CIS 3580 - Chapter 4 Study Guide
What are some of the elements defined by the TIA/EIA 568A standard?
- Cable type - Cable length - connectors - Cable transmission - Testing methods
How do wireless media carry electromagnetic signals?
- Carries signals over the air, (propagates over the air) - Represents binary digits using radio or microwave frequencies
What are the major concerns/limitations for wireless signals?
- Coverage area - interference - security - Shared medium
What are the 4 areas physical layer star nards are applied for wireless media?
- Data to radio signal encoding methods - Frequency and power transmission - Signal reception and decoding requirements
What areas usually implement fiber optic cabling?
- Enterprise networks - Fiber-to-home - Long haul networks
What are the organizations that are responsible for physical layer standards?
- ISO - EIA/TIA - ANSI - IEEE
Which medium uses Manchester encoding?
- Older forms of ethernet - RFID - Near Field Communication
What are the three fundamental functions of the Physical layer?
- Physical components - Encoding - Signaling
What type of materials can be used for fiber optic cabling?
- Pure glass - led/ laser
What are the other two types of copper cabling besides UTP?
- Shielded Twisted Pair (STP) - Coaxial Cable
Where would each type of fiber cable be found?
- Single fiber would be used for really long transmission - Multimode would be at distances up to 550 meters
What is the purpose of encoding?
- The purpose of encoding is to protect data and to compress it into smaller parts - Method of converting a stream of data bits into a predefined "code"
What are the 4 standards for wireless networks?
- Wi-fi (802.11) - Bluetooth (802.15) - Wimax (802.16) - Zigbee (802.15.4)
What colors represent types of fiber cable?
- Yellow ( single fiber) - orange ( multimode fiber)
What is the difference between throughput and goodput?
-> Throughput- The measure of the transfer of bits across the media over a given period of time -> Goodput- •The measure of usable data transferred over a given period of time -> Goodput = Throughput - traffic overhead (Practical Bandwidth)
Copper cable and fiber-optic cable are examples of _________ , which is used to carry the communication signal.
physical media
How do we measure bandwidth?
Bandwidth is measured in bits per second which is the capacity in which a medium can carry data.
What is done to the pairs of wires to minimize signal degradation due to electronic noise?
Cancellation and variation of twists. -Wires are twisted together in opposite polarities to cancel out EMI/ RFI frequencies -Wires are twisted at different feet, helps reduce crosstalk
What type of connector is commonly used in copper cabling?
Coaxial cable
What is a rollover used for?
Connecting a computers serial port to the console port of a router (with an adapter) Host serial port to router or switch
What are the three basic forms of media?
Copper, glass, air
What are the three measures for bandwidth quality?
Latency, Throughput, Goodput
What is a NIC and a WLAN NIC?
Network interface Card WLAN Network interface card
What does the physical layer provide?
Provides physical connection to local networks. Can be wired or wireless.
What are the other methods listed to limit the susceptibility of copper cables to electronic noise?
Shielding helps prevent
What is a signaling method?
Shows how the bit values 1's and 0's will be represented on a physical medium
What are the two types of fiber optic cables?
Single- mode fiber, and multimode fiber
What are the three types of Ethernet cables?
Straight-through crossover cable Rollover
Explain the process of encapsulation the physical layer performs.
The OSI physical layer provides the means to transport the bits that make up a data link layer frame across the network media. This layer accepts a complete frame from the data link layer and encodes it as a series of signals that are transmitted to the local media. The encoded bits that comprise a frame are received by either an end device or an intermediate device. The last part of the process, the bits are sent over the physical medium. The physical layer encodes the frames and creates the electrical, optical, or radio wave signals that represent the bits in each frame. These signals are sent over the media, one at a time. (Page 139)
What does the physical layer consist of?
The physical hardware ( NIC's)
What is crosstalk? What is used to limit crosstalk?
The variation in twists inside the UTP wires.
What changes in the twist from one pair of wires to the next pair to improve the limitation of crosstalk?
The variation of twists determines how good the limitation would be.
Are two cables needed to transmit and receive light signals? Why?
There could be two one for transmission and one for receiving
What is meant when I say fiber is used as a 'light pipe'?
Uses light to encode bits of information to be sent across thin strands of glass
What are the two network devices necessary to implement a wireless network?
WAP's and WLAN's
What are the properties of UTP cabling?
-UTP is the most common networking media. -Key Characteristics of UTP 1.The outer jacket protects the copper wires from physical damage. 2.Twisted pairs protect the signal from interference. 3.Color-coded plastic insulation electrically isolates the wires from each other and identifies each pair.
How are the bits of the frame transmitted by the physical layer?
1's and 0's Converts bits into format that is recognizable by next device
What are the components of a wireless access point?
1. The wireless antennas (which are embedded inside the router version) 2. Several Ethernet switchports 3. An internet port
What determines the practical bandwidth of a network?
Goodput
What is a crossover used for and when would I possibly need it?
Host to host, switch to switch, router to router.
What is a straight-through used for?
Host to network device such as a hub or switch
How do we represent digital information across a medium?
Isn't this just bandwidth?
