Ethernet Cabling

Question 1

Copper Cable

Answer 1

• Cable between two nodes creates low voltage circuit between node interfaces
• Two main types: Twisted Pair and Coaxial
• Suffers from high attenuation, signal is lost quickly over long links
• Twisted Pair is rated to Cat standards

Question 2

Fiber Optic Cable

Answer 2

• Carries high frequency radiation in infrared light
• Not affected by interference from other sources
• Less attenuation
• Supports higher bandwidth and longer distances than copper
• Divided into Single Mode (SMF) and MultiMode (MMF)

Question 3

802.3 Ethernet Standards

Answer 3

• Assure network cabling will meet bandwidth requirements of applications
• Specify bit rate achieved over different media to supported distance
• Uses 3 part conventions: xBASE-y, which describes:

The bit rate in megabits per second (Bbps) or gigabits per second (Gbps)
The signal moda (Base or broadband). All mainstream types of ethernet use baseband, so you will likely only see xBASE-y
A designator for media type

10BASE-T denotes 10Mbps, Baseband signal and runs of Twisted pair copper cabling (T)

Question 4

Multiple Access Area Network

Answer 4

• Communications capacity is shared between the nodes that are connected on same media.

Question 5

MAC

Answer 5

Media Access Control
- The methods a network technology uses to determine when nodes can communicate on shared media and how to deal with problems

Question 6

Collision Domain

Answer 6

• Each network node connected to same media is in same collision domain
• When two nodes transmit at same time signals “collide” and neither reach destination.
• They must be resent, which reduces bandwidth
• More nodes increased collisions and reduces effective data rate

Question 7

CSMA/CD

Answer 7

Collision Sense Multiple Access/ Collision Detection

• On detecting a collision, node broadcasts jam signal
• Each node then waits a randomized amount of time before retransmitting
• Collision detection means only half-duplex transmission is possible(node can transmit or receive, but not both at the same time)

Question 8

Fast Ethernet Standard

Answer 8

• Uses same CSMA/CD as 10BASE-T but with higher frequency and better encoding methods
• This raises bit rate to 100Mbps
• 100BASE-TX refers to Fast Ethernet working over Cat 5 or better Twister Pair with max length of 100 meters
• Not deployed on new networks

Question 9

Gigabit Ethernet

Answer 9

• Over copper, specified as 1000BAS-T over Cat 5e or better
• Does not support hubs, only switches
• Max distance 100m
• Mainstream choice for new networks
• Main decision is to use copper or fiber

Question 10

10 Gigabit Ethernet

Answer 10

10GbE

• Because of higher frequency, can only run over UTP at reduced distances
• Can be run further on higher Cat of cable
• Not deployed in standard networks, sometimes used for TV or film production
• UTP(Cat )(55m)
• Cat 6A (100m)
• Cat 7 (100m)

40GBASE-T
- Cat 8 (30m)

Question 11

Encoding

Answer 11

• modulation in a carrier wave to transmit digital information
• More bandwidth in the media, greater amount of data that can be encoded