BIW 10103 – Introduction to Web TechnologyFirkhan Ali Bin Hamid Ali

FSKTM, UTHM

Chapter2: LOCAL ARE NETWORK – LAN (4 HRS)

Contents

Ethernet technology Media and internetworking devices Wireless network

INTRODUCTION LAN is a computer network that is designed

for a limited geographic area such as building or campus.

LAN can be used as isolated network or connected to WAN or Internet.

There is several technologies in LAN – Ethernet, Token Ring, Token Bus, FDDI and ATM LAN.

WIRED LAN - Ethernet

Widely used LAN protocol. IEEE 802.3 Standards defines 1-persistent

CSMA/CD as the access method for 10-Mbps Ethernet.

The MAC sublayer is responsible for the operation of the CSMA/CD access method and framing.

Each station – unique 48-bit address (NIC) Frame length – 64 to 1518 bytes.

Example of an Ethernet address in hexadecimal notation

Ethernet 2

Common implementation of 10-Mbps Ethernet are 10Base5 (Thick Ethernet), 10Base2 (Thin Ethernet),10Base-T and 10Base-F.

Bridge can increase the bandwidth and separate the collision domains on Ethernet LAN.

A switch allow each station on an Ethernet LAN to have entire capacity of the network to itself.

Collision domains in an unbridged network and a bridged network

Switched Ethernet

Full-duplex switched Ethernet

Ethernet 3 Full-duplex mode doubles the capacity of each

domain and removes the need for CSMA/CD method.

Fast Ethernet has data rate of 100Mbps. In Fast Ethernet, autonegotiation allow 2

devices to negotiate the mode or data rate of operation.

100Base-TX, 100Base-FX, 100Base-T4

Ethernet 4

Gigabit Ethernet – Data rate of 1000Mbps Gigabit Ethernet access method – half and

full duplex. 1000Base-SX,100Base-LX, 1000BaseT. Latest Standard is 10 Gbps. 10GBase-S,10GBase-L, 10Base-E. Use fiber optic cables in full duplex mode.

Summary of Standard Ethernet implementations

Summary of Fast Ethernet implementations

Summary of Gigabit Ethernet implementations

Summary of Ten-Gigabit Ethernet implementations

Classes of transmission media

GUIDED MEDIA

Guided media, which are those that provide a conduit from one device to another, include twisted-pair cable, coaxial cable, and fiber-optic cable.

Twisted-Pair CableCoaxial CableFiber-Optic Cable

Topics discussed in this section:

Twisted-pair cable

UTP and STP cables

Categories of unshielded twisted-pair cables

UTP connector

Coaxial cable

Categories of coaxial cables

BNC connectors

Optical fiber

Propagation modes

Modes

Fiber types

Fiber construction

Fiber-optic cable connectors

UNGUIDED MEDIA: WIRELESS

Unguided media transport electromagnetic waves without using a physical conductor. This type of communication is often referred to as wireless communication.

Figure 7.18 Propagation methods

Bands

Wireless transmission waves

Radio waves are used for multicast communications, such

as radio and television, and paging systems.

Note

Microwaves are used for unicast communication such as cellular telephones, satellite networks,

and wireless LANs.

Note

Ethernet Product Tranceiver (Penghantar-Terima) NIC Hub/Repeater Switch Router

Tranceiver (Sender-Receiver)

Transceiver is a short form for Transmitter receiver.

It use to connect all nodes in local area network - LAN.

 It’s transfer an electrical signal to another connector interface without change it.

NIC Network Interface Card (NIC) is use for

computer to make connection with networking.

1. Slot ISA, 8 dan 16 bit2. Slot PCI, 32 dan 64 bit 3. Slot PCMCIA, 8, 16 dan 32 bit4. Slot USB, USB 1.1 dan USB 2.0

Hub/Repeaters Hub/repeater is use to connect 2 or more

network segment. Repeater can extend the maximum longer

of the cable. One broadcast domain and one collision

domain.

Bridges/SwitchBridges and switches are data communications devices that

operate principally at Layer 2 of the OSI reference model. Bridging and switching occur at the link layer, which

controls data flow, handles transmission errors, provides physical (as opposed to logical) addressing, and manages access to the physical medium.

Bridges are generally used to segment a LAN into a couple of smaller segments. Switches are generally used to segment a large LAN into many smaller segments. Bridges generally have only a few ports for LAN connectivity, whereas switches generally have many.

Router

A router is a computer networking device that forwards data packets across a network toward their destinations, through a process known as routing. Routing occurs at Layer 3 (the network layer i.e. Internet Protocol (IP)) of the OSI seven-layer protocol stack.

Wireless LAN The IEEE 802.11 standard for wireless LAN

defines 2 services : BSS & ESS. The access method used in the distributed

coordination function (DCF) MAC sub layer is CSMA/CA.

The access method used in the point coordination function (PCF) MAC sub layer is polling.

The Network Allocation Vector is a timer used for collision avoidance.

A BSS without an AP is called an ad hoc network;

a BSS with an AP is called an infrastructure network.

Note

Basic service sets (BSSs)

Extended service sets (ESSs)

Wireless LAN (2) The MAC sub layer has 9 fields. The

addressing mechanism can include up to 4. Use management frames control frames

and data frames. IEEE 802.11 defines several physical

layers, with different data rates and modulating techniques.

Bluetooth is a wireless LAN technology that connect devices in a small area.

Wireless LAN (3) Bluetooth network is called a piconet. Multiple

piconets form a network called a scatternet. Bluetooth network consists of 1 primary

devices and up to 7 secondary devices.

Conclusion

In wired LAN technologies, there are Ethernet, Token Ring, FDDI and ATM LAN.

Ethernet is IEEE 802.3 technology that are consist of Fast Ethernet and Gigabit Ethernet.

Using twisted pair, coaxial and fiber optic cable.

In wired LAN technologies, there are wireless Ethernet and Bluetooth.

Conclusion (2)

Wireless Ethernet is IEEE 802.11 technology. Bluetooth is a technology for small wireless

LAN.