Exam Two Study Guide Flashcards
What does the physical layer provide?
Responsible for the physical connection between devices. Handles the transmission of raw data, hardware components, signal encoding, data rates and synchronization.
What are the components of a wireless access point?
Radio transceivers, antennas, processor, memory RAM and ROM, power supply, ethernet ports, and firmware.
- What is a NIC and a WLAN NIC?
NICs operate at the data link layer and the physical layer of the OSI model, handling network protocols and data formatting for transmission over a network. Wired NIC connects to a network via Ethernet cables and a WLAN NIC uses radio waves instead of physical cables, emabling devices to connect to wireless access points and access networks without being physically tethered.
- Explain the process of encapsulation the physical layer performs.
Main role is to convert the data from the data link layer into electrical, optical, or radio signals that can travel over a physical medium.
- What are the three basic forms of media?
Copper cable (electrical media); fiber-optic cable (optical media); wireless (radio or electromagnetic media)
- What does the physical layer consist of?
hardware and transmission components that enable data transfer across a network. It handles the actual transmission of raw bits over a physical medium.
- What are the organizations that are responsible for physical layer standards?
- International Organization for Standardization (ISO)
- Institute of Electrical and Electronics Engineers (IEEE)
- International Telecommunication Union (ITU)
- American Standards Institute (ANSI)
- Electronic Industries Alliance (EIA)
- Telecommunications Industry Association (TIA)
- The four areas these organizations define and govern of the Physical layer standards?
Physical and electrical specifications, data transmission and signaling methods, media and bandwidth specifications, environmental and safety requirements
- What are the three fundamental functions of the Physical layer?
Bit transmission, physical topology, and signal encoding and modulation
- How are the bits of the frame transmitted by the physical layer?
Bit preparation, encoding, modulation, signal transmission, receiving signals, and decoding
- What is a signaling method?
Refers to the technique used to convey information over a communication channel by manipulating signals to represent data.
- How do we represent digital information across a medium?
Before transmission, digital information is encoded into a form suitable for the transmission medium. When transmitting digital information over certain types of media (especially wireless), modulation is used to adpat the digital signals to the medium. The encoded and modulated signals are then transmitted across the physical medium, and at the receiving end , the process is reversed.
- Which medium uses Manchester encoding?
Manchester encoding is particularly used in Ethernet networking technologies, especially for wired networks.
- How do we measure bandwidth?
Throughput (bps) = File Size (bits)/Transfer Time (seconds)
- What determines the practical bandwidth of a network?
Determined by a combination of the physicial medium, network equipment, protocols, traffic load, latency, configuration, and environmental factors.
- What are the three measures for bandwidth quality?
Throughput, latency, and jitter
- What is the difference between throughput and goodput?
Throughput refers to the total amount of data successfully transmited over a network in a given period, typically measured in bits per second (bps). Goodput refers to the actual usable data transmitted over a network in a given period, also measured in bits per second (bps).
- What type of connector is commonly used in copper cabling?
RJ45 is an 8-pin connector that is used primarily for Ethernet networking.
- What are the properties of UTP cabling?
UTP consists of pairs of wires twisted together, which reduces electromagnetif interference and crosstalk between pairs. The maximum distance for UTP cabling is generally up to 100 meters (328 feet)
- What is done to the pairs of wires to minimize signal degradation due to electronic noise?
Twisted Pair Configuration: each pair of wires is twisted together at a specific rates which helps to cancel out electromagnetic interference because the opposing magnetic fields generated by the current in the wires effectively neutralize each other. Proper pairing and color coding. Use of shieled twisted pair (STP), used in environments where electronic noise is a significant concern.
- What are the other methods listed to limit the susceptibility of copper cables to electronic noise?
Shielding, proper installation practices, high-quality materials, reducing loop areas, balancing pairs, grounding and bonding, and the use of ferrite beads.
- What is crosstalk? What is used to limit crosstalk?
Crosstalk occurs when a signal from one circuit or channel interferes with a signal in another nearby circuit or channel. Twisted pair design, shielding, balanced transmission, and highquality cables help to prevent crosstalk.
- What changes in the twist from one pair of wires to the next pair to improve the limitation of crosstalk?
Varying twist rate/length
- What are some of the elements defined by the TIA/EIA 568A standard?
Cable types, performance metrics, wireing schemes, installation pracices, and testing procedures.
- What are the three types of Ethernet cables?
Twisted pair cables, Coaxial cables, and fiber-optic cables.
- What is a straight-through used for?
a straight-through cable is a type of Ethernet cable used primarily to connect different types of network devices in a local area network (LAN). It is typically wired in a way that allows for communication between devices of different roles.
- What is a crossover used for and when would I possibly need it?
A crossover cable is a type of Ethernet cable specifically designed to connect similar devices directly without the need for an intermediary device like a switch or hub.
- What is a rollover used for?
Rollover cables are essential for network administrators when they need direct access to the console ports of networking devices for configuration, management, and troubleshooting.
- What are the other two types of copper cabling besides UTP?
Shielded Twisted Pair (STP), which adds shielding to reduce inteference, and Coaxial Cable, which has a central conductor and shielding designed for high-frequency signal transmission.
- What type of materials can be used for fiber optic cabling?
Fiber optic cabling utilizes glass (for both single-mode and multi-mode fibers) and plastic (for plastic optical fibers) as the primary materials for its core and cladding. Glass fibers are preferred for long-distance telecommunications due to their superior performance, while plastic fibers are valued for their flexibility and cost-effectiveness in short distance applications.
- What is the encoding method for fiber optic?
OOK is the simplest form of modulation used in fiber optics. In this method, the presence of light indicates a binary “1,” while the absence of light represents a binary “0.” This direct representation of data allows for straightforward signal transmission. In PPM, the data is represented by the position of a pulse in time. A pulse is transmitted within a defined time slot, and its position indicates the binary value being sent.FSK involves varying the frequency of the light signal to represent different data values. Different frequencies correspond to different binary values.
- What is meant when I say fiber is used as a ‘light pipe’?
it emphasizes its function of efficiently transmitting light signals over long distances through the principles of total internal reflection.
- What areas usually implement fiber optic cabling?
Fiber optic cabling is implemented across a wide range of areas, including telecommunications, internet service provision, data centers, healthcare, education, industrial applications, smart cities, and broadcasting. Its high bandwidth, low loss, and resistance to interference make it a preferred choice for modern communication and networking needs.
- Are two cables needed to transmit and receive light signals? Why?
While two separate cables are commonly used for transmitting and receiving light signals in traditional duplex fiber optic communication to facilitate simultaneous bidirectional communication, it is also possible to use a single fiber cable with techniques like Wavelength Division Multiplexing or Time Division Multiplexing. The choice between these approaches depends on the specific application requirements, cost considerations, and infrastructure constraints.
- What are the two types of fiber optic cables?
The two primary types of fiber optic cables are Single-Mode Fiber (SMF), designed for long-distance transmission with a small core, and Multi-Mode Fiber (MMF), suited for short-distance applications with a larger core.
- Where would each type of fiber cable be found?
Single-Mode Fiber (SMF) is primarily found in long-distance telecommunications, interconnecting data centers, campus networks, and fiber-to-the-home applications due to its capability to transmit data over long distances with low loss. Multi-Mode Fiber (MMF) is more commonly used in local area networks, within data centers for short-distance connections, in broadcasting applications, and in industrial automation settings.
- What colors represent types of fiber cable?
Single-Mode Fiber (SMF): Yellow
Multi-Mode Fiber (MMF): Orange (for OM1 and OM2) and Aqua (for OM3 and OM4).
OM5: Light Blue
- How do wireless media carry electromagnetic signals?
Wireless media carry electromagnetic signals by generating electromagnetic waves that propagate through the air. These signals are transmitted by devices that convert electrical signals into electromagnetic waves and are received by antennas or receivers that convert them back into electrical signals.
- What is the major concerns/limitations for wireless signals?
Interference, range limitations, security vulnerability, bandwidth limitations, signal attenuation, and latency
- What are the 4 standards for wireless networks?
- IEEE 802.11a: This standard operates in the 5 GHz frequency band and supports data rates up to 54 Mbps
- IEEE 802.11b: Operating in the 2.4 GHz frequency band, this standard supports data rates up to 11 Mbps.
- IEEE 802.11g: This standard is also in the 2.4 GHz band and supports data rates up to 54 Mbps.
- IEEE 802.11n: Operating in both the 2.4 GHz and 5 GHz bands, 802.11n significantly improves throughput, supporting data rates of up to 600 Mbps through the use of MIMO (Multiple Input Multiple Output) technology, which uses multiple antennas for transmission and reception, thereby enhancing performance and range.
- What are the 4 areas physical layer star nards are applied for wireless media?
- Frequency band utilization
- modulation techniques
- signal transmission and reception.
- data rates and throughput
- What are the two network devices necessary to implement a wireless network?
A Wireless Access Ppint (WAP) connects to a wireed network and allows wireless devices to communicate with the wired networks and with each other. A Wireless Network Interface Card (NIC) is installed in a computer or other device to enable it to connect to a wireless network.