Network Architecture (NetArch) 1/5 : Introductionfourmaux/ARes/AResC1v62_en_4.pdf · 1 Course presentation Course objectives Pedagogical approach Instructional methodology 2 Administrative

Course presentationAdministrative questions

Course introduction

Network Architecture (NetArch)1/5 : Introduction

Olivier Fourmaux ([email protected])

Version 6.2

Olivier Fourmaux ([email protected]) Network Architecture (NetArch) 1/5 : Introduction


Course introduction

NetArch: Course 1/5 outline

1 Course presentationCourse objectivesPedagogical approachInstructional methodology

2 Administrative questionsScheduleEvaluation

3 Course introductionNetwork componentsProtocol hierarchyTCP/IP example



Course introduction

Course objectivesPedagogical approachInstructional methodology

NetArch: Course 1/5 Outline






Course introduction


Reinforce your understanding of networking

Deepen and extend beyond a first course in networking

example: LI310 course from the UPMC Licence d’Informatique

prerequisites, both theoretical and technical:

the vocabularyintroduction to signal processingbasic protocol mechanismsclassical protocols (HDLC, X25, IP, routing, UDP, TCP)ISO layered model



Course introduction


Understand fundamental technologies

Study the principal current network architecture and itsenvironment à TCP/IP and Internet

standardized applications (web, DNS, e-mail, . . . )

dynamic mechanisms (congestion control, . . . )

IPv4 adressing (CIDR, DHCP, NAT, tunnels, . . . )

advanced routing (AS hierarchy, OSPF, BGP, . . . )

media architectures (Ethernet, point-to-point links, . . . )

local loop (CATV, ADSL, FTTH, . . . )



Course introduction


Basis for further courses in networking

Prerequisite for advanced networking courses

In M1-S2: for required courses for students in the networkingspeciality, and for elective courses for other students

IPv6, multicast, QoS, security à U.E. INGmobility, autonomous, wireless à U.E. MOB

In M2: for students in the networking speciality (eitherindustry or research)

multimedia applications à U.E. APMMmultimedia transmission over IP à U.E. MMIPmultimedia and quality of service à U.E. MMQoSrouting and routers à U.E. ROUTnetwork security à U.E. SECURmobile services à U.E. SMOBnetwork supervision à U.E. SUPERVnetwork trafic and control à U.E. TCONT . . .



Course introduction


Course content

Top down approach:

Part 1/5 Introduction

Part 2/5 Application: Telnet, FTP, SMTP, HTTP,... DNS, SNMP, peer-to-peer.

Part 3/5 Transport: services, UDP and TCP examples,... congestion control.

Part 4/5 Network: IPv4, CIDR adressing, NAT...... hierarchical routing, OSPF and BGP.

Part 5/5 Link: Switched Ethernet,... point-to-point, local loop.



Course introduction


Labs

Four-hour labs consisting of written exerices (TDs) and practicalones (TMEs):

interlacing of theoretical and practical aspects

illustrated by concrete examples on a networking testbedusing real hardware:

Internet

via ARI

Salle M2-RES de 2003 à 2009

CommutateurX 16

Internet

via ARI

Salle M2-RES depuis 2009

X 16

PC 1U "serveur"

ctrl console ctrl alim.

PC 1U "sonde"

Routeur

PC 1U "client"



Course introduction


Lab schedule (tentative)

week content lab

1 Introduction to the networking testbed n°12 Applications (1): Telnet, FTP, and web analysis n°23 Applications (2): SMTP, DNS, and SNMP analysis n°34 Transport (1): analysis of mechanisms n°45 Review/completion of previous weeks’ labs

6 Transport (2): congestion control n°57 Network (1): IP/ICMP (begin) n°68 Network (2): IP/ICMP (end) n°69 Network (3): routing n°7

10 Review/completion of previous weeks’ labs



Course introduction


Course organization

13 weeks, within which. . .

Lectures: 10 × 2 hrs.

O. Fourmaux, T. Friedman

Labs: 10 × 4 hrs.

T. Bourgeau, O. Fourmaux, T. Friedman, R.Hu, K. Thai

Course website:

Information and updates:http://www-rp.lip6.fr/~fourmaux/index-cours.html



Course introduction


Networking testbed for the labs

The testbed hardware rack, located in theM2-RES computer lab, room 31-208

Each pair of students has access to:

a classical ARI host machine

dedicated hardware for configuringnetworks, and capturing and analyzingtraffic:

1 Cisco switch1 Cisco router3 VMs in on 1U rackable server



Course introduction


Supporting traces and documents

Network traffic traces, on which to test your knowledge

generated on the networking testbed during the labsgenerated by the students (on the testbed or elsewhere)pre-recorded (to use in case the testbed is down, or you wishto work elsewhere), available here:http://www-rp.lip6.fr/~fourmaux/Traces/labV6.html

Documents available on the course website:

course slideslab handouts (including optional exercises)past exams

Textbooks

available in the Math/Info libraries


http://www-rp.lip6.fr/~fourmaux/index-cours.html

http://www-rp.lip6.fr/~fourmaux/Traces/labV6.html


Course introduction


Bibliography

James F. Kurose, Keith W. Ross

Computer Networking: A Top-down Approach Featuringthe Internet, 6th edition (Pearson, 2013)

Andrew S. Tanenbaum, David J. Wetherall

Computer Networks, 5th edition (Prentice Hall, 2011)

Douglas Comer

Internetworking with TCP/IP Vol 1: Principles, Protocolsand Architectures, 5th edition (Prentice Hall, 2006)

Olivier Bonaventure

Computer Networking: Principles, Protocols andPractice, http://inl.info.ucl.ac.be/CNP3



Course introduction

ScheduleEvaluation







Course introduction

ScheduleEvaluation

Tentative schedule for 2012-2013

dates lecture lab comments

19-25/9 1 –

26/9-2/10 2 1

3-9/10 3 2

10-16/10 4 3

17-23/10 5 4

24-30/10 6 5

5-9/11 – – midterm exam

31/10 + 12-16/11 7 6

19-23/11 8 7

26-30/11 9 8

3-7/12 10 9

10-14/12 – 10

7-11/1 – – final exam

13-17/5 – – makeup exam



Course introduction

ScheduleEvaluation

Weekly schedule

U.E. ARES : Emploi du temps du 19/09/2012 au 21/12/2012

Lundi Mardi Mercredi Jeudi Vendredi08:30

08:4509:0009:1509:3009:4510:0010:15

10:3010:45

11:0011:1511:3011:4512:0012:1512:30

12:4513:00

13:1513:30

13:4514:0014:1514:3014:4515:0015:1515:30

15:4516:00

16:1516:3016:4517:0017:1517:3017:45

18:00Attention, les cours de toutes les UE commencent le mercredi 19/09/12 et les TD/TME le mercredi 26/09/12

ARESréservéITIN 131-208


Cours ARESAmphi 41A

ARESréservé ITIN 231-208


ARESTME 231-208

Cours ARESen anglais

ARESTME 331-208

ARESTME 331-208

ARESréservé

AFTI31-208

ARESréservé

AFTI31-208

ARESTME 231-208

ARESTME 131-208

ARESTME 131-208

ARESTME 131-208

ARESTME 4 en anglais

31-208


31-208


31-208


http://inl.info.ucl.ac.be/CNP3


Course introduction

ScheduleEvaluation

Exam details

Three exams:

Midterm exam (application and transport layers only)

Final exam (the whole course)

Makeup (the whole course)

Exam rules

no electronic equipment (mobile phone, calculator, etc.)

no documents except one handwritten A4 page

Definition

handwritten: entirely written by hand (no photocopies)



Course introduction

ScheduleEvaluation

Calculating the grade for the course

1st session: midterm and final exams

NARES1 = 0.4Nmidterm + 0.6Nfinal

Note: If you pass the course in the first session (NARES1 > 50),you may not take the makeup exam.

2nd session: makeup (you didn’t pass the course in the 1st

session)

If your grade is officially compensated for by passing grades inother courses: by default, you keep your grade NARES1 < 50

You may sit the makeup exam iff you explicitly sign up to doso with the RES secretariat

If your grade is not compensated for, you must take themakeup exam (if you do not, NARES2 = 0)

NARES2 = Nmakeup



Course introduction

ScheduleEvaluation

Final grade adjustments

The week after the final exam (1st session) or the makeup exam(2nd session):

exams graded and a curve is applied

grades posted on DBUFR

students consult their graded exams

juries

course jury (determines passing or failing)Networking speciality jury (grade compensation)Masters program jury (final decision)



Course introduction

Network componentsProtocol hierarchyTCP/IP example







Course introduction


The environment we discuss in this lecture

The Internet

omnipresent

heterogeneous

evolving

complex. . .

à difficult tocharacterize!

Let’s look at anexample:

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Course introduction


Internet components

What are the basic elements of the Internet?

communications links

routers (packet forwarding)

hosts (end systems):

Unix workstationsclassical PCsmobile phonesan Internet toaster. . .

networked applications

communication protocols. . .



Course introduction


Protocols: analogy

Temps

Bonjour

Où est la gare ?

Demande d’ouverture

de connexion TCP

... ...

Bonjour établissement de la connexion

Deuxième rue à gauche Envoi de la page d’accueil

GET http://www.upmc.fr

Réponse positive et

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Course introduction


Protocol: definition

Definition

Protocol: protocols define format, order of messages sent andreceived among network entities, and actions taken upon messagetransmission and receipt.

Remarkany interaction between entities over the Internet isbased on protocols

this course focuses mainly on protocols

Examples

web requestresolving name queries into IP addressesroute computationcongestion control. . .



Course introduction


Application services

Internet users use distributed applications:

World Wide Web

electronic mail

peer-to-peer file sharing

distributed games

audio and video streaming

real-time audio and video. . .



Course introduction


Network services

Applications are based on two types of services:

connectionless

analogy with the postal service

connection oriented

analogy with telephone service

and have correspondingly different characteristics:

reliability

ordering

flow control

congestion control. . .



Course introduction


Quality of service

Qualite de Service (QoS) in the Internet

The Internet offers a best effort service

no guarantees; the main concern is connectivity!how many end-systems?

many of the 1.5109 PCs + 1.5109 smartphones. . .2.5109 users active in 2012Internet traffic >>> telephone traffic

multimedia applications must adapt to the uncertainconditions. . .

à U.E. ING (M1-S2)



Course introduction


Internet standardisation

IESGIRSG

IETF

IRTF

ISOC

Working Areas Working Groups

Working Groups

... ...

... ... ...ISOC : Internet SOCiety

IAB : Internet Architecture Board

IRSG : Internet Research Steering Group

IRTF : Internet Research Task Force

IESG : Internet Engineering Steering Group

IETF : Internet Engineering Task Force

IAB

IETF (Internet Engineering Task Force) working groups

over 6000 RFCs (Requests For Comments)

mostly de facto rather than de jure standards

IP, TCP, SMTP, SNMP, HTTP...http://www.rfc-editor.org/


http://www.rfc-editor.org/


Course introduction


Some websites

ISOC (Internet SOCiety), http://www.isoc.org/

IETF (Internet Engineering Task Force),http://www.ietf.org/

IAB (Internet Architecture Board), http://www.iab.org/

W3C (World Wide Web Consortium), http://www.w3.org/

ACM SIGCOMM (Association for Computing Machinery –Special Interest Group in Data Communication),http://www.sigcomm.org/

IEEE Communications Society, http://www.comsoc.org/

IEEE Computer Society, http://www.computer.org/

http://www-npa.lip6.fr/~fourmaux



Course introduction


NetArch: Course 1/5 Outline






Course introduction


Network edge

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Course introduction


Network edge (abstraction)

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http://www.isoc.org/

http://www.ietf.org/

http://www.iab.org/

http://www.w3.org/

http://www.sigcomm.org/

http://www.comsoc.org/

http://www.computer.org/

http://www-npa.lip6.fr/~fourmaux


Course introduction


Distributed applications

client/server model

Client process

Request

Reply

Server process

Client machine Server machine

Network

the client sends requests

receives service from an always-on server

webe-mailDNS. . .

peer-to-peer model

minimal use of dedicated servers

symmetrical communication



Course introduction


Application protocols

Heterogeneous environment à standardised interactions

web: HTTP, HTML

e-mail: SMTP, MIME, POP, IMAP

remote access: Telnet, NVT

file transfer: FTP

directory: DNS

management: SNMP, MIB

à Part 2/5: Applications



Course introduction


End-to-end services

Types of service that the network offers to end-hosts:

connection oriented service

reliabilityorderingflow controlcongestion control. . .

TCP

connectionless service

simplebasis for other protocols

UDP



Course introduction


Impact of end-to-end control

What is the shape of traffic generated by TCP?

tcptahoe.seq

tcptahoe.cwnd

seq (Ko) / cwin (Ko/10)

t0.0000

100.0000

200.0000

300.0000

400.0000

500.0000

600.0000

700.0000

800.0000

0.0000 2.0000 4.0000 6.0000 8.0000 (s)

à Part 3/5: Transport



Course introduction


Inside the network

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Course introduction


Communication links

Physical media

media with waveguide

twisted pair (UTP5+, UTP6,. . . )coaxial cables (baseband, broadband,. . . )optical fibers (multimode, monomode,. . . )

media without waveguide

satellite links (geostationary, constellation, . . . )terrestrial links (radio-waves, micro-waves, infrared,optical,. . . )

Access technology

shared medium

framing

Intermediate elements. . .



Course introduction


Data forwarding

Circuit switching or packet switching?

(a)

(b)

Switching office

Physical copper connection set up when call is made

Packets queued up for subsequent transmission

Computer

Computer

pictures from Tanenbaum A. S. Computer Networks 3rd edition



Course introduction


Virtual circuit transmission

21

32

3

(b)

1

3

(a)

(c)

(d)

2 1

32

1

pictures from Stallings W. High Speed Networks



Course introduction


Message transmission

(b)

(a)

(c)

(d)




Course introduction


Datagram transmission

21

3 2 1

3

(c)

3

1

2

(b)

(a)

(d)

2 1

3




Course introduction


Comparing the three types of transmission

Data

Pkt 1

Pkt 2

Pkt 3

Pkt 1

Pkt 2

Pkt 3

Pkt 1

Pkt 2

Pkt 3

A B C D

Msg

Msg

Msg

A B C DA B C D

Propagation delay

Queuing delay

Call request signal

Time spent

hunting for an

outgoing trunk

Call accept signal

AB trunk

BC trunk

CD trunk

(a) (b) (c)

Tim

e

pictures from Tanenbaum A. S. Computer Networks 3rd edition



Course introduction


Delay recap

Types of delays in packet switching:

nodal processing delay

uncompressible (Dn)

queuing delay

depends on congestion (Dq = 0 if no congestion)

transmission delay

depends on the size of the packet (Dt = L/R)

propagation delay

v = 2.108m/s to 3.108m/s (Dp = d/v)

Formula for end-to-end delay?



Course introduction


Internet addressing

Packets travel from source to destination hop-by-hop, with anaddress-based forwarding decision made at each intermediate node(router).

IPv4 protocol

universal

virtual addressing

abstracts out the lower layer technologieseach technology provides encapsulationfragmentationaddress conversion

Protocols have evolved to adapt to the present network

classless addressing: CIDRaddress translation: NATauto-configuration: DHCPfiltering. . .Olivier Fourmaux ([email protected]) Network Architecture (NetArch) 1/5 : Introduction


Course introduction


Routing mechanisms

When and how to determine the route taken by data?

the type of path followed depends upon the type of network:initially

circuit switchingvirtual circuits

for each packet

datagram

calculating the information

routing algorithmsrouting tables

local or centralizedstatic or dynamic

information exchange

routing protocols. . .



Course introduction


Routing in the Internet

Datagram network

routing of each packet

Hierarchical structure of the network (ASes)

internal routing: OSPF

external routing: BGP

à Part 4/5: Network



Course introduction


Network core

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Course introduction


Ethernet technology

VLAN 2

VLAN 1

VLAN 1

VLAN 3

VLAN 3

VLAN 1

VLAN 1

VLAN 1

100 Mbps 100 Mbps

100 Mbps

1 Gbps

1 Gbps

1 Gbps

1 Gbps

10 Gbps

10 Gbps10 Gbps

10 Gbps

1 Gbps

VLAN 1VLAN 2VLAN 3

SwitchEthernet

SwitchEthernet

SwitchEthernet

SwitchEthernet

SwitchEthernet

CiscoSystems Cisco 7000 SERIES

LAN evolution towards the WAN with Fast Ethernet, GigabitEthernet, 10Gigabit Ethernet and 100Gigabit Ethernet.Integrating switching and structuring through VLANs. . .à Part 5/5 (1): Ethernet



Course introduction


MPLS technology

SwitchEthernet





Integrating switching mechanisms at the network level (ATM,MPLS,. . . ).à U.E. RTEL (M1-S1)



Course introduction


Point-to-point technology

TCP/IP connectionusing PPP

PPP only for old serial connections?

PPP over SONET: POS

PPP over Ethernet: PPPoE

PPP over ATM: PPPoA

PPP over IP: L2TP . . .

à Part 5/5 (2): Point-to-point



Course introduction


Access networks

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Course introduction


Entreprise networks

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Course introduction


Wireless

...

Depending upon the degree of mobility:

micro-mobility

Bluetooth/WPAN (IEEE 802.15)

wireless local network

Wi-Fi/WLAN (IEEE 802.11)

wireless local network

BLR/WMAN (IEEE 802.16)

mobile phone

GSM, GPRS, i-mode,. . .UMTS

à U.E. MOB (M1-S2)



Course introduction


Wired

Copper twisted pair

Switch

Switching office

High-bandwidth fiber trunk

Junction box

(a)

(b)

House

High-bandwidth fiber trunk

Copper cable TV wire

House

Junction box

Fiber

Fiber

Residential (PSTN/ADSL, cable, optical fiber,. . . )à Part 5/5 (3): Local loop



Course introduction








Course introduction


Protocols, layers, and interfaces

Layer 5

Layer 4

Layer 3

Layer 2

Layer 1

Host 1

Layer 4/5 interface

Layer 3/4 interface

Layer 2/3 interface

Layer 1/2 interface

Layer 5 protocolLayer 5

Layer 4

Layer 3

Layer 2

Layer 1

Host 2

Layer 4 protocol

Layer 3 protocol

Layer 2 protocol

Layer 1 protocol

Physical medium

picture from Tanenbaum A. S. Computer Networks 3rd edition



Course introduction


Anthropological analogy

I like rabbits

Location A

3

2

1

3

2

1

Location B

Message Philosopher

Translator

Secretary

Information for the remote translator

Information for the remote secretary

L: Dutch Ik hou van konijnen

Fax #--- L: Dutch Ik hou van konijnen

J'aime les

lapins

L: Dutch Ik hou van konijnen

Fax #--- L: Dutch Ik hou van konijnen




Course introduction


Repeated encapsulation

H2 H3 H4 M1 T2 H2 H3 M2 T2 H2 H3 H4 M1 T2 H2 H3 M2 T2

H3 H4 M1 H3 M2 H3 H4 M1 H3 M2

H4 M H4 M

M M

Layer 2 protocol

2

Layer 3 protocol

Layer 4 protocol

Layer 5 protocol

3

4

5

1

Layer

Source machine Destination machine




Course introduction


OSI (Open Systems Intercon. Reference Model – 1983)

Layer

Presentation

Application

Session

Transport

Network

Data link

Physical

7

6

5

4

3

2

1

Interface

Interface

Host A

Name of unit exchanged

APDU

PPDU

SPDU

TPDU

Packet

Frame

Bit

Presentation

Application

Session

Transport

Network

Data link

Physical

Host B

Network Network

Data link Data link

Physical Physical

Router Router

Internal subnet protocol

Application protocol

Presentation protocol

Transport protocol

Session protocol

Communication subnet boundary

Network layer host-router protocol

Data link layer host-router protocolPhysical layer host-router protocol



Course introduction


TCP/IP reference model (1974)

TCP/IPOSI

Application

Presentation

Session

Transport

Network

Data link

Physical

7

6

5

4

3

2

1

Application

Transport

Internet

Host-to-network

Not present in the model




Course introduction


TCP/IP: comparison

Firmware

Software

OperatingSystem

UserSpace

Hardware

Physical

NetworkAccess

Internet

Application

Transport(host−to−host)

TCP/IP

Application

Presentation

Session

Transport

Network

Data Link

Physical

OSI

these pictures and to the end are from Stallings W. High Speed Networks



Course introduction








Course introduction


TCP/IP: example

Server

FrameRelay

Network

Router

IEEE 802 LAN

Workstation

Physical

MAC

LLC

IP

Physical

MAC

LLC

IP

Physical

FrameRelay

FrameRelay

TCP

Application

Physical

IP

TCP

Application



Course introduction


TCP/IP: concept

Router J

TCP

IP

Physical Physical

IP

NAP 1 NAP 2

Network AccessProtocol #1

Host A

App XApp Y

TCP

IP

Network AccessProtocol #2

Host B

App YApp X

Network 1 Network 2

Global networkaddress

Subnetwork attachmentpoint address

Logical connection(e.g., virtual circuit)

Logical connection(TCP connection)

Port orservice access point (SAP)



Course introduction


TCP/IP: sender actions

DataTI

DataT

Data

Physical

IP

TCP

Application

FrameRelay

DataTIF F



Course introduction


TCP/IP: router actions

DataTIL

Physical

MACDataTILM MDataTIF F

LLC

FrameRelay

DataTI

IP

Physical



Course introduction


TCP/IP: receiver actions

DataTIL

Physical

LLC

IP

TCP

MAC

Data

Application

DataTI

DataT

DataTILM M
