Chapter 3: Planning Network Protocols and Compatibility

Chapter 3: Planning Network Protocols and Compatibility

ProtocolProtocol

A protocol consists of guidelines for:How data is formatted into discrete

units called packets and framesHow packets and frames are

transmitted across one or more networks

How packets and frames are interpreted at the receiving end

Packets and FramesPackets and Frames

Packets and frames are units of data transmitted from one networked computer or device to another.Although packets and frames are often used to have the same meaning, there is a difference. Packets operate at a higher communication layer and contain routing information.

General Sections in Packets and FramesGeneral Sections in Packets and Frames

HeaderDataTrailer or footer

Packet and Frame FormatPacket and Frame Format

Header with source,destination, and routing

information

Variable-length data Footer witherror data

Figure 3-1 Basic packet and frame formatFigure 3-1 Basic packet and frame format

Network DesignNetwork Design

The basic design of a network is its topologyTopology: The physical layout of the cable and the logical path followed by network packets and frames sent on the cable

Local Area NetworkLocal Area Network

Local area network (LAN): Joins computers, printers, and other computer equipment within a limited service area and generally employs only one topology

Example of a LANExample of a LAN

LAN

Figure 3-2 A LAN in a buildingFigure 3-2 A LAN in a building

Metropolitan Area Network Metropolitan Area Network

Metropolitan area network (MAN): A network that links multiple LANs within a large city or metropolitan area

Example of a MANExample of a MAN

LAN

LANLAN

Research hospital

University chemistry building

Pharmaceutical company

MAN connecting buildings in a cityMAN connecting buildings in a city

Enterprise NetworkEnterprise Network

Enterprise Network: A network that often reaches throughout a large area, such as a college campus, a city, or across several states. A distinguishing factor of an enterprise network is that it brings together an array of network resources such as many kinds of servers, mainframes, printers, network devices, intranets, and the Internet

Typical Resources in an Enterprise Network

Typical Resources in an Enterprise Network

Figure 3-3Figure 3-3Resources in anResources in an

enterprise networkenterprise network

Wide Area NetworkWide Area Network

Wide Area Network (WAN): A far-reaching system of networks that can extend across state lines and across continents

Example of a WANExample of a WAN

New YorkLos Angeles

WAN across a continentWAN across a continent

Network Interface Card Communication Medium

Options

Network Interface Card Communication Medium

OptionsCoaxial cable (thick and thinnet)Twisted-pair (shielded and unshielded)Fiber-opticWireless (infrared, radio wave, microwave, satellite)

Connecting a Medium to a NIC

Connecting a Medium to a NIC

Figure 3-4 Connecting cable to a NICFigure 3-4 Connecting cable to a NIC

Device AddressDevice Address

Each NIC has a physical or device address that is burned into a PROM on the card Media access control (MAC) address is another way of describing the device address

Ethernet and Token Ring

Ethernet: A network transport system that uses a carrier sensing and collision detection method to regulate data transmissionsToken ring: A network transport method that uses a token, which is passed from node to node, to coordinate data transmissions

NDISNDIS

Network Driver Interface Specification (NDIS): developed by Microsoft and 3COM enables communication between a NIC and

a protocol enables the use of multiple protocols on the

same network

NDIS ArchitectureNDIS Architecture

N e t w o r k i n t e r f a c e c a r d

N e t w o r k p r o t o c o l ( s u c h a s T C P / I P )

W i n d o w s 2 0 0 0 w i t h N D I Sd r i v e r i n s t a l l e d b i n d i n g t h e

p r o t o c o l w i t h t h e N I C

Figure 3-5 Binding a protocol to a NIC

ODIODI

Open Datalink Interface (ODI) driver: Novell NetWare transport multiple protocols on the

same network

Microsoft-Supported Communication Protocols

Microsoft-Supported Communication Protocols

Protocol Function

TCP/IP (Transmission Control

Protocol/Internet Protocol)

Software drivers for TCP/IP communications with

servers, workstations, mainframes, UNIX computers,

and Internet and intranet servers

NWLink (NetWare Link) Microsoft developed drivers for communications with

Novell NetWare networks

NetBIOS (Network Basic Input/Output

System)

A link to programs that use the NetBIOS interface

Microsoft-Supported Protocols

Microsoft-Supported Protocols

Protocol Function

NetBEUI (NetBIOS Extended User Interface) Software drivers for a data transport protocol used on

small Microsoft-based networks

DLC (Data Link Control protocol) Software drivers for communications with IBM

mainframe and minicomputers and with specific

peripherals such as some types of printers

AppleTalk Software drivers for communications with Apple

Macintosh computers

TCP/IPTCP/IP

Transmission Control Protocol (TCP) portion performs extensive error checking to ensure that data is delivered successfullyInternet Protocol (IP) portion consists of rules for packaging data and ensuring that it reaches the correct destination address

Dotted Decimal NotationDotted Decimal Notation

Dotted Decimal Notation: four octets

100000110.11011110.1100101.00000101converted to decimal (e.g., 134.22.101.005)

Unicasting and Multicasting

Unicasting and Multicasting

Unicast sent to each client

e.g. a multimedia presentation

Multicastsent to all requesting clients as a

group (reducing the total network traffic)

Unicasting and Multicasting Compared

Unicasting and Multicasting Compared

M ultimedia server

Unicasting to five clients

Five separatetransm issionsto reach fiv eseparateworkstations

M ultimedia server

M ulticasting to reach fiveclients as a group

Receiving group

Onetram sm issionto thereceiv inggroup(s) only

Figure 3-6 Unicasting compared to multicastingFigure 3-6 Unicasting compared to multicasting

Subnet MaskSubnet Mask

Subnet mask: used to indicate the class of

addressing on a network divides a network into subnetworks

controls traffic and enforce security

Configuring the IP Address and Subnet Mask

Configuring the IP Address and Subnet Mask

Figure 3-7 IP address and subnet mask setupFigure 3-7 IP address and subnet mask setup

Static and Dynamic Addressing

Static and Dynamic Addressing

Dynamic addressing: automatically assigning an IP address

to a network host

Static addressing: manually assigning an IP address to

a network host

TCP/IP AdvantagesTCP/IP Advantages

Well-suited for medium and large networksDesigned for routing high degree of reliability

Used worldwide for directly connecting to the Internet and by Web serversEnables lower TCO on Microsoft networks

TCP/IP AdvantagesTCP/IP Advantages

Compatible with standard tools for analyzing network performanceParallel ability to use DHCP and WINS through a Windows 2000 serverAbility for diverse networks and operating systems to communicateCompatible with Microsoft Windows Sockets

TCP/IP DisadvantagesTCP/IP Disadvantages

More difficult to set up and maintain than other protocolsSomewhat slower than IPX/SPX and NetBEUI on networks with light to medium traffic

Routing via TCP/IP

Ethernet

Ethernet

Ethernet

Ethernet

Ethernet

TCP/IP-basedintranet server

Transmittedframe

Frameforwardedto the rightnetwork bythe router

F ramereaches thedesignatedworkstation

Router

Figure 3-8Figure 3-8Router forwardingRouter forwarding

packets to a packets to a designated networkdesignated network

Planning TipPlanning Tip

For medium and large sized networks, plan to use TCP/IP because it enables you to manage and secure network traffic through creating subnets

Protocols and Applications in the TCP/IP Suite

Protocols and Applications in the TCP/IP Suite

Protocol or Application Function

TCP A connection-oriented protocol that is used with IP

for reliable end-to-end communications

UDP Used with IP as an alternative to TCP in situations

requiring low overhead and in which connectionless

communications are appropriate

IP Used with TCP or UP, a connectionless protocol

that handles addressing and routing

Telnet Provides terminal emulation

File Transfer Protocol (FTP) Used to transfer files

Protocols and Applications in the TCP/IP Suite

Protocols and Applications in the TCP/IP Suite

Protocol or Application Function

Simple Mail Transfer Protocol (SMTP) Provides electronic mail services

Domain Name Service (DNS) Resolves computer names to IP addresses and IP

addresses to computer names

Address Resolution Protocol (ARP) Enables the sending node to determine the MAC or

physical address of another node

Simple Network Management Protocol

(SNMP)

Enables computers and network devices to gather

network performance information so that a network

administrator can analyze performance and locate

problem areas

Protocols and Applications in the TCP/IP Suite

Protocols and Applications in the TCP/IP Suite

Protocol or Application Function

Internet Group Management Protocol

(IGMP)

Enables multicast packets to reach their recipients, and

routers to determine which workstations belong to a

multicast group

Internet Control Message Protocol

(ICMP)

Used for network error reporting, particularly via routing

devices

Routing Information Protocol (RIP) Used by routing devices to communicate the contents of

routing tables with one another

Protocols and Applications in the TCP/IP Suite

Protocols and Applications in the TCP/IP Suite

Protocol or Application Function

Open Shortest Path First (OSPF) Used by routing devices to share routing table

information and to evaluate network paths to match a

type of transmission to the appropriate path

Hypertext Transfer Protocol (HTTP) Used to transport HTML documents over the Internet or

via an intranet

Protocols and Applications in the TCP/IP Suite

Protocols and Applications in the TCP/IP Suite

Protocol or Application Function

Resource Reservation Protocol (RSVP) Used to enable a network application to reserve the

resources it needs such as bandwidth, service class, and

priority

Quality of Service (QoS) Provides mechanisms to measure and allocate network

resources on the basis of transmission speed, quality,

priority, and reliability

IPX/SPXIPX/SPX

IPX: developed by Novell

particularly for NetWare versions before version 5

SPX: connection-oriented protocol used for

network transport when there is a particular need for data reliability

NWLink

A network protocol that simulates the IPX/SPX protocol for Microsoft Windows 95, 98, NT, and 2000 communications with Novell NetWare file servers and compatible devices

Client Service for NetWare (CSNW)

Components

Client Service for NetWare (CSNW)

Components

Client Service for NetWareNWLink IPX/SPXNWLink NetBIOS

CSNW Installed in Windows 2000

CSNW Installed in Windows 2000

Figure 3-9 Windows 2000 with CSNW components installedFigure 3-9 Windows 2000 with CSNW components installed

Configuring NWLinkConfiguring NWLink

Configure three elements:Frame typeNetwork number Internal network number

When to Configure the Internal Network NumberWhen to Configure the

Internal Network NumberWhen the NetWare server that is accessed uses two or more frame typesWhen the Windows 2000 host has two or more NICs and NWLink is bound to more than one of the NICsWhen an application uses NetWare’s Service Advertising Protocol (SAP)

When to Use NWLinkWhen to Use NWLink

To access a NetWare server pre-version 5

To set up Windows 2000 as a gateway to a NetWare serverTo enable NetWare clients to access a Windows 2000 server

Planning TipPlanning Tip

If you upgrade NetWare servers to version 5.x or higher, convert from IPX/SPX to TCP/IP for better network communication options and better compatibility with Windows 2000 servers

NetBIOSNetBIOS

A combination software interface and network naming conventionAvailable in Windows 2000 through the files Netbt.sys, NetBIOS.sys, and NetBIOS.dll

NetBEUINetBEUI

NetBIOS Extended User Interface (NetBEUI): A non-routable communications protocol native to early Microsoft network communications

NetBEUI and NetBIOS Communication

Started NetB IO S-compatib le application

NetBIO S softwareinterface

NetBEUI protoco l

Sent onto the network

(T ransport driver)

Figure 3-10Figure 3-10NetBIOS/NetBEUINetBIOS/NetBEUI

communicationcommunication

Planning TipPlanning Tip

When you upgrade from Windows NT Server to Windows 2000 Server, plan to retire NetBEUI implementations (if possible) and convert upgraded servers and clients to TCP/IP for more functionality

When to Use NetBEUIWhen to Use NetBEUI

For temporary backward compatibility when converting from Windows NT Server to Windows 2000 ServerFor small networks that do not have Internet access, that do not use the Active Directory, that do not use routing, and that require only a basic installationFor backward compatibility with particular applications

DLC

Data Link Control (DLC) protocol: Enables communication with older IBM mainframes and minicomputers, and with some older HP print server cards

When to Use DLC

To connect to IBM and other computers that use Systems Network Architecture (SNA) communicationsTo connect to older peripheral devices, such as printers that use DLC

AppleTalk

AppleTalk: A peer-to-peer protocol used in network communication between Macintosh computersWindows 2000 Server Services for Macintosh include:File Server for Macintosh (MacFile)Print Server for Macintosh (MacPrint)AppleTalk protocol

When to Use AppleTalk

Use AppleTalk to enable Macintosh clients to connect to Windows 2000 Server

Binding Order

Establishes the protocol that will be tried first in a network communication (or a communication with a network printer)

Troubleshooting Tip

If network performance is slow and your network uses multiple protocolschange the binding order

Network Planning Considerations

Size and purpose of the organizationPotential growthProportion of mission-critical applicationsRole of the network to the mission of the organization

Network Planning Considerations

Security needsBudgetInternet and intranet requirementsInterconnectivity requirements

Planning Tip

Begin network planning by understanding: User needs Important business processesCurrent resourcesPotential growth

Considerations in Selecting

the Right Protocol(s)Routing needsSize of the network in terms of connectionsPresence of Windows 2000 servers

Considerations in Selecting

the Right Protocol(s)Presence of mainframes and other computers that use SNAPresence of NetWare serversAccess to the Internet or intranetsPresence of mission-critical and multimedia applications

The End