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CSE 5346 – Networks II: High CSE 5346 – Networks II: High Performance NetworksPerformance Networks

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IntroductionIntroduction

Performance and Performance and Quality of Quality of ServiceService

Introduction3

Course Foundation Course Foundation Assumptions (pre-requisites)Assumptions (pre-requisites) Good understanding of packet-switched Good understanding of packet-switched

networking concepts and principles of networking concepts and principles of operationoperation

Good understanding of Internet Good understanding of Internet protocols and architectures (e.g., IP protocols and architectures (e.g., IP protocol stack)protocol stack)

Solid foundation in computer operating Solid foundation in computer operating systems fundamentalssystems fundamentals

Ability to learn simple programming Ability to learn simple programming languages (such as ns/2 tcl, C/C++)languages (such as ns/2 tcl, C/C++)

Ability to perform independent research, Ability to perform independent research, analyze findings and document resultsanalyze findings and document results

Introduction4

What will we cover?What will we cover?

Networking Introduction/ReviewNetworking Introduction/Review– Today… setting the stageToday… setting the stage

Frame Relay, ATM & High Speed LANsFrame Relay, ATM & High Speed LANs Performance Modeling and EstimationPerformance Modeling and Estimation Congestion, Network Traffic Congestion, Network Traffic

Analysis/Management and RoutingAnalysis/Management and Routing Quality of ServiceQuality of Service Compression Standards and PracticeCompression Standards and Practice Advanced Topics (time permitting): VoIP, Advanced Topics (time permitting): VoIP,

Mobile IP, Mobile AgentsMobile IP, Mobile Agents

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Introduction5

How will we cover it?How will we cover it?

Classroom lecturesClassroom lecturesQuizzes and examsQuizzes and exams Incremental modeling and Incremental modeling and

simulation project using ns/2simulation project using ns/2Self-study research, and simulation Self-study research, and simulation

reports by studentsreports by studentsStudy and student presentations on Study and student presentations on

relevant papers & RFCsrelevant papers & RFCs

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Chapter 1 - IntroductionChapter 1 - Introduction

An Overview of An Overview of Networking - the Networking - the Need for Need for SpeedSpeed and Quality of and Quality of ServiceService

Introduction8

Growth of the InternetGrowth of the Internet

As of January 2005 … As of January 2005 … > 300 million “computers” > 300 million “computers” in 209 countriesin 209 countries

Introduction9

What is an/the Internet?What is an/the Internet? connected computing connected computing

devices: devices: hosts, end-hosts, end-systemssystems– PC’s, workstations, PC’s, workstations,

serversservers– PDA’s, phones, PDA’s, phones,

toasters, carstoasters, cars

running running network network applicationsapplications

communication linkscommunication links– fiber, copper, radio, fiber, copper, radio,

satellitesatellite routers/switches:routers/switches:

forward packets forward packets (chunks) of data thru (chunks) of data thru networknetwork

router workstation

servermobile

local ISPlocal ISP

companycompanynetworknetwork

regional ISPregional ISP

Introduction10

The The Need for Speed!Need for Speed! ScaleScale

– growing growing number number of hostsof hosts -> -> growing demands growing demands on bandwidthon bandwidth

– new technologiesnew technologies result in new result in new paradigms for paradigms for device and device and connection typesconnection types

e.g. ??e.g. ??

ApplicationApplication– demand for demand for large large

to huge file to huge file transferstransfers

– increasing critical increasing critical nature of Internet nature of Internet useuse

– demand for demand for “real-“real-time”time” performance performance characteristicscharacteristics

– demand for demand for guarantees of guarantees of serviceservice levels levels

e.g. ??e.g. ??

User User Expectations!Expectations!

Introduction11

High-Speed Networks: High-Speed Networks: IDN to ATMIDN to ATM IDNIDN (Integrated Digital Network) (Integrated Digital Network)

– early ’60s, answer to growth of digital, early ’60s, answer to growth of digital, computer-controlled, circuit-switched computer-controlled, circuit-switched networkingnetworking

– WE 4ESS introduced in 1976, 1WE 4ESS introduced in 1976, 1stst large scale large scale commercial time-division switchcommercial time-division switch

ISDNISDN (Integrated Services Digital (Integrated Services Digital Network)Network)– integratedintegrated voice and data on the same voice and data on the same

digital transmission links/exchangesdigital transmission links/exchanges– small incremental cost for data over existing small incremental cost for data over existing

digital voice networkdigital voice network

Introduction12

High-Speed Networks: High-Speed Networks: IDN to ATMIDN to ATMFrame RelayFrame Relay

– popularized standard (c. 1988) for popularized standard (c. 1988) for packet switching over ISDNpacket switching over ISDN

– most widely deployed WAN technology most widely deployed WAN technology in use todayin use today

B-ISDNB-ISDN (Broadband ISDN) (Broadband ISDN)– c. 1988: emerging demand for c. 1988: emerging demand for

broadband servicesbroadband services– new high-speed technologies availablenew high-speed technologies available– emerging bandwidth hungry emerging bandwidth hungry

applicationsapplications

Introduction13

High-Speed Networks: High-Speed Networks: IDN to ATMIDN to ATM ATM ATM (Asynchronous Transfer Mode)(Asynchronous Transfer Mode)

– early ’90s outgrowth of emerging need for early ’90s outgrowth of emerging need for high-speed switching over B-ISDN WANhigh-speed switching over B-ISDN WAN

– rapidly evolved as high-speed rapidly evolved as high-speed packet packet switchingswitching technology of its own accord technology of its own accord

– primary deployment today is:primary deployment today is: public network infrastructure LAN backbone private network, VPN WAN

– services not widely deployed/available until services not widely deployed/available until late-’90s.late-’90s.

Introduction14

High-Speed Networks: High-Speed Networks: ATM Backbone ExampleATM Backbone Example

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High-Speed Networks: High-Speed Networks: LANsLANsHigh-speed LANsHigh-speed LANs

– driven by explosive growth in speed driven by explosive growth in speed and and computing powercomputing power of PCs in 1990s of PCs in 1990s

– emergence of emergence of client-serverclient-server computing computing architecturearchitecture

– use of centralized use of centralized serverserver farms farms– emergence of “power workgroups” emergence of “power workgroups”

and and workgroup applicationsworkgroup applications– need for local high-speed LAN need for local high-speed LAN

backbonesbackbones

Introduction16

IP-based Internets (aka IP-based Internets (aka TCP/IP networks)TCP/IP networks)Internetworking:Internetworking: the dominant the dominant

paradigm of computer networkingparadigm of computer networking

Evolution - key internetworking Evolution - key internetworking technologies:technologies: packet switching packet switching TCP/IPTCP/IP

– TCP: reliable end-to-end transportTCP: reliable end-to-end transport– IP: internet routing and deliveryIP: internet routing and delivery

dynamic routing, load balancingdynamic routing, load balancing high speed Ethernet LANshigh speed Ethernet LANs

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The Need for Improved The Need for Improved (better) Levels of Service(better) Levels of Service Internet Internet Best-Best-

EffortEffort Service Service– all packets all packets

treated equallytreated equally– designed for designed for

elastic trafficelastic traffic– no guarantees of no guarantees of

bandwidth or bandwidth or throughputthroughput

– no guarantees of no guarantees of delaydelay

– no guarantee of no guarantee of jitter (delay jitter (delay variation)variation)

ApplicationsApplications– often create often create

inelasticinelastic traffic traffic– often sensitive to often sensitive to

delaydelay– often sensitive to often sensitive to

jitterjitter– often critical in often critical in

naturenature– generate elastic generate elastic

traffic as welltraffic as well

User User Requirements!Requirements!

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Delay Sensitivity & Delay Sensitivity & CriticalityCriticality

Introduction20

Delays in Packet Switched Delays in Packet Switched (e.g. IP) Networks(e.g. IP) Networks End-to-end delay (simplified) =End-to-end delay (simplified) =

(d(dpropprop + d + dtranstrans + d + dqueuequeue + d + dprocproc) x Q) x Q

BA

Where:Propagation delay (dprop)

Transmission delay (dtrans)

Queuing delay (dqueue)

Processing delay (dproc)Number of links (Q)

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So what’s the problem?So what’s the problem?

What makes this so What makes this so hard?hard?(I.e., what are we going to focus (I.e., what are we going to focus on in this course.)on in this course.)

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Delays in Packet Switched Delays in Packet Switched (e.g. IP) Networks(e.g. IP) Networks End-to-end delay (simplified) =End-to-end delay (simplified) =

– (d(dpropprop + d + dtranstrans + d + dqueuequeue + d + dprocproc)) … … on each linkon each link

More laterMore later

BA Where:

Propagation delay (dprop) = d/s

Transmission delay (dtrans) = L/R

Queuing delay (dqueue) = ??

Processing delay (dproc) = ??Number of links (Q) = ??