Jaringan Komputer LanjutEthernet dan IEEE 802.3 LAN Standard

-Aurelio Rahmadian-

Pemodelan Lapisan Jaringan

Physical Layer

Physical LayerMedia is the actual physical environment

through which data travels as it moves from one component to another, and it connects network devices. The most common types of net-work media are twisted-pair cable, coaxial cable, fiber-optic cable, and wireless. Each media type has specific capabilities and serves specific purposes.

Understanding the types of connections that can be used within a network provides a better understanding of how networks function in transmitting data from one point to another.

Physical Layer

Jenis-jenis Media

Jenis-jenis Media

Jenis-jenis Media

Jenis-jenis Media

Type Max Segment Length

Speed Cost Advantages Disadvantages

UTP 100 m 10 Mbps100 Mbps

Least expensive

Easy to install, widely available, widely used

Susceptible to interference; can cover only a limited distance

STP 100 m 10-100 Mbps

More expensive than UTP

Reduced crosstalk, less susceptible to EMI than UTP or Thinnet

Difficult to work with; can cover only a limited distance

Coaxial

500 meters (Thicknet)

185 meters (Thinnet)

10-100 Mbps

Relatively inexpensive but more costly than UTP

Less susceptible to EMI than other types of copper media

Difficult to work with (Thicknet); limited bandwidth; limited application (Thinnet); damage to cable can bring down entire network

Type Max Segment Length

Speed Cost Advantages Disadvantages

FO 3 km and further (singlemode)

2 km and further (multimode)

10-1000 Mbps (singlemode)

100 Mbps-9.92 Gbps (multimode)

Expensive

Cannot be tapped easily; great distances; not susceptible to EMI; higher data rate

Difficult to terminate

Wireless

50 km - global

1-54 Mbps Expensive

Does not require installation of media

Susceptible to atmospheric conditions

Ethernet

Logical Link Control (LLC)Makes the connection with the

upper layers.Frames the Network layer packet.Identifies the Network layer

protocol.Remains relatively independent

of the physical equipment.Uses IEEE 802.2 standard.

Media Access Control (MAC)Data Encapsulation: Includes frame

assembly before transmission, frame parsing upon reception of a frame, data link layer MAC addressing, and error detection.

Media Access Control: Because Ethernet is a shared media and all devices can transmit at any time, media access is controlled by a method called Carrier Sense Multiple Access with Collision Detection (CSMA/CD).

Alasan Penggunaan EthernetSimplicity and ease of

maintenanceAbility to incorporate new

technologiesReliabilityLow cost of installation and

upgrade

Sejarah EthernetCoaxial-10BASE5 (Thicknet)-10BASE2 (Thinnet)

Sejarah Ethernet

UTP-10BASE-T-Half-duplex communication

Sejarah Ethernet

UTP-100BASE-TX-Full-duplex communication

Struktur Frame Ethernet

Struktur Frame EthernetHeader

◦Preamble◦Start of Frame Delimiter◦Address◦Length

Data (Packet)Trailer

Struktur Frame EthernetPreamble

◦ 7 octet of 10101010Start of Frame Delimiter

◦ 1 octet of 10101011Address

◦ Source MAC Address◦ Destination MAC Address

Length/EthertypeData (Packet-Segment-Data)Frame Check Sequence

◦ Cyclic Redundancy Check (CRC) Interframe Gap

◦ 12 octet of idle-line state

MAC Address

MAC Address