Protocols and Compatibility

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27 Οκτ 2013 (πριν από 4 χρόνια και 8 μήνες)

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Chapter 3:

Planning Network

and Compatibility


A protocol consists of guidelines for:

How data is formatted into discrete
units called packets and frames

How packets and frames are transmitted
across one or more networks

How packets and frames are interpreted
at the receiving end

Packets 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 Frames



Trailer or footer

Packet and Frame Format

Figure 3
1 Basic packet and frame format

Network Design

The basic design of a network is its

Topology: The physical layout of the
cable and the logical path followed by
network packets and frames sent on
the cable

Local 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 LAN

Figure 3
2 A LAN in a building

Metropolitan Area Network

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

Example of a MAN

Research hospital

University chemistry


Pharmaceutical company

MAN connecting buildings in a city

Enterprise 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

Figure 3

Resources in an

enterprise network

Wide Area Network

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

Example of a WAN

WAN across a continent

Network Interface Card
Communication Medium Options

Coaxial cable (thick and thinnet)

pair (shielded and


Wireless (infrared, radio wave,
microwave, satellite)

Connecting a Medium to a

Figure 3
4 Connecting cable to a NIC

Device 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 transmissions

Token ring: A network transport
method that uses a token, which is
passed from node to node, to
coordinate data transmissions


Network Driver Interface Specification

developed by Microsoft and 3COM

enables communication between a NIC and a

enables the use of multiple protocols on the
same network

NDIS Architecture

Figure 3
5 Binding a protocol to a NIC


Open Datalink Interface (ODI)

Novell NetWare

transport multiple protocols on the same

Communication Protocols




Transmission Control Protocol (TCP)
portion performs extensive error
checking to ensure that data is
delivered successfully

Internet Protocol (IP) portion
consists of rules for packaging data
and ensuring that it reaches the
correct destination address

Dotted Decimal Notation

Dotted Decimal Notation:

four octets


converted to decimal (e.g.,

Unicasting and Multicasting


sent to each client

e.g. a multimedia presentation


sent to all requesting clients as a group
(reducing the total network traffic)

Unicasting and

Multicasting Compared

Figure 3
6 Unicasting compared to multicasting

Subnet 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

Figure 3
7 IP address and subnet mask setup

Static and Dynamic

Dynamic addressing:

automatically assigning an IP address to
a network host

Static addressing:

manually assigning an IP address to a
network host

TCP/IP Advantages

suited for medium and large networks

Designed for routing

high degree of reliability

Used worldwide for directly connecting to
the Internet and by Web servers

Enables lower TCO on Microsoft networks

TCP/IP Advantages

Compatible with standard tools for
analyzing network performance

Parallel ability to use DHCP and WINS
through a Windows 2000 server

Ability for diverse networks and operating
systems to communicate

Compatible with Microsoft Windows

TCP/IP Disadvantages

More difficult to set up and maintain
than other protocols

Somewhat slower than IPX/SPX and
NetBEUI on networks with light to
medium traffic

Routing via TCP/IP

Figure 3

Router forwarding

packets to a

designated network

Planning 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

Protocols and Applications

in the TCP/IP Suite

Protocols and Applications

in the TCP/IP Suite

Protocols and Applications

in the TCP/IP Suite



developed by Novell

particularly for NetWare versions before
version 5


oriented protocol used for
network transport when there is a
particular need for data reliability


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)

Client Service for NetWare



CSNW Installed in

Windows 2000

Figure 3
9 Windows 2000 with CSNW components installed

Configuring NWLink

Configure three elements:

Frame type

Network number

Internal network number

When to Configure the

Internal Network Number

When the NetWare server that is
accessed uses two or more frame

When the Windows 2000 host has
two or more NICs and NWLink is
bound to more than one of the NICs

When an application uses NetWare’s
Service Advertising Protocol (SAP)

When to Use NWLink

To access a NetWare server

version 5

To set up Windows 2000 as a gateway
to a NetWare server

To enable NetWare clients to access
a Windows 2000 server

Planning 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


A combination software interface and
network naming convention

Available in Windows 2000 through
the files Netbt.sys, NetBIOS.sys,
and NetBIOS.dll


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


Figure 3



Planning 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 NetBEUI

For temporary backward compatibility
when converting from Windows NT Server
to Windows 2000 Server

For 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 installation

For backward compatibility with particular


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

When to Use DLC

To connect to IBM and other
computers that use Systems Network
Architecture (SNA) communications

To connect to older peripheral
devices, such as printers that use


AppleTalk: A peer
peer protocol
used in network communication
between Macintosh computers

Windows 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

Binding Order

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

Troubleshooting Tip

If network performance is slow and
your network uses multiple protocols

change the binding order

Network Planning

Size and purpose of the organization

Potential growth

Proportion of mission

Role of the network to the mission of
the organization

Network Planning

Security needs


Internet and intranet requirements

Interconnectivity requirements

Planning Tip

Begin network planning by

User needs

Important business processes

Current resources

Potential growth

Considerations in Selecting

the Right Protocol(s)

Routing needs

Size of the network in terms of

Presence of Windows 2000 servers

Considerations in Selecting

the Right Protocol(s)

Presence of mainframes and other
computers that use SNA

Presence of NetWare servers

Access to the Internet or intranets

Presence of mission
critical and
multimedia applications

The End