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EE-832: Advanced Computer NetworksFall 2015Image source: http://www.nd.edu/~networks/Image%20Gallery/Large%20Images/eick1_lg.png1Junaid Qadir (junaid.qadir@seecs.edu.pk)

Assistant Professor,Electrical Engineering Dept.,SEECS, NUST.

Director, Cognet Lab, SEECS

Room no: 215, Academic Block, SEECSOffice hours: Monday, 9 AM to 10 AM, or through appointment via email. Introduction2Motivation:Why study Computer Networking?Increased professional opportunitiesIncreased productivity through efficient usage of networking technologyDevelop skills to engineer state-of-the-art innovationsImproved employment and earning potential3Approaches to studying Computer NetworksThere is a tendency in our field to believe that everything we currently use is a paragon of engineering, rather than a snapshot of our understanding at the time. We build great myths of spin about how what we have done is the only way to do it, to the point that our universities now teach the flaws to students (and professors and textbook authors) who dont know any better.

John Day (an Internet pioneer and historian)4Course Outline5 topics (topic 0 - 4) on the architecture, algorithms, and protocols used for developing scalable networks4 advanced topics (topic A1 to A4) on the technical foundations through which future generation networks can be designed5Course Introduction; Basics (week 1)

A high-level top-down view of computer networkingPacket switching vs. Circuit switchingApplications of networkingRequirements---Connectivity, Resource Sharing, Support for Common Services

Topic 0: Course Introduction6Advanced Topic A1---Brief introduction to networking research (week 2)

Tips for doing networking researchIntroduction to the research-based term projectIntroduction to modeling and network performance evaluationAnalytical modeling and evaluationSimulation modeling and evaluationTopic AI: Intro. to Net. Research7Topic 1: Direct link networks

Direct Link Networks (weeks 3, 4)

Building blocks: Encoding, Framing, Error Detection, Reliable TransmissionExample DL networks: Ethernet and Wireless (802.11)The simplest network possible is one in which two hosts are directly connected by some physical medium. This is also called a point to point link. This point to point link can be a length of wire, a piece of optical fiber, or a medium through electromagnetic radiation can be transmitted.

There are five problems that must be addressed before nodes can directly exchange packet even when they are directly connected.

Encoding problemFraming problemError detection problemReliable delivery problemMedia Access Control problem

These five issues are dealt separately by different protocols that work at the direct link layer level.

8Topic 2: Packet Switching and Internetworking

Packet Switching and Internetworking (weeks 5, 6, 7,8)

Switching and ForwardingBridges and LAN SwitchesSimple Internetworking Internet ProtocolIn the directly linked network topic (topic 1), there are two primary limitations.

Limit of number of nodes that may be attached.Limit to how large a geographical area can be covered.

E.g., Ethernet can span only 2.5 Km and allow no more than 1024 hosts.

Since our overall problem is to form networks that are global in scope, we need to enable communications between nodes that are not directly connected.

This problem is similar to that addressed in a telephone network. We are not physically connected with every person having a telephone in the world but is connected to an exchange called a switch. Computer networks use packet switches to give the illusion that we are connected to all possible receivers.

A packet switch is a device with many inputs and outputs learning to and from devices that connect to the packet switch. The core job of a switch is to take packets that arrive on input and switch them to the right output so that they will reach their appropriate destination.

Two kinds of packet switching. The first is LAN switching which evolved from Ethernet bridging to become the dominant technology for LAN environments. The second core technology is ATM/ MPLS which is used in wired environments.

9Advanced Topic A2---Network Architecture (week 9)

Control plane and the Data planeTraditional Internet architectureModern architecture as proposed by Software Defined Networking (SDN)Topic A2: Adv. Net. Architectures10Topic 3: Process Communication

End-to-End Protocols (week 10 and 11)

UDP and TCPTCP Congestion ControlCongestion Avoidance

We have seen how computers can be connected---direct links, switches, and internets. Now we want this host-to-host delivery service to service process-to-process communication. This problem is also called the end-to-end protocol problem.

We not only have to connect hosts in different network, but also ensure:

Guaranteed and Ordered message delivery between processesAllow receiver to apply flow controlSupport multiple processes on each host.11Topic 4: Application protocols

Applications (weeks 13)

Traditional Applications: FTP, SMTP, HTTPName Service: DNSOverlay NetworksIn the end, the end-users of networks interact using applications. Applications also must have a protocol to ensure their operation.

For example, web browsers use the HTTP protocol for exchanging data with webservers. We will cover in this topic popular application layer protocols.

12Advanced Topic A3---Mathematical Foundations of Networking (week 14 and 15)

Brief introduction to:Queueing theory, Optimization theory, Game theory, etc.Input Modeling and Output Analysis

Topic A3: Math. Foundations13Advanced Topic A4---Modern Networking Trends (week 16)

Brief introduction to:Cloud ArchitectureNetwork VirtualizationCognitive Radio NetworksNetwork Science

Topic A4: Modern net. trends14Course ``books

15Computers Networks a systems approachby Peterson and DavieText book:

[P&D]004.65 PET16Books philosophy:Systems approach

Problem-solving approach

Focus on core design choices

Focus on perspective rather than solely on specifications

Examples with real Internet protocols17Computers Networksby Kurose and Ross

Ref. book:[K&R]004.6 KUR18Mathematical Foundations of Computer networkingby Srinivasan Keshav[Keshav]Ref. book:

19Finding original research doc.

Vint Cerf

Bob KahnProposed TCP/IP as a single integrated protocol in 1974 for internetworking

20Course Policies21 Evaluation breakdown22Administrative policiesClass disciplinebeneficial learning requires students to pay attention and the teacher to be dedicated; its important to be punctual in the class.

Attendance policy (i.e., 75% minimum, Will be taken on LMS, final once taken)

Quizzes (announced/ unannounced)Course website on LMS; Forum at Piazza 23

Stats from a previous sessionhttps://piazza.com/seecs.edu.pk/fall2015/ee832/home 24To-do-list (1st day)Register yourself for the LMS course and for the Piazza forum1Read the course outline and get comfortable with the course site2Complete the online introduction questionnaire on LMS.3http://lms.seecs.edu.pk/lms/course/view.php?id=107525