Networking Training

GUEST

INTRODUCTION OF NETWORK

Table of Contents

Chapter 1 Basic Knowledge on Networking ………………1-11.1 High Growth in PC Technology as a Trigger …………………1-2

1.2 From Stand-alone to Networking ………………………… 1-3

1.3 Implementation via LAN…………………………………………… 1-4

1.4 Groupware ……………………………………………………… 1-6

1.5 LAN Topologies……………………………………………………… 1-8

1.6 LAN Operation Types …………………………………………… 1-9

1.7 LAN Access Methods …………………………………………… 1-10

1.8 LAN in Practice ……………………………………………………… 1-12

1.9 Protocol ……………………………………………………… 1-15

Chapter 2 LAN Components ……………………………… 2-12.1 NIC ……………………………………………………………… 2-2

2.2 Cable ……………………………………………………………… 2-4

2.3 Repeater ……………………………………………………… 2-8

2.4 Hub ……………………………………………………………… 2-9

2.5 Keys to Hub Selection …………………………………………… 2-13

2.6 Bridge ……………………………………………………………… 2-14

2.7 Router ……………………………………………………………… 2-15

2.8 Keys to Router Selection …………………………………… 2-18

2.9 Gateway ……………………………………………………… 2-19

2.10Other Components …………………………………………… 2-20

Print Server …………………………………………………….. 2-20

UPS ……………………………………………………………… 2-21

Chapter 3 Network OS and Protocols ………………………3-13.1 Network OS ……………………………………………………… 3-2

Overview of NOS …………………………………………… 3-2

Windows NT ……………………………………………………… 3-3

Netware ……………………………………………………… 3-4

UNIX ……………………………………………………………… 3-5

Keys to NOS Selection …………………………………… 3-6

Keys to Server Selection …………………………………… 3-7

3.2 Protocol Overview …………………………………………… 3-8

TCP/IP ……………………………………………………… 3-8

IPX/SPX ……………………………………………………… 3-10

NetBEUI ……………………………………………………… 3-11

AppleTalk ……………………………………………………… 3-12

Chapter 4 Internet and TCP/IP ……………………………… 4-14.1 Internet ……………………………………………………………… 4-2

4.2 Line Types ……………………………………………………… 4-5

Private Line ……………………………………………………… 4-5

ISDN ……………………………………………………………… 4-6

Frame Relay ……………………………………………………… 4-7

4.3 Internet Connection …………………………………………… 4-8

4.4 IP Address ……………………………………………………… 4-10

Overview of IP Address …………………………………… 4-10

Subnet Mask ……………………………………………………… 4-13

4.5 Domain Name ……………………………………………………… 4-15

4.6 Applications on the Upper Layer ………………………… 4-18

DNS ……………………………………………………………… 4-18

Mail ……………………………………………………………… 4-20

TELNET,FTP ……………………………………………………… 4-21

SNMP ……………………………………………………… 4-22

DHCP ……………………………………………………… 4-23

4.7 Port Number ……………………………………………………… 4-24

4.8 Data Exchange between Layers…………………………………… 4-25

4.9 Ethernet Frame……………………………………………………… 4-26

Chapter 5 Technical Trend ……………………………… 5-15.1 Intranet ……………………………………………………………… 5-2

5.2 Fast Ethernet ……………………………………………………… 5-4

5.3 Giga-bit Ethernet …………………………………………… 5-6

5.4 ATM ……………………………………………………………… 5-7

5.5 Mobile Computing …………………………………………… 5-8

5.6 IPv6 ……………………………………………………………… 5-9

5.7 Firewall……………………………………………………………… 5-10

5.8 Proxy Server ……………………………………………………… 5-12

Chapter 1 Basic Knowledge on Networking

1. High Growth in PC Technology as a Trigger

2. From Stand-alone to Networking

3. Implementation via LAN

4. Groupware

5. LAN Topologies

6. LAN Operation Types

7. LAN Access Methods

8. LAN in Practice

9. Protocol

1-2

Memo

RAMCPU (Intel) HDD OS (Microsoft)

1985

80286(8MHz)

128KB MS-DOS8086

640KB 10MB

80386(20MHz)1990 2MB 100MB

80486(50MHz) 8MB 500MBWindows3.1

Pentium(90MHz) 16MB 1GB WindowsNT3.5Windows951995

PentiumPro(200MHz) 32MB 3GB

PentiumMMX(200MHz)

General-purpose Computer10 Years Ago

Per-formance

1.1 High Growth in PC Technologyas a Trigger

WindowsNT4.0

Pentium II(400MHz)Windows984～8GB64MB

2000

Year

WindowsNT5.0

Capacity

n High growth in PC technology as a trigger

• Rapid enhancement in CPU power

• Enhanced operability via OS with GUI function

• Established network environment and standard support of network function byOS

• Machine-per-person environment implemented via cost cut in machine price

GUIGraphical User Interface

1-3

Memo

1.2 From Stand-alone to Networking

• Use of network allows you to:Recycle data created by someone else.This saves time and effort as compared to creating data fromscratch and allows you to use existing know-how.Use a peripheral device, such as a printer, whenever you like to use.This allows you to request a process from your computer.

Com-fortable!

I wish I had his data...…

n Stand-alone computer

• Data exchange involves a lot of work.

• A peripheral device, such as a printer, can not be shared.

• Data management must be done individually.

n Computer over network

• Data exchange is easy.

• A peripheral device, such as a printer, can be shared.

• Centralized data management is available.

1-4

Memo

1.3 Implementation via LAN (1)

• Resource sharing

Printer sharingDisk unit sharing

• Information sharing

Sales data sharingCustomer data sharingDocument sharing

n Resource sharing

• Printer sharing

• Disk unit sharing

n Information sharing

• Sales data sharing

• Customer data sharing

• Document sharing

1-5

Memo

1.3 Implementation via LAN (2)

• Message exchangeElectronic mailElectronic bulletin boardElectronic conference room

• Information managementSchedule managementFacility reservation systemDocument management systemWork flow

Improved Communication

n Message exchange

• Electronic mail

• Electronic bulletin board

• Electronic conference room

n Information management

• Schedule management

• Facility reservation system

• Document management system

• Work flow

1-6

Memo

1.4 Groupware (1)

• GroupwareMessage functions and data management functionPowerful tool for establishing the Intranet

n Groupware

• Integrated software for collaboration used in the same group

• Implementation of various functions, such as electronic mail, electronicbulletin board, and schedule management

• Information sharing and improved communication among users

• Powerful tool for establishing the Intranet IntranetIntranetIntranetIntranet(See page 5-2.)

1-7

Memo

1.4 Groupware (2)

Notes

Domino

Notesdocument

HTML

document

SQL Server

MS-IIS

DB

HTML

document

Exchange ServerMail box

• Groupware

n Lotus Notes

• World’s No. 1 share

• Complete user interface and document management functions

n Microsoft Exchange

• Easy to collaborate with other Microsoft products (SQL server, IIS).

• Provides the Microsoft Outlook 97 (multi-functional data management tool) asa client.

n Others

• Novell GroupWise

• Fujitsu TeamWare

• HITACHI Groupmax

• Oracle InterOffice

TipsThe latest groupware provides the gateway function via SMTP or NNTP as astandard function to allow collaboration with the mail over the Internet and newsystems.

1-8

Memo

1.5 LAN Topologies

バス型バス型バス型バス型スター型スター型スター型スター型

リング型リング型リング型リング型

ＨＵＢ

• LAN topologies

Bus type Star type

Ring type

n Bus Type

• The terminator is required at both ends of the bus.

n Star Type

• A wiring type using a hub at the center

n Ring Type

• The initial cost for deployment is expensive.

n Comparison among Topologies

The star type is most commonly used; then the bus type; and finally the ring type.

Bus type Star type Ring type

Cost Better Best Normal

Reliability Normal Better Best

Flexibility Better Best Better

Product Availability Better Better Normal

Popularity Better Best Normal

TipsThe bus and star types may be combined to use for the LAN that extends overseveral floors.

1-9

Memo

1.6 LAN Operation Types

Server

Clients

Client-server architecture

Printer Disk

Pier-to-pier architecture

DiskPrinter

• Pier-to-pier architecture• Client-server architecture

n Pier-to-pier Architecture

• Suitable for a small network

• Inexpensive and easy to deploy.

n Client-server Architecture

• Divided functions between the client and the server.

• Main stream of the current LAN architectures.

1-10

Memo

• CSMA/CD MethodData transmission over the shared line.Re-transmission is attempted when a data collision occurs.

Woops! A collision isdetected.

Gee, someone wasalready there!

Each node is provided with the function to detect a collision.

1.7 LAN Access Methods (1)

n CSMA/CD Method

• A method in which a single line is shared by multiple nodes for datatransmission.

1) Each node on the network listens first and transmits only when the lineis free.

2) Each node on the network listens the line until a data transmissioncompletes to avoid a collision.

3) If two nodes transmit at exactly the same time and a collision occurs,both nodes waits for a different random length of time beforeattempting to transmit again.

CSMA/CDCarrier Sense Multiple Accesswith Collision Detection

NodeAny network-connected devicefor communications, includingthe compute, router, and hub.

Re-transmissionUp to 16 re-transmissionattempts will be made.

TipsThe above example illustrates data exchange over the coaxial cable. When thetwisted-pair cable is used for LAN, the LAN provides a separate path fortransmission and reception. Thus a collision occurs when a node receives datafrom another node at exactly the same time it transmits.

1-11

Memo

1.7 LAN Access Methods (2)

• Token passing method

C

DB

A

C

DB

A

(1) The free token circulates on the LANwhen no data is transmitted.

C

DB

AFreetoken

C

DB

A

(2) A transmits a data frame to C followingthe busy token.

Busytoken

(3) When C receives the data addressed toitself, it transmits a response frame to A.

(4) When A receives the response, it againtransmits the free token onto the ring.

Busytoken

Freetoken

n Token Passing Method

• Circulation of the token (the right to transmit)

• The free token and the busy token

• Collision prevention

TipsThe token passing method is classified into the token bus type and the token ringtype depending on its topology.

1-12

Memo

1.8 LAN in Practice (1)

• Ethernet

Repeater

HUB

2.5m500m

50m

185m

0.5m

100m

AUI cable(Transceiver cable)

Transceiver 10Base-5 (standard coaxial cable)

10Base-2 (Thin coaxial cable)

10Base-T (twisted-pair cable)NIC

Terminator

T-connector

AUI cable

n Ethernet

• Developed by Xerox, DEC, and Intel

• Defacto standard of the current LAN

• The transmission speed of 10 Mbps is most commonly used, but thetransmission speed of 100 Mbps has been widely used recently.

• The CSMA/CD method is used as the transmission control method.

• 10BASE-T, -2, and -5 are popular.

Item 10BASE 5 10BASE 2 10BASE-TTransmission Medium Coaxial Cable Thin Coaxial Cable UTPTransmission Method Baseband Baseband BasebandTransmission Speed 10 Mbps 10 Mbps 10 Mbps

Maximum Segment Length 500m 185m 100 m (between eachnode and the hub)

Connected Units / Segment 100 30 1Node-to-node Distance 2.5m 0.5m None

Maximum Network Length 2500m (5 segments)

925m (5 segments)

200 m with 1 hub inthe middle

100MbpsThe Fast Ethernet standardfalls into this category. (Seepage 5-4.)

1-13

Memo


• Token ringToken passing methodThe transmission speed is 16 Mbps.Used for connection with the largegeneral-purpose computer.

n Token Ring

• Ring-type network using the token passing method

• Widely used for connection with the mainframe.

• The transmission speed is 4 or 16 Mbps.

• The Token Ring network is about 1/5 as popular as the Ethernet networkbecause its components are rather expensive.

• Additional nodes does not affect the network response.

1-14

Memo


Networkproblem!

FDDI

• FDDIUsed for a backbone network.The transmission speed is 100 Mbps.Append token methodDual-ring configuration

n FDDI

• High-speed network using the fiber-optic cable (100 Mbps)

• Used as a large-scale backbone network in a building or a campus.

• The total cable length can be extended up to 100 km.

• A dual ring is available for improving tolerance (reliability).

• The append token method derived from the token passing method isemployed.

Append Token MethodA method in which eachnode adds a frame to thetoken and transmitregardless of the tokenstatus (free or busy) whenit receives the token.

TipsWhen a problem occurs on the FDDI dual ring, the primary ring and thesecondary ring are connected each other at the nearest hub or other device.

1-15

Memo

• ProtocolA standard way of communicating between computers. (Communications Protocol)

Bon jour!

Buenos dias! Buon jorno!

Hello!

Protocol

1.9 Protocol (1)

n Protocol

• A standard way of communicating between computers. (CommunicationsProtocol)

• The same protocol must be used by each computer for communications.

n Analogy of the protocol with human conversation

(1) Whom do you talk to?

(2) Which language do you use for communication?

(3) Which medium do you use to get the meaning across?

(4) What do you tell?

1-16

Memo

1.9 Protocol (2)

• OSI Reference Model7th Layer Application

LayerWhat kind of communications services are available?What will be implemented?(Describes application types.)

6th Layer PresentationLayer

Which format is to be used for data transmission?(Describes data types and the transmission bit number.)

5th Layer SessionLayer

Which communications mode is to be used for data transmission?(Describes communications modes and synchronization methods.)

UpperLayer

4th Layer TransportLayer

How is it ensured that data has successfully been received at the destination?(Describes confirmation of data transmission and reception, and identificationof an application.)

3rd Layer NetworkLayer

How is the network to be used? How is the destination address identified?(Describes communications path selections and identification addresses.)

2nd Layer Data-linkLayer

How will an path error be checked?(Describes security of the communications path and error correction.)

1st Layer PhysicalLayer

Which medium is to be used for data transmission?How is data to be transmitted?(Describes physical lines, devices, and electric signals.)

LowerLayer

OSI

Open System Interconnection

ISO

International StandardOrganization

n OSI Reference Model

• International standard model proposed by the ISO.

• Established in 1978 as a standard model for protocol development.

• Established the management system in which hardware and software areclearly defined using layers.

• Each layer individually functions without interfering with one another butinterworks as a whole.

TipsThe OSI reference model was defined along with establishment of the OSIprotocol to identify the layered structure of the protocol. The OSI protocol itselfis not as popular as TCP/IP but the OSI reference model is widely used forexplanation of the network protocols.

1-17

Memo

1.9 Protocol (3)

• Various protocols

TCP/IP

AppleTalk

SNA

NetBEUI

n TCP/IP

• Protocol used for the Internet.

n IPX/SPX

• Protocol integrated with the Novell NetWare/IntranetWare.

n NetBEUI

• Protocol for small LANs that was developed by IBM, Microsoft, and 3COM.

n AppleTalk

• Standard protocol for the Apple Macintosh series.

n SNA

• Protocol for the mainframe network developed by IBM.

• This protocol was used as a base for the ISO to define the OSI reference modeland for mainframe makers to develop protocols.

TCP/IPTransmission ControlProtocol / Internet Protocol(See page 3-8.)

IPX/SPXInternet Packet eXchange /Sequenced Packet eXchange(See page 3-10.)

NetBEUINetBIOS Extended UserInterface(See page 3-11.)

AppleTalk(See page 3-12.)

SNASystems NetworkArchitecture

Chapter 2 LAN Components

1.1.1.1. NICNICNICNIC2.2.2.2. CableCableCableCable3.3.3.3. RepeaterRepeaterRepeaterRepeater4.4.4.4. HubHubHubHub5.5.5.5. Keys to Hub Selection

6.6.6.6. BridgeBridgeBridgeBridge

7.7.7.7. RouterRouterRouterRouter8.8.8.8. Keys to Router Selection

9.9.9.9. GatewayGatewayGatewayGateway10.10.10.10. Other ComponentsOther ComponentsOther ComponentsOther Components

•••• Print ServerPrint ServerPrint ServerPrint Server•••• UPSUPSUPSUPS

2-2

Memo

2.1 2.1 2.1 2.1 NIC (Network Interface Card) (1)NIC (Network Interface Card) (1)NIC (Network Interface Card) (1)NIC (Network Interface Card) (1)

LAN board (for desk-top PCs)

LAN card (for laptop PCs)

• NICAdds the network function to PC.

n Classification by PC types

• Desk-top type (board type) and laptop type (PCMCIA card type)

n Classification by models and expansion slots

• DOS/V computer ISA Bus, PCI Bus

• Macintosh series Nu Bus, PCI Bus

n Classification by access methods and cable types

• Ethernet (CSMA/CD), Token Ring (Token Passing)

• 10BASE2/5/T (BNC/AUI/RJ-45)

PCMCIAPersonal Computer MemoryCard International Association

ISAIndustry Standard Architecture

PCIPeripheral ComponentInterconnect

TipsLess PCs with the old-type slot (ISA bus, Nu bus, etc.) as the expansion slot arebeing manufactured because of the recent trend requiring higher speed; andmanufacturers’ interest is shifting to producing PCs with the PCI bus enablinghigh-speed data transfer.

2-3

Memon MAC address

• Node identification address assigned to the NIC.

• Consists of the 3-byte vender code and the 3-byte node number.

00 - 00 - 86 - 01 - AB - CD

• Typical vender codes

2.1 2.1 2.1 2.1 NIC (Network Interface Card) (2)NIC (Network Interface Card) (2)NIC (Network Interface Card) (2)NIC (Network Interface Card) (2)

Vendor code Node number

• MAC address

0 0 - 0 0 - 8 6 - 0 1 - A B - C D

MAC addressMedia Access Control Address

Node number: Numbers assigned notto be duplicated by a vender.Vender code: Vender-specific codes

V en d o r co d e V en d o r n am e

0 0 0 0 0 C C is co

0 0 0 0 0 E F u jit s u

0 0 A 0 D E Y A M A H A

0 0 A A 0 0 In t e l

0 2 6 0 8 C 3 C o m

0 8 0 0 2 0 Su n

0 8 0 0 2 B D E C

0 8 0 0 4 6 So n y

0 8 0 0 6 9 Silico n G rap h ics

2-4

Memo

2.2.2.2.2 Cable (1)

• Coaxial cable

Braided copper shield

Conductor

Plastic insulation

NIC

BNC connector

Thin coaxial cable

10BASE2 10BASE5

NIC

AUI cable

Coaxial cable

Transceiver

n Coaxial cable

• Thick cable (10BASE5, yellow cable)

(1) Almost noise-free and capable of extending up to 500 m.

(2) A transceiver and an AUI cable is used to connect one node to another.

(3) Hard to install due to its thickness.

• Thin cable (10BASE2)

(1) Can be connect directly to the computer with a T-connector.

(2) Easier to install than 10BASE5.

(3) Capable of extending up to 185 m.

TransceiverA device detecting a collision.

AUI CableAlso called a transceiver cable.It is used to connect atransceiver and an NIC andcapable of extending up to 50m.

TipsBoth 10BASE2 and 10BASE5 are a coaxial cable used for the bus-type LAN andrequire a 50-ohm terminator at both ends.

2-5

Memo

2.2 2.2 2.2 2.2 Cable (2)

• Twisted-pair cable

Plastic insulation

HUBNIC Twisted-pair cable

n Twisted-pair cable

• Similar structure to the telephone wire.

• Often affected by noise and capable of extending up to 100 m (UTP).

• Mainly used on the Ethernet (10BASE-T) network.

• Easy to install due to its softness.

• Classified into STP and UTP depending on whether it’s shielded or not.

n 4-wire type and 8-wire type

• The twisted-pair cable is classified into an 8-wire (4-pair) type and a 4-wire (2-pair) type.

• When the 8-wire (4-pair) type cable is used on the Ethernet network, only 4wires (2 pairs) used.

• The 8-wire (4-pair) type cable can also be used as an ISDN cable.

UTPUnshield Twist PareMainly used on theEthernet network.

STPUsed on the Token-ringand Apple LocalTalknetwork.

TipsThe twisted-pair cable is available in 5 types, Category 1 through 5, according totransmission speed. The category 5 cable (100 Mbps max.) is currently popularin use, but the category 3 (10 Mbps max.) and category 4 (16 Mbps max.) arealso used.

Only 4 wires (2 pairs) areused.Whole 8 wires (4 pairs) areused in a rare case, such aswhen the cable is used as the100BASE-T4 cable (seepage 5-4).

2-6

Memo

2.2 2.2 2.2 2.2 Cable (3)

• Cable name indication format

-

Data transmission rate (Mbps)

Signal trans-mission system

Maximum cable-segment length÷÷÷÷100m

Data transmission rate (Mbps)

Signal transmission system

Transmission medium

2: 185m

5: 500m

F: Fiber-optic

T: Twisted-pair

BASE Baseband transmission system

BROAD Broadband transmission system

n Cable name indication format

• Indicated as “n1 BASE n2” or “n1 BASE-n2”.

n n1 BASE n2

• “n1” indicates a transmission rate.

• “n2” indicates a maximum cable length. “5” indicates approximately 500 m;and “2 indicates approximately 200 m.

• “BASE” indicates the baseband transmission system.

n n1 BASE-n2

• “n1” indicates a transmission rate.

• “n2” indicates a cable type. “T” indicates a twisted-pair cable; and “F”indicates a fiber-optic cable.

• “BASE” indicates the baseband transmission system.

2-7

Memo

2.2 2.2 2.2 2.2 Cable (4)

• Fiber-optic cable

Outer jacket Kelvar

Core (optical fiber)

Light signals are conducted along the cable as the signals are reflected from the sheath.

High-speed cable capable ofconnecting over a long distance

n Fiber-optic cable

• Capable of high-speed and long-distance communications.

• Because light signals, not electric signals, are carried, the cable is immune toelectromagnetic interference.

• More expensive than other cables.

• Requires special techniques for installation and setups.

• Used on the ATM, FDDI, Fast Ethernet, and Token-ring networks.ATMAnsynchronous TransferMode(See page 5-7.)

Fast Ethernet(See page 5-4.)

2-8

Memo

2.3 Repeater

• RepeaterCable extension, signal amplification

RepeaterSignal

amplification!

n Features of the repeater

• Removes limitations on cable extension.

• Generates attenuated signals by amplifying them.

• Up to 4 repeaters (5 segments) can be connected onto one network.

TipsCurrently few repeaters are used on the network using 10BASE2 or 10BASE5cables and have paved the way to hubs, bridges, and routers.

2-9

Memo

2.4 2.4 2.4 2.4 HUB (1)HUB (1)HUB (1)HUB (1)

AUI //

MDI-X

Model 8xx

• Typical hub

• Eight 10BASE-T ports and a cascade port• One AUI or BNC port• LEDLink lamp and data LED per port

• 8-port hub

MDI-X/MDI

n Functions of the hub

• Connects cables from computers.

• Function to extend the cable length (repeater function)

n Cascade connection

• Multiple hub connection to expand the number of ports.

• Up to 4 hubs can be connected for limitations of the repeater are applied.

n Transmission rate

• 10 Mbps for Ethernet (10BASE-T)

• 100 Mbps for Fast Ethernet (100BASE-T)Fast Ethernet(See page 5-4.)

2-10

Memo

2.4 2.4 2.4 2.4 HUB (2)HUB (2)HUB (2)HUB (2)

• Straight-through cable

• Cross-over cable

n Straight-through cable

• Cable connecting transmit terminals of Ethernet signals.

• Mainly used to connect a hub and a node.

n Cross-over cable

• Cable connecting transmit and receive terminals of Ethernet signals.

• Mainly used for cascade connection between hubs.

Cascade ConnectionThe cross-over cable is usedfor a cascade connection toan additional hub usingEthernet ports; but thestraight-through cable isused for a cascadeconnection using cascadeports.

Node(See page 1-10.)

2-11

Memo

2.4 2.4 2.4 2.4 HUB (3)HUB (3)HUB (3)HUB (3)

．．．．．．

．．．．．．．．．．．．

．．．．．．．．．．．．

．．．．．．．．．．．．

．．．．．．．．．．．．

A

C

B

D

E

• Hub types

Stackable type Modular type

n Stackable type

• Multiple hub connection using stackable ports.

• No standard is developed and specifications vary depending on makers.

n Modular type

• Used for intelligent buildings or large LANs.

• Integrates other devices such as bridges and routers.

n Intelligent type

• Hub with the network management function.

• Used along with network management software and capable of detecting andisolating troubles.

Intelligent TypeA typical hub is called a non-intelligent hub as opposed toan intelligent hub.

2-12

Memo

2.4 2.4 2.4 2.4 HUB (4)HUB (4)HUB (4)HUB (4)

D

B

A C

20Mbpsin total

10Mbps

10Mbps

MAC address A MAC address C

MAC address D

MAC address BThe switching circuit stores MAC addresses.

• Switching Hub

The switching circuit stores MAC addresses.

n Switching hub

• Automatically learns the MAC address of a node connected to each port.

• Immediately switches the circuit to the destination port according to thedestination MAC address.

• Enables parallel activities between ports with no collision.

• Reduces network traffic by eliminating collisions.

TipsA switching hub can store thousands of MAC address per port, thus it is oftenused as a bridge device by connecting a repeater hub to another.

MAC addressMedia Access Control Address(See page 2-3.)

2-13

Memo

2.5 2.5 2.5 2.5 Keys to Hub Selection

• Keys to hub selectionSelection should be made based onexpandability and high-speed support of ahub.

n Expandability

• Houses extra ports?

• Stackable hub?

• Houses an AUI or BNC port for backbone connection?

n High-speed support

• Supports Fast Ethernet (100BASE-T)?

• Supports the switching function and full-duplex transmission?

n Intelligent function

• Supports SNMP?SNMPSimple Network ManagementProtocol(See page 4-22.)

2-14

Memo

2.6 2.6 2.6 2.6 Bridge

Bridge

From (1) to (4)From (1) to (4) From (4) to (3)From (4) to (3)

②②

①① ③③

④④

(1) (2) (3) (4)

O.K !

• BridgeFilters redundant packets.

n Functions of the bridge

• Connects 2 networks.

• Filters data not to transfer any data with an invalid destination address.

• Automatically learns MAC addresses and determines whether to transfer data.MAC addressMedia Access Control Address(See page 2-3.)

2-15

Memo

2.7 2.7 2.7 2.7 Router (1)Router (1)Router (1)Router (1)

• RouterConnects multiple networks that are logically different.

WAN

n Functions of the router

• Connects multiple networks that are logically different.

• Links LAN segments at the network layer to route received packets.

n Additional functions of the router

• IP address translation function

• Packet filtering function

• DHCP function

• Bridging function

IP address translation(See page 4-12.)

DHCPDynamic Host ConfigurationProtocol(See page 4-23.)

2-16

Memo


Router-4

Router-5 Router-2

Router-3

Router-1Trouble!

• Effective route selection

DestinationRouter-4

(1)

(2)(3)

n Static routing

• Requires maintenance according to the network configuration.

• Hard to deal with network troubles.

n Dynamic routing

• Dynamically selects an appropriate path and deals with network troubles.

• Provides several routing protocols according to the priority (hop count, linespeed, line charge).

TipsRIP, RIP2, IGRP, OSPF, and others are available as the dynamic routingprotocol.

Hop CountThe number of routers thatmust be crossed to getfrom the source node to thedestination node.

2-17

Memo


• Local router and remote router

LAN

WAN

LAN

LAN LANLocal router

Remote router

n Local router

• Segments the corporate network and reduces traffic.

• Requires no exclusive hardware and can be implemented by using functions ofthe NOS.

n Remote router

• Connects to a remote network

• Uses external lines provided by carriers.

Functions of the NOSImplemented by usingmultiple NIC’s and anetwork OS supporting therouting function.

Lines provided bycarriersPrivate lines (see page 4-5), ISDN lines (see page 4-6), Frame Relay networks(see page 4-7)

2-18

Memo

2.8 Keys to Router Selection

• Applicable lines• Support protocols• Packet filtering function• Number of interfaces• Routing protocol• Other additional functions (DHCP function, NAT function)

n Applicable lines

• Private lines, ISDN lines Frame Relay networks, etc.

n Support protocols

• TCP/IP, IPX/SPX, AppleTalk, etc.

n Packet filtering function

• Availability of the function and flexibility of filtering

n Number of interfaces

• LAN interface types (10BASE2/5/-T)

• Number of interfaces at LAN side and WAN side

n Routing protocols

• Static routing and dynamic routing

n Other additional functions

• DHCP function, address translation function (NAT) , etc.

• Built-in DSU and hub, availability of an analog port in the ISDN router

2-19

Memo

2.9 Gateway

• GatewayConnects between LANs with different protocols.

n Gateway

• Connects between LANs with different systems, such as data formats andprotocols.

n Sample gateway

• Mail gateway

• Host gateway

TipsGateway may indicate a router in the Internet (TCP/IP protocol).

2-20

Memo

2.102.102.102.10 Other Components - Print Server -

• Print server

Exclusive hardware

Ethernet support printer

Use of a PC as the print server

n Use of a PC as the print server

• Requires no exclusive hardware and provides the most inexpensive connection.

• Requires the PC to be always powered.

n Ethernet support printer

• Expensive and suitable for high-speed and large volume printing

• Must be a network printer.

n Exclusive hardware (exclusive print server)

• Compact in size and can be connected to any type of network.

• Requires a wiring layout with a main focus on the printer location.

2-21

Memo

2.102.102.102.10 Other Components -UPS--UPS--UPS--UPS-

ServerPower plugPower plug

• UPSSupplies power at emergency.

UPS

n UPS

• Supplies power to the computer for a certain period of time at a power outage.

• Provides the automatic shutdown function using proprietary software.

• Classified into the constant commercial power system and the constantinverter power system according to a power supply method.

UPSUninterruptible PowerSupply (System)

Constant CommercialPower SystemSupplies power from abattery only at a poweroutage. It is inexpensivebut does not provided anabsolute uninterruptiblepower supply condition.

Constant Inverter PowerSystemAlways supplies powerfrom a battery. It providesan absolute uninterruptiblepower supply conditionbut is expensive.

Chapter 3 Network OS andChapter 3 Network OS andChapter 3 Network OS andChapter 3 Network OS andProtocolsProtocolsProtocolsProtocols

1. 1. 1. 1. Network OSNetwork OSNetwork OSNetwork OS•••• Overview of NOSOverview of NOSOverview of NOSOverview of NOS•••• Windows NTWindows NTWindows NTWindows NT•••• NetWareNetWareNetWareNetWare•••• UNIXUNIXUNIXUNIX•••• Keys to NOS SelectionKeys to NOS SelectionKeys to NOS SelectionKeys to NOS Selection•••• Keys to Server SelectionKeys to Server SelectionKeys to Server SelectionKeys to Server Selection

2. 2. 2. 2. ProtocolProtocolProtocolProtocolOverviewOverviewOverviewOverview•••• TCP/IPTCP/IPTCP/IPTCP/IP•••• IPX/SPXIPX/SPXIPX/SPXIPX/SPX•••• NetBEUINetBEUINetBEUINetBEUI•••• AppleTalkAppleTalkAppleTalkAppleTalk

3-2

Memo

3.1 Network OS -Overview of NOS-

• Network OSResource managementUser managementSecurity management

n Network OS (NOS)

• OS for centralized network management and network security

• OS to be installed on the server of the client-server system

n Key functions of the NOS

• Resource management

• Includes printer output requests and disk device space management.

• User management

• Includes user authentication (password management) and access rightsetup.

• Security management

• Includes duplicated data storage and exclusive control against networkdevice troubles.

3-3

Memo

3.1 Network OS -Windows NT-

• Windows NTIntegrated Internet server functionsEnhanced security functionOutstanding operability via GUIMultiprocessor support

Windows NT

n Windows NT

• Product of Microsoft Corporation marking No.1 growth in the market share

• The standard protocol stack includes NetBEUI, TCP/IP, IPX/SPX, andAppleTalk.

• Comprehensive network resource management function and access right setup

• Identical GUI to Windows 95

• Two types of product, Window NT Server and Windows NT Workstation, areavailable.

• Integrates various server functions, such as DNS, WWW, FTP, DHCP, andRAS.

DHCPDynamic Host ConfigurationProtocolSee page 4-23.

RASRemote Access Service

Integrated server functionsThe mail server function(SMTP) is, however,optional.

TipsBackOffice for SBS (Small Business Server) that includes Window NT Server,Exchange Server, SQL Server, and FAX Server has come in market in 1998andexpected to expand its share in the future SOHO market.

3-4

Memo

3.1 3.1 3.1 3.1 Network OS Network OS Network OS Network OS -NetWare--NetWare--NetWare--NetWare-

•••• NetWare/NetWare/NetWare/NetWare/IntranetWareIntranetWareIntranetWareIntranetWareNovell developed NOS for personalNovell developed NOS for personalNovell developed NOS for personalNovell developed NOS for personalcomputerscomputerscomputerscomputersEmployed IPX/SPX as the standard protocol.Employed IPX/SPX as the standard protocol.Employed IPX/SPX as the standard protocol.Employed IPX/SPX as the standard protocol.High-speed file serverHigh-speed file serverHigh-speed file serverHigh-speed file server

NetWareNetWare

n NetWare/IntranetWare

• Novell developed NOS for personal computers

• Employed IPX/SPX as the standard protocol.

• High-speed file search (memory cache function)

• Used to hold 70% of the global share of the NOS up until a few years before.

• The latest version (Version 4 or later) includes the global directory service,called NDS, which provides seamless access to shared resources on the WAN.

• The protocol stack occupies less resident memory, thus suitable for use of theDOS (Windows 3.1) machines as the client machine.

NDSNovell Directory Service

TipsIntranetWare is a suite product that includes NetWare and its optional packagesand bundled with many functions that used be optional, such as NetWare/IP,NetWare DHCP, NetWare Web Server, and NetWare for Macintosh.

3-5

Memo

3.1 3.1 3.1 3.1 Network OS Network OS Network OS Network OS -UNIX--UNIX--UNIX--UNIX-

• UNIXMost stable OS to implement server functions for the Internet

n UNIX

• OS that used to be used on the workstation.

• Employs TCP/IP as the standard protocol.

• Most stable OS to implement various server (WWW, Mail, DNS, etc.)functions for the Internet.

• Highly durable, thus suitable for the large system.

TipsUNIX is a collective name for the OS and available in more than 100 productsincluding Sun Solaris, HP-UX, DEC Digital UNIX, IBM AIX, and SGI IRIX.

3-6

Memo

WindowsNT

NetWare

UNIX

If you wantto build the LAN environment easily…to use the network OS in the environment mixed with several protocols...

to use the network OS mainly for file sharing...to use the network OS in the environment mixed with another OS suchas DOS…

to focus on network security and reliability...to use the network OS mainly for Internet connection...

• Keys to NOS selection

3.1 3.1 3.1 3.1 Network OS Network OS Network OS Network OS ----Keys to NOS Selection----

n Windows NT is suitable for

• the network configuration mainly with Windows 95.

• the small LAN environment and easy configuration.

• the multi-protocol environment.

n NetWare is suitable for

• the environment with poor client resources, such as MS-DOS.

• the network configuration with the main focus on the file server.

n UNIX is suitable for

• the network configuration with the main focus on security over the Internet.

• the large and reliable network configuration.

• the network configuration based on the LAN environment using TCP/IP.

3-7

Memo

3.1 Network OS -Keys to Server Selection-

• Keys to server selectionScale and applications, trouble-tolerance functions,network OS

n Selection based on the scale and applications

• Workstation

• Server PC (middle-range computer)

• Typical PC (entry-model computer)

n Trouble-tolerance functions

• Duplicated disks

• Backup device

• Redundant power

• Management system

3-8

Memo

3.2 Protocol Overview -TCP/IP (1)-

FTP SMTP RIPTELNET

DNS

Other

EthernetTokenRing

OtherMedia

Application Layer

Presentation Layer

Session Layer

Transport Layer

Network Layer

Data-link Layer

Physical Layer

OSI Protocol TCP/IP Protocol

TCP UDP

ARP RARPIP

ICMP

n TCP/IP

• Protocol used for the Internet

• Used for may NOS’s, such as UNIX and Windows NT, as the industrystandard protocol of the pragmatic client-server LAN.

• Collective name for more than 100 computer communications protocols,including TCP equivalent to the OSI transport layer and IP equivalent to theOSI network layer as the representing protocols.

TCPTransmission ControlProtocol

IPInternet Protocol

3-9

Memo

Client RARP server

The MAC address is

00-00-86-01-AB-CD.The IP address is

192.168.0.50.

3.2 3.2 3.2 3.2 Protocol Overview Protocol Overview Protocol Overview Protocol Overview -TCP/IP (2)--TCP/IP (2)--TCP/IP (2)--TCP/IP (2)-

• TCP/IP protocol suiteA set of protocols including TCP and IP of the OSI protocols

ARP

RARP

The RARP server contains information.

Node A Node B

The MAC address is

00-00-86-01-AB-CD.The IP address is

192.168.0.50.

n ARP (Address Resolution Protocol)

• Protocol used to find the MAC address corresponding to the IP address.

n RARP ( Reverse Address Resolution Protocol)

• Protocol used to find the IP address corresponding to the MAC address.

n ICMP (Internet Control Message Protocol)

• Protocol used for notification and diagnosis.

n RIP ( Routing Information Protocol)

• Broadcasts current routing control information to obtain routing information.

• Selects a rout based on the hop counter.

3-10

Memo

3.2 Protocol Overview -IPX/SPX-

Session Layer

Presentation Layer

Application Layer

LAN adapter

LAN driver

SPX

IPX

Upper layer（NCP, SAP, etc.）

• IPX/SPX

Transport Layer

Network Layer

Data-link Layer(MAC layer)

Physical Layer

n IPX/SPX

• Standard protocol for the Novell NetWare/IntranetWare.

• IPX is equivalent to the network layer of the OSI protocols; and SPX is to thetransport layer. (IPX is equivalent to IP of TCP/IP; SPX is to TCP.)

• When mounting a LAN board (NIC), make sure that you have a LAN driverfor NetWare (ODI driver).

• To connect to WAN through a router, the router must support IPX.

IPX/SPXInternet Packet eXchange /Sequenced Packet eXchange

ODIOpen Data link Interface

3-11

Memo

3.2 Protocol Overview -NetBEUI-

LAN adapter

LAN driver

NetBEUI

Upper Layer（SMB, etc.）

• NetBEUI

Session Layer

Presentation Layer

Application Layer

Transport Layer

Network Layer


Physical Layer

n NetBEUI

• Protocol for a small LAN developed by IBM, Microsoft, and 3COM.(Integrated with Windows and OS/2.)

• Does not support the address system of the network layer, thuscommunications (routing) through routers is not available.

NetBEUINetBIOS Extended UserInterfaceIntegrated with MicrosoftLanManager, a traditionalNOS.

3-12

Memo

3.2 Protocol Overview -AppleTalk-

LAN adapter

LAN driver

ATP

DDP

Upper Layer（Appleshare, etc.）

• AppleTalk

Session Layer

Presentation Layer

Application Layer

Transport Layer

Network Layer


Physical Layer

n AppleTalk

• Standard protocol for Apple Macintosh series.

• Requires no complicated settings for a network with only Macintosh computersand is easy to manage.

• Classified into LocalTalk using printer ports, EtherTalk using Ethernet, andTokenTalk using Token-ring according to physical media.

Chapter 4 Internet and TCP/IP

1. Internet2. Line Types

• Private Line• ISDN• Frame Relay

3. Internet Connection4. IP Address

• Overview of IP Address• Subnet Mask

5. Domain Name6. Applications on the Upper Layer

• DNS• Mail• TELNET,FTP• SNMP• DHCP

7. Port Number8. Data Exchange between Layers9. Ethernet Frame

4-2

Memo

4.1 Internet (1)

• InternetProvides information via home pages and electronic mails.

n Internet

• Global network interconnecting corporate networks, university networks,organization network, and others.

• Unites approximately 200 countries centering the US.

• Some 100 million estimated users

• Provides information via home pages and electronic mails.

• Uses TCP/IP as the communications protocol.

4-3

Memo

4.14.14.14.1 Internet (2)

n What you can do with the Internet

• WWWProvides and obtain information to and from all over the world.

• Electronic mailMost easy communication tool of the accumulation type.

• FTPFile exchange through networks

• TELNETEnables operation of a remote computer through networks.

• NetNewsEnables communications with people all over the world.

• Internet telephoneTelephone technology using the Internet with no international telephonecharge.

4-4

Memon Fixed connection type

• Holds connection to an ISP through a private line or a Frame Relay network.

• Charges a fixed amount of money, thus suitable for corporations that use theInternet frequently.

n Dial-up connection type

• Connects to an ISP through a analog network or ISDN when necessary.

• Charges every time a connection is made.

• Suitable for individuals or small offices that uses the Internet occasionally.

4.14.14.14.1 Internet (3)

• Connection to the Internet

ISDN

Internet

Internet service providerTelephonenetwork

Personal computer communication

LANAnalog Digital

Dial-upconnection type Fixed connection type

ISPInternet Service Provider

4-5

Memo

4.2 Line Types -Private Line-

Router

Provider

Router

Corporate LAN

ProvidesProvidesinformationinformation

Private linePrivate line

ChargesChargesCommercial providers

(1) Provider service charge(2) Line service charge

• Digital Private Line

Internet

n Digital private line

• Provides the line speed of some tens kbps through some tens Mbps accordingto applications.

• The line service charge depends on the line speed and distance.

• Charges a fixed amount of money, thus rather expensive for non-frequentusers.

• Does not require to consider the amount of data to transfer because connectionis fixed.

TipsBefore making a contract for a private line, you should compare the runningcost with the ISDN and determine which is economical. (Typical estimation:amount of time to use times 22 days (business days per month) Compare thetotal with the fixed charge for a private line.)

4-6

Memo

4.2 Line Types -ISDN-

• ISDN

Internetserviceprovider

Corporate LAN

ISDNrouter

ISDN

ISDNrouter

Example of dial-up connection of the LAN type

n ISDN

• Enables simultaneous connections to 2 different points by using 2 B channels(INS64).

• Enables dial-up connections of the terminal type and the LAN type.

• Enables a LAN-type connection with a terminal-type dial-up connection byusing the address translation function of ISDN routers.

• Charges according to the amount of use, thus suitable for relatively shortdistance connections with occasional data exchange.

LAN-type Dial-up

To establish a LAN-type dial-up connection with ISDN, aprovider must support theLAN-type dial-up service.

Address TranslationFunction

(See page 4-12.)

4-7

Memo

4.2 Line Types -Frame Relay-

• Frame Relay

RouterRouter

RouterRouter

RouterRouter

Frame Relay

network

n Frame Relay

• Provides higher speed by simplifying the communications protocols.

• Suitable for long distance connections because the line service charge does notdepend on communication distance.

• Implements the frame multiplex function that enables simultaneouscommunications with multiple destinations by establishing multiple logicalchannels simultaneously on a single line.

4-8

Memo

4.3 4.3 4.3 4.3 Internet Connection (1)Internet Connection (1)Internet Connection (1)Internet Connection (1)

• Steps to establish an Internet connection• Application for a domain name and an IP address• Selection and contract with an Internet service provider• Selection of a line to use for connection to an Internet service provider• Installation and setup of a router• Setup of a DNS server• Setup of a WWW server (FTP server)• Setup of a mail server• Setup of a group server• Setup of a firewall

n to establish an Internet connection I

• Application for a domain name and an IP address for a organization network

• Selection and contract with an Internet service provider

(1) Available services: Connection line service types and details

(2) Business history: Business history of services (private line)to corporations

(3) Backbone: Stable line quality and line capacity percustomer

(4) Support: Troubleshooting system and business hourof the support

(5) Price plans: Comparison with the market price

(6) Connection distance: Connection distance between anInternet service provide and an organization

(7) Line enhancement plane: Backbone enhancement plan forthe future (to reduce line congestion)

Troubleshooting System

It is important to determine ifyou can use the network whenyou want, which requires 24-hour support.

4-9

Memo

4.3 4.3 4.3 4.3 Internet Connection (2)Internet Connection (2)Internet Connection (2)Internet Connection (2)

Internet

Router

Router

DNS server Mail server WWW server Clients

Inside corporation

Provider side

Private line, ISDN, OCN, etc.

Corporate network

n Steps to establish an Internet connection II

• Selection of a line to use for connection to an Internet service provider

• Installation and setup of a router

• Setup of a DNS server

• Setup of a WWW server (FTP server)

• Setup of a mail server

• Setup of a group server

• Setup of a firewall

4-10

Memo

4.44.44.44.4 IP Address -IP Address -IP Address -IP Address -IP Address OverviewIP Address OverviewIP Address OverviewIP Address Overview- (1)- (1)- (1)- (1)

0 Network Host

10 Network Host

110 Network Host

1110 Multicast address

1 byte

3 bytes

3 bytes

1 byte

2 bytes 2 bytes

1111 Experiment address

Class A

Class B

Class C

Class D

Class E

• IP Address

n IP address

• Identifies a host on a network in TCP/IP protocol.

• Contains 2 types of information: network part and host part.

• The overall IP addresses are managed by InterNIC and regional agenciesmanage IP addresses used in their regions.

• To make an Internet connection, you must apply for an IP address to yourregional NIC.

InterNICThe Inter-networkInformationCenterOrganization founded in1993 that manages theInternet by managing IPaddresses and domain namesand investigatingtechnologies.

TipsYou can not obtain a Class A address anymore. Also, the more popular theInternet becomes, the less the number of addresses is available, which made itunder consideration to take back assigned Class A addresses and reassign ClassB or C addresses to users. Thus Class B addresses are now assigned to limitedorganization only.

4-11

Memo

4.4 4.4 4.4 4.4 IP Address -IP Address -IP Address -IP Address -IP Address OverviewIP Address OverviewIP Address OverviewIP Address Overview- (2)- (2)- (2)- (2)

• Classes of IP Address

• Network address• Broadcast address• Private address

Address class First 1 byteNumber of bytes in the

network partClass A 0-127 1Class B 128-191 2Class C 192-223 3Class D 224-239 -Class E 240-255 -

n Classification of the IP address

• Class A through Class C:Assigned to organizations including business corporations.

• Class D through Class E:Multicast addresses and experiment addresses, thus not distributed to thepublic.

n Network address

• IP address with 0 in all bits of the host part

n Broadcast address

• IP address with 1 in all bits of the host part

n Private address

• IP address used only in an organization which does not require an applicationto NIC

1 Byte8 bits. It can represent 256values from 0 through 255.

MulticastA form of broadcast inwhich copies of a messageare transmitted to aparticular group ofdestinations.

Class A 10. 0. 0. 1 to 10.255.255.254

Class B 172. 16. 0. 1 to 172. 31.255.254

Class C 192.168. 0. 1 to 192.168.255.254

4-12

Memo

4.4 4.4 4.4 4.4 IP Address -IP Address -IP Address -IP Address -IP Address OverviewIP Address OverviewIP Address OverviewIP Address Overview- (3)- (3)- (3)- (3)

• NATA system that translates IP addresses on the communication path.

IP Masquerade

NAT

192.168.0.10

192.168.0.10

192.168.0.15

202.12.30.134

202.12.30.134

Local address Global address Internet

n Address translation function

• A system that translates IP addresses on the communication path.

• Used to save IP addresses and conceal the network configuration.

n NAT

• One-to-one translation between a local address and a global address

• One global address gives external access to a single terminal.

n IP Masquerade

• Translation between multiple local addresses and a single global address

• A single global address can be shared by multiple terminals for simultaneousexternal access.

NATNetwork AddressTranslator

Local addressPrivate IP addresses usedin a local network only

Global addressPublic IP addresses usedon the Internet

IP MasqueradeCurrently, a clear line isnot drawn between NATand IP Masquerade. Bothare often considered asaddress translationbetween multiple localaddress and a single globaladdress.

TipsCurrently, each maker provides its own enhanced address translation functionthat translates multiple local addresses to a single global address.

4-13

Memo

4.4 4.4 4.4 4.4 IP Address IP Address IP Address IP Address ----SubnetSubnetSubnetSubnet Mask Mask Mask Mask- (1)- (1)- (1)- (1)

Network Host

Network Subnet Host part

• SubnetExpands the network address.

IP address(Class B)

Subnetspecification

Network Subnet Host part

all bit 1 all bit 0

Subnet mask

Valid network address (external use)

Network address used in an organization only (internal use)

n Netmask

• Information to identify the network part and host part

n Subnet

• Network created by dividing a single network

• Used to divide a network of an organization

n Subnet mask

• Netmask to identify a subnet size

• Example of creating 16 subnets in a single Class C address

IP address 202.215.167.0 11001010.11010111.10100111.00000000

Subnet m 255.255.255.240 11111111.11111111.11111111.11110000

4-14

Memo

4.4 4.4 4.4 4.4 IP AddressIP AddressIP AddressIP Address - - - -SubnetSubnetSubnetSubnet Mask Mask Mask Mask- (2)- (2)- (2)- (2)

• CIDRTechnology to effectively use the IP address

IP address assignmentusing CIDR methodTraditional IP address assignment

Organization A IP address 4 addresses






Organization A Class C 1 address 4 out of 256addresses in ise

Class C

2 02 .2 1 5.1 6 7.0

2 55 .2 5 5.2 5 5.2 5 2 2 0 2 .2 1 5 .1 6 7 .0 /3 0

2 02 .2 1 5.1 6 7.0

2 55 .2 5 5.2 5 5.2 4 8 2 0 2 .2 1 5 .1 6 7 .0 /2 9

2 0 2 .2 1 5 .1 6 7 .0

2 5 5 .2 5 5 .2 5 5 .2 4 0 2 0 2 .2 1 5 .1 6 7 .0 /2 8

Organization B Class C 1 address 8 out of 256addresses in ise

Organization C Class C 1 address 16 out of 256addresses in ise

n CIDR

• Technology to deal with IP address shortage in a short term

• Implemented by abandoning a theory of IP address class, reviewing andrearranging the address space comprehensively.

n Notation using the CIDR technology

• Noted as “IP address / prefix value”.

• 16 subnets created in a single Class C address

Traditional notation CIDR notation

CIDRClassless Inter-DomainRouting

Short-termcountermeasureThere is a technology calledIPv6 as a long-termcountermeasure to IPaddress shortage. (See page5-9.)

Prefix valueNumber of bits used forsubnet masks

202.215.167.0

255.255.255.240202.215.167.0/28

4-15

Memo

4.5 4.5 4.5 4.5 Domain Name (1)Domain Name (1)Domain Name (1)Domain Name (1)

•••• Domain nameDomain nameDomain nameDomain name• Network names that identifies business corporations and organizations• Managed by NIC(Network Information Center).

pc01 . sales . sharp . co . uk

Top-level domain(country name)

Third-level domain(organization name)

Sub-domain(departments, etc.)

Host name(Computer identification name)

Domain name

Application to NIC is required.Defined in an organization.

Second-level domain(organization name)

n Host name

• Identification name assigned to each computer.

• Must be unique in the same regional assignment unit.

n Domain name

• Network names that identifies business corporations and organizations.

• Must be unique to identify each organization on the Internet.

• Sub-domains may be defined to segment branches and departments.

4-16

Memo


• Domain name

root

edu com org … fr jp tw uk

ac ad co gr go ne Area

Konica nec fujitsu ibm sony yamaha ...

Top level

Second level

Third level

n Top-level domains in the United States

• The top-level domain (country name: us) may be omitted because the Internetwas born in the United States.

com: business corporations edu: educational institutions

gov: government institutions org: organizational institutions

mil: military institutions net: network institutions

n Other top-level domains (country names)

au: Australis ca: Canada

sg: Singapore fr: France

hk: Hong Kong es: Spain

kr: Korea ph: Philippines

th: Thailand to: Tonga

tw: Taiwan nl: New Zealand

id: Indonesia ru: Russia

4-17

Memo


• Expansion of top-level domains (gTLD)Operation by CORE established as a new registration agencyFree application regardless of nationalities, individuals, orcorporations

firm: business corporationsstore: retailersweb: organizations engaged in web-related activitiesarts: o r g a n i z a t i o n s e n g a g e d i n c u l t u r a l a n d

entertainment activitiesrec: organizations engaged in entertainment activitiesinfo: organization providing information servicesnom: individuals

n Expansion of top-level domains

• Top-level domains are expanded to deal with shortage in domain names.

• Every one can apply for a domain regardless of nationalities, individuals, orcorporations.

• This gTLD is operated by a new registration agency (CORE).

gLTDgeneric Top Level Domain

COREinternet COuncil ofREgistrars

4-18

Memo

4.6 4.6 4.6 4.6 Applications at the Upper Layers -DNS- (1)-DNS- (1)-DNS- (1)-DNS- (1)

• DNS• Manages addresses, domain names, and host names.

DNS client(resolver)

DNS server(name server)

.

.

www.konica.com 207.79.42.252

.

.

.

Database

What is an IP address forwww.konica.com?

It’s 207.79.42.252!

Request

Answer

n DNS

• Management system of organizations using a tree structure

• Consists of a DNS server (name server) and DNS clients (resolvers).

n Functions of the DNS server

• Creates a database table that matches all host (domain) names in the segmentand IP addresses.

• Resolves names in the following ways in response to client requests.

(1) Normal lookup (from a host (domain) name to an IP address)

(2) Reverse lookup (form an IP address to a host (domain) name)

TipsThe DNS server provides another function, called mail exchange (MX: MaileXchange), to look up main destinations.

DNSDomain Name System(Service)

4-19

Memo

4.6 4.6 4.6 4.6 Applications at the Upper Layers -DNS- (2)-DNS- (2)-DNS- (2)-DNS- (2)

Jimmy’s addressis 202.215.167.15,but Taro’s addressis unknown.

Taro‘s address is203.179.56.26.

Primary DNS server

Upper DNS server

Secondary DNS server

n DNS server types

• Primary DNS server

• Secondary DNS server

n Name resolution

• The local DNS server provides name resolution for the hosts in anorganization.

• For host names in other organizations, the local DNS server sends requests toits upper DNS server for name resolution.

• Once requests are made for information on hosts in other segments, the resultsare stored in a cache on the local DNS server for a certain period of time. Cache

A way to store frequentlyused information for quickretrieval. Usually theprimary DNS server alsoworks as the cache server.

4-20

Memo

Mail server Mail serverSMTP Simple MailTransfer Protocol

POPPost Office Protocol

POPPost Office Protocol

sendmail sendmail

Mail clients Mail clients

• Mechanism of electronic mail

4.6 4.6 4.6 4.6 Applications at the Upper Layers -Mail--Mail--Mail--Mail-

n SMTP

• TCP/IP protocol for exchanging electronic mail.

n POP

• Protocol used between the mail server and mail clients.

n IMAP

• Solves problems in exchanging electronic mail using POP.

• Transfers only header information and read/unread information of theelectronic mail.

SMTPSimple Mail TransferProtocol

POPPost Office ProtocolThe current version is calledPOP3.

IMAP

Internet Message AccessProtocol

This protocol transfers lessinformation as comparedwith POP, thus it is expectedto be used for mobilecommunications via thetelephone line.

TipsSMTP is a mail transfer protocol used between hosts and requires a receive-sidemachine to be always up in operation. Thus POP or IMAP is used for mailexchange with a personal machine (client).

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4.6 4.6 4.6 4.6 Applications at the Upper Layers-TELNET,FTP--TELNET,FTP--TELNET,FTP--TELNET,FTP-

• TELNET

• FTP

n TELNET

• Protocol used to connect a remote terminal via a network.

• Consists of a TELNET server and TELNET clients.

• The TELNET server is provided with UNIX but optional to Windows NT.

n FTP (File Transfer Protocol)

• Protocol used for file transfer via a network.

• Consists of a FTP server and FTP clients.

• Provides the anonymous FTP functions that does not require userauthentication.

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4.6 4.6 4.6 4.6 Applications at the Upper Layers -SNMP--SNMP--SNMP--SNMP-

• SNMP

Manages network resources and objects.

Management station

(Manager)

Management target node

(Agent)Management protocol

(SNMP)

Standard MIB

Enhanced MIB

Trap

Polling

n SNMP (Simple Network Management Protocol)

• Protocol used to manage various resources and objects on a network andimplement a mechanism to detect various events that occur.

n Components of SNMP

• Management station (SNMP manager)

• Management target node (SNMP agent)

• Management model (MIB)

n Basic SNMP model

• Trap (issued by a management target node)

A management target node reports its exceptional and abnormal status to themanagement station on a real-time basis.

• Polling (issued by the management station)

The management station periodically accesses to a management target node tocheck status of management target objects.

MIB

Management Information

Block

Management informationdatabase with a tree structure.Two types of MIB exist:standard MIB specified inRFC and enhanced MIB tomanage vendor-specificinformation.

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4.6 4.6 4.6 4.6 Applications at the Upper Layers -DHCP--DHCP--DHCP--DHCP-

IP address scope Subnet mask

Default router

DNS server address

.

.

.

192.168.0.10

to

192.168.0.100

Everything is unknown.

Give me configuration!

• DHCP

Automatically configures network information.

Use this configuration.

n DHCP (Dynamic Host Configuration Protocol)

• Protocol to automatically configure information including the host IP address,subnet masks, and a default router.

• Consists of a server that manages and distributes configuration information andclients that obtain information and configure automatically.

n DHCP server

• Provides configuration information including a continuous IP address spacecalled a scope and subnet masks.

• Provides configuration information in response to client requests. IP addressesmay be leased for a certain period of time.

• Manages which IP address is leased to which client to avoid IP addressoverlap.

n DHCP client

• Receives configuration information from the DHCP server to use it only for aleased period of time.

• Releases an IP address when the leased period of time expires.

ServerSome low-price routersmanufactured recently mayhave the DHCP serverfunction.

ScopeScope creation may also becalled address loop.

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4.7 4.7 4.7 4.7 Port NumberPort NumberPort NumberPort Number

telnettelnettelnettelnet telnettelnettelnettelnet telnettelnettelnettelnet telnettelnettelnettelnet

Client computer Server computer

Client application Serverprocess

Port 23Port 23Port 8097Port 14172

• Port numberThe port number is used to identify communication services at the transport layer.

n Port number

• 16-bit identification number used at the transport layer in TCP/IP.

• Identifies communication services and implements multiplex communications.

n Destination port number

• Defined according to a service to use.

• Port numbers 0 through 1023 are defined as well-known ports.

n Source port number

• Port numbers 1024 and greater are available for users.

• Randomly extracted from available port numbers.

ftp-data 20/tcp

ftp 21/tcp

telnet 23/tcp

smtp 25/tcp

domain 53/tcp

http 80/tcp

nntp 119/tcp

snmp 161/tcp

pop3 110/udp

ntp 123/tcp

Transport layerTCP and UDP layers areequivalent in TCP/IP. (Seepage 3-8.)

16-bit number

0 through 65535 (2 to thepower of 16)

Port numbers 1024 orgreaterSome of port numbers 1024or greater may used by otherapplications, thus portnumbers 8000 or greater areusually used.

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Memo

4.8 Data Exchange between Layers

MAC

IP

TCP

DataDataDataData

DataDataDataData

TCP DataDataDataData

IP TCP DataDataDataData

DataDataDataData

MAC IP TCP Data

Header

Header

Header

Header part Data part

Packet

Ethernet cable

Node A Node B

MAC

IP



IP TCP DataDataDataData

Header

Header

Header

Application layerApplication layerApplication layerApplication layer

Transport layerTransport layerTransport layerTransport layer

Network layerNetwork layerNetwork layerNetwork layer

Data-link layerData-link layerData-link layerData-link layer

Physical layerPhysical layerPhysical layerPhysical layer

(Port numberprocessing

(IP addressprocessing

SMTP,TELNET,FTP,SNMP

(MAC addressprocessing

n TCP/IP protocol layers

• The highest (application) layer defines application services (software),including electronic mail programs; and the lowest (physical) layer definesphysical media (hardware), including LAN boards and lines.

• At transmission, data is transferred vertically from the top layer to the bottomlayer and transmitted to a destination via the physical layer. The received datais transferred from the bottom layer to the top layer.

n Data processing at each layer

• Communication service processing at the application layer

• Port number processing at the transport layer

• IP address processing at the network layer

• MAC address processing at the network layer

• Data packet transmission and reception at the physical layer

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4.94.94.94.9 Ethernet Frame

EthernetIEEE802.2 IEEE802.2 IEEE802.2 IEEE802.2

IEEE802.3 IEEE802.4 IEEE802.5 FDDI

Ethernet V2.0 IEEE network

• Frame types

There are 2 types of Ethernet frames.

NetworkLayer

CoaxialCable

NetworkLayer

CoaxialCable

NetworkLayer

CoaxialCable

NetworkLayer

Ring Cable

NetworkLayer

Ring Cable

n Frame types

There are 2 types of Ethernet frames.

(1) Ethernet V1.0 specification called the DIX specification was formedin 1980.

(2) IEEE standardized IEEE802.3 based on the DIX specification in1985.

(3) Ethernet V2.0 specification was formed with reflections from theIEEE specification in 1982.

n IEEE network

IEEE standardized the IEEE802 series as the low-speed LAN technologyincluding Ethernet.

Many media, such as Ethernet and fiber-optic, are supported by dividing thedata-link layer into 2 parts.

DIXIndicates Dec, Intel, andXerox that developedEthernet.

Chapter 5 Technical TrendChapter 5 Technical TrendChapter 5 Technical TrendChapter 5 Technical Trend

1.1.1.1. IntranetIntranetIntranetIntranet2.2.2.2. FastEthernetFastEthernetFastEthernetFastEthernet3.3.3.3. Giga-bitGiga-bitGiga-bitGiga-bit Ethernet Ethernet Ethernet Ethernet4.4.4.4. ATMATMATMATM5.5.5.5. Mobile ComputingMobile ComputingMobile ComputingMobile Computing6.6.6.6. IPv6IPv6IPv6IPv67.7.7.7. FirewallFirewallFirewallFirewall8.8.8.8. Proxy ServerProxy ServerProxy ServerProxy Server

5-2

Memo

5.1 5.1 5.1 5.1 Intranet (1)Intranet (1)Intranet (1)Intranet (1)

IntranetBrowser

Router

WWW server

Facility reservation system

Internet

Bulletin board system

WWW server

Browser Browser Browser

WWWWWW

n Intranet

• Corporate information system using the Internet technology (WWW) for LAN.

• Seamlessly integrates the traditionally closed corporate network environmentwith the global Internet.

n Implementation by the Intranet

• Hardware resource sharing and information sharing, including customerinformation and documentation

• Use of services, including electronic mail, electronic bulletin board, electronicconference, schedule management, and database lookup.

• Access to in-house resources from remote sites via the Internet.

5-3

Memo

5.1 5.1 5.1 5.1 Intranet (2)Intranet (2)Intranet (2)Intranet (2)

Internet

Firewall

WWW server

Intranet(Corporate information

network)

Multimedia

Character

Voice

Movie

• WWW• NetNews• FTP• Electronic mail

n Intranet service types

• Information sharing and offering type

• Database collaboration type

• Groupware collaboration type

n Merits in using the Intranet

• Inexpensive to build a system

• Very low educational cost. Learning browser operations is only required.

• Whatever is possible via a browser.

• Integrated operability between a corporate network and the Internet.

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5.5.5.5.2 2 2 2 Fast Ethernet (1)Fast Ethernet (1)Fast Ethernet (1)Fast Ethernet (1)

10BASE-T100BASE-T4 100BASE-TX 100BASE-FX

100BASE-T

10 Mbps in total 100 Mbps in total 100 Mbps in total 100 Mbps in total

Controluse

33Mbps

33Mbps

33Mbps

4-pair UTPCategories 3, 4,and 5

2-pair UTPCategory 5, 2-pairSTP

2 optic cores<62.5/125>

2-pair UTPCategories 3, 4,and 5

• 100BASE-T

n 100BASE-T (Fast Ethernet)

• Standard with the baseband speed that is 10 times faster than traditional10BASE-T

• Employment of CSMA/CD method enables a gradual shift from traditional10BASE-T.

• Give stricter limitations on the total cable length and the cascade levels of hubsfor collision detection. (2 cascade levels and cable length of up to 205 m for100BASE-TX)

Tips100BASE-T (Fast Ethernet) has variants of 100BASE-T4, 100BASE-TX,100BASE-FX, etc., as shown in the above figure. Currently 100BAE-TX is themost popular one and inexpensive as compared with the other 100BASEproducts.

5-5

Memo

5.5.5.5.2 2 2 2 Fast Ethernet (2)Fast Ethernet (2)Fast Ethernet (2)Fast Ethernet (2)

• 100 BASE-T components

．．．．

．．

ServerClient Client

．．．．

．．

ServerClient Client

NIC

100 m 100 m

5 mHUB HUB

CABLE

n 100 BASE-TX components

• 100BASE-T support hub

• Twisted-pair cable (category 5)

• NIC (Network Interface Card)

• 100 Mbps support products (Some supports 10/100 Mbps automaticswitching.)

• The PCI slot is common as the bus type to enable high-speed transfer.

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Memo

5.3 5.3 5.3 5.3 Giga-bitGiga-bitGiga-bitGiga-bit Ethernet Ethernet Ethernet Ethernet

1M 10M 100M 1G

FDDI

ATM(～620Mbps)

Ethernet

Token-ring

N ov. 1995 O rga niza tion o f H S S G ( H igh S pe e d S tudy G roup) Jun. 1996 A pprova l of P A R ( P ro je c t A utor iza tion R e que s t ) N ov . 1996 Deadline for proposals

Ja n. 1997 D ra f t ve rs ion 1M a r. 1997 D ra f t ve rs ion 2Ju l. 1997 W G vote fo r D ra f t ve rs ion 3N o.v 1997 S pons or vote for D ra f t ve rs ion 4M a r. 1998 IE E E s ta nda rd boa rd a pprova l (D ra f t ve rs ion 5)

Date Description

First Ethernet

Giga-bit Ethernet

• Transfer speed

• Standardization schedule

n Giga-bit Ethernet

• Ethernet with the transmission rate of 1 Gbps based on the CSMA/CD method

• Seamless integration with existing networks

• Fiber-optic cable connection

• Connection standard for the twisted-pair cable (UTP) is also under discussion.

TipsATM was the center of attentions because it was the only network technologythat offered data transfer at a speed of over 100 Mbps. However, productdevelopment has been taking too long due to pursuit of an ideal technology, andnow attentions have shifted to Giga-bit Ethernet with which productdevelopment is rather easy.

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Memo

5.45.45.45.4 ATMATMATMATM

Router

PBX

Multimedia terminal

ＭＭ－ＮｏＭＭ－ＮｏＭＭ－ＮｏＭＭ－Ｎｏｄｅｄｅｄｅｄｅ９５１９５１９５１９５１００００ＮＥＣＮＥＣＮＥＣＮＥＣ

NPCNPCCLC SWC SWC CLC

Router

ATM SW

Fixed-length cell

ＭＭ－ＮｏＭＭ－ＮｏＭＭ－ＮｏＭＭ－Ｎｏｄｅｄｅｄｅｄｅ９５１９５１９５１９５１００００ＮＥＣＮＥＣＮＥＣＮＥＣ

NPCNPCCLC SWC SWC CLC

DataDataDataData(Payload)(Payload)(Payload)(Payload)

HeaderHeaderHeaderHeader

48 48 48 48 bytesbytesbytesbytes 5 5 5 5 bytesbytesbytesbytes

53 53 53 53 bytesbytesbytesbytes

ATM SW

PBX

n ATM

• Fixed-length cell of 53 bytes

• High-speed processing by hardware

• Provide a secured network band and multiplex communications.

• Transfer control in accordance with the transmitted contents

• Integrates computer data and multimedia data into the same transfer system.

TipsRegardless of its superior characteristics, the ATM technology has not been aspopular as expected due to its high implementation cost and competitiveproducts, such as Fast Ethernet and Giga-bit Ethernet.However, with a multimedia era around the corner, it now starts drawing greatattention. This is because there is a need for a technology that easily integrateswith WAN as well as ATM is faster than Ethernet.

ATMAsynchronous TransferMode

5-8

Memo

5.5 5.5 5.5 5.5 Attractiveness of Mobile Computing

Office

Laptop PC Where you are is your office.Where you are is your office.Where you are is your office.Where you are is your office.

n New business style born with use of laptop computers

• “Where you are is your office” made available by a mobile computingtechnology

n Widely spread smaller portable personal computers

• Improved portability by down-sizing (Introduction of portable PC’s smallerthan A5 size)

n Improvement of PDAs

• Integration of the modem communications (Internet connection) function andcolor support

n Introduction of Windows CE machines

• Microsoft’s 32-bit OS running with a memory of only a few mega bytes

PDAPersonal Data Assistant

PHSPersonal HandyphoneSystem

PIAFSPHS Internet Access ForumStandard

5-9

Memo

5.6 5.6 5.6 5.6 IPv6IPv6IPv6IPv6

IPv4

DHCP IPSEC RSVP CIDR

32-bit space

IP-related technologies that offer additional functions

Standard integrationof additional

functions (Super set)

To allow Internetaccess from moredevices

128-bit space

Stamdard integrationof QoS function

Standard integration of the security function

Plug and Playfunction

Effectiverouting

DHCP : Dynamic Host Configuration Protocol

IPSEC : IP Security ProtocolRSVP : Resource Reservation Setup ProtocolCIDR : Classless Inter-Domain Routing

IPv6

n Features of IPv6

• Expansion of the IP address space (from 32 bits to 128 bits)

• Automatic configuration of IP address information (Plug and play)

• Integration of a security mechanism

• Effective routing mechanism

• Specifications that allow future expansion in functions

TipsIPv6 is a method to expand the address space to 128 bits while maintainingcompatibility with the current IP addresses (IPv4) and provides an availableaddress space 4 billion times (2 to the power of 96) larger than the currentaddress space. It is said that it can assign at least 1564 addresses in a squaremeter provided that the surface of the earth is all covered with computers.

5-10

Memo

5.7 5.7 5.7 5.7 Firewall (1)Firewall (1)Firewall (1)Firewall (1)

FireWall

Router

WWW FTP

Internet• Segments internal and externalnetworks.

• Configured using more than 2NICs

• Implemented by isntalling apublic server on the barriersegment

n Firewall server

• Implemented by installing 2 or more NIC’s to a computer running an NOS,such as Windows NT or UNIX, and installing firewall software.

• Installed at a connection point between internal (corporate) networks andexternal networks (Internet) to isolate internal and external segments.

• Public servers, such as WWW and FTP servers, are installed outside thefirewall (on the barrier segment) to prevent the internal LAN from any externalaccess. The firewall has nothing to do with protection of public servers.

TipsInstalling multiple NIC’s to a single computer consumes IP addresses (networks)of the same number.

5-11

Memo

5.7 5.7 5.7 5.7 Firewall (2)Firewall (2)Firewall (2)Firewall (2)

Internet

Firewall

Firewall

Router

DMZ 2

DMZ 2 DMZ 1

DMZ 1

Packet filtering typePacket filtering type

Application proxy typeApplication proxy type

Controls messages according tothe port number and direction.

Controls message at the application layer.

n What the firewall server can do...

• Monitoring and logging

• Alarm generation when an invalid access is detected (mailing to the systemadministrator, etc.)

• Flexible settings at application levelFor example: regulation based on time, permission and rejection at applicationlevel

n What the firewall server can not do...

• Rejection of an invalid access made by an insider

• Protection of communications that does not pass the firewall

Flexible settingsThe firewall server software isclassified into “packet filteringtype” and “application proxytype” according to itsfunctions. Flexible settings atapplication level require thelatter type.

5-12

Memo

5.85.85.85.8 Proxy ServerProxy ServerProxy ServerProxy Server

Insidecorporation

ProxyStores requesteddata in a cache onthe hard disk.

Internet

Obtains requested data from aWWW server when it is not storedin a cache.

Caching function

Controls by protocols

Internet

• Role of the proxy server

Security function

Proxy

Insidecorporation

n Role of the proxy server

• Proxy response function to requests from clients

• Caching function

• Concealment of internal IP addresses

TipsThe proxy server is now often considered to be part of the firewall server. Manyfirewall servers on the market have functions of the proxy server.

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