Chapter 6 Computer Networking The Link Layer A TOP-DOWN APPROA⊙升TH0T米 and LANs KUROSE·ROSS A note on the use of these Powerpoint slides: We're making these slides freely available to all (faculty,students,readers). Theyre in PowerPoint form so you see the animations:and can add,modify. and delete slides (including this one)and slide content to sut your needs. They obviously represent a lot of work on our part.In return for use,we only ask the following: Computer If you use these slides (e.g..in a class)that you mention their source Networking:A Top (after all,we'd like people to use our book!) If you post any slides on a www site.that you note that they are adapted from (or perhaps identical to)our slides,and note our copyright of this Down Approach material. 7th edition Thanks and enjoy!JFK/KWR Jim Kurose,Keith Ross noReered Pearson/Addison Wesley April 2016 Link Layer and LANs 6-1
Computer Networking: A Top Down Approach 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 animations; and can add, modify, and delete slides (including this one) and slide content to suit your needs. They obviously represent a lot of work on our part. In return for use, we only ask the following: ▪ If you use these slides (e.g., in a class) that you mention their source (after all, we’d like people to use our book!) ▪ If you post any slides on a www site, that you note that they are adapted from (or perhaps identical to) our slides, and note our copyright of this material. Thanks and enjoy! JFK/KWR All material copyright 1996-2016 J.F Kurose and K.W. Ross, All Rights Reserved 7 th edition Jim Kurose, Keith Ross Pearson/Addison Wesley April 2016 Chapter 6 The Link Layer and LANs Link Layer and LANs 6-1
Chapter 6:Link layer and LANs our goals: understand principles behind link layer services: error detection,correction sharing a broadcast channel:multiple access link layer addressing local area networks:Ethernet,VLANs instantiation,implementation of various link layer technologies Link Layer and LANs 6-2
Chapter 6: Link layer and LANs our goals: ▪ understand principles behind link layer services: • error detection, correction • sharing a broadcast channel: multiple access • link layer addressing • local area networks: Ethernet, VLANs ▪ instantiation, implementation of various link layer technologies Link Layer and LANs 6-2
Link layer,LANs:outline 6.I introduction,services 6.5 link virtualization: 6.2 error detection, MPLS correction 6.6 data center 6.3 multiple access networking protocols 6.7 a day in the life of a 6.4 LANs web request ·addressing,ARP ·Ethernet ·switches ·VLANS Link Layer and LANs 6-3
Link layer, LANs: outline 6.1 introduction, services 6.2 error detection, correction 6.3 multiple access protocols 6.4 LANs • addressing, ARP • Ethernet • switches • VLANS 6.5 link virtualization: MPLS 6.6 data center networking 6.7 a day in the life of a web request Link Layer and LANs 6-3
Link layer:introduction terminology: hosts and routers:nodes communication channels that connect adjacent nodes along communication path:links 。wired links ·wireless links ·LANs layer-2 packet:frame, encapsulates datagram data-link layer has responsibility of transferring datagram from one node to physically adjacent node over a link Link Layer and LANs 6-4
Link layer: introduction terminology: ▪ hosts and routers: nodes ▪ communication channels that connect adjacent nodes along communication path: links • wired links • wireless links • LANs ▪ layer-2 packet: frame, encapsulates datagram data-link layer has responsibility of transferring datagram from one node to physically adjacent node over a link Link Layer and LANs 6-4
Link layer:context datagram transferred by transportation analogy: different link protocols over trip from Princeton to Lausanne different links: limo:Princeton to JFK e.g.,Ethernet on first link, ·plane:JFK to Geneva frame relay on train:Geneva to Lausanne intermediate links,802.II ■tourist=datagram on last link transport segment each link protocol provides communication link different services ■ transportation mode link 。eg,may or may not layer protocol provide rdt over link travel agent routing algorithm Link Layer and LANs 6-5
Link layer: context ▪ datagram transferred by different link protocols over different links: • e.g., Ethernet on first link, frame relay on intermediate links, 802.11 on last link ▪ each link protocol provides different services • e.g., may or may not provide rdt over link transportation analogy: ▪ trip from Princeton to Lausanne • limo: Princeton to JFK • plane: JFK to Geneva • train: Geneva to Lausanne ▪ tourist = datagram ▪ transport segment = communication link ▪ transportation mode = link layer protocol ▪ travel agent = routing algorithm Link Layer and LANs 6-5