Jaringan Komputer Lanjut
Ethernet dan IEEE 802.3 LAN Standard
-Aurelio Rahmadian-
Pemodelan Lapisan Jaringan
Physical Layer
Physical Layer
Media 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, fiberoptic 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 Mbps
100 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)
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
185 meters
(Thinnet)
Type
Max Segment
Length
Speed
Cost
Advantages
FO
3 km and
further
(singlemode)
10-1000 Mbps
(singlemode)
Expensive
Cannot be
Difficult to
tapped easily; terminate
great
distances;
not
susceptible
to EMI;
higher data
rate
Expensive
Does not
require
installation of
media
2 km and
further
(multimode)
Wireless 50 km -
global
100 Mbps-9.92
Gbps
(multimode)
1-54 Mbps
Disadvantages
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 Ethernet
Simplicity and ease of maintenance
 Ability to incorporate new technologies
 Reliability
 Low cost of installation and upgrade

Sejarah Ethernet
Coaxial
-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 Ethernet

Header
◦
◦
◦
◦
Preamble
Start of Frame Delimiter
Address
Length
Data (Packet)
 Trailer

Struktur Frame Ethernet

Preamble
◦ 7 octet of 10101010

Start of Frame Delimiter
◦ 1 octet of 10101011

Address
◦ Source MAC Address
◦ Destination MAC Address



Length/Ethertype
Data (Packet-Segment-Data)
Frame Check Sequence
◦ Cyclic Redundancy Check (CRC)

Interframe Gap
◦ 12 octet of idle-line state
MAC Address
MAC Address