MJ02/0704 1

Session 02

Network Components

Adapted from Network Management: Principles and Practice © Mani Subramanian 2000 and solely used for Network Management course at Universitas Bina Nusantara

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Technology and Management

• What are the technologies that need to

managed?

• Challenges of technological progress on

network management

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Computer Network Technology

• Network comprises• Nodes• Links

• Topology: How they’re configured• LAN• WAN

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LAN

•Type of LANs• Ethernet• Fast Ethernet• Gigabit Ethernet• Half-duplex vs Full-duplex• Switched Ethernet• VLAN• Token ring• FDDI• ATM / LANE

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WAN

• Facilities / Media• Wired: Copper, Coaxial, Fiber• Wireless: Terrestrial, Satellite

• Mode: Digital, Analog• Services: POTS, ISDN, Broadband

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Nodes

• Hubs• Bridges/Remote bridges• Routers• Gateways• Switches

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Network Node Components

• Hub• Bridge, Remote bridge• Router, Gateway• Switch

Router

SwitchedHub

Bridge

RemoteBridge

ATMSwitch

GatewayExternalNetwork

Router HubWorkstation

Dial-upNetwork

ExternalNetwork

Hub

Hub

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Basic Network Nodes

Routing

ATM Switch

ATMATM

Bridge

Local LANEthernetPackets

Filter

Router

Local NetworkIP Packets

Filter Routing

Gateway

X.25NetworkPackets

IPNetworkPackets

Formatchange

External LANEthernetPackets

External NetworkIP Packets

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Basic LAN Topologies

• Bus topology• Used in Ethernet LAN family• Common shared medium• Randomized access (CSMA/CD)• Easy to implement• Lower utilization under heavy traffic 30%-40%• Single culprit could effect the entire LAN

Ethernet

DTE DTE DTE

DTE DTE

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Basic LAN Topologies

DTE DTE

DTE

DTE

• Ring Topology• Used in token ring and FDDI• Shared medium• Deterministic access• Master DTE has control• High utilization >90%

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Star & Hybrid LAN Topologies

• Star topology used with bus and ring topology • Hub is “LAN in a box”• What does the electronic LAN inside the box look like?• Why has hub become so popular?

DTE

DTE

DTE

DTE

DTE

DTE

DTE

DTE

Token Ring HubEthernet Hub

DTE

DTE

DTE

DTE

DTE DTE

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WAN Topologies

• Mesh topology• Implemented in network layer level• Multiple paths between nodes• Flat topology, Redundancy, Load balancing, Shortest path

• Tree topology• Used with Ethernet bridges • Hierarchical• Efficient for small networks and, special purpose networks

N3

N4

N2

N5N1

Mesh Topology

N6

N1

N2 N3

N6N5N4

Tree Topology

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Transmission Technology

Transmission Technology

Medium Mode

Wired Wireless

LAN WAN

Digital Analog

LAN

• Physical transport media• UTP• Coax• Fiber• Terrestrial wireless• Satellite transmission

Mobile Satellite

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Transmission Modes

User 1 User 2 User 3 User 4User 30

Time

Ch

an

ne

lB

an

dw

idth

Time

TimeDivision

Multiplexing(TDM)

E1 Time Division Multiplexing (TDM) Transmission

channel 2

channel 1

channel 30

Cell Transmission (ATM)

User 1

Ba

nd

wid

th

Time

User 3

User 4

User 2

User 3

User 1

5

User 1

User 4

User 1

User 1

5Cell

Multiplexing

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LAN Data Rate

Ethernet10Mbps

FDDI100 Mbps

Fast Ethernet100Mbps

ATM155.52 Mbps

Gigabit E’Net1 Gbps

ATMSTM-n

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Hubs

• Hub is a platform• Function dependent on what is housed

• LAN (Bus/Ethernet)• Switched LAN (Ethernet)• Bridge

Hub

Patch Panel

DTE DTE DTE DTE

Wiring Closet

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Stacked Hubs

• Hub ports can be scaled up using stacked hubs• Stacked hub

• extend back plane• connected as daisy chain

Hub 2

Hub 1

BackplaneInterconnection

To

DT

Es

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Switched Ethernet

• Maximum throughput increased ~N/2 in N-port hub• Snooping capability lost for management

Switchedhub

DTE

DTE DTE

DTE

DTE DTE

DTE DTE

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Client/Server Using Switched Hub

Server

Switched hub

Workstation Workstation Workstation

10 Mbps 10 Mbps10 Mbps

100 Mbps

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Router

• Routes packets between nodes of similar network protocols• Routing table used to route packets• DLC and Physical layers could be different under the same

common network layer protocol

Protocol interface

Physical medium A

TP

NP

DP

Phy

TP

NP

DP'

Phy'

Network AProtocol P

Network BProtocol P

Router

NP

DP

Phy

NP

DP'

Phy'

Physical medium B

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Gateway

• Gateway is router connecting two networks with dissimilar network protocols

• Gateway does the protocol conversion at the network layer• Protocol converter does the conversion at the application layer

Protocol interface

Physical medium

TP

NP

DP

Phy

TP

NP'

DP'

Phy'

Network AProtocol P

Network BProtocol QGateway

DP

Phy

NP'

DP'

Phy'

NP

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Switched Networks

• Switches are embedded in bridges and routers• Switched network used in WAN• Two types of switched networks

• Circuit-switched• Packet-switched

• Datagram service• Virtual circuit

B

A D

C

DTE A DTE Z

Pkt3 Pkt2 Pkt1Pkt3 Pkt2 Pkt1

Pkt3

Pkt2

Pkt1

Virtual Circuit Configuration

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Switched Networks

B

A D

C

DTE A DTE Z

Pkt3 Pkt2 Pkt1Pkt2 Pkt3 Pkt1

Pkt1Pkt3

Pkt2

Pkt2Pkt2

Datagram Configuration

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Broadband Services

SDH WAN

CampusATM / LAN

Network

CampusATM / LAN

Network

ResidentialCustomerNetwork

ResidentialCustomerNetwork

STM-nSTM-n

ServiceProviders

Gateway

BroadbandAccess

BroadbandAccess

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• Integrated services: Voice, video, and data• Narrow band ISDN (Integrated Services Digital

Network)• Basic rate:2B + D (B channel 64 kbps and D channel 16 kbps• Primary rate: 23B + D channels

• Broadband Services• ATM • SDH (Synchronous Digital Hierarchy)• Access technologies:

• HFC (Hybrid Fiber Coaxial) / Cable modem• ADSL (Asymmetric Digital Subscriber Line)

Broadband Services