Microsoft

Windows 2003Network Infrastructure

MCSEExam 70-293

Planning a Planning a Network TopologyNetwork Topology

ChapterOne

Exam Objectives in this Chapter: Plan and modify a network topology Plan the physical placement of network

resources Identify network protocols to be used

Lessons in this Chapter: Windows Server 2003 and the Network

Infrastructure Selecting Data-Link Layer Protocols Selecting Network/Transport Layer

Protocols Locating Network Resources

Windows Server 2003 and the NetworkInfrastructure A network infrastructure is a set of

physical and logical components that provide connectivity, security, routing, management, access, and other integral features on a network.

During a network’s planning phase, engineers select the hardware and software components that will compose the network infrastructure and specify the particular location, installation, and configuration of those components.

A Network Infrastructure Implementing a network infrastructure is

the process of evaluating, purchasing, and assembling the specified components, and installing them in the manner prescribed by the design plan.

Physical Infrastructure A network’s physical infrastructure is its

topology—the physical design of the network—along with hardware components such as cabling, routers, switches, hubs, servers, and workstations.

Exam Tip Familiarity with the physical infrastructure

of a network is prerequisite knowledgefor the 70-293 exam.

You should be familiar with the functions of all the basic hardware components and how to connect them to construct a network.

Logical Infrastructure A network’s logical infrastructure comprises the

many software elements that connect, manage, and secure hosts on the network.

The logical infrastructure allows communication between computers over the pathways described in the physical topology.

The logical infrastructure of a network consists of both abstract software elements, such as networking protocols, and concrete elements, such as specific software products.

Planning a Network Infrastructure To plan the infrastructure properly, a

network designer must consider the requirements of the network’s users, its owners, and its hardware and software components.

A basic question What tasks do the network users have to

accomplish?

Exam Tip A large part of the 70-293 exam is devoted

to the planning, implementation, and maintenance of Windows Server 2003 services, such as the DHCP Server service, the DNS Server service, and the Windows Internet Name Service (WINS) service. The planning process for services like these involves not only determining whether to use them, but also designingan IP addressing strategy and a Domain Name System (DNS) namespace

Implementing a Network Infrastructure The elements of the implementation process that

are covered in the 70-293 exam focus largely on the selection of protocols, operating systems, applications, and security mechanisms that satisfy the requirements of a network’s owners, administrators, and users, as determined in the planning process.

The exam also covers the process of deploying technologies such as the TCP/IP protocols, the DNS and WINS name-resolution mechanisms, and the IPSec protocol extensions.

Maintaining a Network Infrastructure To maintain the network properly,

administrators must have an intimate knowledge of the infrastructure and the technologies used to implement it.

Selecting Data-Link Layer Protocols Connecting a group of computers to the

same physical network gives them a medium for communication, but unless the computers can speak the same language, no meaningful exchanges are possible.

Understand the OSI reference model.

OSI Reference Model

Physical

Data-Link

Network

Transport

Session

Presentation

ApplicationAll

People

Seem

To

Need

Data

Processing

OSI Reference Model Layer Layer Name Header Protocols & Services Details

7Application

(All)Protocol Data Unit

Telnet, FTP, SMTP, HTTP, File and Print, E mail, (WWW), EDI, SMB, NCP

User requests network services here. Database and application services but not the applications

6Presentation

(People)Protocol Data Unit

ASCII, EBCDIC, TIFF, JPEG, GIF, PICT, MIDI, MPEG, QuickTime

Data representation and translation. Formats data for “presentation” to the layers above and below. Encryption, compression and translation.

5Session (Seem)

Protocol Data UnitRPC, ZIP, SCP, SQL, X Window, NetBIOS, NFS, ASP, DNA SCP

Establishes, maintains and manages communication sessions between computers. Think dialog control.

4Transport

(To)Segments

TCP, NBP, UDP, NCP, SPX, ADP, Windowing, flow control, synchronization

Reliable transmission of data segments. Sets the stage for disassembly and assembly of data before and after transmission. Remember: end-to-end connectivity.

3Network (Need)

Datagrams or Packets

IP, IPX, RARP, ARP, BootP, DHCP, ICMP, BGP, OSPF, RIP.

If it’s routing, it takes place here. Decides how data will be routed across the network, in addition to the structure and use of logical (IP) addressing. Routers operate here.

2

Data Link Sublayers are MAC and LLC

(Data)

Frames

MAC, LLC, Frame Relay, LAPB, PPP, calculating CRC or FCS, controls access to the physical medium

Deals with the links and mechanisms to move data. Topology (Ethernet or Token Ring) is defined here. Switches and Bridges operate here. Remember: Framing.

1Physical

(Processing) Bits (1s and 0s)

Ethernet, Token Ring, HSSI, 802.3, bit synchronization, physical connector specifications.

The electrical and physical specifications for the network media that carry data bits across a network. Hubs and repeaters operate here.

Selecting a Data-Link Layer Protocol Selecting a Media Type

Unshielded Twisted Pair UTP 10 Mbps Ethernet standard uses the 5-4-3 rule, which

says that a network can consist of no more than five network segments, connected by four repeaters, with no more than three of those segments being mixing segments

Fiber Optic Fiber-optic cables are also much less susceptible to

attenuation than copper cables. Wireless Networking

Selecting a Transmission Speed Standard Ethernet Gigabit Ethernet

EthernetDesignation

Media Type

Max Cable Length Max Transfer

Speed Connector Topology

10BASE-T Cat 3 or better

Unshielded Twisted Pair

(UTP)

100 meters 10MBps RJ-45 Star

100BASE-TX Cat 5 UTP 100 meters 100MBps RJ-45 Star

10BASE2 Thin Coaxial(RG-58 A/U)

185 meters 10MBps BNC Bus

10BASE5 Coaxial 500 meters 10MBps AUI/DIX Bus

100BASE-FX Fiber optic 412 meters (half duplex) or 2000

meters (full duplex)

100 MBps (half duplex) or 200

MBps (full duplex)

Fiber optic

connector

Star (often setup

only as point-to-point)

Gigabit EthernetDesignation

Media Type

Max Cable Length

Max Transfer Speed

Connector Topology

1000BASE-SX Fiber optic 260 meters 1GBps SC Fiber

Optic connector

Star (either buffered

distributor hub or point-to-point)

1000BASE-LX Fiber optic

440 meters (multimode) or 5000 meters (singlemode)

1GBps SC Fiber

Optic connector

Star (either buffered

distributor hub or point-to-point)

1000BASE-CX

Twinax (usually a specialty cable)

25 meters 1 GBps DB-9 Fiber

Optic connector

Star

1000BASE-T Cat 5 100 meters 1GBps RJ-45 Star

Using Token Ring802.4 Token Bus

802.5 Token Ring

Mixing Media A router can connect any type of network

to any other, so it is possible to select a different data-link layer protocol for each LAN.

Practice: Choosing an Ethernet Variant

Page 1-23

Selecting Network/Transport Layer Protocols Using TCP/IP

TCP/IP is a large collection of protocols that provides a comprehensive array of networking services in addition to basic Windows file sharing.

TCP UDP

IP

Transport Layer

Network Layer

IP Almost all TCP/IP traffic is carried using IP

packets called datagrams. An IP datagram is something like the

envelope you use to mail a letter.

TCP TCP is a connection-oriented protocol,

which means that before two computers can communicate, they exchange a series of messages that establish a connection between them.

Reliable.

UDP UDP is a connectionless protocol, which

means that two computers can communicate without establishing a connection first, and they do not transmit dedicated acknowledgment messages.

Unreliable.

IPX IPX is also a suite of protocols that

provides some of the same basic communications features as TCP/IP.

The IPX protocols were developed by Novell for use with their Net-Ware operating system.

NetBEUI NetBEUI was the default networking

protocol of the Windows NT 3.1 and Windows for Workgroups operating systems when these systems were first released in 1993.

NetBEUI is a relatively simple NetBEUI is intended for use on small LANs

and is not suitable for a large enterprise network.

Locating Network Resources Determining Location Criteria

The network blueprint also determines where the workstations for the network’s users will be located, and this obviously concerns thepeople responsible for the office floor plan.

Locating Workstations Locating Peripherals Locating Cables Locating Connectivity Devices Locating Servers

Example Network PlanHub

Hub

Hub

Router

Router

Router

Practice: Blueprinting a Network Infrastructure

Page 1-35

Summary Case Scenario Exercise

Page 1-37 Exam Highlights

Key Points Key Terms

Page 1-40