Presentation is loading. Please wait.

Presentation is loading. Please wait.

Hyrje Qellimi: Trajtohet “idea” dhe terminologjia e rrjetave

Published byWilfrid Ryan Modified over 6 years ago

Similar presentations

Presentation on theme: "Hyrje Qellimi: Trajtohet “idea” dhe terminologjia e rrjetave"— Presentation transcript:

1 Hyrje Qellimi: Trajtohet “idea” dhe terminologjia e rrjetave
Me ne detaje, trajtohet me vone Perqasja: Perdorimi I Internetit si shembull Perseritje: C’eshte Interneti? Cfare quajme protokoll? Cepi I rrjetit; hostet, Rrjetat e aksesit, mjedisi fizik Berthama e rrjetit: transmetimi me pakete/qark, struktura e Internetit performanca: humbje, vonesa, Siguria , Shtresat e protokollet protocol layers, service models history Introduction

2 Chapter 1: Permbajtja 1.1 C’eshte interneti? 1.2 network edge
end systems, access networks, links 1.3 network core packet switching, circuit switching, network structure 1.4 delay, loss, throughput in networks 1.5 protocol layers, service models 1.6 networks under attack: security 1.7 history Introduction

3 Pamja e pergjithshme e Internetit, elementet perberes
smartphone PC server wireless laptop miliona kompj. te lidhur: hosts = sistemet skajore Ekzekutojne applikime te rrjetave mobile network global ISP ISP rajonale home network institutional Linjat e komunikimit fiber, tel bakri, radio, satellite Shpejtesia e transmetimit: gjeresi e brezit=bandwidth wired links wireless Transmetim me pakete: transmeton paketa (grupime te dhenash) Ruterat dhe centralet router Introduction 3

4 Pajisje Interneti te cuditshme
Web-enabled toaster + weather forecaster IP picture frame Tweet-a-watt: monitor energy use Slingbox: watch, control cable TV remotely Internet refrigerator Internet phones Introduction

5 Si do te jete pamja ne detaje e Internetit
mobile network global ISP regional ISP home network institutional Internet: “Rrjet I rrjetave” ISP te nderlidhura protokollet kontrollojne dergimin dhe marrjen e mesazheve P.sh, TCP, IP, HTTP, Skype, Standaret e Internetit RFC: Request for comments IETF: Internet Engineering Task Force Introduction

6 C’eshte Interneti: sherbimet
mobile network global ISP regional ISP home network institutional Infrastructura qe u siguron sherbime aplikimevetions: Web, VoIP, , lojera, e-commerce, rrjetat sociale, … Siguron nderfaqe programimi te applikimeve Hallka lidhese qe lejojne marrjen dhe dergimin e programeve aplikative per t’u “lidhur “ me Internetin Siguron mundesi sherbimi te ngjashme me sherbimin postar Introduction

7 C’eshte nje protokoll? Protokollet njerezore: Protokollet e rrjetit:
“Sa eshte ora?” “Kam nje pyetje” Prezantimet … mesazhe specifike dergohen … veprime specifike kryhen kur merren mesazhet ose ndodhin ngjarje te tjera Protokollet e rrjetit: Jane makina jo njerez I gjithe aktiviteti i komunikimit ne Internet drejtohet nga protokollet protokollet percaktojne formatin, rradhen e mesazheve te derguara dhe te marra ndermjet njesive te rretit, dhe aksionet e kryera ne transmetim ose marrje te mesazheve Introduction

8 C’eshte nje protokoll? Shembulli I nje protokolli human dhe te rrjetit te kompjuterave: Hi TCP connection request Hi TCP connection response Got the time? Get 2:00 <file> time Introduction

9 Chapter 1: roadmap 1.2 Skajet e Rrjetit
Sistemet skajore, Rrjetat e aksesit, linjat Introduction 9

10 Nje veshtrim me i afert ne structure
Skaji i rrjetit: hostet: kliente dhe server Serveret ndodhen shpesh ne qendra te dhenash mobile network global ISP regional ISP home network institutional Rrjetat e aksesit, mjedisi fizik: linjat e komunikimit me tel ose pa tel Berthama e rrjetit: Ruterat e nderlidhur Rrjetat e rrjetave Introduction

11 Rrjetat e aksesit dhe mjedisi fizik
Q: Si te lidhim sistemet skajore me ruterin e periferise? Rastet e: Rrjetave rezidenciale te aksesit Rrjetat e aksesit institucional (shkolle, kompany) Rrjetat e aksesit mobil Mba ne mend: Gjeresi e brezit-bandwidth (bite per second) te aksesit te rrjetit? Akses i ndare ose dedikuar? Introduction

12 Rrjeti i Aksesit: digital subscriber line (DSL)
central office telephone network Zeri, te dhenat te transmetuara ne frekuena te ndryshme dedicated line to central office DSL modem splitter DSLAM DSL access multiplexer ISP Perdor linjat te tel. ekzistuese drejt zyres qendrore DSLAM Te dhenat ne linjat e telefonit DSL shkojne drejt Internetit Zeri ne linjat DSL shkon ne rrjetin telephonik < 2.5 Mbps,Shp. Transmetimit drejt klientit (typically < 1 Mbps) < 24 Mbps shpejtesia e transm. drejt qend(typically < 10 Mbps) Introduction

13 Rrjeti i aksesit: rrjeti kabllor
cable headend … cable modem splitter Channels V I D E O A T C N R L 1 2 3 4 5 6 7 8 9 frequency division multiplexing (FDM): kanale te ndryshme transmetojne ne breza te ndryshme frekuencash. Introduction

14 Rrjeti i aksesit kabllor:
cable headend … data, TV transmitted at different frequencies over shared cable distribution network cable modem splitter cable modem termination system CMTS ISP HFC: hybrid fiber coax- Hibrid fiber dhe koasial asymmetrik: deri ne 30Mbps para shperndarjes, 2 Mbps te klienti Rrjeti kabllor dhe fiber per te lidhur shtepite me ruterin ISP Shtepite ndajne rrjetin e aksesit me terminalet kablore Ndryshe nga DSL, qe ka akses te dedikuar me zyren qendrore Introduction

15 Prej/nga terminali I zyres qendrore (central)
Rrjeti i shtepise Pajisjet pa tel Prej/nga terminali I zyres qendrore (central) Shpesh te kombinuar ne nje kuti te vetme wireless access point (54 Mbps) router, firewall, NAT cable or DSL modem wired Ethernet (100 Mbps) Introduction

16 Rrjetat e aksesit te kompanive
institutional link to ISP (Internet) Ruter Institucioni Central Etherneti institutional mail, web servers Perdoret kryesisht ne kompani, universitete, etj Shpejtesi transmetimi: 10 Mbps, 100Mbps, 1Gbps, 10Gbps Ne ditet e sotme sistemet skajore kryesisht lidhen me centralin e Eternetit. Introduction

17 Rrjetat e aksesit celular (wireless)
Rrjetat e perbashket te aksesit celular lidhin sistemet skajore me ruteret. via base station aka “access point” Aksesi celular ne zone te gjere Jepet nga telco (cellular) operator, 10’s km between 1 and 10 Mbps 3G, 4G: LTE wireless LANs: within building (100 ft) 802.11b/g (WiFi): 11, 54 Mbps transmission rate drejt Internet drejt Internet Introduction

18 Hosti: dergon paketa me te dhena
Funksioni dergues i hostit: merr mesazhin e applikimit Copeton ne copeza me te vogla, qe njihen si paketa me gjatesi me te vogel L bite. Transmeton paketat ne rrjetat e aksesit me shpejtesi transmetimi:R Shpejtesia e transmetimit ne linje two packets, L bits each 2 1 R: link transmission rate host L (bits) R (bits/sec) Vonesa e transm. te paketes Koha qe duhet per =te transmetuar paketen ne linje =

19 Mjedisi fizik bit: perhapet ndermjet cifteve transmetues/marres
Linja fizike: cfare shtrihet ndermjet transmetuesit dhe marresit. Mjedisi i orientuar: Sinjalet perhapen ne mjedis te ngurte ne baker, apo ne fibra: Ato perhapen lirisht p.sh. Radio.g., radio Telat dyshe (twisted pair) te nderthurura Category 5: 100 Mbps, 1 Gpbs Ethernet Category 6: 10Gbps Introduction

20 Ambienti fizik dhe media: coax, fiber
Kablli koaksial: Dy percjellesa koncentrik bakri Dydrejtimshe dband: shume kanale ne kabell HFC Kabell me fiber optike: Fiber qelqi qe bart impulse drite , cdo puls 1bit. Veprimi ne shpejtesi te madhe Transmetim i larte pike me pike me shpejtesi te madhe (e.g., 10’s-100’s Gpbs trarate) Shkalla e vogel e gabimeve: Perseriten repeaters te vendosur larg njeri tjetrit, Te mbrojtur nga zhurma electromagnetike. I

21 Mjedisi fizik: radiovalet
Tipet e linjave radio: Tokesore mikrovale P.sh.kanale 45 Mbps LAN (p.sh, WiFi) 11Mbps, 54 Mbps wide-area (p.sh, cellular) 3G cellular: ~ few Mbps Satelit Kbps to 45Mbps channel (or multiple smaller channels) Vonesa skaj –me skaj (end-to-end) 70 msec geosynchronous versus low altitude Sinjali i bartur ne spektrin elektromagnetik Nuk ka “tel” fizik dydrejtimesh Effektet e perhapjes ne mjedis: reflektimi Mbulim nga objektet interference Introduction

22 Chapter 1: roadmap 1.3 Rrjeti
(packet switching, circuit switching, network structure) Transmetimi me paket, me qark, struktura e rrjetit 22

23 Berthama e rrjetit Nderthurje ruterash te nderlidhur mes tyre
Transmetimi me pakete: hosti ndan mesazhet nga shtresa e aplikimit ne paketa Transmeton paketat nga nje ruter tek tjetri permes linjave te zgjedhura nga burimi ne destinacion Cdo pakete transmetohet me kapacitet te plote te linjes Introduction

24 Tranmetimi me pakete: magazino dhe transmeto (store-and-forward)
L bits per pakete 3 2 1 burimi destinacioni R bps R bps Duhen L/R sekonda per te transmetuar (push out) paketen me L-bit ne linjen me R bps Magazini dhe transmeto (store and forward): e gjithe paketa duhet te arrije ne ruter para se te transmetohet ne linjen tjeter Shembull numerik me nje hope: L = 7.5 Mbits R = 1.5 Mbps Vonesa e transmetimit per nje ho: = 5 sec Vonesa skaj me skaj(end-end dela)y = 2L/R (vonesen e perhapjes e konsiderojme 0) more on delay shortly … Introduction

25 Rradhe paketash qe presin per linjen e daljes
Transmetimi me pakete: vonesa e pritjes ne rradhe (queueing delay), humbjet C A R = 100 Mb/s D R = 1.5 Mb/s B E Rradhe paketash qe presin per linjen e daljes Rradha dhe humbja: Ne se ritmi i mbrritjes (ne bite) ne linje eshte me e madhe se sa ritmi i transmetimit te linjes per nje periudhe kohe: Paketat do te vihen ne rradhe, te presin per tu transmetuar ne linje Paketat mund edhe te humbin nese memoria (buferi) mbushet plot

26 Dy funksione celes te berthames te rrjetit
Rugezimi (routing): percakton rrugen burim-destinacion te marre nga paketat Algoritmet e routing transmetimi: zhvendos paketat nga hyrja ne ruter tek dalja e tij routing algorithm local forwarding table header value output link 0100 0101 0111 1001 3 2 1 1 2 3 0111 Adresa e dest. ne header te paketes mbrritese Network Layer

27 Alternativa (mundesia tjeter): tranmetimi me qark
Burimet skaj me skaj te rezevuara per “thirrje” ndermjet burimit dhe destinacionit: Ne diagrame, cdo linje ka 4 qarqe. -Thirrja okupon qarkun e dyte ne linjen e pare dhe qarkun e dyte ne linjen e djathte. Burimet e dedikuara: nuk ka perdorim te perbashket -Si-qark (performance e garantuar) Segmenti i qarkut qendron i lire nese nuk perdoret nga asnje thirrje (no sharing) I perdorur gjeresisht nga rrjetat telefonike tradicionale

28 Transmetimi me qark: FDM kundrejt TDM
4perdorues Shembull: FDM frequenca koha TDM frequenca koha Two simple multiple access control techniques. Each mobile’s share of the bandwidth is divided into portions for the uplink and the downlink. Also, possibly, out of band signaling. As we will see, used in AMPS, GSM, IS-54/136

29 Transmetimi me Pakete kundrejt atij me qark
Transmetimi me pakete ben te mundur qe me shume perdorues te perdorin rrjetin Shembull: Linja 1 Mb/s Cdo perdorues: 100 kb/s kur eshte “aktiv” activ 10% te kohes Transmetimi me qark: 10 perdorues Transmetimi me pakete: me 35 perdorues, probabiliteti > 10 active at same time is less than * ….. N users Linje 1 Mbps Q: Cfare ndodh nese > 35 perdorues? * Check out the online interactive exercises for more examples

30 Transmetimi me Pakete kundrejt atij me qark
A eshte fitues transmetimi me pakete? I pershtatshem per te dhena me fluks te madh Perdorim te perbashket te burimeve Me i thjeshte, s’ka nevoje per vendosje te thirrjes. Bllokim eksesiv i mundshem : vonesa paketash dhe humbje Nevojiten protokolle per transferim te sakte te te dhenave, kontroll te bllokimit Q: Si te sigurohet sjellje sikur te ishte transmetim me qark? Gjeresi brezi e garantuar e domosdoshme per applikime ze/figure Introduction

31 Struktura e Internetit: rrjeti i rrjetave
Sistemet skajore lidhen ne Internet permes ISP te aksesit (Internet Service Providers) ISP u sherbejne rezidenteve, kompanive dhe universiteteve Por dhe ISP-te duhet te nderlidhen mes tyre. Ne menyre qe cdo 2 hoste(kliente) mund t’I dergojne paketa njeri-tjetrit. Rrjeti i rrjetave rezultues eshte shume komplex. Evolucioni i struktures se rrjetit u udhehoq nga politika ekonomike dhe nacionale. Le te bejme nje analize hap pas hapi per te pershkruar Stukturen aktuale te Internetit.

32 Struktura e Internetit: Rrjeti i rrjetave
Pyetje: Meqenese ekzistojne miliona ISP te akseseve, si t’i lidhim ato se bashku? access net …

33 Struktura e Internetit: rrjeti i rrjetave
Opsion: lidh cdo ISP te aksesit me cdo ISP tjeter? access net … … Duke lidhur cdo ISP te aksesit me njera tjetren rezulton ne kompleksitet te madh: O(N2) lidhje.

Download ppt "Hyrje Qellimi: Trajtohet “idea” dhe terminologjia e rrjetave"

Similar presentations

Chapter 1: roadmap 1.1 What is the Internet? 1.2 Network edge

Chapter 1: roadmap 1.1 What is the Internet? 1.2 Network edge
Introduction to Physical Layer

Introduction to Physical Layer
Chapter 1 Introduction Computer Networking: A Top Down Approach 6th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 Introduction.

Chapter 1 Introduction Computer Networking: A Top Down Approach 6th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 Introduction.
CS 381 Introduction to computer networks Lecture 2 1/29/2015.

CS 381 Introduction to computer networks Lecture 2 1/29/2015.
James 1:5 If any of you lacks wisdom, he should ask God, who gives generously to all without finding fault, and it will be given to him.

James 1:5 If any of you lacks wisdom, he should ask God, who gives generously to all without finding fault, and it will be given to him.
Introduction1-1 Introduction to Computer Networks Our goal:  get “feel” and terminology  more depth, detail later in course  approach:  use Internet.

Introduction1-1 Introduction to Computer Networks Our goal:  get “feel” and terminology  more depth, detail later in course  approach:  use Internet.
Introduction1-1 Chapter 1 Introduction All material copyright 1996-2007 J.F Kurose and K.W. Ross, All Rights Reserved.

Introduction1-1 Chapter 1 Introduction All material copyright J.F Kurose and K.W. Ross, All Rights Reserved.
Lecture 1 Internet Overview: roadmap 1.1 What is the Internet? 1.2 Network edge  end systems, access networks, links 1.3 Network core  network structure,

Lecture 1 Internet Overview: roadmap 1.1 What is the Internet? 1.2 Network edge  end systems, access networks, links 1.3 Network core  network structure,
Lecture 1 1-1 Chapter 1: roadmap 1.1 What is the Internet? 1.2 Network edge  end systems, access networks, links 1.3 Network core  network structure,

Lecture Chapter 1: roadmap 1.1 What is the Internet? 1.2 Network edge  end systems, access networks, links 1.3 Network core  network structure,
Lecture 2 1-1 Internet Overview: roadmap 1.1 What is the Internet? (A simple overview last week) Today, A closer look at the Internet structure! 1.2 Network.

Lecture Internet Overview: roadmap 1.1 What is the Internet? (A simple overview last week) Today, A closer look at the Internet structure! 1.2 Network.
Lets begin…. Introduction1-2 Access networks and physical media Q: How to connect end systems to edge router? residential access nets institutional access.

Lets begin…. Introduction1-2 Access networks and physical media Q: How to connect end systems to edge router? residential access nets institutional access.
Networking Based on the powerpoint presentation of Computer Networking: A Top Down Approach Featuring the Internet, Third Edition, J.F. Kurose and K.W.

Networking Based on the powerpoint presentation of Computer Networking: A Top Down Approach Featuring the Internet, Third Edition, J.F. Kurose and K.W.
Kapitulli 1 Hyrje Computer Networking: A Top Down Approach 6th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 Hyrje.

Kapitulli 1 Hyrje Computer Networking: A Top Down Approach 6th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 Hyrje.
Lecture 1 Overview: roadmap 1.1 What is computer network? the Internet? 1.2 Network edge  end systems, access networks, links 1.3 Network core  network.

Lecture 1 Overview: roadmap 1.1 What is computer network? the Internet? 1.2 Network edge  end systems, access networks, links 1.3 Network core  network.
Lecture 1 Internet Overview: roadmap 1.1 What is the Internet? 1.2 Network edge  end systems, access networks, links 1.3 Network core  network structure,

Lecture 1 Internet Overview: roadmap 1.1 What is the Internet? 1.2 Network edge  end systems, access networks, links 1.3 Network core  network structure,
Introduction to Packet Switching 1-1. Introduction 1-2 What is the Internet 1.1 What is the Internet? 1.2 Network edge  end systems, access networks,

Introduction to Packet Switching 1-1. Introduction 1-2 What is the Internet 1.1 What is the Internet? 1.2 Network edge  end systems, access networks,
Introduction1-1 Lecture 1 – Introduction slides are modified from J. Kurose & K. Ross University of Nevada – Reno Computer Science & Engineering Department.

Introduction1-1 Lecture 1 – Introduction slides are modified from J. Kurose & K. Ross University of Nevada – Reno Computer Science & Engineering Department.
Introduction to Physical Layer Computer Networks Computer Networks Term B14.

Introduction to Physical Layer Computer Networks Computer Networks Term B14.
1: Introduction1 Part I: Introduction Goal: r get context, overview, “feel” of networking r more depth, detail later in course r approach: m descriptive.

1: Introduction1 Part I: Introduction Goal: r get context, overview, “feel” of networking r more depth, detail later in course r approach: m descriptive.
Chapter 1 Introduction Computer Networking: A Top Down Approach 6th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 A note on the use of these.

Chapter 1 Introduction Computer Networking: A Top Down Approach 6th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 A note on the use of these.

Similar presentations

Ads by Google