Introduction to Networking Chapter 1
61 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the relationship between the traffic intensity La/R and average queueing delay?

As La/R approaches 0, the average queueing delay is small; as La/R approaches 1, the average queueing delay becomes large; and if La/R is greater than 1, the average delay is infinite.

What does the traceroute program measure?

  • Number of routers in the path
  • Delay measurement from source to router (correct)
  • Bandwidth of the link
  • Packet loss during transmission

    • What happens when a packet arrives at a full queue?

    The packet is dropped or lost.

    The average end-to-end throughput in a network is determined by the minimum of Rc, Rs, and ___.

    <p>R/10</p> Signup and view all the answers

    If Rs is greater than Rc, then average end-to-end throughput is limited by Rc.

    <p>True</p> Signup and view all the answers

    A lost packet may never be retransmitted.

    <p>True</p> Signup and view all the answers

    What is the Internet?

    <p>A network of networks.</p> Signup and view all the answers

    What are the types of access networks mentioned?

    <p>All of the above</p> Signup and view all the answers

    The ______ is a network of interconnected routers.

    <p>network core</p> Signup and view all the answers

    Protocols define the format, order, and actions taken for message transmission.

    <p>True</p> Signup and view all the answers

    What does TCP stand for?

    <p>Transmission Control Protocol</p> Signup and view all the answers

    Which of the following is NOT a type of physical medium?

    <p>Browser</p> Signup and view all the answers

    What is the typical upstream transmission rate for DSL?

    <p>&lt; 1 Mbps</p> Signup and view all the answers

    The method used for joining different channel frequencies in cable networks is called ______.

    <p>frequency division multiplexing</p> Signup and view all the answers

    What is the role of protocols in networks?

    <p>Govern communication and data transfer between machines.</p> Signup and view all the answers

    What is the definition of 'packet' in networking?

    <p>A small chunk of data transmitted over a network.</p> Signup and view all the answers

    Queueing delays occur when packets arrive at a router faster than they can be transmitted.

    <p>True</p> Signup and view all the answers

    What is a key characteristic of end systems in network architecture?

    <p>They run network applications.</p> Signup and view all the answers

    Which of the following best describes the function of communication links in a network?

    <p>To connect end systems to access networks.</p> Signup and view all the answers

    What type of information do protocols regulate in networking?

    <p>Formats, order, and actions for message transmission.</p> Signup and view all the answers

    What does RFC stand for in the context of Internet standards?

    <p>Request for Comments</p> Signup and view all the answers

    Which role does the Internet Engineering Task Force (IETF) play?

    <p>Creating and reviewing standards for the Internet.</p> Signup and view all the answers

    What defines the performance characteristics of a packet-switching network?

    <p>Transmission rate and bandwidth.</p> Signup and view all the answers

    Which type of application is NOT typically provided as an Internet service?

    <p>Database management</p> Signup and view all the answers

    What is a primary benefit of programming interfaces in internet applications?

    <p>They provide hooks for sending and receiving programs.</p> Signup and view all the answers

    What best describes human protocols?

    <p>They include actions like asking questions or making introductions.</p> Signup and view all the answers

    Which statement about network protocols is true?

    <p>They dictate the specific actions taken when messages are received.</p> Signup and view all the answers

    What is the primary purpose of access networks?

    <p>To connect end systems to edge routers.</p> Signup and view all the answers

    What best describes the network core?

    <p>It is made up of interconnected routers forming a network of networks.</p> Signup and view all the answers

    Which of the following is an example of a question relevant to human protocols?

    <p>What time is it?</p> Signup and view all the answers

    Which feature is NOT characteristic of network protocols?

    <p>They allow only human communication.</p> Signup and view all the answers

    What aspect of access networks is essential for performance?

    <p>Bandwidth measured in bits per second.</p> Signup and view all the answers

    What is the relationship between host and access networks?

    <p>Hosts are part of the access networks that provide physical links.</p> Signup and view all the answers

    What is one of the effects on the propagation environment that can cause interference?

    <p>Reflection by surfaces</p> Signup and view all the answers

    Which of the following types of delay is primarily caused by the time a packet spends waiting at the output link?

    <p>Queueing delay</p> Signup and view all the answers

    What factors influence transmission delay?

    <p>Packet length and link bandwidth</p> Signup and view all the answers

    Which type of network architecture includes elements such as end systems and access networks?

    <p>Network edge</p> Signup and view all the answers

    What is the typical end-to-end delay associated with geosynchronous satellite communication?

    <p>270 msec</p> Signup and view all the answers

    Which of the following represents the primary addition to the calculation of total nodal delay?

    <p>Queueing delay</p> Signup and view all the answers

    What can cause packet loss in a network?

    <p>Excessive package arrival rates</p> Signup and view all the answers

    Which of the following is NOT a source of packet delay?

    <p>Security delay</p> Signup and view all the answers

    What is the standard propagation speed used for calculating propagation delays in networks?

    <p>2 x 10^8 m/sec</p> Signup and view all the answers

    Which of the following access methods provides speeds of up to 45 Mbps?

    <p>Satellite</p> Signup and view all the answers

    What does the traceroute method utilize to measure the delay in packets?

    <p>Sends three packets and times the interval of replies.</p> Signup and view all the answers

    In the context of packet queues, what happens to packets when they arrive at a full queue?

    <p>They are dropped and may be retransmitted.</p> Signup and view all the answers

    What is not a characteristic of throughput in a network?

    <p>It is solely determined by the receiving end's capability.</p> Signup and view all the answers

    When considering throughput rates Rs and Rc, what characterizes a scenario where Rs < Rc?

    <p>The throughput is limited by the receiving capacity Rc.</p> Signup and view all the answers

    Which of these is not a possible outcome for a lost packet in a network?

    <p>Being stored for future transmission.</p> Signup and view all the answers

    What does an asterisk (*) indicate in the traceroute output?

    <p>The probe was lost or the router did not reply.</p> Signup and view all the answers

    What does the throughput measure in a networking context?

    <p>The rate at which bits are successfully transmitted.</p> Signup and view all the answers

    Why can packets be lost in a network?

    <p>Due to congestion leading to full queues.</p> Signup and view all the answers

    Which of the following describes instantaneous throughput?

    <p>The rate at a specific moment.</p> Signup and view all the answers

    In comparison, what is the effect of higher link capacity on average end-to-end throughput?

    <p>It has no impact on throughput if Rs is lower.</p> Signup and view all the answers

    How long does it take for a ten-car caravan to fully pass through a toll booth that takes 12 seconds to service each car?

    <p>120 seconds</p> Signup and view all the answers

    What is the impact on average queueing delay when the traffic intensity La/R approaches 1?

    <p>Average queueing delay becomes large</p> Signup and view all the answers

    If cars in a caravan travel at 1000 km/hr and the toll booth takes one minute to service each car, will the cars arrive at the second booth before all cars are serviced at the first booth?

    <p>Yes, some cars will arrive before</p> Signup and view all the answers

    What happens when the traffic intensity La/R exceeds 1?

    <p>More packets are arriving than can be serviced</p> Signup and view all the answers

    Which of the following best describes the concept of propagation in networking, as illustrated by the caravan analogy?

    <p>The effect of distances on data transmission times</p> Signup and view all the answers

    What does the 'toll booth' represent in the caravan analogy related to networking?

    <p>The processing time for data packets</p> Signup and view all the answers

    In which scenario will the average queueing delay be minimally affected?

    <p>La/R is close to 0</p> Signup and view all the answers

    What is the main purpose of using the traceroute program?

    <p>To provide delay measurements from source to router</p> Signup and view all the answers

    Study Notes

    Introduction to Networking: Key Concepts

    • Free access to PowerPoint slides provided for educational purposes; attribution requested when used.
    • Slides cover foundational topics in networking, including the structure and protocols of the Internet.

    Understanding the Internet

    • The Internet comprises millions of connected devices, including PCs, servers, laptops, smartphones, and more.
    • Key components include end systems (hosts), communication links (fiber, copper, radio, satellite), and packets for data transfer.

    Internet Structure and Functionality

    • Defined as a "network of networks" created by interconnected Internet Service Providers (ISPs).
    • Protocols (e.g., TCP, IP, HTTP) govern the sending and receiving of messages across the network.
    • Internet standards established through Requests for Comments (RFC) by the Internet Engineering Task Force (IETF).

    Network Architecture

    • Network edge involves end systems such as clients and servers, often located in data centers.
    • Access networks use varied physical media (wired and wireless) to connect end systems to the network core.
    • The core consists of interconnected routers that manage data traffic.

    Access Networks

    • Residential, institutional, and mobile access networks exist to connect users to the Internet.
    • Transmission rates and bandwidth can vary significantly among different access methods.

    Types of Access Networks

    • DSL (Digital Subscriber Line): Utilizes existing telephone lines; offers upstream speeds <2.5 Mbps and downstream speeds <24 Mbps.
    • Cable Network: Hybrid fiber coaxial (HFC) cable provides asymmetric speeds with up to 30 Mbps downstream.
    • Wireless Networks: Include wireless LANs (WiFi) with speeds of 11-54 Mbps and cellular networks (3G, 4G).

    Packet Transmission

    • End systems break application messages into packets for transmission.
    • Packet transmission delays depend on link transmission rates and sizes, defined as transmission and propagation delay.

    Types of Delay in Networks

    • Four primary sources of packet delay:
      • Nodal Processing Delay: Time for routers to check errors and determine output links.
      • Queueing Delay: Time packets spend waiting in queues when network congestion occurs.
      • Transmission Delay: Time required to push packet bits onto the outgoing link.
      • Propagation Delay: Time taken for a signal to traverse the physical link.

    Impact of Congestion and Delay

    • Packet loss can occur when incoming packets exceed the router's capacity to handle them, resulting in dropped packets.
    • Average queueing delay is affected by traffic intensity, calculated as La/R (arrival rate over transmission rate).

    Real-World Internet Performance

    • Tools like traceroute measure actual Internet delays and paths, helping assess performance.
    • Real Internet conditions can significantly influence both delay and data loss during transmission.

    Comparison Analogies

    • The caravan analogy illustrates how packets move through the network, emphasizing the importance of processing and propagation times.
    • Variations in transmission and propagation speeds affect overall performance, exemplifying the intricate balancing act of networking delays.### Internet Delay Measurements
    • Traceroute from gaia.cs.umass.edu to www.eurecom.fr provides metrics for the journey through the network.
    • Nodes and their respective delays (in milliseconds):
      • cs-gw (128.119.240.254): 1 ms, 1 ms, 2 ms
      • border1-rt-fa5-1-0.gw.umass.edu (128.119.3.145): Consistent delays around 1-2 ms
      • Various nodes display increasing delays, peaking at 135 ms at eurecom-valbonne.r3t2.ft.net.

    Packet Loss

    • Packet loss occurs when a packet arrives at a full queue (buffer) and is dropped.
    • Lost packets may be retransmitted by:
      • Previous node in the route
      • Source end system
      • Not retransmitted at all

    Understanding Throughput

    • Throughput: The rate of bits transferred over time (bits/time unit).
    • Two types of throughput:
      • Instantaneous: Rate at a specific moment.
      • Average: Rate over an extended period.
    • Key elements affecting throughput include:
      • Rs: Sending rate of the server.
      • Rc: Capacity of the link/pipeline.

    Average End-to-End Throughput

    • When Rs (sending rate) is less than Rc (link capacity), the average end-to-end throughput is determined by Rs.
    • When Rs is greater than Rc, average throughput is limited by Rc, highlighting potential bottlenecks.
    • The bottleneck link is the constraining factor on end-to-end throughput across the network path.
    • Per-connection end-to-end throughput is often calculated as:
      • min(Rc, Rs, R/10), where R represents the capacity of the backbone link.
    • In practice, the bottleneck typically arises from either Rc or Rs, which limits data transfer rates.
    • For 10 connections sharing a backbone link, throughputs are distributed based on overall capacity.

    Network Edge

    • End systems include devices like PCs, laptops, smartphones, and servers that run network applications.
    • Access networks connect end systems to the Internet, utilizing wired (fiber, copper) and wireless (radio, satellite) communication links.
    • Packets, the fundamental units of data, are forwarded by devices like routers and switches.

    Internet Structure

    • The Internet is regarded as a "network of networks," interlinking various Internet Service Providers (ISPs).
    • Communication adheres to protocols, governing the sending and receiving of messages, such as TCP, IP, and HTTP.
    • Internet standards are developed and maintained by organizations like the Internet Engineering Task Force (IETF) and through Requests for Comments (RFC).

    Protocols

    • Protocols are essential for communication, outlining how messages are formatted, sent, and acted upon by network entities.
    • Examples of human protocols can include greetings, while network protocols manage all communication activities over the Internet.

    Network Edge Infrastructure

    • Hosts in the network edge include both clients and servers, often located in data centers.
    • Access networks are classified into residential, institutional (like schools and companies), and mobile networks.

    Access Network Characteristics

    • Bandwidth varies by access type: wired networks can offer higher bandwidth (up to 45 Mbps), while mobile networks typically provide lower bandwidth (e.g., 3G ~ few Mbps).
    • Additional influences on network performance include propagation environment, signal interference, and physical obstacles.

    Delay and Loss in Networks

    • Packet delay occurs when the arrival rate of packets exceeds the output capacity of a link, leading to queuing.
    • Types of delays include:
      • Transmission Delay (dtrans): Time taken to push all packet bits onto the wire.
      • Propagation Delay (dprop): Time for a signal to traverse the physical link.
      • Processing Delay (dproc): Time spent checking for errors and deciding on routing.
      • Queueing Delay (dqueue): Time spent waiting in line to be transmitted.

    Queueing and Packet Loss

    • Queueing delay intensifies with the level of router congestion; limits exist on the size of the buffer (queue), leading to packet loss when no space is available.
    • Packet loss can result in the need for retransmission by the source or previous nodes in the network.

    Throughput

    • Throughput refers to the rate at which data is successfully transferred from sender to receiver, typically measured in bits per time unit.
    • Average throughput is influenced by the capacity of the link along with the sender's transmission rate, factoring into the overall network performance.

    Traceroute Utility

    • Traceroute is a diagnostic tool that measures delays along the path to a destination, providing a list of routers and their respective response times.

    Real Internet Attributes

    • Environmental factors affect both delay and loss, making it crucial for networking applications to account for variations in real-world conditions and performance metrics.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Computer Networking: A Top-Down Approach, 6th Edition (PDF)
    Computer Networking: A Top-Down Approach 6th Edition PDF

    Description

    This quiz covers the introductory concepts presented in Chapter 1 of the Networking: A Top-Down Approach. It emphasizes the importance of understanding basic networking principles and the utilization of the provided PowerPoint slides for faculty and students. Engage with the material to enhance your comprehension of networking fundamentals.

    More Like This

    1100 Ch05: Networking Principles Overview
    25 questions

    1100 Ch05: Networking Principles Overview

    ExtraordinaryMars avatar
    ExtraordinaryMars
    Networking Principles Quiz
    8 questions

    Networking Principles Quiz

    TenderTungsten avatar
    TenderTungsten
    Introduction to Networking
    46 questions

    Introduction to Networking

    ResplendentClearQuartz avatar
    ResplendentClearQuartz
    Networking Principles Overview
    47 questions

    Networking Principles Overview

    EasedCesium avatar
    EasedCesium
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser