Flashcards in MIDTERM REVIEW Deck (37)
Identify the possible causes of LAN traffic congestion.
Too many hosts in a broadcast domain, broadcast storms, multicasting, and low bandwidth are all possible causes of LAN traffic congestion.
Describe the difference between a collision domain and a broadcast domain.
Collision domain is an Ethernet term used to describe a network collection of devices in which on particular device sends a packet on a network segment, forcing every other device on that same segment to pay attention to it. With a broadcast domain, a set of all devices on a network hears all broadcasts sent on all segments.
Differentiate a MAC address and an IP address and describe how and when each address type is used in a network.
A MAC address is a hexadecimal number identifying the physical connection of a host. A MAC address is a hexadecimal number identifying the physical connection of a host. MAC addresses are said to operate on layer 2 of the OSI model. IP addresses, which can be expressed in binary or decimal format, are logical identifiers that are said to be on layer 3 of the OSI model. Hosts on the same physical segment locate one another with MAC addresses, while IP addresses are used when they reside on different LAN segments or subnets.
Understand the difference between a hub, a bridge, a switch, and a router.
A hub creates on collision domain and one broadcast domain. A bridge breaks up collision domains but creates on large broadcast domain. They use hardware addresses to filter the network. Switches are really just multiple-port bridges with more intelligence; they break up collision domains but create on large broadcast domain by default. Bridges and switches use hardware addresses to filter the network. Routers break up broadcast domains ( and collision domains) and use logical addressing to filter the network.
Identify the functions and advantages of routers.
Routers perform packet switching, filtering, and path selection, and they facilitate internetwork communication. One advantage of routers is that they reduce broadcast traffic.
Differentiate connection-oriented and connectionless network services and describe how each is handled during network communications.
Connection-oriented services use acknowledgements and flow control to create a reliable session. More overhead is used than in a connectionless network service. Connectionless services are used to send data with no acknowledgements or flow control. This is considered unreliable.
Define the OSI layers, understand the function of each, and describe how devices and networking protocols can be mapped to each layer.
You must remember the seven layers of the OSI model and what function each layer provides. The Application, Presentation, and Session layers are upper layers and are responsible for communicating from a user interface to an application. The Transport layer provides segmentation, sequencing, and virtual internetwork. The Data Link layer provides framing and placing of data on the network medium. The Physical layer is responsible for taking 1's and 0's and encoding them into a digital signal for transmission on the network segment.
1. Which layer chooses and determines the availability of communicating partners along with the resources necessary to make the connection, coordinates partnering applications, and forms a consensus on procedures for controlling data integrity and error recovery?
The Application layer is responsible for finding the network resources broadcast from a server and adding flow control and error control (if the application developer chooses).
2. Which layer is responsible for converting data packets from the Data Link layer into electrical signals?
The Physical layer takes frames from the Data Link Layer and encodes the 1's and 0's into a digital or analog (Ethernet or wireless) signal for transmission on the network medium.
3. At which layer is routing implemented, enabling connections and path selection between two end systems?
The Network layer provides routing through an internetwork and logical addressing.
4. Which layer defines how data is formatted, presented, encoded, and converted for use on the network.
The Presentation layer makes sure the data is in a readable format for the Application layer.
5. Which layer is responsible for creating, managing, and terminating sessions between applications?
The Session layer sets up, maintains, and terminates sessions between applications.
6. Which layer ensures the trustworthy transmission of data across a physical link and is primarily concerned with physical addressing, line discipline, network topology, error notification, ordered delivery of frames, and flow control?
PDU's at the Data Link layer are called frames and provide physical addressing plus other options to place packets on the network medium.
7. Which layer is used for reliable communication between end nodes over the network and provides mechanisms for establishing, maintaining, and terminating virtual circuits; transport-fault detection and recovery; and controlling the flow of information?
The Transport layer uses virtual circuits to create a reliable connection between two hosts.
8. Which layer provides logical addressing that routers will use for path determination?
The Network layer provides logical addressing, typically IP addressing and routing.
9. Which layer specifies voltage, wire speed, and cable pinouts and moves bits between devices?
The physical layer is responsible for the electrical and mechanical connections between devices.
10. Which layer combines bits into bytes and bytes into frames, uses MAC addressing, and provides error detection?
The Data Link layer is responsible for the framing of data packets.
11. Which layer is responsible for keeping the data from different applications separate on the network?
The Session layer creates sessions between different hosts' applications
12. Which layer is represented by frames?
The Data Link layer frames packets received from the Network layer.
13. Which layer is represented by segments?
The Transport layer segments user data.
14. Which layer is represented by packets?
The Network layer creates packets out of segments handed down from the Transport layer.
15. Which layer is represented by bits?
The Physical layer is responsible for transporting 1s and 0s (bits) in a digital signal.
16. Rearrange the following in order of encapsulation:
Segments, packets, frames, bits
17. Which layer segments and reassembles data into a data stream?
18. Which layer provides the physical transmission of the data and handles error notification, network topology and flow control?
19. Which layer manages logical device addressing, tracks the location of devices on the internetwork, and determines the best way to move data?
20. What is the bit length and expression form of a MAC address?
48 bits (6 bytes) expressed as a hexadecimal number.
Describe the operation of Carrier Sense Multiple Access with Collision Detection (CSMA/CD).
CSMA/CD is a protocol that helps devices share the bandwidth evenly without having two devices transmit at the same time on the network medium. Although it does not eliminate collisions, it helps to greatly reduce them, which reduces retransmissions, resulting in a more efficient transmission of data for all devices.
Differentiate half-duplex and full-duplex communication and define the requirements to utilize each method.
Full-duplex Ethernet uses two pairs of wires at the same time instead of one wire pair like half-duplex.Full-duplex allows for sending and receiving at the same time, using different wires to eliminate collisions, while half-duplex can send or receive but not at the same time and still can suffer collisions. To use full-duplex, the devices at both ends of the cable must be capable of and configured to perform full-duplex.