Links. Error Detection. Link Layer. Multiple access protocols. Nodes Links Frame. Shared channel Problem: collisions How nodes share a channel

Save this PDF as:

Size: px
Start display at page:

Download "Links. Error Detection. Link Layer. Multiple access protocols. Nodes Links Frame. Shared channel Problem: collisions How nodes share a channel"

Transcription

1 Link Layer Error Detection Nodes Links Frame R yclic Redundancy hecksum Parity its More about this in exercise! Data Link Layer -1 Data Link Layer -2 Links Two types of links : point-to-point broadcast (shared medium) old-fashioned Ethernet WLN Multiple access protocols Shared channel Problem: collisions How nodes share a channel shared wire (e.g., cabled Ethernet) shared RF (e.g., WiFi) shared RF (satellite) humans at a cocktail party (shared air, acoustical) Data Link Layer -3 Data Link Layer - M Protocols hannel Partitioning divide channel into smaller pieces Random ccess channel not divided, allow collisions Taking turns nodes take turns, but nodes with more to send can take longer turns hannel Partitioning M protocols: TDM TDM: time division multiple access each station gets slot 6-slot frame Data Link Layer - Data Link Layer -6 1

2 frequency bands hannel Partitioning M protocols: FDM FDM: frequency division multiple access FDM cable Random ccess Protocols No coordination Sender uses all capacity ollisions may occur Random access M protocol specifies: how to detect collisions how to recover from collisions Data Link Layer -7 Data Link Layer -8 Slotted LOH Pure (unslotted) LOH Simpler, no synchronization When frame arrives: send at once Pros single active node can transmit at full rate highly decentralized simple ons collisions, wasting slots idle slots clock synchronization Data Link Layer -9 Data Link Layer -10 SM (arrier Sense Multiple ccess) SM collisions Listen before sending: If idle: send frame If busy, send later Data Link Layer -11 Data Link Layer -12 2

3 SM/D (ollision Detection) SM/D collision detection collisions detected within short time colliding transmissions aborted ompare transmitted and received signal Easy for wires Difficult for radio Data Link Layer -13 Data Link Layer -1 Taking Turns M protocols Taking Turns M protocols Polling: master node T typically used with dumb slave devices problems: overhead latency single point of failure (master) slaves poll master Token passed Data Link Layer -1 Data Link Layer -16 LN ddresses and RP Ethernet 1-2F D roadcast address = FF-FF-FF-FF-FF-FF cheap $20 for network interface card first widely used LN technology simpler, cheaper than token LNs and TM kept up with speed race: 10 Mbps 10 Gbps LN (wired or wireless) 71-6-F D7-F-20-0 Metcalfe s Ethernet sketch F-E3-98 Data Link Layer -17 Data Link Layer -18 3

4 Star topology bus topology popular through mid 90s today: star topology prevails Ethernet Frame Structure (more) Preamble: pattern used to clock rates ddresses: 6 bytes Type: indicates higher layer protocol (mostly IP) R: if error, frame is dropped switch bus: coaxial cable star Data Link Layer -19 Data Link Layer -20 Ethernet: Unreliable, connectionless onnectionless: No handshaking Unreliable: no acks or nacks to sender Ethernet uses SM/D Ethernet SM/D algorithm 1. If channel idle, start transmission If channel busy, wait until channel idle, then transmit 2. If entire frame sent without detecting another transmission or jam signal, finished! Otherwise, go to If collision detected, abort and send jam signal. fter aborting, NI enters exponential backoff: after m:th collision, NI chooses K at random from {0,1,2,,2 m -1}. NI waits K 12 bit times, returns to Step 1 Data Link Layer -21 Data Link Layer -22 Manchester encoding Hubs Dumb repeaters: bits coming go out to all other links all nodes connected to hub can collide with one another no SM/D at hub: host NIs detect collisions twisted pair hub Data Link Layer -23 Data Link Layer -2

5 Switch: allows multiple simultaneous transmissions hosts have dedicated, direct connection to switch switches buffer packets Ethernet protocol used on each incoming link, but no collisions; full duplex each link is its own collision domain switching: -to- and - to- simultaneously, without collisions not possible with dumb hub switch with six interfaces (1,2,3,,,6) Switch: self-learning switch learns where hosts are M addr interface TTL Source: Dest: Data Link Layer -2 Data Link Layer -26 Interconnecting switches switches can be connected together S S 1 S 2 D E F G S 3 H I Data Link Layer -27

Adaptors Communicating. Link Layer: Introduction. Parity Checking. Error Detection. Multiple Access Links and Protocols

Adaptors Communicating. Link Layer: Introduction. Parity Checking. Error Detection. Multiple Access Links and Protocols Link Layer: Introduction daptors ommunicating hosts and routers are nodes links connect nodes wired links wireless links layer-2 packet is a frame, encapsulates datagram datagram controller sending host

More information

Adaptors Communicating. Link Layer: Introduction. Parity Checking. Error Detection. Multiple Access Links and Protocols

Adaptors Communicating. Link Layer: Introduction. Parity Checking. Error Detection. Multiple Access Links and Protocols Link Layer: Introduction daptors ommunicating Terminology: hosts and routers are nodes communication channels that connect adjacent nodes along communication path are links wired links wireless links LNs

More information

Chapter 5: The Data Link Layer. Chapter 5 Link Layer and LANs. Ethernet. Link Layer. Star topology. Ethernet Frame Structure.

Chapter 5: The Data Link Layer. Chapter 5 Link Layer and LANs. Ethernet. Link Layer. Star topology. Ethernet Frame Structure. hapter 5 Link Layer and LNs omputer Networking: Top Down pproach 5 th edition. Jim Kurose, Keith Ross ddison-wesley, pril 2009. hapter 5: The Data Link Layer Our goals: understand principles behind data

More information

Link Layer: Introduction. Chapter 5 Link Layer & LANS. Link layer: context. Link Layer Services

Link Layer: Introduction. Chapter 5 Link Layer & LANS. Link layer: context. Link Layer Services Chapter 5 Link Layer & LNS Link Layer: Introduction Some terminology: hosts and routers are nodes communication channels that connect adjacent nodes along communication path are links wired links wireless

More information

Link Layer: Introduction. Chapter 5 Link Layer & LANS. Link layer: context. Link Layer Services

Link Layer: Introduction. Chapter 5 Link Layer & LANS. Link layer: context. Link Layer Services Chapter 5 Link Layer & LNS Link Layer: Introduction Some terminology: hosts and routers are nodes communication channels that connect adjacent nodes along communication path are links wired links wireless

More information

Master Course Computer Networks IN2097

Master Course Computer Networks IN2097 Chair for Network Architectures and Services Prof. Carle Department for Computer Science TU München Master Course Computer Networks IN2097 Prof. Dr.-Ing. Georg Carle Christian Grothoff, Ph.D. Dr. Nils

More information

The Link Layer and LANs: Ethernet and Swiches

The Link Layer and LANs: Ethernet and Swiches The Link Layer and LNs: Ethernet and Swiches EECS3214 2018-03-21 Link layer, LNs: outline 6.1 introduction, services 6.2 error detection, correction 6.3 multiple access protocols 6.4 LNs addressing, RP

More information

Announcements. CS 5565 Network Architecture and Protocols. Ethernet. Ethernet. Ethernet Model. Ideal Multiple Access Protocol

Announcements. CS 5565 Network Architecture and Protocols. Ethernet. Ethernet. Ethernet Model. Ideal Multiple Access Protocol nnouncements CS 5565 Network rchitecture and Protocols Lecture 4 odmar ack Project due in parts: pr 5 and May xtra Credit Opportunities: xpand simulator (and your implementation) to introduce multiple

More information

Chapter V: Link Layer

Chapter V: Link Layer Chapter V: Link Layer UG3 Computer Communications & Networks (COMN) Myungjin Lee myungjin.lee@ed.ac.uk Slides copyright of Kurose and Ross Link layer services framing, link access: encapsulate datagram

More information

Master Course Computer Networks IN2097

Master Course Computer Networks IN2097 Chair for Network Architectures and Services Prof. Carle Department for Computer Science TU München Master Course Computer Networks IN2097 Prof. Dr.-Ing. Georg Carle Christian Grothoff, Ph.D. Chair for

More information

Redes de Computadores. Medium Access Control

Redes de Computadores. Medium Access Control Redes de Computadores Medium Access Control Manuel P. Ricardo Faculdade de Engenharia da Universidade do Porto 1 » How to control the access of computers to a communication medium?» What is the ideal Medium

More information

CMPE 150/L : Introduction to Computer Networks. Chen Qian Computer Engineering UCSC Baskin Engineering Lecture 18

CMPE 150/L : Introduction to Computer Networks. Chen Qian Computer Engineering UCSC Baskin Engineering Lecture 18 CMPE 150/L : Introduction to Computer Networks Chen Qian Computer Engineering UCSC Baskin Engineering Lecture 18 1 Final project demo Please do the demo THIS week to the TAs. Or you are allowed to use

More information

Topics. Link Layer Services (more) Link Layer Services LECTURE 5 MULTIPLE ACCESS AND LOCAL AREA NETWORKS. flow control: error detection:

Topics. Link Layer Services (more) Link Layer Services LECTURE 5 MULTIPLE ACCESS AND LOCAL AREA NETWORKS. flow control: error detection: 1 Topics 2 LECTURE 5 MULTIPLE ACCESS AND LOCAL AREA NETWORKS Multiple access: CSMA/CD, CSMA/CA, token passing, channelization LAN: characteristics, i basic principles i Protocol architecture Topologies

More information

Computer Networks. Today. Principles of datalink layer services Multiple access links Adresavimas, ARP LANs Wireless LANs VU MIF CS 1/48 2/48

Computer Networks. Today. Principles of datalink layer services Multiple access links Adresavimas, ARP LANs Wireless LANs VU MIF CS 1/48 2/48 Computer Networks VU MIF CS 1/48 Today Principles of datalink layer services Multiple access links Adresavimas, ARP LANs Wireless LANs 2/48 1 Link layer: introduction terminology: hosts and routers: nodes

More information

CS 43: Computer Networks Media Access. Kevin Webb Swarthmore College November 30, 2017

CS 43: Computer Networks Media Access. Kevin Webb Swarthmore College November 30, 2017 CS 43: Computer Networks Media Access Kevin Webb Swarthmore College November 30, 2017 Multiple Access Links & Protocols Two classes of links : point-to-point dial-up access link between Ethernet switch,

More information

Chapter V: Link Layer

Chapter V: Link Layer Chapter V: Link Layer UG3 Computer Communications & Networks (COMN) Myungjin Lee myungjin.lee@ed.ac.uk Slides copyright of Kurose and Ross Link layer: introduction terminology: hosts and routers: nodes

More information

Chapter 5 Link Layer and LANs

Chapter 5 Link Layer and LANs Chapter 5 Link Layer and LANs A note on the use of these ppt slides: All material copyright 1996-2007 J.F Kurose and K.W. Ross, All Rights Reserved Computer Networking: A Top Down Approach 4 th edition.

More information

The Link Layer and LANs. Chapter 6: Link layer and LANs

The Link Layer and LANs. Chapter 6: Link layer and LANs The Link Layer and LANs EECS3214 2018-03-14 4-1 Chapter 6: Link layer and LANs our goals: understand principles behind link layer services: error detection, correction sharing a broadcast channel: multiple

More information

Module 10 Data Link Layer CS655! 10-1!

Module 10 Data Link Layer CS655! 10-1! Module 10 Data Link Layer CS655! 10-1! Please note: Most of these slides come from this book. Note their copyright notice below! A note on the use of these ppt slides: We re making these slides freely

More information

Links Reading: Chapter 2. Goals of Todayʼs Lecture. Message, Segment, Packet, and Frame

Links Reading: Chapter 2. Goals of Todayʼs Lecture. Message, Segment, Packet, and Frame Links Reading: Chapter 2 CS 375: Computer Networks Thomas Bressoud 1 Goals of Todayʼs Lecture Link-layer services Encoding, framing, and error detection Error correction and flow control Sharing a shared

More information

CS 43: Computer Networks Switches and LANs. Kevin Webb Swarthmore College December 5, 2017

CS 43: Computer Networks Switches and LANs. Kevin Webb Swarthmore College December 5, 2017 CS 43: Computer Networks Switches and LANs Kevin Webb Swarthmore College December 5, 2017 Ethernet Metcalfe s Ethernet sketch Dominant wired LAN technology: cheap $20 for NIC first widely used LAN technology

More information

Link Layer and LANs. Our Goals. Link Layer

Link Layer and LANs. Our Goals. Link Layer Link Layer and LANs Instructor: Anirban Mahanti Office: ICT 745 Email: mahanti@cpsc.ucalgary.ca Class Location: ICT 121 Lectures: MWF 12:00 12:50 hours Notes derived from Computer Networking: A Top Down

More information

Chapter 6: Link layer and LANs. Link layer, LANs: outline. Link layer: introduction. Link layer: context. Link layer services (more)

Chapter 6: Link layer and LANs. Link layer, LANs: outline. Link layer: introduction. Link layer: context. Link layer services (more) Chapter 6: Link layer and LANs our goals: understand principles behind layer services: error detection, sharing a broadcast channel: multiple access layer addressing local area networks: ernet, VLANs instantiation,

More information

Lecture 6. Data Link Layer (cont d) Data Link Layer 1-1

Lecture 6. Data Link Layer (cont d) Data Link Layer 1-1 Lecture 6 Data Link Layer (cont d) Data Link Layer 1-1 Agenda Continue the Data Link Layer Multiple Access Links and Protocols Addressing Data Link Layer 1-2 Multiple Access Links and Protocols Two types

More information

Principles behind data link layer services

Principles behind data link layer services Data link layer Goals: Principles behind data link layer services Error detection, correction Sharing a broadcast channel: Multiple access Link layer addressing Reliable data transfer, flow control: Done!

More information

Medium Access Control

Medium Access Control Medium Access Control All material copyright 1996-2009 J.F Kurose and K.W. Ross, All Rights Reserved 5: DataLink Layer 5-1 Link Layer Introduction and services Multiple access protocols Ethernet Wireless

More information

CSC 4900 Computer Networks: Link Layer (2)

CSC 4900 Computer Networks: Link Layer (2) CSC 4900 Computer Networks: Link Layer (2) Professor Henry Carter Fall 2017 Link Layer 6.1 Introduction and services 6.2 Error detection and correction 6.3 Multiple access protocols 6.4 LANs addressing,

More information

Chapter 5 Link Layer. Computer Networking: A Top Down Approach. 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012

Chapter 5 Link Layer. Computer Networking: A Top Down Approach. 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 Chapter 5 Link Layer Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 All material copyright 1996-2012 J.F Kurose and K.W. Ross, All Rights Reserved

More information

Lecture 6 The Data Link Layer. Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it

Lecture 6 The Data Link Layer. Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it Lecture 6 The Data Link Layer Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it Link Layer: setting the context two physically connected devices: host-router, router-router, host-host,

More information

CS 43: Computer Networks. 27: Media Access Contd. December 3, 2018

CS 43: Computer Networks. 27: Media Access Contd. December 3, 2018 CS 43: Computer Networks 27: Media Access Contd. December 3, 2018 Last Class The link layer provides lots of functionality: addressing, framing, media access, error checking could be used independently

More information

Summary of MAC protocols

Summary of MAC protocols Summary of MAC protocols What do you do with a shared media? Channel Partitioning, by time, frequency or code Time Division, Code Division, Frequency Division Random partitioning (dynamic) ALOHA, S-ALOHA,

More information

Chapter 4. DataLink Layer. Reference: Computer Networking: A Top Down Approach 4 th edition. Jim Kurose, Keith Ross Addison-Wesley, July 2007.

Chapter 4. DataLink Layer. Reference: Computer Networking: A Top Down Approach 4 th edition. Jim Kurose, Keith Ross Addison-Wesley, July 2007. Chapter 4 DataLink Layer Reference: Computer Networking: A Top Down Approach 4 th edition. Jim Kurose, Keith Ross Addison-Wesley, July 2007. DataLink Layer Link Layer 4.1 Link-Layer Addressing 4.2 Ethernet

More information

Link Layer: Introduction. Chapter 5 Link Layer & LANS. Link layer: context. Link Layer Services

Link Layer: Introduction. Chapter 5 Link Layer & LANS. Link layer: context. Link Layer Services Chapter 5 Link Layer & LANS Link Layer: Introduction Some terminology: hosts and routers are nodes communication channels that connect adjacent nodes along communication path are links wired links wireless

More information

Broadcast Links, Addressing and Media Access Control. Link Layer B. Link and Physical Layers. MAC Addresses

Broadcast Links, Addressing and Media Access Control. Link Layer B. Link and Physical Layers. MAC Addresses roadcast Links, ddressing and Media ccess Control Message M C Message M Link Layer In a broadcast, there are two additional issues that must be resolved How do the nodes agree on who gets to use the next?

More information

Lecture 5 The Data Link Layer. Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it

Lecture 5 The Data Link Layer. Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it Lecture 5 The Data Link Layer Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it Link Layer: setting the context two physically connected devices: host-router, router-router, host-host,

More information

Medium Access Protocols

Medium Access Protocols Medium Access Protocols Summary of MAC protocols What do you do with a shared media? Channel Partitioning, by time, frequency or code Time Division,Code Division, Frequency Division Random partitioning

More information

CS 455/555 Intro to Networks and Communications. Link Layer

CS 455/555 Intro to Networks and Communications. Link Layer CS 455/555 Intro to Networks and Communications Link Layer Dr. Michele Weigle Department of Computer Science Old Dominion University mweigle@cs.odu.edu http://www.cs.odu.edu/~mweigle/cs455-s13 1 Link Layer

More information

transferring datagram from one node data-link layer has responsibility of to adjacent node over a link 5-1 TDTS06 Computer networks

transferring datagram from one node data-link layer has responsibility of to adjacent node over a link 5-1 TDTS06 Computer networks TDTS06 Computer networks Lecture 7: The link layer I Link Layer: Introduction Some terminology: hosts and routers are nodes communication channels that connect adjacent nodes along communication path are

More information

ECE 4450:427/527 - Computer Networks Spring 2017

ECE 4450:427/527 - Computer Networks Spring 2017 ECE 4450:427/527 - Computer Networks Spring 2017 Dr. Nghi Tran Department of Electrical & Computer Engineering Lecture 5.4: Multiple Access Protocols Dr. Nghi Tran (ECE-University of Akron) ECE 4450:427/527

More information

Link Layer and Ethernet

Link Layer and Ethernet Link Layer and Ethernet 14-740: Fundamentals of Computer Networks Bill Nace Material from Computer Networking: A Top Down Approach, 6 th edition. J.F. Kurose and K.W. Ross traceroute Data Link Layer Multiple

More information

Chapter 5: DataLink Layer

Chapter 5: DataLink Layer Chapter 5: DataLink Layer Course on Computer Communication and Networks, CTH/GU The slides are adaptation of the slides made available by the authors of the course s main textbook Slides with darker background

More information

Chapter 5 Link Layer and LANs

Chapter 5 Link Layer and LANs Chapter 5 Link Layer and LANs A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add, modify, and

More information

Chapter 5 Link Layer and LANs

Chapter 5 Link Layer and LANs Chapter 5 Link Layer and LANs Computer Networking: A Top Down Approach 4 th edition. Jim Kurose, Keith Ross Addison-Wesley, July 2007. All material copyright 1996-2007 J.F Kurose and K.W. Ross, All Rights

More information

CS 455/555 Intro to Networks and Communications. Link Layer Addressing, Ethernet, and a Day in the Life of a Web Request

CS 455/555 Intro to Networks and Communications. Link Layer Addressing, Ethernet, and a Day in the Life of a Web Request CS 455/555 Intro to Networks and Communications Link Layer Addressing, ernet, and a Day in the Life of a Web Request Dr. Michele Weigle Department of Computer Science Old Dominion University mweigle@cs.odu.edu

More information

Link Layer and Ethernet

Link Layer and Ethernet Link Layer and Ethernet 14-740: Fundamentals of Computer Networks Bill Nace Material from Computer Networking: A Top Down Approach, 6 th edition. J.F. Kurose and K.W. Ross traceroute Data Link Layer Multiple

More information

Principles behind data link layer services:

Principles behind data link layer services: Data link layer Goals: Principles behind data link layer services: Error detection, correction Sharing a broadcast channel: Multiple access Link layer addressing Reliable data transfer, flow control Example

More information

CSCI Computer Networks Fall 2016

CSCI Computer Networks Fall 2016 source: computer-networks-webdesign.com CSCI 4760 - Computer Networks Fall 2016 Instructor: Prof. Roberto Perdisci perdisci@cs.uga.edu These slides are adapted from the textbook slides by J.F. Kurose and

More information

CMPE 150/L : Introduction to Computer Networks. Chen Qian Computer Engineering UCSC Baskin Engineering Lecture 16

CMPE 150/L : Introduction to Computer Networks. Chen Qian Computer Engineering UCSC Baskin Engineering Lecture 16 CMPE 150/L : Introduction to Computer Networks Chen Qian Computer Engineering UCSC Baskin Engineering Lecture 16 1 Final project demo Please do the demo next week to the TAs. So basically you may need

More information

Principles behind data link layer services:

Principles behind data link layer services: Data link layer Goals: Principles behind data link layer services: Error detection, correction Sharing a broadcast channel: Multiple access Link layer addressing Reliable data transfer, flow control Example

More information

Lecture 8 Link Layer: functionality, error detection, media access algorithm

Lecture 8 Link Layer: functionality, error detection, media access algorithm Lecture 8 Link Layer: functionality, error detection, media access algorithm From Kurose & Ross Book slightly modified by Romaric Duvignau duvignau@chalmers.se Thanks and enjoy! JFK/KWR All material copyright

More information

Chapter 5 Link Layer. Computer Networking: A Top Down Approach. 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012

Chapter 5 Link Layer. Computer Networking: A Top Down Approach. 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 Chapter 5 Link Layer A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you see the animations; and can

More information

CSCI Computer Networks Spring 2017

CSCI Computer Networks Spring 2017 source: computer-networks-webdesign.com CSCI 6760 - Computer Networks Spring 2017 Instructor: Prof. Roberto Perdisci perdisci@cs.uga.edu These slides are adapted from the textbook slides by J.F. Kurose

More information

Chapter 5: Link layer

Chapter 5: Link layer Chapter 5: Link layer our goals: v understand principles behind link layer services: error detection, correction sharing a broadcast channel: multiple access link layer addressing local area networks:

More information

Discussions. What are the main service. Ch06 Link Layer. The Data Link Layer. Link Layer. Link Layer: Teminology. What are the services

Discussions. What are the main service. Ch06 Link Layer. The Data Link Layer. Link Layer. Link Layer: Teminology. What are the services Mobile network Discussions The Link Layer Yanmin Zhu Department of Computer Science and Engineering Global ISP Home network Regional ISP Institutional network What are the services provided by the link

More information

High Level View. EE 122: Ethernet and Random Access protocols. Medium Access Protocols

High Level View. EE 122: Ethernet and Random Access protocols. Medium Access Protocols High Level View EE 122: Ethernet and 802.11 Ion Stoica September 18, 2002 Goal: share a communication medium among multiple hosts connected to it Problem: arbitrate between connected hosts Solution goals:

More information

CSC 8560 Computer Networks: Link Layer

CSC 8560 Computer Networks: Link Layer CSC 8560 Computer Networks: Link Layer Professor Henry Carter Fall 2017 Last Time We talked about intra-as routing protocols: Which routing algorithm is used in RIP? OSPF? What techniques allow OSPF to

More information

Multiple Access Links and Protocols

Multiple Access Links and Protocols Multiple Access Links and Protocols Two types of links : point-to-point PPP for dial-up access point-to-point link between Ethernet switch and host broadcast (shared wire or medium) old-fashioned Ethernet

More information

Module 4 Data Link Layer CS655! 4-1!

Module 4 Data Link Layer CS655! 4-1! Module 4 Data Link Layer CS655! 4-1! Please note: Most of these slides come from this book. Note their copyright notice below! A note on the use of these ppt slides: We re making these slides freely available

More information

Chapter 5 Link Layer. Computer Networking: A Top Down Approach. 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012

Chapter 5 Link Layer. Computer Networking: A Top Down Approach. 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 Chapter 5 Link Layer A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you see the animations; and can

More information

COS 140: Foundations of Computer Science

COS 140: Foundations of Computer Science COS 140: Foundations of Computer Science ALOHA Network Protocol Family Fall 2017 Homework 2 Introduction 3 Network Protocols.......................................................... 3 Problem.................................................................

More information

EE 122: Ethernet and

EE 122: Ethernet and EE 122: Ethernet and 802.11 Ion Stoica September 18, 2002 (* this talk is based in part on the on-line slides of J. Kurose & K. Rose) High Level View Goal: share a communication medium among multiple hosts

More information

Lecture 9 The Data Link Layer part II. Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it

Lecture 9 The Data Link Layer part II. Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it Lecture 9 The Data Link Layer part II Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it Physical Addresses Physical (or LAN or MAC) address: 48 bit string Hexadecimal representation

More information

Principles behind data link layer services:

Principles behind data link layer services: Data Link Layer Goals: Principles behind data link layer services: Error detection, correction Sharing a broadcast channel: multiple access Link layer addressing Reliable data transfer, flow control: Done!

More information

COS 140: Foundations of Computer Science

COS 140: Foundations of Computer Science COS 140: Foundations of C S Network Protocol Family Fall 2017 Copyright c 2002 2017 UMaine School of Computing and Information S 1 / 25 Homework Homework Slides, book Chapter 24 on line Homework: All exercises

More information

Data Link Layer. Our goals: understand principles behind data link layer services: instantiation and implementation of various link layer technologies

Data Link Layer. Our goals: understand principles behind data link layer services: instantiation and implementation of various link layer technologies Data Link Layer Our goals: understand principles behind data link layer services: link layer addressing instantiation and implementation of various link layer technologies 1 Outline Introduction and services

More information

CC451 Computer Networks

CC451 Computer Networks CC451 Computer Networks Lecture 9 Link Layer 5: DataLink Layer 5-1 Chapter 5 Link Layer and LANs A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students,

More information

CSMA/CD (Collision Detection)

CSMA/CD (Collision Detection) CSMA/CD (Collision Detection) CD (collision detection): easy in wired LANs: measure signal strengths, compare transmitted, received signals difficult in wireless LANs: received signal strength overwhelmed

More information

Chapter 5 Link Layer. Link Layer 5-1

Chapter 5 Link Layer. Link Layer 5-1 Chapter 5 Link Layer Link Layer 5-1 Link layer: introduction terminology: hosts and routers: nodes communication channels that connect adjacent nodes along communication path: links wired links wireless

More information

Chapter 5 Data Link Layer

Chapter 5 Data Link Layer Chapter 5 Data Link Layer Reti degli Elaboratori Canale AL Prof.ssa Chiara Petrioli a.a. 2013/2014 We thank for the support material Prof. Kurose-Ross All material copyright 1996-2012 J.F Kurose and K.W.

More information

Review. Error Detection: CRC Multiple access protocols. LAN addresses and ARP Ethernet. Slotted ALOHA CSMA/CD

Review. Error Detection: CRC Multiple access protocols. LAN addresses and ARP Ethernet. Slotted ALOHA CSMA/CD Review Error Detection: CRC Multiple access protocols Slotted ALOHA CSMA/CD LAN addresses and ARP Ethernet Some slides are in courtesy of J. Kurose and K. Ross Overview Ethernet Hubs, bridges, and switches

More information

Chapter 5 Link Layer. Computer Networking: A Top Down Approach. 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012

Chapter 5 Link Layer. Computer Networking: A Top Down Approach. 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 Chapter 5 Link Layer A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you see the animations; and can

More information

Getting Connected (Chapter 2 Part 4) Networking CS 3470, Section 1 Sarah Diesburg

Getting Connected (Chapter 2 Part 4) Networking CS 3470, Section 1 Sarah Diesburg Getting Connected (Chapter 2 Part 4) Networking CS 3470, Section 1 Sarah Diesburg Five Problems Encoding/decoding Framing Error Detection Error Correction Media Access Five Problems Encoding/decoding Framing

More information

Link layer, LANs: outline. Chapter 5-2 Link Layer. MAC addresses (more) MAC addresses

Link layer, LANs: outline. Chapter 5-2 Link Layer. MAC addresses (more) MAC addresses Chapter 5-2 Link Layer Computer Networking: Top Down pproach 6 th edition Jim Kurose, Keith Ross ddison-wesley March 2012 Link layer, LNs: outline 5.1 introduction, services 5.2 error detection, correction

More information

CSE 461: Multiple Access. Homework: Chapter 2, problems 1, 8, 12, 18, 23, 24, 35, 43, 46, and 58

CSE 461: Multiple Access. Homework: Chapter 2, problems 1, 8, 12, 18, 23, 24, 35, 43, 46, and 58 CSE 461: Multiple Access Homework: Chapter 2, problems 1, 8, 12, 18, 23, 24, 35, 43, 46, and 58 Next Topic Key Focus: How do multiple parties share a wire? This is the Medium Access Control (MAC) portion

More information

Chapter 5 Data Link Layer

Chapter 5 Data Link Layer Chapter 5 Data Link Layer Reti di Elaboratori Corso di Laurea in Informatica Università degli Studi di Roma La Sapienza Canale A-L Prof.ssa Chiara Petrioli Parte di queste slide sono state prese dal materiale

More information

Chapter 5: The Data Link Layer

Chapter 5: The Data Link Layer Chapter 5: The Data Link Layer Our goals: principles behind data link layer services: error detection, correction sharing a broadcast channel: multiple access link layer addressing reliable data transfer,

More information

Lecture 9: Bridging. CSE 123: Computer Networks Alex C. Snoeren

Lecture 9: Bridging. CSE 123: Computer Networks Alex C. Snoeren Lecture 9: Bridging CSE 123: Computer Networks Alex C. Snoeren Lecture 9 Overview Finishing up media access Ethernet Contention-free methods (rings) Moving beyond one wire Link technologies have limits

More information

MULTIPLE ACCESS PROTOCOLS 2. 1

MULTIPLE ACCESS PROTOCOLS 2. 1 MULTIPLE ACCESS PROTOCOLS AND WIFI 1 MULTIPLE ACCESS PROTOCOLS 2. 1 MULTIPLE ACCESS LINKS, PROTOCOLS Two types of links : point-to-point broadcast (shared wire or medium) POINT-TO-POINT PPP for dial-up

More information

Lecture 19. Principles behind data link layer services Framing Multiple access protocols

Lecture 19. Principles behind data link layer services Framing Multiple access protocols Link Layer Lecture 19 Principles behind data link layer services Framing Multiple access protocols ALOHA *The slides are adapted from ppt slides (in substantially unaltered form) available from Computer

More information

Data Link Layer: Multi Access Protocols

Data Link Layer: Multi Access Protocols Digital Communication in the Modern World Data Link Layer: Multi Access Protocols http://www.cs.huji.ac.il/~com1 com1@cs.huji.ac.il Some of the slides have been borrowed from: Computer Networking: A Top

More information

ECE 4450:427/527 - Computer Networks Spring 2017

ECE 4450:427/527 - Computer Networks Spring 2017 ECE 4450:427/527 - Computer Networks Spring 2017 Dr. Nghi Tran Department of Electrical & Computer Engineering Lecture 5.5: Ethernet Dr. Nghi Tran (ECE-University of Akron) ECE 4450:427/527 Computer Networks

More information

CCM 4300 Lecture 5 Computer Networks, Wireless and Mobile Communications. Dr Shahedur Rahman. Room: T115

CCM 4300 Lecture 5 Computer Networks, Wireless and Mobile Communications. Dr Shahedur Rahman. Room: T115 CCM 4300 Lecture 5 Computer Networks, Wireless and Mobile Communications Dr Shahedur Rahman s.rahman@mdx.ac.uk Room: T115 1 Recap of Last Session Described the physical layer Analogue and Digital signal

More information

Outline. Introduction to Networked Embedded Systems - Embedded systems Networked embedded systems Embedded Internet - Network properties

Outline. Introduction to Networked Embedded Systems - Embedded systems Networked embedded systems Embedded Internet - Network properties Outline Introduction to Networked Embedded Systems - Embedded systems Networked embedded systems Embedded Internet - Network properties Layered Network Architectures - OSI framework descriptions of layers

More information

Chapter 5: Link layer

Chapter 5: Link layer Chapter 5: Link layer our goals: v understand principles behind link layer services: error detection, correction sharing a broadcast channel: multiple access link layer addressing local area networks:

More information

Link layer, LANs: outline. Chapter 5-1 Link Layer. Link layer: introduction. Link layer services

Link layer, LANs: outline. Chapter 5-1 Link Layer. Link layer: introduction. Link layer services Chapter 5 Link Layer Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 Link layer, LANs: outline 5.1 introduction, services 5.2 error detection, correction

More information

CSC 4900 Computer Networks: The Link Layer

CSC 4900 Computer Networks: The Link Layer CSC 4900 Computer Networks: The Link Layer Professor Henry Carter Fall 2017 Last Time We talked about intra-as routing protocols: Which routing algorithm is used in RIP? OSPF? What techniques allow OSPF

More information

Lecture 6 - Link layer. Lecture 5 Review. Link Layer. Introduction, Services. Notes. Notes. Notes. Notes. Networks and Security. Jacob Aae Mikkelsen

Lecture 6 - Link layer. Lecture 5 Review. Link Layer. Introduction, Services. Notes. Notes. Notes. Notes. Networks and Security. Jacob Aae Mikkelsen Lecture 6 - Link layer Networks and Security Jacob Aae Mikkelsen IMADA October 21, 2013 October 21, 2013 1 / 91 Lecture 5 Review Explain in short the following abbreviations, and the concept behind it.

More information

Chapter 6 The Link Layer and LANs

Chapter 6 The Link Layer and LANs Chapter 6 The Link Layer and LANs A note on the use of these Powerpoint slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you see the

More information

Chapter 6 The Link Layer and LANs

Chapter 6 The Link Layer and LANs Chapter 6 The Link Layer and LANs Andrei Gurtov TDTS04/TDTS11/TDDD93 All material copyright 1996-2016 J.F Kurose and K.W. Ross, All Rights Reserved Computer Networking: A Top Down Approach 7 th edition

More information

Chapter 6 The Link Layer and LANs

Chapter 6 The Link Layer and LANs Chapter 6 The Link Layer and LANs Andrei Gurtov All material copyright 1996-2016 J.F Kurose and K.W. Ross, All Rights Reserved Computer Networking: A Top Down Approach 7 th edition Jim Kurose, Keith Ross

More information

CSC 401 Data and Computer Communications Networks

CSC 401 Data and Computer Communications Networks CSC 401 Data and Computer Communications Networks Link Layer: Intro, Errors, Multiple Access Sec 6.1, 6.2, 6.3 Prof. Lina Battestilli Fall 2017 Chapter 6: Link layer Goals: understand principles behind

More information

Chapter 6 The Link Layer and LANs

Chapter 6 The Link Layer and LANs Chapter 6 The Link Layer and LANs A note on the use of these Powerpoint slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you see the

More information

Link Layer and LANs. CMPS 4750/6750: Computer Networks

Link Layer and LANs. CMPS 4750/6750: Computer Networks Link Layer and LANs CMPS 4750/6750: Computer Networks 1 Outline overview (6.1) multiple access (6.3) link addressing: ARP (6.4.1) a day in the life of a web request (6.7) 2 Link layer: introduction terminology:

More information

Chapter 6 The Data Link layer

Chapter 6 The Data Link layer Chapter 6 The Data Link layer 6.1 introduction, services 6.2 error detection, correction 6.3 multiple access protocols 6.4 LANs addressing, ARP Ethernet layer-2 switches VLANS 6.5 link virtualization:

More information

Chapter 5 Link Layer and LANs

Chapter 5 Link Layer and LANs Chapter 5 Link Layer and LANs Computer Networking: A Top Down Approach Featuring the Internet, A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students,

More information

Contention Protocols and Networks

Contention Protocols and Networks 4/13/2005 314 Lecture Contention Protocols and Networks 1 Contention Protocols and Networks Contention Protocols CSMA/CD Network Topologies Ethernet 4/13/2005 314 Lecture Contention Protocols and Networks

More information

Link Layer and LANs 안상현서울시립대학교컴퓨터 통계학과.

Link Layer and LANs 안상현서울시립대학교컴퓨터 통계학과. Link Layer and LANs 안상현서울시립대학교컴퓨터 통계학과 ahn@venus.uos.ac.kr Data Link Layer Goals: understand principles behind data link layer services: error detection, correction sharing a broadcast channel: multiple

More information

EITF25 Internet Techniques and Applications L4: Network Access. Stefan Höst

EITF25 Internet Techniques and Applications L4: Network Access. Stefan Höst EITF25 Internet Techniques and Applications L4: Network Access Stefan Höst Repetition The link layer protocol should make sure that the data is correctly transmitted over the physical link using error

More information

Computer Networks Medium Access Control. Mostafa Salehi Fall 2008

Computer Networks Medium Access Control. Mostafa Salehi Fall 2008 Computer Networks Medium Access Control Mostafa Salehi Fall 2008 2008 1 Outline Issues ALOHA Network Ethernet Token Ring Wireless 2 Main Issues Local Area Network (LAN) : Three or more machines are physically

More information

Chapter 6 The Link Layer and LANs

Chapter 6 The Link Layer and LANs Chapter 6 The Link Layer and LANs Chapter 6: Link layer and LANs our goals: understand principles behind link layer services: error detection, correction sharing a broadcast channel: multiple access link

More information