ict 6621 : advanced networkingkhaled mahbub, iict, buet, 2008 ict 6621 advanced networking course...

Khaled Mahbub IICT BUET 2008 ICT 6621 Advanced Networking

ICT 6621Advanced Networking

Course TeacherDr Khaled Mahbub

Assistant Professor IICT BUETEmail khaledmahbubiictbuetacbd


Course Informationbull Structure

ndash 14 week of lecturesndash 2 mid-term exams (one hour each )

- Mid-term 1 in 5th6th week (30 of course marks) - Mid-term 2 in 10th11th week (30 of course marks)ndash Final exam after 14 weeks of classes (40 of course marks)

bull Recommended textbookso Text1 - ldquoTCPIP Illustrated Volume 1 The protocolsrdquo by W Richard

Stevens Publisher Addison Wesleyo Text2 ndash ldquoComputer Networksrdquo 4th edition by Andrew S Tanenbaum

Publisher Prentice Hallo Text3 ndash ldquoComputer Networking A Top-Down Approach Featuring the

Internetrdquo 3rd edition by James F Kurose and Keith W Ross Publisher Addison Wesley

o Additional materials will be suggested as needed


Resources

bull Lecture slides and the textbooks can be downloaded from the following pagehttpteacherbuetacbdkhaledmahbubanthtml

bull Lecture slides will be uploaded after each class and it will stay there for next 2 weeks

bull The e-copies of the books will stay there for the first 3 weeks


Course Outlinebull The TCPIP protocol stack

IP ARP TCP and UDP DNS ICMP Internet addressing routing IP multicast RSVP Next Generation IP Interior gateway protocols RIPv2IGRP EIGRP OSPF

bull Wireless Radio basics satellite systems WAP current trends issues with wireless overTCP

bull Congestion Control control avoidance control and avoidance algorithms congestion in the Internet

bull Network Security IP security firewalls

bull Management Quality of service (QoS) network vs distributed systems management integrated service differentiated service protocols web-based management


Todayrsquos Outline

bull Review of Computer Network Basics


Computer Network amp Internet

bull Computer Network Interconnected collection of autonomous computers and other devices

bull Internet network of networks

local ISP

companynetwork

regional ISP

router workstation

servermobile


Types of Networksbull Local Area Networks (LAN) are generally privately owned networks

ndash restricted in size ie within a single building or campus of up to a few kilometers in size

ndash Traditionally uses a transmission technology consisting of a cable to which all machines are attached

ndash Various topologies are possible eg Bus Ringbull Metropolitan Area Networks (MAN) covers a city or townbull Wide Area Networks (WAN) spans a large geographical area eg a

country or continentndash Collection of machines (hosts) are connected by subnet(s)ndash Subnets are composed of (i) transmission lines (eg copper wire optical

fiber or radio links) that move bits between machines and (ii) switching elements (specialized computers known as router) that connect three or more transmission lines

bull Wireless Networksndash eg System interconnection wireless LANs wireless WANs not

necessarily mobilebull Internetworks (or Internet) connect different networks

ndash Incompatible networks are connected by means of machines called gateway that provide necessary translation (both hw and sw)


Whatrsquos a protocol

human protocolsbull ldquowhatrsquos the timerdquobull ldquoI have a questionrdquobull introductions

bull hellip specific msgs sentbull hellip specific actions

taken when msgs received or other events

network protocolsbull machines rather than

humansbull all communication

activity in Internet governed by protocols


Protocol Example

Hi

Hi

Got thetime

200

TCP connection req

TCP connectionresponseGet httpwwwawlcomkurose-ross

ltfilegttime

Time Request Human Protocol

URL Request Network Protocol


Protocols

bull A protocol definesndash the format and the order of the messages

exchangedndash the syntax semantics and actions on

receipttransmission of a message

bull Why use protocolsndash to provide a common languagendash rules must be unambiguous and followed

exactly


Network Software

bull Network software is highly structured and are organized as a stack of layers or levels

bull Layered structure is used to deal with complex systemsndash explicit structure allows identification

relationship of complex systemrsquos piecesbull layered reference model for discussion

ndash modularization eases maintenance updating of system

bull change of implementation of layerrsquos service transparent to rest of system


Protocol Stackbull Layer n on one machine

interacts with layer n on another machine

bull The rules and conversations used in this interaction are collectively known as the layer n protocol

bull A set of layers and protocols is called a network architecture

bull A list of protocols used by certain system one protocol per layer is called a protocol stack


The protocol stackOSI (7 layers) proposed by ISO in 1983 as first step toward international standardization of protocols

TCPIP (4 layers) proposed by DARPA in 1970 as a specification for computer network protocols


TCPIP protocol stack

bull Each layerrsquos responsibilityndash The link layer (data-link layer network interface layer)

bull handle all the hardware details and interaction of physical devices (eg cables network cards)

ndash The network layer (internet layer)bull handles the movement of packets around the network

ndash The transport layerbull provides a flow of data between two hosts for the application

layer abovebull TCP =gt provides a reliable flow of data between two hostsbull UDP =gt unreliable reliability must be added by the

application layer

ndash The application layerbull handles the details of the particular application





Two networks connected with a router


TCPIP LayeringVarious protocols at the different layers in TCPIP protocol suite


IP address and port numbersbull Every host on a network is identified by a unique

number called IP address

bull IP address is a 32 bit number and this number is written in dotted decimal notation ie four decimal numbers one for each byte Eg 140351345

bull Applications in the application layer are identified by unique numbers called port numbers

bull Some well known port numbers arendash 1048716 FTP server is on TCP port 21ndash 1048716 Telnet server is on TCP port 23ndash 1048716 TFTP is on UDP port 69ndash 1048716 Rlogin is on TCP port 513


Encapsulation

message

segment

datagram

frame


Encapsulation example

Encapsulation of data as it goes down the protocol stack


Demultiplexing

The demultiplexing of a received Ethernet frame


Client-Server Model

bull Typical network application has two pieces client and serverndash Client

bull initiates contact with server (ldquospeaks firstrdquo)bull typically requests service from serverbull for Web client is implemented in browser for e-

mail in mail reader

ndash Serverbull provides requested service to clientbull eg Web server sends requested Web page mail

server delivers e-mail


Client-Server Model

bull Two classes of serversndash iterative

bull I1 Wait for a client request to arrivebull I2 Process the client requestbull I3 Send the response back to the client that send the

requestbull I4 Go back to step I1

ndash concurrentbull C1 Wait for a client request to arrivebull C2 Start a new server to handle this clientrsquos request This

may involve creating a new process task or thread depending on the operating system This new server handles this clientrsquos entire request When complete this new server terminates

bull C3 Go back to step C1


Reading Materialbull Chapter 1 ndash text1 (Stevens)

bull Chapter 1 ndash text2 (Tanenbaum)


Course Informationbull Structure

ndash 14 week of lecturesndash 2 mid-term exams (one hour each )

- Mid-term 1 in 5th6th week (30 of course marks) - Mid-term 2 in 10th11th week (30 of course marks)ndash Final exam after 14 weeks of classes (40 of course marks)

bull Recommended textbookso Text1 - ldquoTCPIP Illustrated Volume 1 The protocolsrdquo by W Richard

Stevens Publisher Addison Wesleyo Text2 ndash ldquoComputer Networksrdquo 4th edition by Andrew S Tanenbaum

Publisher Prentice Hallo Text3 ndash ldquoComputer Networking A Top-Down Approach Featuring the

Internetrdquo 3rd edition by James F Kurose and Keith W Ross Publisher Addison Wesley

o Additional materials will be suggested as needed


Resources












Todayrsquos Outline






local ISP

companynetwork

regional ISP

router workstation

servermobile




















Protocol Example

Hi

Hi

Got thetime

200

TCP connection req


ltfilegttime




Protocols





exactly


Network Software






















application layer
















Encapsulation

message

segment

datagram

frame





Demultiplexing



Client-Server Model



mail in mail reader




Client-Server Model











Resources












Todayrsquos Outline






local ISP

companynetwork

regional ISP

router workstation

servermobile




















Protocol Example

Hi

Hi

Got thetime

200

TCP connection req


ltfilegttime




Protocols





exactly


Network Software






















application layer
















Encapsulation

message

segment

datagram

frame





Demultiplexing



Client-Server Model



mail in mail reader




Client-Server Model


















Todayrsquos Outline






local ISP

companynetwork

regional ISP

router workstation

servermobile




















Protocol Example

Hi

Hi

Got thetime

200

TCP connection req


ltfilegttime




Protocols





exactly


Network Software






















application layer
















Encapsulation

message

segment

datagram

frame





Demultiplexing



Client-Server Model



mail in mail reader




Client-Server Model














local ISP

companynetwork

regional ISP

router workstation

servermobile




















Protocol Example

Hi

Hi

Got thetime

200

TCP connection req


ltfilegttime




Protocols





exactly


Network Software






















application layer
















Encapsulation

message

segment

datagram

frame





Demultiplexing



Client-Server Model



mail in mail reader




Client-Server Model





























Protocol Example

Hi

Hi

Got thetime

200

TCP connection req


ltfilegttime




Protocols





exactly


Network Software






















application layer
















Encapsulation

message

segment

datagram

frame





Demultiplexing



Client-Server Model



mail in mail reader




Client-Server Model











Protocols





exactly


Network Software






















application layer
















Encapsulation

message

segment

datagram

frame





Demultiplexing



Client-Server Model



mail in mail reader




Client-Server Model











Network Software






















application layer
















Encapsulation

message

segment

datagram

frame





Demultiplexing



Client-Server Model



mail in mail reader




Client-Server Model


























application layer
















Encapsulation

message

segment

datagram

frame





Demultiplexing



Client-Server Model



mail in mail reader




Client-Server Model
























Encapsulation

message

segment

datagram

frame





Demultiplexing



Client-Server Model



mail in mail reader




Client-Server Model














Demultiplexing



Client-Server Model



mail in mail reader




Client-Server Model











Client-Server Model



mail in mail reader




Client-Server Model











Client-Server Model










ict 6621 : advanced networkingkhaled mahbub, iict, buet, 2008 ict 6621 advanced networking course...

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