PTE 1564 Jaringan Komputer 0812 7770 9019 Abdillah

PTE 1564 Jaringan Komputer 0812 7770 9019 Abdillah Mahyuddin abdill 01@gmail. com abdill 01. wordpress. com

Tujuan Mahasiswa mengerti dan memahami jaringan komputer melalui model referensi Open System Interconnections (OSI).

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Referensi Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012

Referensi Jaringan Komputer, Edisi ke-4 Andrew S. Tanenbaum, Prenhallindo, 2000

Bobot Penilaian Aktifitas Bobot (%) Tugas 20 Quiz 20 Ujian Tengah Semester 30 Ujian Akhir Semester 30 Total 100

Silabus Mata Kuliah v v v v v Pertemuan 1. Konsep Internet Pertemuan 2 -3. Application Layer Pertemuan 4 -5. Transport Layer Pertemuan 6 -7. Network Layer Pertemuan 8. UTS Pertemuan 9 -10. Data-link layer Pertemuan 11 -12. Konsep Jaringan Nirkabel Pertemuan 13. Konsep Jaringan Multimedia Pertemuan 14. UAS

Chapter 1: Introduction our goal: v get "feel" and terminology v more depth, detail later in course v approach: § use Internet as example overview: v v v v What’s the Internet? What’s a protocol? network edge; hosts, access net, physical media network core: packet/circuit switching, Internet structure performance: loss, delay, throughput security protocol layers, service models history Introduction 1 -8

Chapter 1: roadmap 1. 1 what is the Internet? 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 1 -9

What’s the Internet: "nuts and bolts" view PC server mobile network v millions wireless laptop smartphone of connected computing devices: § hosts = end systems § running network apps global ISP home network v communication wireless links wired links § fiber, copper, radio, satellite § transmission rate: bandwidth v Packet router switches: forward packets (chunks of data) § routers and switches regional ISP institutional network [ Internet Revealed ] Introduction 1 -10

"Fun" Internet appliances Web-enabled toaster + weather forecaster IP picture frame http: //www. ceiva. com/ Tweet-a-watt: monitor energy use Slingbox: watch, control cable TV remotely Internet refrigerator Internet phones Introduction 1 -11

What’s the Internet: "nuts and bolts" view v Internet: "network of networks" mobile network § Interconnected ISPs v protocols control sending, receiving of msgs § e. g. , TCP, IP, HTTP, Skype, 802. 11 v global ISP home network Internet standards regional ISP § RFC: Request for comments § IETF: Internet Engineering Task Force institutional network Introduction 1 -12

What’s the Internet: a service view mobile network v Infrastructure that provides services to applications: § Web, Vo. IP, email, games, e-commerce, social nets, … v global ISP home network regional ISP provides programming interface to apps § hooks that allow sending and receiving app programs to "connect" to Internet § provides service options, analogous to postal institutional network Introduction 1 -13

What’s a protocol? a human protocol and a computer network protocol: Hi TCP connection request Hi TCP connection response Got the time? Get http: //www. awl. com/kurose-ross 2: 00 <file> time Q: other human protocols? Introduction 1 -14

What’s a protocol? human protocols: v v v "what’s the time? " "I have a question" introductions … specific msgs sent … specific actions taken when msgs received, or other events network protocols: v v machines rather than humans all communication activity in Internet governed by protocols define format, order of msgs sent and received among network entities, and actions taken on msg transmission, receipt Introduction 1 -15

Chapter 1: roadmap 1. 1 what is the Internet? 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 1 -16

A closer look at network structure: v network edge: § § hosts: clients and servers often in data centers access networks, physical media: wired, wireless communication links v network core: v § interconnected routers § network of networks mobile network global ISP home network regional ISP institutional network Introduction 1 -17

Host: sends packets of data host sending function: v takes application two packets, message L bits each v breaks into smaller chunks, known as packets, of length L bits 2 1 v transmits packet into access network at R: link transmission rate host transmission rate R § link transmission rate, aka link capacity, aka link bandwidth time needed to packet L (bits) transmission = transmit L-bit = R (bits/sec) packet into link delay 1 -18

Physical media v v bit: propagates between transmitter/receiver pairs physical link: what lies between transmitter & receiver guided media: § signals propagate in solid media: copper, fiber, coax unguided media: § signals propagate freely, e. g. , radio twisted pair (TP) v two insulated copper wires § § Category 5: 100 Mbps, 1 Gpbs Ethernet Category 6: 10 Gbps Introduction 1 -19

Physical media: coax, fiber coaxial cable: v v v two concentric copper conductors bidirectional broadband: § multiple channels on cable § HFC fiber optic cable: v v glass fiber carrying light pulses, each pulse a bit high-speed operation: § high-speed point-to-point transmission (e. g. , 10’s-100’s Gpbs transmission rate) v low error rate: § repeaters spaced far apart § immune to electromagnetic noise Introduction 1 -20

Physical media: radio v v signal carried in electromagnetic spectrum no physical "wire" bidirectional propagation environment effects: § reflection § obstruction by objects § interference radio link types: v terrestrial microwave § e. g. up to 45 Mbps channels v LAN (e. g. , Wi. Fi) § 11 Mbps, 54 Mbps v wide-area (e. g. , cellular) § 3 G cellular: ~ few Mbps v satellite § Kbps to 45 Mbps channel (or multiple smaller channels) § 270 msec end-end delay § geosynchronous versus low altitude Introduction 1 -21

Chapter 1: roadmap 1. 1 what is the Internet? 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 1 -22

The network core v mesh of interconnected routers Introduction 1 -23

Network communication methods v Packet-switching § hosts break application-layer messages into packets § forward packets from one router to the next, across links on path from source to destination § each packet transmitted at full link capacity v Circuit-switching § end-end resources allocated to, reserved for "call" between source & dest. v Analogy § Car vs Train Introduction 1 -24

Packet-switching: store-andforward L bits per packet source v v v 3 2 1 R bps takes L/R seconds to transmit (push out) L-bit packet into link at R bps store and forward: entire packet must arrive at router before it can be transmitted on next link end-end delay = 2 L/R (assuming zero propagation delay) R bps destination one-hop numerical example: § L = 7. 5 Mbits § R = 1. 5 Mbps § one-hop transmission delay = 5 sec more on delay shortly … Introduction 1 -25

Packet Switching: queueing delay, loss A B C R = 100 Mb/s R = 1. 5 Mb/s queue of packets waiting for output link D E queuing and loss: v If arrival rate (in bits) to link exceeds transmission rate of link for a period of time: § packets will queue, wait to be transmitted on link § packets can be dropped (lost) if memory (buffer) fills up Introduction 1 -26

Two key network-core functions routing: determines source- forwarding: move packets destination route taken by packets § routing algorithms from router’s input to appropriate router output routing algorithm local forwarding table header value output link 0100 0101 0111 1001 1 3 2 2 1 3 2 11 01 dest address in arriving packet’s header Network Layer 4 -27

Alternative core: circuit switching End-end resources allocated to, reserved for "call" between source & dest: v v In diagram, each link has four circuits. § call gets 2 nd circuit in top link and 1 st circuit in right link. dedicated resources: no sharing § circuit-like (guaranteed) performance circuit segment idle if not used by call (no sharing) Commonly used in traditional Introduction 1 -28

Packet switching versus circuit switching is packet switching a "slam dunk winner? " within same capacity, allows more users to use network v great for bursty data § resource sharing § simpler, no call setup v excessive congestion possible: packet delay and loss § protocols are needed; for reliable data transfer, congestion control v Q: How to provide circuit-like behavior? § bandwidth guarantees needed for audio/video apps § still an unsolved problem (chapter 7) Q: human analogies of reserved resources (circuit switching) versus on-demand allocation (packetswitching)? Introduction 1 -29 v

Internet structure: network of networks Question: given millions of access ISPs, how to connect them together? access net … access net … … access net access net … access net …

Internet structure: network of networks Option: connect each access ISP to every other access ISP? access net … access net … … Low Scalability … … access net access net … … access net …

Internet structure: network of networks Option: connect each access ISP to a global transit ISP? Customer ISPs and provider ISPs have economic agreement. access net … access net … … access net global ISP access net access net … access net …

Internet structure: network of networks But if one global ISP is viable business, there will be competitors …. access net … access net access net … … ISP A access net ISP B ISP C access net access net … … access net

Internet structure: network of networks But if one global ISP is viable business, there will be competitors …. which must be interconnected Internet exchange point access net … … net access net IXP access net … … ISP A IXP access net ISP B ISP C access net peering link access net … … access net

Internet structure: network of networks … and regional networks may arise to connect access nets to ISPS access net … … access net IXP access net … … ISP A IXP access net ISP B ISP C access net regional net access net … … access net

Internet structure: network of networks … and content provider networks (e. g. , Google, Microsoft, Akamai ) may run their own network, to bring services, content close to end users access net … … access net IXP access net Content provider network IXP access net ISP B access net regional net access net … … access net … … ISP A access net

Internet structure: network of networks Tier 1 ISP IX P Regional ISP access ISP v access ISP Google access ISP IX P Regional ISP access ISP at center: small # of well-connected large networks § "tier-1" commercial ISPs (e. g. , Level 3, Sprint, AT&T, NTT), national & international coverage § content provider network (e. g, Google): private network that connects it data centers to Internet, often bypassing tier-1, regional Introduction 1 -37

Chapter 1: roadmap 1. 1 what is the Internet? 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 1 -38

See you next week! Any question? Introduction 1 -39