Komunikasi Data

Local Area Network

SAP Komunikasi Data

Pendahuluan Protokol dan

Arsitektur

Transmisi Data dan Media

Transmisi

Pengkodean Data Komunikasi Data Digital

Data Link Control

Switching Multiplexing Jaringan selular dan Komputer

Spread Spectrum

Start

Finish

UTS

UU/UAS

Tugas 1

Tugas 2

Topologi Jaringan

• Bus Topology

• Star Topology

• Ring Topolgy

A

A

C transmits frame addressed to A

Frame is not addressed to B; B ignores it

A copies frame as it goes by

A

A

Figure 11.1 Frame Transmission on a Bus LAN

B C

A B C

A B C

Central Hub,

switch,

or repeater

Figure 11.2 Star Topology

Physical

Data Link

Medium

Network

Transport

Session

Presentation

Application

OSI ReferenceModel

Physical

Medium AccessControl

Medium

Logical Link Control

( ) ( ) ( )

UpperLayer

ProtocolsLLC ServiceAccess Point

(LSAP)

Scopeof

IEEE 802Standards

Figure 11.3 IEEE 802 Protocol Layers Compared to OSI Model

IEEE 802Reference

Model

IEEE 802 Reference Model

• Lowest layer corresponds to the physical layer of the OSI model

Includes a specification of the transmission medium and the topology

Includes functions such as:

Encoding/decoding of signals

Preamble generation/removal

Bit transmission/reception

IEEE 802 Layers

• Logical Link Control Layer (LLC) – Provide interface to

higher levels

– Perform flow and error control

• Media Access Control (MAC) – On transmit assemble

data into frame

– On reception disassemble frame, perform address recognition and error detection

– Govern access to LAN transmission medium

TCP segment

IP datagram

LLC protocol data unit

MAC frame

Application data

TCPheader

IPheader

LLCheader

MACheader

MACtrailer

Figure 11.4 LAN Protocols in Context

Application Layer

TCP Layer

IP Layer

LLC Layer

MAC Layer

Logical Link Control

Transmisi PDU level antar stasiun

Harus mendukung multi-akses, media bersama

Dibebaskan dari beberapa perincian akses tautan oleh lapisan MAC

Mengatasi melibatkan menentukan sumber dan tujuan pengguna LLC Disebut sebagai titik akses layanan (SAP)

LLC Services

Unacknowledged connectionless service

• Layanan Data-gram

• Pengiriman data tidak dijamin

Connection-mode service

• Logical connection diatur antar 2 pengguna

• Kontrol aliran dan kesalahan disediakan

Acknowledged connectionless service

•Datagrams diketahui, tetapi tidak ada pegaturan logical connection

LLC Protocol

Dimodelkan setelah HDLC

Mode Asynchronous balanced Connection mode (type 2) LLC service

Layanan Unacknowledged connectionless • Menggunakan PDU informasi yang tidak

bernomor (tipe 1)

Layanan Acknowledged connectionless Using 2 new unnumbered PDUs (type 3)

multiplexing menggunakan LSAPs

Figure 11.5 LLC PDU in a Generic MAC Frame Format

MAC

Frame

LLC

Address FieldsI/G

I/G = Individual/Group

C/R = Command/Response

DSAP value C/R SSAP value

MAC

Control

Destination

MAC Address

Source

MAC Address LLC PDU CRC

LLC

PDUDSAP

1 octet 1 1 or 2 variable

SSAP LLC Control Information

Medium Access Control (MAC) Protocol

Mengontrol akses ke media transmisi

Parameter kunci : Where

• Kontrol lebih besar, satu titik kegagalan

• Lebih kompleks, tetapi lebih redundant

• How • Synchronous

Kapasitas yang didedikasikan untuk koneksi, tidak optimal

Asynchronous Respon terhadap permintaan

Round robin, reservation, contention

Sistem Asynchronous

Round robin

• Each station given turn to transmit data

Reservation

• Divide medium into slots

• Good for stream traffic

Contention

• All stations contend for time

• Good for bursty traffic

• Simple to implement

• Tends to collapse under heavy load

MAC Frame Handling

Bridges

Menghubungkan LAN serupa dengan protokol physical and link layer protocols

Pemrosesan minimal

Dapat memetakan antara format MAC

Alasan Penggunaan:

Reliability

Performance

Security

Geography

LAN A

LAN B

Bridge

Figure 11.6 Bridge Operation

Frames withaddresses 11 through20 are accepted andrepeated on LAN B

Frames withaddresses 1 through10 are accepted andrepeated on LAN A

Station 1 Station 2 Station 10

Station 11 Station 12 Station 20

PhysicalPhysical

MAC

MAC-H LLC-H MAC-TUser Data

LLC-H User Data

User Data

LLC

Usert1

t3, t4, t5, t6

t2, t7

t1, t8

t2

t3 t4 t5 t6

t7

t8

Physical

MAC

LLC

User

MAC

(a) Architecture

(b) Operation

Figure 11.7 Connection of Two LANs by a Bridge

PhysicalLAN LAN

LAN A

LAN B LAN C

LAN D LAN E LAN GLAN F

Bridge

101Bridge

107

Bridge

102

Bridge

103

Bridge

104

Bridge

105

Bridge

106

Station 1

Station 4 Station 5 Station 6 Station 7

Station 2 Station 3

Figure 11.8 Configuration of Bridges and LANs, with Alternate Routes

Spanning Tree

Bridge secara otomatis mengembangkan tabel routing

Secara otomatis memperbarui tabel routing sebagai respons terhadap perubahan topologi

Algorithm consists of three mechanisms:

Frame forwarding Address learning Loop resolution

Station Station Station Station

Station

HHUB

Figure 11.10 Two-Level Star Topology

IHUBIHUB

Two cables

(twisted pair or

optical fiber)

Transmit

Receive

Shared Bus - 10 Mbps

10

Mb

ps

10

Mb

ps

10

Mb

ps

10

Mb

ps

A B C D

(a) Shared medium bus

A B C D

(b) Shared medium hub

10 Mbps 10 Mbps

10 Mbps10 Mbps

Total capacity

up to 10 Mbps

A B C D

(c) Layer 2 switch

10 Mbps 10 Mbps

10 Mbps10 Mbps

Total capacity

N 10 Mbps

Figure 15.11 LAN Hubs and Switches

Figure 11.12 A LAN Configuration

Inaho for takeout. Love to All Tricia

Z

W

XY

Internet

Server

RouterEthernet

switch

Printer

Workstation

Figure 11.13 A Partitioned LAN

Internet

Server

RouterEthernet

switch

Printer

Workstation

Z

V

W

XY

Figure 11.14 A VLAN Configuration

Internet

VLAN

E

VLAN C

VLAN A

VLAN

A

VLAN

A

VLAN

A

VLAN

B

VLAN

B

VLAN

D

Server

Ethernet

switch with

VLAN and

IP routing

capability

Printer

Workstation

Z

W

XY

THANKS! Any questions?

You can find me at:

pakrobbyug@gmail.com

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