Lecture 7 Datalink Ethernet, Home. Datalink Layer Architectures

Size: px
Start display at page:

Download "Lecture 7 Datalink Ethernet, Home. Datalink Layer Architectures"

Transcription

1 Lecture 7 Dataink Ethernet, Home Peter Steenkiste Schoo of Computer Science Department of Eectrica and Computer Engineering Carnegie Meon University Networking, Spring Peter A. Steenkiste, SCS, CMU 1 Dataink Layer Architectures Packet forwarding. Error and fow contro. Media access contro. Scaabiity. Peter A. Steenkiste, SCS, CMU 2 Page 1

2 Mutipe Access Protocos Prevent two or more nodes from transmitting at the same time over a broadcast channe.» If they do, we have a coision, and receivers wi not be abe to interpret the signa Severa casses of mutipe access protocos.» Partitioning the channe, e.g. frequency-division or time division mutipexing With fixed partitioning of bandwidth not fexibe» Taking turns, e.g. token-based, reservation-based protocos, poing based» Contention based protocos, e.g. Aoha, Ethernet Peter A. Steenkiste, SCS, CMU 3 Today s Lecture LAN technoogies: Ethernet. Bridges and LAN switches. Connectivity to the home. Peter A. Steenkiste, SCS, CMU 4 Page 2

3 Aoha Nodes sends the message when it has data to send. If it receives an ack, it considers the transmission competed, otherwise it retransmits after a random deay. Simpe, distributed protoco, but not very efficient» 18% maximum utiization Sotted Aoha: more efficient.» Reduces chances of coision» 37% maximum utiization Centra Computer Peter A. Steenkiste, SCS, CMU Ethernet Broadcast technoogy host host host host host host host host Hub Carrier-sense mutipe access with coision detection (CSMA/CD).» MA = mutipe access» CS = carrier sense» CD = coision detection Base Ethernet standard is 10 Mbs.» Origina design was ~2 Mbs» Faster versions discussed ater Peter A. Steenkiste, SCS, CMU 6 Page 3

4 Contention-Based Protoco Goa: share the communication channe among mutipe hosts sharing it. Probem: how to arbitrate between the connected hosts. Desired properties:» High bandwidth utiization» Avoid starvation, achieve fairness» Simpe soution Idea: access the channe in a random way - when coisions occur, recover.» Coision: two or more nodes transmitting at the same time Peter A. Steenkiste, SCS, CMU 7 CSMA/CD Agorithm Sense for carrier. If carrier present, wait unti carrier ends.» Sending woud force a coision and waste time Send packet and sense for coision. If no coision detected, consider packet deivered. Otherwise, abort immediatey, perform exponentia back off and send packet again.» Start to send at a random time picked from an interva» Length of the interva increases with every retransmission Peter A. Steenkiste, SCS, CMU 8 Page 4

5 Coision Detection A B C Time Peter A. Steenkiste, SCS, CMU 9 Coision Detection: Impications A B C A nodes must be abe to detect the coision.» Any node can be sender The impication is that either we must have a short wires, or ong packets.» Or a combination of both Can cacuate ength/distance based on transmission rate and propagation speed.» Messy: propagation speed is media-dependent, ow-eve protoco detais,..» Minimum packet size is 64 bytes Cabe ength ~256 bit times» Exampe: maximum coax cabe ength is 2.5 km Peter A. Steenkiste, SCS, CMU 10 Page 5

6 CSMA/CD: Some Detais Successive frames are separated by an interframe gap.» Nodes must switch from send to receive mode» Set to 9.6 µsec or 96 bit times When a sender detects a coision, it sends a jam signa.» Make sure that a nodes are aware of the coision» Length of the jam signa is 32 bit times Exponentia backoff operates in mutipes of 512 bit times.» Longer than a roundtrip time» Guarantees that nodes that back off onger wi notice the earier retransmission before starting to send Peter A. Steenkiste, SCS, CMU 11 Why a Minimum Packet Size Give a host enough time to detect a coision. In Ethernet, the minimum packet size is 64 bytes.» 18 bytes of header and 46 data bytes» If the host has ess than 46 bytes to send, the adaptor (pads) bytes to increase the ength to 46 bytes What is the reationship between the minimum packet size and the size of LAN? LAN = (min frame size) * ight speed / (2 * bandwidth) How did they pick the minimum packet size? Peter A. Steenkiste, SCS, CMU 12 Page 6

7 Ethernet Frame Format Preambe Dest Source Type Data Pad CRC Preambe marks the beginning of the frame.» Aso provides cock synchronization Source and destination are 48 bit IEEE MAC addresses.» Fat address space» Hardwired into the network interface Type fied is a demutipexing fied.» What network ayer (ayer 3) shoud receive this packet?» Is actuay a ength fied in the standard CRC for error checking. Peter A. Steenkiste, SCS, CMU 13 Ethernet Physica Layer 10Base2 standard based on thin coax.» Thick coax no onger used» Nodes are connected using thin coax cabes and T connectors in a bus topoogy 10-BaseT uses twisted pair and hubs.» Hub acts as a concentrator The two designs have the same protoco properties.» Key: eectrica connectivity between a nodes» Depoyment is different host host host host Host host host host host Hub Peter A. Steenkiste, SCS, CMU 14 Page 7

8 Traditiona IEEE 802 Networks: MAC in the LAN and MAN Ethernet defined as IEEE The IEEE 802.* set of standards defines a common framing and addressing format for LAN protocos.» Simpifies interoperabiity» Addresses are 48 bit strings, with no structure (Ethernet) (Token bus) (Token ring) (Distributed queue dua bus) (Wireess LAN) (Cabe Modem) (Wireess Persona Area networks) (Broadband wireess access) Peter A. Steenkiste, SCS, CMU 15 LAN Properties Expoit physica proximity.» Often a imitation on the physica distance» E.g. to detect coisions in a contention based network» E.g. to imit the overhead introduced by token passing Reies on singe administrative contro and some eve of trust.» Broadcasting packets to everybody and hoping everybody (other than the receiver) wi ignore the packet» Token-based protocos: everybody pays by the rues Broadcast: nodes can send messages that can be heard by a nodes on the network.» Amost essentia for network administration» Can aso be used for appications, e.g. video conferencing But broadcast fundamentay does not scae. Peter A. Steenkiste, SCS, CMU 16 Page 8

9 How Do We Go Faster? How about FDDI?» Too compex How about switching, e.g. ATM?» Too expensive and compicated How about a faster Ethernet? Or How about switching Ethernet?» It is simpe» It inter-operates with a arge instaed base» It is Ethernet» Fast Ethernet and Gigabit Ethernet Peter A. Steenkiste, SCS, CMU 17 Why Ethernet? Easy to manage.» You pug in the host and it basicay works» No configuration at the dataink ayer Broadcast-based.» In part expains the easy management» Some of the LAN protocos (e.g. ARP) rey on broadcast Networking woud be harder without ARP» Not having natura broadcast capabiities adds a ot of compexity to a LAN Exampe: ATM Drawbacks.» Broadcast-based: imits bandwidth since each packets consumes the bandwidth of the entire network» Distance (if shared) Peter A. Steenkiste, SCS, CMU 18 Page 9

10 802.3u Fast Ethernet Appy origina CSMA/CD medium access protoco at 100Mbps Must change either minimum frame or maximum diameter: change diameter Requires» 2 UTP5 pairs (4B5B) or» 4 UTP3 pairs (8B6T) or» 1 fiber pair No more shared wire connectivity.» Hubs and switches ony Peter A. Steenkiste, SCS, CMU z Gigabit Ethernet Same frame format and size as Ethernet.» This is what makes it Ethernet Fu dupex point-to-point inks in the backbone are ikey the most common use.» Added fow contro to dea with congestion Aternative is haf-dupex shared-medium access.» Cannot cut the diameter any more (set to 200m)» Raise the min frame time (256 bytes), but not frame size Choice of a range of fiber and copper transmission media. Defining jumbo frames for higher efficiency. Peter A. Steenkiste, SCS, CMU 20 Page 10

11 Buiding Larger LANs: Bridges Bridges connect mutipe IEEE 802 LANs at ayer 2.» Ony forward packets to the right port» Reduce coision domain compared with singe LAN In contrast, hubs rebroadcast packets. host host host host host host Bridge host host host host host host Peter A. Steenkiste, SCS, CMU 21 Transparent Bridges Design goas:» Pug and pay capabiity» Sef-configuring without hardware or software changes» Bridge do not impact the operation of the individua LANs Three parts to making bridges transparent: 1) Forwarding of frames 2) Learning of addresses 3) Spanning tree agorithm Peter A. Steenkiste, SCS, CMU 22 Page 11

12 Frame Forwarding Each switch maintains a forwarding database: <MAC address, port, age> MAC address: host or group address Port: port number on the bridge Age: age of the entry Meaning: A machine with MAC address ies in the direction of number port of the bridge For every packet, the bridge ooks up the entry for the packets destination MAC address and forwards the packet on that port.» Other packets are broadcasted why? Peter A. Steenkiste, SCS, CMU 23 Address Lookup 3 1 Bridge 2 Address Next Hop A21032C9A A323C C98900AA 2 301B C Info 8:36 8:01 8:15 8:16 8:11 Address is a 48 bit IEEE MAC address. Next hop: output port for packet. Timer is used to fush od entries Size of the tabe is equa to the number of hosts. Peter A. Steenkiste, SCS, CMU 24 Page 12

13 Learning Bridges Bridge tabes can be fied in manuay.» Time consuming, error-prone» Sef-configuring preferred Keep track of source address of packets arriving on every ink, showing what segment hosts are on.» Fi in the forwarding tabe based on this information host host host host host host Bridge host host host host host host Peter A. Steenkiste, SCS, CMU 25 Spanning Tree Bridges More compex topoogies can provide redundancy.» But can aso create oops. What is the probem with oops? host host host host host host Bridge Bridge host host host host host host Peter A. Steenkiste, SCS, CMU 26 Page 13

14 Spanning Tree Protoco Overview Embed a tree that provides a singe unique path to each destination: 1) Eect a singe bridge as a root bridge 2) Each bridge cacuates the distance of the shortest path to the root bridge 3) Each LAN identifies a designated bridge, the bridge cosest to the root. It wi forward packets to the root. 4) Each bridge determines a root port, which wi be used to send packets to the root 5) Identify the ports that form the spanning tree Peter A. Steenkiste, SCS, CMU 27 Spanning Tree Agorithm Steps Root of the spanning tree is the bridge with the owest identifier.» A ports are part of tree Each bridge finds shortest path to the root.» Remembers port that is on the shortest path» Used to forward packets Seect for each LAN the designated bridge that has the shortest path to the root.» Identifier as tie-breaker» Responsibe for that LAN 1 2 B3 B5 1 B2 B1 B6 1 1 B4 1 B7 Peter A. Steenkiste, SCS, CMU 28 Page 14

15 Spanning Tree Agorithm Each node sends configuration message to a neighbors.» Identifier of the sender» Id of the presumed root» Distance to the presumed root» E.g. B5 sends (B5, B5, 0) When B receive a message, it decide whether the soution is better than their oca soution.» A root with a ower identifier?» Same root but ower distance?» Same root, distance but sender has ower identifier? After convergence, each bridge knows the root, distance to root, root port, and designated bridge for each LAN. B2 B3 B6 B1 B5 B4 B7 Peter A. Steenkiste, SCS, CMU 29 Spanning Tree Agorithm (part 2) Each bridge B can now seect which of its ports make up the spanning tree:» B s root port» A ports for which B is the designated bridge on the LAN Bridges can not configure their ports.» Forwarding state or bocked state, depending on whether the port is part of the spanning tree Root periodicay sends configuration messages and bridges forward them over LANs they are responsibe for. B2 B3 B6 B1 B5 B4 B7 Peter A. Steenkiste, SCS, CMU 30 Page 15

16 Spanning Tree Agorithm Exampe Node B2:» Sends (B2, B2, 0)» Receives (B1, B1, 0) from B1» Sends (B2, B1, 1) up» Continues the forwarding forever Node B1:» Wi send notifications forever Node B7:» Sends (B7, B7, 0)» Receives (B1, B1, 0) from B1» Sends (B7, B1, 1) up and right» Receives (B5, B5, 0) - ignored» Receives (B5, B1, 1) - better» Continues forwarding the B1 messages forever to the right 1 2 B3 B5 1 B2 B1 B6 1 1 B4 1 B7 Peter A. Steenkiste, SCS, CMU 31 Ethernet Switches Bridges make it possibe to increase LAN capacity.» Packets are no onger broadcasted - they are ony forwarded on seected inks» Adds a switching favor to the broadcast LAN Ethernet switch is a specia case of a bridge: each bridge port is connected to a singe host.» Can make the ink fu dupex (reay simpe protoco!)» Simpifies the protoco and hardware used (ony two stations on the ink) no onger fu CSMA/CD» Can have different port speeds on the same switch Unike in a hub, packets can be stored An aternative is to use cut through switching Peter A. Steenkiste, SCS, CMU 32 Page 16

17 Virtua LANs Singe physica LAN infrastructure that carries mutipe virtua LANs simutaneousy. Each virtua LAN has a LAN identifier in the packet.» Switch keeps track of what nodes are on each segment and what their virtua LAN id is Can bridge and route appropriatey. Broadcast packets stay within the virtua LAN.» Limits the coision domain for the packet host host host host host host Switch host host host host host host Peter A. Steenkiste, SCS, CMU 33 Exampe LAN Configuration 10 or 100 Mbit/second connectivity to the desk top using switch or hubs in wiring cosets. 100 or 1000 Mbit/second switch fabric between wiring cosets or foors. Management simpified by having wiring based on star topoogy with wiring coset in the center. Network manager can manage capacity in two ways:» speed of individua inks» hub/bridge/switch tradeoff Foor 4 Foor 3 Foor 2 Foor 1 Peter A. Steenkiste, SCS, CMU 34 Page 17

Ethernet. Ethernet Frame Structure. Ethernet Frame Structure (more) Ethernet: uses CSMA/CD

Ethernet. Ethernet Frame Structure. Ethernet Frame Structure (more) Ethernet: uses CSMA/CD Ethernet dominant LAN technology: cheap -- $20 for 100Mbs! first widely used LAN technology Simpler, cheaper than token rings and ATM Kept up with speed race: 10, 100, 1000 Mbps Metcalfe s Etheret sketch

More information

EECS 122: Introduction to Computer Networks Multiaccess Protocols. ISO OSI Reference Model for Layers

EECS 122: Introduction to Computer Networks Multiaccess Protocols. ISO OSI Reference Model for Layers EECS 122: Introduction to Computer Networks Multiaccess Protocols Computer Science Division Department of Electrical Engineering and Computer Sciences University of California, Berkeley Berkeley, CA 94720-1776

More information

Based on Computer Networking, 4 th Edition by Kurose and Ross

Based on Computer Networking, 4 th Edition by Kurose and Ross Computer Networks Ethernet Hubs and Switches Based on Computer Networking, 4 th Edition by Kurose and Ross Ethernet dominant wired LAN technology: cheap $20 for NIC first widely used LAN technology Simpler,

More information

RTT 60.5 msec receiver window size: 32 KB

RTT 60.5 msec receiver window size: 32 KB Real-World ARQ Performance: TCP Ex.: Purdue UCSD Purdue (NSL): web server UCSD: web client traceroute to planetlab3.ucsd.edu (132.239.17.226), 30 hops max, 40 byte packets 1 switch-lwsn2133-z1r11 (128.10.27.250)

More information

Data Link Protocols. TCP/IP Suite and OSI Reference Model

Data Link Protocols. TCP/IP Suite and OSI Reference Model Data Link Protocols Relates to Lab. This module covers data link layer issues, such as local area networks (LANs) and point-to-point links, Ethernet, and the Point-to-Point Protocol (PPP). 1 TCP/IP Suite

More information

Gigabit Ethernet: Architectural Design and Issues

Gigabit Ethernet: Architectural Design and Issues Gigabit Ethernet: Architectural Design and Issues Professor of Computer and Information Sciences Columbus, OH 43210 http://www.cis.ohio-state.edu/~jain/ 9-1 Overview Distance-Bandwidth Principle 10 Mbps

More information

Computer Networks. Definition of LAN. Connection of Network. Key Points of LAN. Lecture 06 Connecting Networks

Computer Networks. Definition of LAN. Connection of Network. Key Points of LAN. Lecture 06 Connecting Networks Computer Networks Lecture 06 Connecting Networks Kuang-hua Chen Department of Library and Information Science National Taiwan University Local Area Networks (LAN) 5 kilometer IEEE 802.3 Ethernet IEEE 802.4

More information

Fast Ethernet and Gigabit Ethernet. Networks: Fast Ethernet 1

Fast Ethernet and Gigabit Ethernet. Networks: Fast Ethernet 1 Fast Ethernet and Gigabit Ethernet Networks: Fast Ethernet 1 Fast Ethernet (100BASE-T) How to achieve 100 Mbps capacity? MII LLC MAC Convergence Sublayer Media Independent Interface Media Dependent Sublayer

More information

Local Area Networks transmission system private speedy and secure kilometres shared transmission medium hardware & software

Local Area Networks transmission system private speedy and secure kilometres shared transmission medium hardware & software Local Area What s a LAN? A transmission system, usually private owned, very speedy and secure, covering a geographical area in the range of kilometres, comprising a shared transmission medium and a set

More information

CSE331: Introduction to Networks and Security. Lecture 6 Fall 2006

CSE331: Introduction to Networks and Security. Lecture 6 Fall 2006 CSE331: Introduction to Networks and Security Lecture 6 Fall 2006 Open Systems Interconnection (OSI) End Host Application Reference model not actual implementation. Transmits messages (e.g. FTP or HTTP)

More information

Local Area Networks. Guest Instructor Elaine Wong. Elaine_06_I-1

Local Area Networks. Guest Instructor Elaine Wong. Elaine_06_I-1 Local Area Networks Guest Instructor Elaine Wong Elaine_06_I-1 Outline Introduction to Local Area Networks (LANs) Network architecture Geographical area LAN applications LAN Technologies Ethernet Fiber

More information

TCP/IP Gateways and Firewalls

TCP/IP Gateways and Firewalls Gateways and Firewas 1 Gateways and Firewas Prof. Jean-Yves Le Boudec Prof. Andrzej Duda ICA, EPFL CH-1015 Ecubens http://cawww.epf.ch Gateways and Firewas Firewas 2 o architecture separates hosts and

More information

Network Categories. Network Types for the Local Range. Ethernet. Carrier Sense Multiple Access

Network Categories. Network Types for the Local Range. Ethernet. Carrier Sense Multiple Access Sicherungsebene Network Categories Local Area Networks (LAN): 0m - few km, simple connection structure Ethernet/Fast Ethernet/Gigabit Ethernet Token Bus, Token Ring LAN Wireless LAN (WLAN, up to a few

More information

Computer Network. Interconnected collection of autonomous computers that are able to exchange information

Computer Network. Interconnected collection of autonomous computers that are able to exchange information Introduction Computer Network. Interconnected collection of autonomous computers that are able to exchange information No master/slave relationship between the computers in the network Data Communications.

More information

11/22/2013 1. komwut@siit

11/22/2013 1. komwut@siit 11/22/2013 1 Week3-4 Point-to-Point, LAN, WAN Review 11/22/2013 2 What will you learn? Representatives for Point-to-Point Network LAN Wired Ethernet Wireless Ethernet WAN ATM (Asynchronous Transfer Mode)

More information

Chapter 9A. Network Definition. The Uses of a Network. Network Basics

Chapter 9A. Network Definition. The Uses of a Network. Network Basics Chapter 9A Network Basics 1 Network Definition Set of technologies that connects computers Allows communication and collaboration between users 2 The Uses of a Network Simultaneous access to data Data

More information

High Speed Ethernet. Dr. Sanjay P. Ahuja, Ph.D. Professor School of Computing, UNF

High Speed Ethernet. Dr. Sanjay P. Ahuja, Ph.D. Professor School of Computing, UNF High Speed Ethernet Dr. Sanjay P. Ahuja, Ph.D. Professor School of Computing, UNF Hubs and Switches Hubs and Switches Shared Medium Hub The total capacity in the shared medium hub configuration (figure

More information

Data Link Layer. Page 1. Ethernet

Data Link Layer. Page 1. Ethernet Sicherungsebene Network Categories Local Area Networks (LAN): 10m - few km, simple connection structure Ethernet/Fast Ethernet/Gigabit Ethernet Token Bus, Token Ring LAN Wireless LAN (WLAN, up to a few

More information

Level 2 Routing: LAN Bridges and Switches

Level 2 Routing: LAN Bridges and Switches Level 2 Routing: LAN Bridges and Switches Norman Matloff University of California at Davis c 2001, N. Matloff September 6, 2001 1 Overview In a large LAN with consistently heavy traffic, it may make sense

More information

Computer Networks Vs. Distributed Systems

Computer Networks Vs. Distributed Systems Computer Networks Vs. Distributed Systems Computer Networks: A computer network is an interconnected collection of autonomous computers able to exchange information. A computer network usually require

More information

Gigabit Ethernet. Abstract. 1. Introduction. 2. Benefits of Gigabit Ethernet

Gigabit Ethernet. Abstract. 1. Introduction. 2. Benefits of Gigabit Ethernet Table of Contents Abstract... 2 1. Introduction... 2 2. Benefits of Gigabit Ethernet... 2 2.1 Easy Migration to Higher Performance Levels... 3 2.2 Decreased Overall Costs Over Time... 3 2.3 Supports for

More information

TCOM 370 NOTES 99-12 LOCAL AREA NETWORKS AND THE ALOHA PROTOCOL

TCOM 370 NOTES 99-12 LOCAL AREA NETWORKS AND THE ALOHA PROTOCOL 1. Local Area Networks TCOM 370 NOTES 99-12 LOCAL AREA NETWORKS AND THE ALOHA PROTOCOL These are networks spanning relatively short distances (e.g. within one building) for local point-to-point and point-to-multipoint

More information

Ethernet, VLAN, Ethernet Carrier Grade

Ethernet, VLAN, Ethernet Carrier Grade Ethernet, VLAN, Ethernet Carrier Grade Dr. Rami Langar LIP6/PHARE UPMC - University of Paris 6 Rami.langar@lip6.fr www-phare.lip6.fr/~langar RTEL 1 Point-to-Point vs. Broadcast Media Point-to-point PPP

More information

Local-Area Network -LAN

Local-Area Network -LAN Computer Networks A group of two or more computer systems linked together. There are many [types] of computer networks: Peer To Peer (workgroups) The computers are connected by a network, however, there

More information

WINMAG Graphics Management System

WINMAG Graphics Management System SECTION 10: page 1 Section 10: by Honeywe WINMAG Graphics Management System Contents What is WINMAG? WINMAG Text and Graphics WINMAG Text Ony Scenarios Fire/Emergency Management of Fauts & Disabement Historic

More information

Fast Ethernet and Gigabit Ethernet. Computer Networks: Fast and Gigabit Ethernet

Fast Ethernet and Gigabit Ethernet. Computer Networks: Fast and Gigabit Ethernet Fast Ethernet and Gigabit Ethernet 1 Fast Ethernet (100BASE-T) How to achieve 100 Mbps capacity? MII LLC MAC Convergence Sublayer Media Independent Interface Media Dependent Sublayer Data Link Layer Physical

More information

EXAMPLES AND PROBLEMS. Competence Based Education Internet Protocols

EXAMPLES AND PROBLEMS. Competence Based Education Internet Protocols EXAMPLES AND PROBLEMS Competence Based Education Internet Protocols Example 1 In following figure frames are generated at node A and sent to node C through node B. Determine the minimum transmission rate

More information

Frame Burst Adjusting for Transmitting Video Conference in Gigabit Ethernet

Frame Burst Adjusting for Transmitting Video Conference in Gigabit Ethernet Frame Burst Adjusting for Transmitting Video Conference in Gigabit Ethernet Han-Chieh Chao and Yao-Chung Chang Institute of Electrical Engineering National Dong Hwa University Hualien, Taiwan E-mail: hcc@cc.ndhu.edu.tw

More information

Introduction to Ethernet

Introduction to Ethernet Technical Tutorial 2002 12-06 Table of Contents 1: Introduction 2: Ethernet 3: IEEE standards 4: Topology 5: CSMA/CD 6: Wireless-LAN 7: Transmission Speed 8: Limitations of Ethernet 9: Sena Products and

More information

Random Access Protocols

Random Access Protocols Lecture Today slotted vs unslotted ALOHA Carrier sensing multiple access Ethernet DataLink Layer 1 Random Access Protocols When node has packet to send transmit at full channel data rate R. no a priori

More information

Howstuffworks "How LAN Switches Work" Click here to go back to the normal view!

Howstuffworks How LAN Switches Work Click here to go back to the normal view! Page 1 of 17 Search ComputerStuff AutoStuff ElectronicsStuff ScienceStuff HomeStuff EntertainmentStuff MoneyStuff TravelStuff Main > Computer > Hardware Click here to go back to the normal view! How LAN

More information

Unit of Learning # 2 The Physical Layer. Sergio Guíñez Molinos sguinez@utalca.cl 2-2009

Unit of Learning # 2 The Physical Layer. Sergio Guíñez Molinos sguinez@utalca.cl 2-2009 Unit of Learning # 2 The Physical Layer Sergio Guíñez Molinos sguinez@utalca.cl 2-2009 Local Area Network (LAN) Redes de Computadores 2 Historic topologies more used in LAN Ethernet Logical Bus and Physical

More information

Overview of Network Hardware and Software. CS158a Chris Pollett Jan 29, 2007.

Overview of Network Hardware and Software. CS158a Chris Pollett Jan 29, 2007. Overview of Network Hardware and Software CS158a Chris Pollett Jan 29, 2007. Outline Scales of Networks Protocol Hierarchies Scales of Networks Last day, we talked about broadcast versus point-to-point

More information

Chapter 8: Computer Networking. AIMS The aim of this chapter is to give a brief introduction to computer networking.

Chapter 8: Computer Networking. AIMS The aim of this chapter is to give a brief introduction to computer networking. Chapter 8: Computer Networking AIMS The aim of this chapter is to give a brief introduction to computer networking. OBJECTIVES At the end of this chapter you should be able to: Explain the following terms:

More information

SNMP Reference Guide for Avaya Communication Manager

SNMP Reference Guide for Avaya Communication Manager SNMP Reference Guide for Avaya Communication Manager 03-602013 Issue 1.0 Feburary 2007 2006 Avaya Inc. A Rights Reserved. Notice Whie reasonabe efforts were made to ensure that the information in this

More information

Operating System Concepts. Operating System 資 訊 工 程 學 系 袁 賢 銘 老 師

Operating System Concepts. Operating System 資 訊 工 程 學 系 袁 賢 銘 老 師 Lecture 7: Distributed Operating Systems A Distributed System 7.2 Resource sharing Motivation sharing and printing files at remote sites processing information in a distributed database using remote specialized

More information

Virtual trunk simulation

Virtual trunk simulation Virtua trunk simuation Samui Aato * Laboratory of Teecommunications Technoogy Hesinki University of Technoogy Sivia Giordano Laboratoire de Reseaux de Communication Ecoe Poytechnique Federae de Lausanne

More information

LAN Switching. 15-441 Computer Networking. Switched Network Advantages. Hubs (more) Hubs. Bridges/Switches, 802.11, PPP. Interconnecting LANs

LAN Switching. 15-441 Computer Networking. Switched Network Advantages. Hubs (more) Hubs. Bridges/Switches, 802.11, PPP. Interconnecting LANs LAN Switching 15-441 Computer Networking Bridges/Switches, 802.11, PPP Extend reach of a single shared medium Connect two or more segments by copying data frames between them Switches only copy data when

More information

COMPUTER NETWORKS - LAN Interconnection

COMPUTER NETWORKS - LAN Interconnection LAN interconnection Telecommunication s Group firstname.lastname@polito.it http://www.telematica.polito.it/ COMPUTER NETWORKS - LAN interconnection- 1 Copyright Quest opera è protetta dalla licenza Creative

More information

Objectives. The Role of Redundancy in a Switched Network. Layer 2 Loops. Broadcast Storms. More problems with Layer 2 loops

Objectives. The Role of Redundancy in a Switched Network. Layer 2 Loops. Broadcast Storms. More problems with Layer 2 loops ITE I Chapter 6 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 1 Objectives Implement Spanning Tree Protocols LAN Switching and Wireless Chapter 5 Explain the role of redundancy in a converged

More information

Industrial Networks & Databases. Protocols and Networks - Device Bus - - Field Bus -

Industrial Networks & Databases. Protocols and Networks - Device Bus - - Field Bus - Industrial Networks & Databases - Device Bus - - Field Bus - - Data Bus - Recall MODBUS protocol is a messaging structure used to set up master/client type communications with slaves/servers between intelligent

More information

Lecture 6 Types of Computer Networks and their Topologies Three important groups of computer networks: LAN, MAN, WAN

Lecture 6 Types of Computer Networks and their Topologies Three important groups of computer networks: LAN, MAN, WAN Lecture 6 Types of Computer Networks and their Topologies Three important groups of computer networks: LAN, MAN, WAN LAN (Local Area Networks) 10/28/2008 Vasile Dadarlat - Computer Networks 1 MAN (Metropolitan

More information

Chapter 3: e-business Integration Patterns

Chapter 3: e-business Integration Patterns Chapter 3: e-business Integration Patterns Page 1 of 9 Chapter 3: e-business Integration Patterns "Consistency is the ast refuge of the unimaginative." Oscar Wide In This Chapter What Are Integration Patterns?

More information

Module 15: Network Structures

Module 15: Network Structures Module 15: Network Structures Background Topology Network Types Communication Communication Protocol Robustness Design Strategies 15.1 A Distributed System 15.2 Motivation Resource sharing sharing and

More information

Advanced ColdFusion 4.0 Application Development - 3 - Server Clustering Using Bright Tiger

Advanced ColdFusion 4.0 Application Development - 3 - Server Clustering Using Bright Tiger Advanced CodFusion 4.0 Appication Deveopment - CH 3 - Server Custering Using Bri.. Page 1 of 7 [Figures are not incuded in this sampe chapter] Advanced CodFusion 4.0 Appication Deveopment - 3 - Server

More information

524 Computer Networks

524 Computer Networks 524 Computer Networks Section 1: Introduction to Course Dr. E.C. Kulasekere Sri Lanka Institute of Information Technology - 2005 Course Outline The Aim The course is design to establish the terminology

More information

Ethernet (LAN switching)

Ethernet (LAN switching) Ethernet ( switching) 1 Outline Interconnection devices Bridges/ switches vs. Routers Bridges Learning Bridges Transparent bridges 2 1 Bridges/ switches Interconnect multiple, possibly with different type

More information

Wired & Wireless LAN Connections

Wired & Wireless LAN Connections Lecture 5 Wired & Wireless LAN Connections Network Interface Card (NIC) Ethernet Wiring - Thick Ethernet - Thin Ethernet - Star (Hub) Ethernet Extending LAN - Fiber Modem - Repeater - Bridge - Switch Short

More information

Secure Network Coding with a Cost Criterion

Secure Network Coding with a Cost Criterion Secure Network Coding with a Cost Criterion Jianong Tan, Murie Médard Laboratory for Information and Decision Systems Massachusetts Institute of Technoogy Cambridge, MA 0239, USA E-mai: {jianong, medard}@mit.edu

More information

DATA COMMUNICATION AND NETWORKS

DATA COMMUNICATION AND NETWORKS DATA COMMUNICATION AND NETWORKS 1. Define the term Computer Networks. A Computer network is a number if computers interconnected by one or more transmission paths. The transmission path often is the telephone

More information

Controlled Random Access Methods

Controlled Random Access Methods Helsinki University of Technology S-72.333 Postgraduate Seminar on Radio Communications Controlled Random Access Methods Er Liu liuer@cc.hut.fi Communications Laboratory 09.03.2004 Content of Presentation

More information

2. What is the maximum value of each octet in an IP address? A. 128 B. 255 C. 256 D. None of the above

2. What is the maximum value of each octet in an IP address? A. 128 B. 255 C. 256 D. None of the above 1. How many bits are in an IP address? A. 16 B. 32 C. 64 2. What is the maximum value of each octet in an IP address? A. 128 B. 255 C. 256 3. The network number plays what part in an IP address? A. It

More information

GREEN: An Active Queue Management Algorithm for a Self Managed Internet

GREEN: An Active Queue Management Algorithm for a Self Managed Internet : An Active Queue Management Agorithm for a Sef Managed Internet Bartek Wydrowski and Moshe Zukerman ARC Specia Research Centre for Utra-Broadband Information Networks, EEE Department, The University of

More information

Chapter 14: Distributed Operating Systems

Chapter 14: Distributed Operating Systems Chapter 14: Distributed Operating Systems Chapter 14: Distributed Operating Systems Motivation Types of Distributed Operating Systems Network Structure Network Topology Communication Structure Communication

More information

Zarząd (7 osób) F inanse (13 osób) M arketing (7 osób) S przedaż (16 osób) K adry (15 osób)

Zarząd (7 osób) F inanse (13 osób) M arketing (7 osób) S przedaż (16 osób) K adry (15 osób) QUESTION NO: 8 David, your TestKing trainee, asks you about basic characteristics of switches and hubs for network connectivity. What should you tell him? A. Switches take less time to process frames than

More information

Communication Systems Internetworking (Bridges & Co)

Communication Systems Internetworking (Bridges & Co) Communication Systems Internetworking (Bridges & Co) Prof. Dr.-Ing. Lars Wolf TU Braunschweig Institut für Betriebssysteme und Rechnerverbund Mühlenpfordtstraße 23, 38106 Braunschweig, Germany Email: wolf@ibr.cs.tu-bs.de

More information

Communication Networks. MAP-TELE 2011/12 José Ruela

Communication Networks. MAP-TELE 2011/12 José Ruela Communication Networks MAP-TELE 2011/12 José Ruela Network basic mechanisms Introduction to Communications Networks Communications networks Communications networks are used to transport information (data)

More information

LANs. Local Area Networks. via the Media Access Control (MAC) SubLayer. Networks: Local Area Networks

LANs. Local Area Networks. via the Media Access Control (MAC) SubLayer. Networks: Local Area Networks LANs Local Area Networks via the Media Access Control (MAC) SubLayer 1 Local Area Networks Aloha Slotted Aloha CSMA (non-persistent, 1-persistent, p-persistent) CSMA/CD Ethernet Token Ring 2 Network Layer

More information

Network Topologies. Network Topologies

Network Topologies. Network Topologies Network Topologies LANs and WANs - Geographical coverage LANs A single geographical location, such as office building, school, etc Typically High speed and cheaper. WANs Spans more than one geographical

More information

Chapter 16: Distributed Operating Systems

Chapter 16: Distributed Operating Systems Module 16: Distributed ib System Structure, Silberschatz, Galvin and Gagne 2009 Chapter 16: Distributed Operating Systems Motivation Types of Network-Based Operating Systems Network Structure Network Topology

More information

LAN / WAN Technologies

LAN / WAN Technologies The Hong Kong Polytechnic University Industrial Centre Knowledge Update Course for Secondary Computer Teachers LAN / WAN Technologies By Edward Cheung email: icec@polyu.edu.hk 15 July, 2003. 030715 LAN

More information

An FDD Wideband CDMA MAC Protocol for Wireless Multimedia Networks

An FDD Wideband CDMA MAC Protocol for Wireless Multimedia Networks An FDD ideband CDMA MAC Protoco for ireess Mutimedia Networks Xudong ang Broadband and ireess Networking (BN) Lab Schoo of Eectrica and Computer Engineering Georgia Institute of Technoogy Atanta, GA 3332

More information

3.3 SOFTWARE RISK MANAGEMENT (SRM)

3.3 SOFTWARE RISK MANAGEMENT (SRM) 93 3.3 SOFTWARE RISK MANAGEMENT (SRM) Fig. 3.2 SRM is a process buit in five steps. The steps are: Identify Anayse Pan Track Resove The process is continuous in nature and handed dynamicay throughout ifecyce

More information

Network Categories. Network Types for the Local Range. Ethernet

Network Categories. Network Types for the Local Range. Ethernet Sicherungsebene Network Categories Chapter 2: Computer Networks 2.1: Physical Layer: representation of digital signals 2.2: Data Link Layer: error protection and access control 2.3: Network infrastructure

More information

CSE 123A Computer Networks

CSE 123A Computer Networks CSE 123A Computer Networks Winter 2005 Lecture 5: Data-Link II: Media Access Some portions courtesy Srini Seshan or David Wetherall Last Time Framing: How to translate a bitstream into separate packets

More information

Layer 3 Network + Dedicated Internet Connectivity

Layer 3 Network + Dedicated Internet Connectivity Layer 3 Network + Dedicated Internet Connectivity Client: One of the IT Departments in a Northern State Customer's requirement: The customer wanted to establish CAN connectivity (Campus Area Network) for

More information

Wide Area Networks. Learning Objectives. LAN and WAN. School of Business Eastern Illinois University. (Week 11, Thursday 3/22/2007)

Wide Area Networks. Learning Objectives. LAN and WAN. School of Business Eastern Illinois University. (Week 11, Thursday 3/22/2007) School of Business Eastern Illinois University Wide Area Networks (Week 11, Thursday 3/22/2007) Abdou Illia, Spring 2007 Learning Objectives 2 Distinguish between LAN and WAN Distinguish between Circuit

More information

ESSENTIALS. Understanding Ethernet Switches and Routers. April 2011 VOLUME 3 ISSUE 1 A TECHNICAL SUPPLEMENT TO CONTROL NETWORK

ESSENTIALS. Understanding Ethernet Switches and Routers. April 2011 VOLUME 3 ISSUE 1 A TECHNICAL SUPPLEMENT TO CONTROL NETWORK VOLUME 3 ISSUE 1 A TECHNICAL SUPPLEMENT TO CONTROL NETWORK Contemporary Control Systems, Inc. Understanding Ethernet Switches and Routers This extended article was based on a two-part article that was

More information

Optimizing Enterprise Network Bandwidth For Security Applications. Improving Performance Using Antaira s Management Features

Optimizing Enterprise Network Bandwidth For Security Applications. Improving Performance Using Antaira s Management Features Optimizing Enterprise Network Bandwidth For Security Applications Improving Performance Using Antaira s Management Features By: Brian Roth, Product Marketing Engineer April 1, 2014 April 2014 Optimizing

More information

Telecommunications, Networks, and Wireless Computing

Telecommunications, Networks, and Wireless Computing Objectives Telecommunications, Networks, and Wireless Computing 1. What are the features of a contemporary corporate telecommunications system? On what major technology developments are they based? 2.

More information

Agenda. Distributed System Structures. Why Distributed Systems? Motivation

Agenda. Distributed System Structures. Why Distributed Systems? Motivation Agenda Distributed System Structures CSCI 444/544 Operating Systems Fall 2008 Motivation Network structure Fundamental network services Sockets and ports Client/server model Remote Procedure Call (RPC)

More information

Computer Networking: A Survey

Computer Networking: A Survey Computer Networking: A Survey M. Benaiah Deva Kumar and B. Deepa, 1 Scholar, 2 Assistant Professor, IT Department, Sri Krishna College of Arts and Science College, Coimbatore, India. Abstract- Computer

More information

Ring Local Area Network. Ring LANs

Ring Local Area Network. Ring LANs Ring Local Area Network Ring interface (1-bit buffer) Ring interface To station From station Ring LANs The ring is a series of bit repeaters, each connected by a unidirectional transmission link All arriving

More information

1B11 Operating Systems. Input/Output and Devices

1B11 Operating Systems. Input/Output and Devices University Coege London 1B11 Operating Systems Input/Output and s Prof. Steve R Wibur s.wibur@cs.uc.ac.uk Lecture Objectives How do the bits of the I/O story fit together? What is a device driver? 1B11-5

More information

Networks. The two main network types are: Peer networks

Networks. The two main network types are: Peer networks Networks Networking is all about sharing information and resources. Computers connected to a network can avail of many facilities not available to standalone computers: Share a printer or a plotter among

More information

Network Design. Yiannos Mylonas

Network Design. Yiannos Mylonas Network Design Yiannos Mylonas Physical Topologies There are two parts to the topology definition: the physical topology, which is the actual layout of the wire (media), and the logical topology, which

More information

The Domain Name System (DNS)

The Domain Name System (DNS) D 1 The Domain Name System (D) Prof. Jean-Yves Le Boudec Prof. ndrzej Duda IC, EPFL CH-1015 Ecubens http://cawww.epf.ch o o Domain Name System: D Objective of D support user friendy naming of resources:

More information

CWNA: Official Certification Guide Unit 1 Introduction to Wireless LANs

CWNA: Official Certification Guide Unit 1 Introduction to Wireless LANs CWNA: Official Certification Guide Unit 1 Introduction to Wireless LANs Wireless LANs were once considered expensive and slow solutions to certain network connectivity issues. Wireless LAN sales are now

More information

Infrastructure Components: Hub & Repeater. Network Infrastructure. Switch: Realization. Infrastructure Components: Switch

Infrastructure Components: Hub & Repeater. Network Infrastructure. Switch: Realization. Infrastructure Components: Switch Network Infrastructure or building computer networks more complex than e.g. a short bus, some additional components are needed. They can be arranged hierarchically regarding their functionality: Repeater

More information

Local Area Network By Bhupendra Ratha, Lecturer School of Library and Information Science Devi Ahilya University, Indore Email: bhu261@gmail.com Local Area Network LANs connect computers and peripheral

More information

1 Which network type is a specifically designed configuration of computers and other devices located within a confined area? A Peer-to-peer network

1 Which network type is a specifically designed configuration of computers and other devices located within a confined area? A Peer-to-peer network Review questions 1 Which network type is a specifically designed configuration of computers and other devices located within a confined area? A Peer-to-peer network B Local area network C Client/server

More information

Simultaneous Routing and Power Allocation in CDMA Wireless Data Networks

Simultaneous Routing and Power Allocation in CDMA Wireless Data Networks Simutaneous Routing and Power Aocation in CDMA Wireess Data Networks Mikae Johansson *,LinXiao and Stephen Boyd * Department of Signas, Sensors and Systems Roya Institute of Technoogy, SE 00 Stockhom,

More information

Non-orthogonal Direct Access for Small Data Transmission in Cellular MTC Networks

Non-orthogonal Direct Access for Small Data Transmission in Cellular MTC Networks Non-orthogona Direct Access for Sma Data Transmission in Ceuar MTC Networks Keng-Te Liao, Chia-Han Lee, Tzu-Ming Lin, Chien-Min Lee, and Wen-Tsuen Chen Academia Sinica, Taipei, Taiwan Industria Technoogy

More information

(12) Patent Application Publication (10) Pub. N0.: US 2006/0105797 A1 Marsan et al. (43) Pub. Date: May 18, 2006

(12) Patent Application Publication (10) Pub. N0.: US 2006/0105797 A1 Marsan et al. (43) Pub. Date: May 18, 2006 (19) United States US 20060105797A (12) Patent Appication Pubication (10) Pub. N0.: US 2006/0105797 A1 Marsan et a. (43) Pub. Date: (54) METHOD AND APPARATUS FOR (52) US. C...... 455/522 ADJUSTING A MOBILE

More information

28 Networks and Communication Protocols

28 Networks and Communication Protocols 113 28 Networks and ommunication Protocols Trend in computer systems: personal computing. Reasons why: ost: economies of scale. lso, avoids large initial investment in timesharing system. Performance:

More information

CS 5480/6480: Computer Networks Spring 2012 Homework 4 Solutions Due by 1:25 PM on April 11 th 2012

CS 5480/6480: Computer Networks Spring 2012 Homework 4 Solutions Due by 1:25 PM on April 11 th 2012 CS 5480/6480: Computer Networks Spring 2012 Homework 4 Solutions Due by 1:25 PM on April 11 th 2012 Important: The solutions to the homework problems from the course book have been provided by the authors.

More information

Transport and Network Layer

Transport and Network Layer Transport and Network Layer 1 Introduction Responsible for moving messages from end-to-end in a network Closely tied together TCP/IP: most commonly used protocol o Used in Internet o Compatible with a

More information

Chapter 3. Enterprise Campus Network Design

Chapter 3. Enterprise Campus Network Design Chapter 3 Enterprise Campus Network Design 1 Overview The network foundation hosting these technologies for an emerging enterprise should be efficient, highly available, scalable, and manageable. This

More information

Fast Robust Hashing. ) [7] will be re-mapped (and therefore discarded), due to the load-balancing property of hashing.

Fast Robust Hashing. ) [7] will be re-mapped (and therefore discarded), due to the load-balancing property of hashing. Fast Robust Hashing Manue Urueña, David Larrabeiti and Pabo Serrano Universidad Caros III de Madrid E-89 Leganés (Madrid), Spain Emai: {muruenya,darra,pabo}@it.uc3m.es Abstract As statefu fow-aware services

More information

CORPORATE NETWORKING

CORPORATE NETWORKING CORPORATE NETWORKING C. Pham Université de Pau et des Pays de l Adour Département Informatique http://www.univ-pau.fr/~cpham Congduc.Pham@univ-pau.fr Typical example of Ethernet local networks Mostly based

More information

Candidates should attempt FOUR questions. All questions carry 25 marks.

Candidates should attempt FOUR questions. All questions carry 25 marks. UNIVERSITY OF ABERDEEN Exam 2010 Degree Examination in ES 3567 Communications Engineering 1B Xday X Notes: 9.00 a.m. 12 Noon (i) CANDIDATES ARE PERMITTED TO USE APPROVED CALCULATORS (II) CANDIDATES ARE

More information

1. The subnet must prevent additional packets from entering the congested region until those already present can be processed.

1. The subnet must prevent additional packets from entering the congested region until those already present can be processed. Congestion Control When one part of the subnet (e.g. one or more routers in an area) becomes overloaded, congestion results. Because routers are receiving packets faster than they can forward them, one

More information

ECE 358: Computer Networks. Homework #3. Chapter 5 and 6 Review Questions 1

ECE 358: Computer Networks. Homework #3. Chapter 5 and 6 Review Questions 1 ECE 358: Computer Networks Homework #3 Chapter 5 and 6 Review Questions 1 Chapter 5: The Link Layer P26. Let's consider the operation of a learning switch in the context of a network in which 6 nodes labeled

More information

Module 5. Broadcast Communication Networks. Version 2 CSE IIT, Kharagpur

Module 5. Broadcast Communication Networks. Version 2 CSE IIT, Kharagpur Module 5 Broadcast Communication Networks Lesson 1 Network Topology Specific Instructional Objectives At the end of this lesson, the students will be able to: Specify what is meant by network topology

More information

Leased Line + Remote Dial-in connectivity

Leased Line + Remote Dial-in connectivity Leased Line + Remote Dial-in connectivity Client: One of the TELCO offices in a Southern state. The customer wanted to establish WAN Connectivity between central location and 10 remote locations. The customer

More information

Ethernet/IEEE 802.3 evolution

Ethernet/IEEE 802.3 evolution Ethernet/IEEE 802.3 evolution Pietro Nicoletti www.studioreti.it 8023-Evolution-Engl - 1 P. Nicoletti: see note pag. 2 Copyright note These slides are protected by copyright and international treaties.

More information

Assessment of Traffic Prioritization in Switched Local Area Networks Carrying Multimedia Traffic

Assessment of Traffic Prioritization in Switched Local Area Networks Carrying Multimedia Traffic Assessment of Traffic Prioritization in Switched Local Area Networks Carrying Multimedia Traffic F. A. Tobagi, C. J. Fraleigh, M. J. Karam, W. Noureddine Computer Systems Laboratory Department of Electrical

More information

DATA COMMUNICATIONS AND NETWORKING. Solved Examples

DATA COMMUNICATIONS AND NETWORKING. Solved Examples Page 1 of 10 DATA COMMUNICATIONS AND NETWORKING Solved Examples References: STA: Stallings, Data and Computer Communications, 6 th ed. TAN: Tannenbaum, Computer Networks, 4 th ed.) 1. Given the following

More information

NETWORKING TECHNOLOGIES

NETWORKING TECHNOLOGIES NETWORKING TECHNOLOGIES (October 19, 2015) BUS3500 - Abdou Illia, Fall 2015 1 LEARNING GOALS Identify the major hardware components in networks. Identify and explain the various types of computer networks.

More information

Axon: A Flexible Substrate for Source- routed Ethernet. Jeffrey Shafer Brent Stephens Michael Foss Sco6 Rixner Alan L. Cox

Axon: A Flexible Substrate for Source- routed Ethernet. Jeffrey Shafer Brent Stephens Michael Foss Sco6 Rixner Alan L. Cox Axon: A Flexible Substrate for Source- routed Ethernet Jeffrey Shafer Brent Stephens Michael Foss Sco6 Rixner Alan L. Cox 2 Ethernet Tradeoffs Strengths Weaknesses Cheap Simple High data rate Ubiquitous

More information