Aleksandar, Accounts have been created for any students in EECS 340 who did not already have one. Physical access to the labs has also been granted. If.

Slides:



Advertisements
Similar presentations
Introduction 2 1: Introduction.
Advertisements

CS 381 Introduction to computer networks Lecture 2 1/29/2015.
James 1:5 If any of you lacks wisdom, he should ask God, who gives generously to all without finding fault, and it will be given to him.
Introduction 1-1 Chapter 1 Introduction slides are modified from J. Kurose & K. Ross CPE 400 / 600 Computer Communication Networks Lecture 2.
Introduction© Dr. Ayman Abdel-Hamid, CS4254 Spring CS4254 Computer Network Architecture and Programming Dr. Ayman A. Abdel-Hamid Computer Science.
Introduction1-1 Introduction to Computer Networks Our goal:  get “feel” and terminology  more depth, detail later in course  approach:  use Internet.
CSE401N1 CSE401N Computer Networks Lecture-2 Network Structure[KR ] S. M. Hasibul Haque Dept. of CSE BUET.
Welcome to CS 340 Introduction to Computer Networking.
Welcome to CS 340 Introduction to Computer Networking.
1-1 Foundation Objectives: 1.1 What’s the Internet? 1.2 Network edge 1.3 Network core 1.4 Network access and physical media 1.5 Internet structure and.
Lecture Internet Overview: roadmap 1.1 What is the Internet? (A simple overview last week) Today, A closer look at the Internet structure! 1.2 Network.
Lets begin…. Introduction1-2 Access networks and physical media Q: How to connect end systems to edge router? residential access nets institutional access.
1: Introduction1 Part I: Introduction Chapter goal: r get context, overview, “feel” of networking r more depth, detail later in course r approach: m descriptive.
Networking Based on the powerpoint presentation of Computer Networking: A Top Down Approach Featuring the Internet, Third Edition, J.F. Kurose and K.W.
Lecture Internet Overview: roadmap 1.1 What is the Internet? 1.2 Network edge  end systems, access networks, links 1.3 Network core  circuit switching,
Introduction1-1 Chapter 1: Introduction Our goal:  get context, overview, “feel” of networking  more depth, detail later in course  approach: m descriptive.
Introduction to Packet Switching 1-1. Introduction 1-2 What is the Internet 1.1 What is the Internet? 1.2 Network edge  end systems, access networks,
What’s the Internet: “nuts and bolts” view
1-1 CS 456 – Computer Networks □ Instructor: Ian Goldberg □ Classes: Tuesday and Thursday 8:30 – 9:50am MC 4063 (section.
Introduction1-1 Lecture 1 – Introduction slides are modified from J. Kurose & K. Ross University of Nevada – Reno Computer Science & Engineering Department.
1: Introduction1 Part I: Introduction Goal: r get context, overview, “feel” of networking r more depth, detail later in course r approach: m descriptive.
Chapter 1 Introduction Computer Networking: A Top Down Approach 6th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 A note on the use of these.
Introduction A closer look at network structure: network edge: – hosts: clients and servers – servers often in data centers  access networks, physical.
CS 3830 Day 2 Introduction 1-1. Announcements  Program 1 posted on the course web  Project folder must be in 1DropBox on S drive by: 9/14 at 3pm  Must.
Computer Networks & The Internet University of Management & Technology
1: Introduction1a-1 Part I: Introduction Chapter goal: r get context, overview, “feel” of networking r more depth, detail later in course r approach: m.
Computer Networking Introduction, Part I. Lecture #1: Part I: Introduction Chapter goal: get context, overview, “feel” of networking.
Introduction1-1 Chapter 1: Introduction Our goal:  get “feel” and terminology  more depth, detail later in course  approach:  use Internet as example.
CS448 Computer Networking Chapter 1 Introduction to Computer Networks Instructor: Li Ma Office: NBC 126 Phone: (713)
Introduction 1-1 Chapter 1: roadmap 1.1 What is the Internet? 1.2 Network edge  end systems, access networks, links 1.3 Network core  circuit switching,
Slides originally from Professor Williamson at U Calgary1-1 Introduction Part II  Network Core  Delay & Loss in Packet-switched Networks  Structure.
Sharif University of Technology, Kish Islan Campus 1 Internet networking basics These power point slides have been adapted from slides prepared by authors.
Introduction 1-1 Chapter 1 Part 2 Network Core These slides derived from Computer Networking: A Top Down Approach, 6 th edition. Jim Kurose, Keith Ross.
Introduction 1-1 Chapter 1: Introduction Our goal:  get “feel” and terminology  more depth, detail later in course  approach:  use Internet as example.
Review of Networking Concepts Part 1: Switching Networks
Introduction1-1 Course Code:EE/TE533 Instructor: Muddathir Qamar.
CS 3214 Computer Systems Godmar Back Lecture 23. Announcements Project 5 due Dec 8 Exercise 10 handed out Exercise 11 coming before Thanksgiving CS 3214.
Introduction Switches and Access. 2 Chapter 1 Introduction Computer Networking: A Top Down Approach Featuring the Internet, 5 rd edition. Jim.
ECE 466 Switching Networks. ECE 466 A communication network provides a scalable solution to connect a large number of end systems Communication Networks.
T. S. Eugene Ngeugeneng at cs.rice.edu Rice University1 COMP/ELEC 429 Introduction to Computer Networks Lecture 4: Fundamental network design issues Slides.
Chapter 1 Introduction Circuit/Packet Switching Protocols Computer Networking: A Top Down Approach, 5 th edition. Jim Kurose, Keith Ross Addison-Wesley,
RSC Part I: Introduction Redes y Servicios de Comunicaciones Universidad Carlos III de Madrid These slides are, mainly, part of the companion slides to.
Ch 1. Computer Networks and the Internet Myungchul Kim
1 End-user Protocols, Services and QoS. 2 Layering: logical communication application transport network link physical application transport network link.
1 Network Core and Network Edge By Muhammad Hanif To BS IT 4 th Semester.
Introduction1-1 Chapter 1 Computer Networks and the Internet Computer Networking: A Top Down Approach Featuring the Internet, 2 nd edition. Jim Kurose,
A Taxonomy of Communication Networks
Ch 1. Computer Networks and the Internet Myungchul Kim
Introduction1-1 Chapter 1 Computer Networks and the Internet Computer Networking: A Top Down Approach Featuring the Internet, 2 nd edition. Jim Kurose,
Department of Computer and IT Engineering University of Kurdistan
Introduction1-1 Computer Network (  Instructor  Ai-Chun Pang 逄愛君, m Office Number: 417  Textbook.
CSE 413: Computer Network Circuit Switching and Packet Switching Networks Md. Kamrul Hasan
Introduction1-1 Data Communications and Computer Networks Chapter 1 CS 3830 Lecture 2 Omar Meqdadi Department of Computer Science and Software Engineering.
A special acknowledge goes to J.F Kurose and K.W. Ross Some of the slides used in this lecture are adapted from their original slides that accompany the.
Lecture # 3: WAN Data Communication Network L.Rania Ahmed Tabeidi.
CSEN 404 Introduction to Networks Amr El Mougy Lamia AlBadrawy.
Introduction1-1 Data Communications and Computer Networks Chapter 1 CS 3830 Lecture 3 Omar Meqdadi Department of Computer Science and Software Engineering.
Administrative Things
CS 5565 Network Architecture and Protocols
Graciela Perera Introduction Graciela Perera
Part 0: Networking Review
Chapter 1: Introduction
A Taxonomy of Communication Networks
An Aleksandar,   Accounts have been created for any students in EECS 340 who did not already have one.  Physical access to the labs has.
CS 5565 Network Architecture and Protocols
Part I: Introduction Chapter goal:
Network Core and QoS.
Part I: Introduction Chapter goal:
Part I: Introduction Overview: what’s the Internet what’s a protocol?
Network Core and QoS.
Presentation transcript:

Aleksandar, Accounts have been created for any students in EECS 340 who did not already have one. Physical access to the labs has also been granted. If any of your students require either physical or electronic access, please have them contact with their NetID and student ID number. An

Network Edge: Connection-oriented Service Goal: data transfer between end systems handshaking: setup (prepare for) data transfer ahead of time –Hello, hello back human protocol –set up “state” in two communicating hosts TCP - Transmission Control Protocol –Internet’s connection- oriented service TCP service [RFC 793] reliable, in-order byte- stream data transfer –loss: acknowledgements and retransmissions flow control: –sender won’t overwhelm receiver congestion control: –senders “slow down sending rate” when network congested

Network Edge: Connectionless Service Goal: data transfer between end systems –same as before! UDP - User Datagram Protocol [RFC 768]: Internet’s connectionless service –unreliable data transfer –no flow control –no congestion control App’s using TCP: HTTP (Web), FTP (file transfer), Telnet (remote login), SMTP ( ) App’s using UDP: streaming media, teleconferencing, DNS, Internet telephony

The fundamental question: how is data transferred through net (including edge & core)? Communication networks can be classified based on how the nodes exchange information: A Taxonomy of Communication Networks Communication Networks Switched Communication Network Broadcast Communication Network Circuit-Switched Communication Network Packet-Switched Communication Network Datagram Network Virtual Circuit Network TDM FDM

Broadcast communication networks –Information transmitted by any node is received by every other node in the network Examples: usually in LANs (Ethernet) –Problem: coordinate the access of all nodes to the shared communication medium (Multiple Access Problem) Switched communication networks –Information is transmitted to a sub-set of designated nodes Examples: WANs (Telephony Network, Internet) –Problem: how to forward information to intended node(s) This is done by special nodes (e.g., routers, switches) running routing protocols Broadcast vs. Switched Communication Networks

The fundamental question: how is data transferred through net (including edge & core)? Communication networks can be classified based on how the nodes exchange information: A Taxonomy of Communication Networks Communication Networks Switched Communication Network Broadcast Communication Network Circuit-Switched Communication Network Packet-Switched Communication Network Datagram Network Virtual Circuit Network TDM FDM

Circuit-Switched Network End-end resources reserved for “call” Link bandwidth, switch capacity Three phases 1.circuit establishment 2.data transfer 3.circuit termination Dedicated resources + Guaranteed performance - no sharing

Circuit Switching Examples Telephone networks ISDN (Integrated Services Digital Networks) network resources (e.g., bandwidth) divided into “pieces” Pieces allocated to calls Resource piece idle if not used by owning call (no sharing) Dividing link bandwidth into “pieces” –frequency division –time division

Circuit Switching: FDM and TDM FDM frequency time TDM frequency time 4 users Example:

The fundamental question: how is data transferred through net (including edge & core)? Communication networks can be classified based on how the nodes exchange information: A Taxonomy of Communication Networks Communication Networks Switched Communication Network Broadcast Communication Network Circuit-Switched Communication Network Packet-Switched Communication Network Datagram Network Virtual Circuit Network TDM FDM

Packet Switching Data is sent as formatted bit-sequences (Packets) Packets have the following structure: –Header and Trailer carry control information (e.g., destination address, check sum) Each packet traverses the network from node to node along some path (Routing) At each node the entire packet is received, stored briefly, and then forwarded to the next node (Store-and-Forward Networks) No dedicated allocation or resource reservation – no guarantees! HeaderData Trailer

Packet Switching: Statistical Multiplexing Sequence of A & B packets does not have fixed pattern  statistical multiplexing. In TDM each host gets same slot in revolving TDM frame. A B C 10 Mbs Ethernet 1.5 Mbs D E statistical multiplexing queue of packets waiting for output link

Packet Switching versus Circuit Switching 1 Mbit link Each user: –100 kbps when “active” –active 10% of time Circuit-switching: –10 users Packet switching: –with 35 users, probability > 10 active less than.0004 Packet switching allows more users to use network! N users 1 Mbps link

Packet Switching versus Circuit Switching Great for bursty data –resource sharing –simpler, no call setup Excessive congestion: packet delay and loss –protocols needed for reliable data transfer, congestion control Q: How to provide circuit-like behavior? –bandwidth guarantees needed for audio/video apps –still an unsolved problem (chapter 7)

The fundamental question: how is data transferred through net (including edge & core)? Communication networks can be classified based on how the nodes exchange information: A Taxonomy of Communication Networks Communication Networks Switched Communication Network Broadcast Communication Network Circuit-Switched Communication Network Packet-Switched Communication Network Datagram Network Virtual Circuit Network TDM FDM

Datagram Packet Switching Each packet is independently switched –Each packet header contains destination address which determines next hop –Routes may change during session –E.g., post-office analogy No resources are pre-allocated (reserved) in advance Example: IP networks

Packet 1 Packet 2 Packet 3 Packet 1 Packet 2 Packet 3 Timing of Datagram Packet Switching Packet 1 Packet 2 Packet 3 processing delay of Packet 1 at Node 2 Host 1Host 2 Node 1Node 2 propagation delay between Host 1 and Node 2 transmission time of Packet 1 at Host 1

Datagram Packet Switching Host A Host B Host E Host D Host C Node 1 Node 2 Node 3 Node 4 Node 5 Node 6 Node 7

The fundamental question: how is data transferred through net (including edge & core)? Communication networks can be classified based on how the nodes exchange information: A Taxonomy of Communication Networks Communication Networks Switched Communication Network Broadcast Communication Network Circuit-Switched Communication Network Packet-Switched Communication Network Datagram Network Virtual Circuit Network TDM FDM

Virtual-Circuit Packet Switching Hybrid of circuit switching and packet switching –All packets from one packet stream are sent along a pre-established path (= virtual circuit) –Each packet carries tag (virtual circuit ID), tag determines next hop Features –Guarantees in-sequence delivery of packets (+) –However, packets from different virtual circuits may be interleaved (+) –Requires per-flow state in the network (-)

Virtual-Circuit Packet Switching Communication with virtual circuits takes place in three phases 1.VC establishment 2.data transfer 3.VC disconnect Note: packet headers don’t need to contain the full destination address of the packet

Packet 1 Packet 2 Packet 3 Packet 1 Packet 2 Packet 3 Timing of Virtual-Circuit Packet Switching Packet 1 Packet 2 Packet 3 Host 1Host 2 Node 1Node 2 propagation delay between Host 1 and Node 1 VC establishment VC termination Data transfer

Virtual-Circuit Packet Switching Host A Host B Host E Host D Host C Node 1 Node 2 Node 3 Node 4 Node 5 Node 6 Node 7

Reminder Project 1 out –If you don’t have a TLAB account contact –To enter the TLAB classroom (Tech F-252), again contact –Find partner (groups of 2-3 preferred) Recitation on Tuesday (01/13) and Thursday (01/15) on UNIX programming and project 1 at 11:00 AM in TBA. Homework 1 out, due 1/23

Overview Network access and physical media Internet structure and ISPs Delay & loss in packet-switched networks Protocol layers, service models

Access networks and physical media Q: How to connect end systems to edge router?  residential access nets  institutional access networks (school, company)  mobile access networks Keep in mind:  bandwidth (bits per second) of access network?  shared or dedicated?

telephone network Internet home dial-up modem ISP modem (e.g., AOL) home PC central office  uses existing telephony infrastructure  home directly-connected to central office  up to 56Kbps direct access to router (often less)  can’t surf, phone at same time: not “always on” Dial-up Modem

telephone network DSL modem home PC home phone Internet DSLAM Existing phone line: 0-4KHz phone; 4-50KHz upstream data; 50KHz- 1MHz downstream data splitter central office Digital Subscriber Line (DSL)  uses existing telephone infrastructure  up to 1 Mbps upstream (today typically < 256 kbps)  up to 8 Mbps downstream (today typically < 1 Mbps)  dedicated physical line to telephone central office

Residential access: cable modems  uses cable TV infrastructure, rather than telephone infrastructure  HFC: hybrid fiber coax  asymmetric: up to 30Mbps downstream, 2 Mbps upstream  network of cable, fiber attaches homes to ISP router  homes share access to router  unlike DSL, which has dedicated access

Residential access: cable modems Diagram:

home cable headend cable distribution network (simplified) Typically 500 to 5,000 homes Cable Network Architecture: Overview

home cable headend cable distribution network server(s) Cable Network Architecture: Overview

home cable headend cable distribution network (simplified)

home cable headend cable distribution network Channels VIDEOVIDEO VIDEOVIDEO VIDEOVIDEO VIDEOVIDEO VIDEOVIDEO VIDEOVIDEO DATADATA DATADATA CONTROLCONTROL FDM (more shortly): Cable Network Architecture: Overview

ONT OLT central office optical splitter ONT optical fiber optical fibers Internet Fiber to the Home  optical links from central office to the home  two competing optical technologies:  Passive Optical Network (PON) (shown in the figure)  Active Optical Network (AON)  much higher Internet rates (10-20 Mbps download; 1-2 Mbps upload); fiber also carries television and phone services

100 Mbps 1 Gbps server Ethernet switch institutional router to institution’s ISP Ethernet Internet access  typically used in companies, universities, etc –10 Mbps, 100Mbps, 1Gbps, 10Gbps Ethernet –today, end systems typically connect into Ethernet switch