Link Layer and Ethernet
|
|
- Clement Poole
- 5 years ago
- Views:
Transcription
1 Link Layer and Ethernet : Fundamentals of Computer Networks Bill Nace Material from Computer Networking: A Top Down Approach, 6 th edition. J.F. Kurose and K.W. Ross
2 traceroute Data Link Layer Multiple (Media / Medium) Access Protocols Ethernet 2
3 Data Link Layer Mission The Data Link Layer transfers frames from one node, over a link, to an adjacent node i.e. service provided to network layer Service received from physical layer is the ability to move a bit across the link 3
4 Data Link Layer Link layer data is called a frame and will encapsulate a network layer datagram Link: Communication channel that connects adjacent nodes (host or router) Point-to-Point Broadcast Router has multiple link layers (one per interface) Each link is a subnet Local ISP Regional ISP Company Network
5 Context A packet is transferred by different link protocols over different links e.g., Ethernet on first link, frame relay on intermediate links, on last link Each data link protocol provides different services e.g., may or may not provide reliable data transfer over link Local ISP Regional ISP Company Network
6 Link Layer Services Framing: encapsulate datagram into frame, adding header, trailer identify source, destination with addresses Different from IP addresses!! Link access: use medium access control (MAC) protocol Point-to-point channels: this is trivial Broadcast channels: more interesting 6
7 Link Layer Services (2) Error Detection: errors caused by signal attenuation, noise, crosstalk, etc if receiver detects errors, signals for retransmission or drops frame Error Correction: receiver identifies and corrects bit error(s) without resorting to retransmission 7
8 Link Layer Services (3) Reliable Delivery: between adjacent nodes similar to Reliable Data Transport seldom used on low bit-error links (fiber, twisted pair) critical for wireless links high error rates 8
9 MTU Remember Max Transmission Unit? A value derived from the technology of the data-link layer The largest number of bytes carried in the payload of a frame Does not include the link-layer header or trailer 9
10 Various Link Layers FDDI: Fiber Distributed Data Interface Frame size: up to 4514 bytes Frame Relay Frame size: 46 to 4470 bytes ATM: Asynchronous Transfer Mode Frame size: always 53 bytes 10
11 traceroute Data Link Layer Multiple (Media / Medium) Access Protocols Ethernet 11
12 Two Types of Links Point-to-point (sender to receiver) point-to-point link between Ethernet switch and host Point-to-Point Protocol (PPP) used to negotiate, establish, authenticate, etc Broadcast (shared wire or medium) traditional Ethernet wireless LAN 12
13 Medium Access Control Protocols For a single shared broadcast channel Simultaneous transmissions by 2 or more nodes interference collision if node receives two or more signals at the same time Multiple access protocol: a distributed algorithm that determines how nodes share channel communication about channel sharing must use channel itself! 13
14 MAC Protocols: A Taxonomy Channel Partitioning Taking Turns Random Access 14
15 Channel Partitioning Divide the channel into pieces time slots, frequency, or code Let each node use a piece of the channel Each node gets R/N bps, where R is channel throughput, N is # of nodes BUT: If < N nodes want to send, they still only get R/N bps 15
16 Taking Turns Taking Turns Like a time slot partition scheme... but, nodes with more to send can take longer turns Polling Protocol Master node asks each node in turn to send Examples: and Bluetooth Token-passing Special-purpose frame is passed in fixed order from node to node (pattern repeats indefinitely) Only the node with the token may send Examples: FDDI and (token-ring) 16
17 Random Access Transmitting node always sends at R bps Multiple nodes can send simultaneously Collision Collisions can be avoided or detected Avoided: Wireless, LocalTalk Detected: CSMA/CD Protocols 17
18 CSMA / CD Carrier Sense: Listen before talking Multiple Access: Broadcast Medium Collision Detection: Listen as you talk. If you hear someone else, be quiet Ethernet is the most famous example 18
19 CSMA / CD Overview Before transmitting, listen If channel is sensed idle, send the frame Else, defer transmission a random time If collision is detected, abort transmission reduces channel wastage 19
20 Collision Detection Easy in wired LANs Measure signal strengths, compare the transmitted and received signals Difficult in wireless LANs Receiver is shut off during transmission Hidden terminal problem You may not hear transmission from someone out of your range, but others will 20
21 Capturing a Channel Transmission is vulnerable for 1 propagation delay collision could occur If no other station initiates transmission during this period, sender has captured the channel No other node will initiate send Node transmits at t=0 Node captures channel at t=tprop
22 Space-Time Diagrams Illustrate propagation delay of message through the channel Message transmission time Time Space
23 Multiple Transmitters Time Signals mix, collision detected!
24 Detecting Collisions Time Min transmission time must be long enough for collisions to propagate
25 traceroute Data Link Layer Multiple (Media / Medium) Access Protocols Ethernet 25
26 History Developed at Xerox PARC, ish By Robert Metcalfe, David Boggs, Chuck Thacker and Butler Lampson Metcalfe founded 3Com and popularized Quickly became the dominant LAN technology Standardized as IEEE Originally 3Mbps, now up to 100Gbps 400Gbps expected
27 Ethernet Services Connectionless No handshaking Unreliable Damaged frames are discarded No ACK or NACK generated by receiver In-order delivery 27
28 Topology Bus Topology: shared cable 28
29 Topology (2) Star Topology!!!!!! High-Speed backplane or interconnection fabric!!!! 29
30 Ethernet Frame Preamble Dest Addr Source Addr Data CRC Type Preamble: 8 bytes 7 bytes with pattern followed by one byte with pattern used to synchronize receiver, sender clock rates 30
31 Ethernet Frame Preamble Dest Addr Source Addr Data CRC Type Dest, Source Addresses: 6 bytes each Flat address space, globally unique 3 bytes indicate adapter manufacturer 3 bytes generated uniquely Watch out: Can be changed/spoofed Broadcast address exists 31
32 Ethernet Frame Preamble Dest Addr Source Addr Data CRC Type Type: 2 bytes Indicates the network-layer protocol Mostly IP, ARP Others include Novell IXP, AppleTalk 32
33 Ethernet Frame Preamble Dest Addr Source Addr Data CRC Type Data: bytes Encapsulated datagram Short datagrams padded to 46 bytes IP receiver discards based on datagram length field in IP header 33
34 Ethernet Frame Preamble Dest Addr Source Addr Data CRC Type CRC: 4 bytes Error Checking Receiver will check simply discard frame on error 34
35 Ethernet Frame Preamble Dest Addr Source Addr Data CRC Type Total Frame Min size: 64 bytes + preamble = 72 bytes Long enough to guarantee collision detection in max length cable (100m) Max size: 1518 bytes + preamble Short enough to minimize wait times, receiver buffer requirements 35
36 Tx Algorithm 1. Ethernet adapter receives datagram from network-layer and builds frame Source address is MAC of sending adapter Destination address chosen based on IP address Address Resolution Protocol (ARP) Generates CRC often via H/W as frame is sent 36
37 Alg: Carrier Sense 2.Adapter listens for 96 bit times of idle channel Bit time is.1usec for 10Mbps Ethernet Variants exist for 1Mbps - 10Gbps If channel is idle, then transmit the frame If not idle, wait for it to be idle for 96 bit times 37
38 Alg: Collision Detection 3.While transmitting, listen and compare to sending values If no difference, great If collision, abort and send jam signal 48 bit times long Inform other transmitters of collision 38
39 Alg: Exponential Backoff 4. If collision happens, wait a random time before attempting transmission again For n th collision in a row, m=min{n,10} choose random value K from {0..2 m -1} {0,1} then {0,1,2,3}... { } wait 512 K bit times before going back to step number 2 (carrier sense) After 16 collisions, give up 39
40 Question #1 For 10Mbps Ethernet, what is the maximum wait time after a collision? 40
41 Question #2 A and B are on a 10 Mbps segment. What is the max separation to still guarantee collision detection? 41
42 Question #3 At t=0, A and B (who are separated by 200 bit times) each try to transmit a frame with 1500 bytes of data. A collision occurs, after which Ka = 0 and Kb = 1. At what time will B start retransmitting the frame? 42
43 Lesson Objectives Now, you should be able to: describe the mission, scope, addressing mechanism, data types and services / responsibilities of the Data Link Layer describe the differences between broadcast and point-to-point links describe three different general types of media access protocols 43
44 You should be able to: describe the CSMA/CD protocol, including the details of Ethernet's implementation use space-time diagrams to describe or solve problems relating to media access, including details of Ethernet's implementation describe the Ethernet frame format solve problems involving interaction of several Ethernet senders and receivers, collisions, propagation times, and the details of Ethernet's CSMA/CD algorithm
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 informationLinks 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 informationLecture 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 informationLecture 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 informationModule 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 informationChapter 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 informationHigh 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 informationPrinciples 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 informationEE 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 informationComputer 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 informationPrinciples 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 informationMaster 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 informationTopics. 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 informationReminder: Datalink Functions Computer Networking. Datalink Architectures
Reminder: Datalink Functions 15-441 15 441 15-641 Computer Networking Lecture 5 Media Access Control Peter Steenkiste Fall 2015 www.cs.cmu.edu/~prs/15-441-f15 Framing: encapsulating a network layer datagram
More informationChapter 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 informationChapter 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 informationSummary 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 informationChapter 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 informationThe 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 informationAdaptors 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 informationModule 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 informationCS 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 informationPrinciples 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 informationPrinciples 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 informationData 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 informationReview. 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 informationData 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 informationCSC 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 informationLink 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 informationCS 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 informationMedium 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 informationChapter 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 informationChapter 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 informationCMPE 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 informationChapter 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 informationCSMA/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 informationChapter 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 informationLecture 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 informationCMPE 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 informationChapter 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 informationMaster 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 informationAdaptors 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 informationThe Link Layer II: Ethernet
Monday Recap The Link Layer II: Ethernet q Link layer services q Principles for multiple access protocols q Categories of multiple access protocols CSC 249 March 24, 2017 1 2 Recap: Random Access Protocols
More informationLink 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 informationChapter 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 informationMedium 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 informationLink 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 informationLecture 8 The Data Link Layer part I. Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it
Lecture 8 The Data Link Layer part I Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it Link Layer: setting the context two physically connected devices: host-router, router-router,
More informationChapter 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 informationLecture 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 informationComputer Network Fundamentals Spring Week 3 MAC Layer Andreas Terzis
Computer Network Fundamentals Spring 2008 Week 3 MAC Layer Andreas Terzis Outline MAC Protocols MAC Protocol Examples Channel Partitioning TDMA/FDMA Token Ring Random Access Protocols Aloha and Slotted
More informationCC451 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 informationChapter 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 informationCSC 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 informationLinks. CS125 - mylinks 1 1/22/14
Links 1 Goals of Today s Lecture Link-layer services Encoding, framing, and error detection Error correction and flow control Sharing a shared media Channel partitioning Taking turns Random access Shared
More informationOutline. 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 informationCARRIER SENSE MULTIPLE ACCESS (CSMA):
Lecture Handout Computer Networks Lecture No. 8 CARRIER SENSE MULTIPLE ACCESS (CSMA): There is no central control management when computers transmit on Ethernet. For this purpose the Ethernet employs CSMA
More informationComputer Networking Lecture 5 Data link Layer Access Control. Based on slides by Peter Steenkiste Copyright, Carnegie Mellon
15-441 Computer Networking Lecture 5 Data link Layer Access Control Based on slides by Peter Steenkiste Copyright, Carnegie Mellon 2007-12 1 Datalink Functions Framing: encapsulating a network layer datagram
More informationIntroductory to Computer Networks Local Area Networks. Lecture 16 Fall Isfahan University of technology Dr.
Introductory to Computer Networks Local Area Networks Lecture 16 Fall 2010 Isfahan University of technology Dr. Faramarz Hendessi What is a LAN? Local area means: Private ownership freedom from regulatory
More informationLinks. Error Detection. Link Layer. Multiple access protocols. Nodes Links Frame. Shared channel Problem: collisions How nodes share a channel
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
More informationComputer Networks Principles LAN - Ethernet
Computer Networks Principles LAN - Ethernet Prof. Andrzej Duda duda@imag.fr http://duda.imag.fr 1 Interconnection structure - layer 3 interconnection layer 3 router subnetwork 1 interconnection layer 2
More informationCSCD 330 Network Programming
CSCD 330 Network Programming Spring 2018 Lecture 17 Link Layer Hardware and Protocols Who is this? Reading: Chapter 5 in text Some slides provided courtesy of J.F Kurose and K.W. Ross, All Rights Reserved,
More informationCSCI 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 informationCSCI 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 informationLink 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 informationChapter 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 informationLecture 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 informationCS 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 informationChapter 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 informationECE 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 informationLink 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 informationLecture 4b. Local Area Networks and Bridges
Lecture 4b Local Area Networks and Bridges Ethernet Invented by Boggs and Metcalf in the 1970 s at Xerox Local area networks were needed to connect computers, share files, etc. Thick or Thin Ethernet Cable
More informationtransferring 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 informationData Link Layer, Part 5. Medium Access Control
CS 455 Medium Access Control, Page 1 Data Link Layer, Part 5 Medium Access Control These slides are created by Dr. Yih Huang of George Mason University. Students registered in Dr. Huang s courses at GMU
More informationCS 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 informationLecture 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 informationData Link Layer, Part 3 Medium Access Control. Preface
Data Link Layer, Part 3 Medium Access Control These slides are created by Dr. Yih Huang of George Mason University. Students registered in Dr. Huang's courses at GMU can make a single machine-readable
More informationThe 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 informationData Link Protocols. TCP/IP Suite and OSI Reference Model. The TCP/IP protocol stack does not define the lower layers of a complete protocol stack
Data Link Protocols TCP/IP Suite and OSI Reference Model The TCP/IP protocol stack does not define the lower layers of a complete protocol stack In this lecture, we will address how the TCP/IP protocol
More informationCSCD 330 Network Programming Fall 2012
CSCD 330 Network Programming Fall 2012 Lecture 17 Link Layer Hardware and Protocols Who is this? Reading: Chapter 5 in text Some slides provided courtesy of J.F Kurose and K.W. Ross, All Rights Reserved,
More informationChapter 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 informationChapter 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 informationChapter 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 informationData Link Layer -2- Network Access
EITF25 Internet: Technology and Applications Data Link Layer -2- Network Access 2015, Lecture 03 Kaan Bür Previously on EITF25 Logical Link Control Sublayer Flow control Send data Wait for ACK Error control
More informationChapter 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 informationECE 158A: Lecture 13. Fall 2015
ECE 158A: Lecture 13 Fall 2015 Random Access and Ethernet! Random Access! Basic idea: Exploit statistical multiplexing Do not avoid collisions, just recover from them When a node has packet to send Transmit
More informationCSC 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 informationCCM 4300 Lecture 6 Computer Networks, Wireless and Mobile Communications. Dr Shahedur Rahman. Room: T115
CCM 4300 Lecture 6 Computer Networks, Wireless and Mobile Communications Dr Shahedur Rahman s.rahman@mdx.ac.uk Room: T115 1 Recap of Last Session Access Control ALOHA FDMA, TDMA, CDMA OSI Model Internetworking
More informationChapter 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 informationComputer 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 informationData and Computer Communications. Chapter 11 Local Area Network
Data and Computer Communications Chapter 11 Local Area Network LAN Topologies Refers to the way in which the stations attached to the network are interconnected Bus Topology Used with multipoint medium
More informationCSE 461: Multiple Access Networks. This Lecture
CSE 461: Multiple Access Networks This Lecture Key Focus: How do multiple parties share a wire? This is the Medium Access Control (MAC) portion of the Link Layer Randomized access protocols: 1. Aloha 2.
More informationData Link Layer -2- Network Access
EITF25 Internet: Technology and Applications Data Link Layer -2- Network Access 2013, Lecture 03 Kaan Bür, Stefan Höst Previously on EITF25 Logical Link Control Sublayer Flow control Send data Wait for
More informationRedes 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 informationChapter 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 informationCOMP211 Chapter 6/7 Link Layer
COMP211 Chapter 6/7 Link Layer All material copyright 1996-2012 J.F Kurose and K.W. Ross, All Rights Reserved Computer Networking: A Top Down Approach 7 th edition Jim Kurose, Keith Ross Pearson/Addison
More informationCS 3516: Computer Networks
Welcome to CS 3516: Computer Networks Prof. Yanhua Li Time: 9:00am 9:50am M, T, R, and F Location: AK219 Fall 2018 A-term 1 Some slides are originally from the course materials of the textbook Computer
More informationLAN PROTOCOLS. Beulah A AP/CSE
LAN PROTOCOLS Beulah A AP/CSE IEEE STANDARDS In 1985, the Computer Society of the IEEE started a project, called Project 802, to set standards to enable intercommunication among equipment from a variety
More informationChapter 6 The Data Link layer
Chapter 6 The Data Link layer 6.1 introduction, services 6.2 error detection, correction 63 6.3 multiple lil access protocols 64LAN 6.4 LANs addressing, ARP Ethernet layer-2 switches VLANS 6.5 link virtualization:
More informationLecture 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