ethernet LAN Connectors

Quiz: Match the type of wiring with the distance
1000BaseCX - copper shielded twisted pair
1000BaseT - that's Cat 5 or 6, four pair UTP
1000BaseSX - that's 780nm laser, 62.5-50micron cores
1000BaseLX - that's 1300nm laser, 9 micron core

(25m, 100m, 250m, 10km)

NIC
An Ethernet NIC (network interface card) is a LAN adapter, which operates both as a Layer 1 (physical layer) and Layer 2 (data-link layer) device, and contains a physical MAC address used in the Layer 2 addressing.

The distance requirements and data rates (available in 10 Mb/s Ethernet, 100 Mb/s Ethernet and 1 Gb/s Ethernet)  will determine the media to use, and the connectors as well.  For example, an RJ-45 connector (has 4 pairs so 8 conductors) is commonly used for unshielded twisted pair (UTP) cable Cat 5. However GigE (Gigabit Ethernet) required Cat 5e (I've heard guyz refer to this as Cat 7 but I believe Cat 5e is the more correct term).

Cables (Copper)
There are two types of Ethernet connection media, copper unshielded twisted pair and fiber optic.
Categories of UTP Cables used for networks at speeds:

• Category 1: telephone, not for data
• Category 2: data transmission up to 4 Mb/s
• Category 3: 10BASE-T, transmit data up to 10 Mb/s
• Category 4: token ring, transmit data up to 16 Mb/s
• Category 5: transmit data up to 100 Mb/s
• Category 5e: transmit data up to 1000 Mb/s (1 Gb/s)
• Category 6: aka thick ethernet, consists of four pairs of 24-gauge copper wires, transmit data up to 1000 Mb/s

When to use a straight through cable or a crossover cable?

Use a Straight-though cable for joining dissimilar equipment together (the switch will do the crossing):

• Switch to router
• Swtich to PC or server
• Hub to PC or server

Use a Crossover cable to connect similar equipment together

• Switch to switch
• Switch to hub
• Hub to hub
• Router to router
• Router Ethernet port to PC NIC
• PC to PC

Fiber Optic  

There are a variety of Fiber Optic Connector tips, but the most common ones I see are
Straight Tip (ST): barrel shaped connector like a BNC, multimode fiber
Subscriber Connector (SC) or SC-Duplex: square face, push pull connection, single mode fiber
Lucent Connector (LC): small connector, popular for use with single mode, can support multimode

Single mode fiber has a single strand of glass, laser light, high bandwidth for longer distances.

Multimode fiber has several strands of glass, LED light, high bandwidth for medium distances.
2km for 100 Mb/s
550m for 1 Gb/s
300m for 10 Gb/s

GBIC
Cisco Fiber-Optic Gigabit Interface Converter (GBIC) is a hot swappable I/O device for the Gigabit Ethernet port in a router; means that other 1000BASE-X can be deployed without having th change the physical interface, or model of router and switch. GBIC can support UTP (copper) and fiber optics.

A fiber optic GBIC is a transciever, by converting serial electric currents to optical signals, and then the optical signals are converted to digital electric currents. Here are three main types:

• Short wavelenth (1000Base-SX)
• Long wavelenth or long haul (1000Base-LX/ LH)
• Extended distance (1000Base-ZX)

I had to order a bunch of Cisco Fiber Optic SFPs and I made a summary list of what formats they came in, to order the correct one. They just slide into the GBIC card. Here are the main types of Cisco SFP, and respectively the application:

• Short haul (1000BASE-T; 1000BASE-SX): Cat 5 100m; multimode fiber to 550m or laser multimode (1km)
• Long haul (1000BASE-LX/LH): both fiber optic (10km) or multimode (550m)
• Long reach (1000BASE-EX, 1000BASE-ZX): single mode 40km; single mode 70 km
• 1000BASE-BX10-D/U: single mode 10km 

Decoding naming conventions.
The "10" refers to the speed, that is 10 Mb/s
"BASE" refers to baseband Ethernet
"T" is twisted Pair
"X" is fiber optic
"L" sounds long, like up to 10km
"S" seems short, like up to 250m
1000BASE-CX is GigE over copper, 25m

FUN FACTS from the Cable Guy
The original purpose of the Multimedia Cable Network Partners Ltd was to develop a product and system standard for providing data and future services on CATV plants.
Cable modems enable two-way high speed data transmission using the same coaxial lines that transmit cable TV.
Cable modems provide access speeds faster than leased lines with lower costs and easier installation.

Exam Quiz
What is the distance of 1000BaseSX?
This is multimode fibre using 62.5 to 50 micron core, 780 nm laser up to 260m

What is needed for Fast Ethernet?
How to run full duplex Ethernet - have two 10 Mbps or 100 Mbps paths, two full duplex compatible NICs, loopback disabled, collision detection disabled, corect software drivers to support two simulataneous data paths, see Ethernet distances

Distance limitation for Cat 5 cabling.
Approximately 100 m or 300 ft.

Distance for T1 cabling, Layer 1 Troubleshooting - about 655 feet.
conf t
controller t1 0

Issue the cablelength long controller configuration command in order to configure transmit and receive levels for a cable length (line build-out) longer than 655 feet for a T1 trunk with a channel service unit (CSU) interface. Issue the cablelength short controller configuration command in order to configure transmit attenuation for a cable length (line build-out) of 655 feet or shorter for a T1 trunk with a DSX-1 interface.