Data Communication Exam 4

These flashcards cover key concepts and definitions related to networking devices, protocols, and technologies based on the lecture notes provided.

What are the three major types of connecting devices in networking?

Hubs, Link-layer switches, and Routers.

What layer of the internet model do hubs operate in?

Physical layer (Layer 1).

How do link-layer switches operate differently from hubs?

Link-layer switches operate at both the physical (Layer 1) and data-link (Layer 2) layers, while hubs operate only at Layer 1.

What is the primary function of routers in a network?

Routers connect independent networks and operate primarily at the network layer (Layer 3) but also interact with Layers 1 and 2.

What type of device is a hub commonly described as?

A multi-port repeater that operates only in the physical layer.

What is a VLAN and how is it configured?

A Virtual Local Area Network (VLAN) is configured by software rather than physical wiring, dividing a physical LAN into multiple logical broadcast domains.

How does a link-layer switch filter frames?

It uses a switching table that connects MAC addresses to ports, allowing it to send frames only to the appropriate port.

What is CSMA/CD and its function in Ethernet networks?

Carrier Sense Multiple Access with Collision Detection; it manages data transmission to avoid collisions in the network.

What are the differences between a router and a switch?

Routers have logical (IP) and physical (MAC) addresses, connect multiple networks, and change physical addresses of packets, while switches operate within a single network.

What is the role of a bridge in networking?

A bridge connects and filters traffic between separate network segments at both the physical and data-link layers.

What kind of topology does a hub typically use in modern networks?

Star topology.

How is a cell structured in Asynchronous Transfer Mode (ATM)?

A cell is a fixed-size data packet that includes a header with Virtual Path Identifier (VPI) and Virtual Circuit Identifier (VCI).

What type of cables does Ethernet LAN use?

Ethernet LAN uses twisted pair cables, coaxial cables, and fiber optics.

What does the acronym PPP stand for in network communication?

Point-to-Point Protocol.

What characteristic distinguishes ADSL from other DSL types?

ADSL (Asymmetric DSL) allows faster download speeds compared to upload speeds.

What is the purpose of the preamble in an Ethernet frame?

It alerts and synchronizes the receiver for the incoming data.

How does CSMA/CA differ from CSMA/CD?

CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) senses the medium to avoid collisions; it requires requests to send and clear to send signals.

What key advancement did Ethernet make in terms of collision domain lengths?

Ethernet technology reduced the maximum collision domain length from 2500m to around 250m to increase speed.

What is the main benefit of using fiber optic cables in networking?

Fiber optic cables offer longer transmission distances, higher speeds, and are less susceptible to interference.

Describe one way wireless LANs avoid collisions.

Wireless LANs use CSMA/CA, which senses the medium and requires acknowledgment signals to manage transmissions.