Network Technology Foundations

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23 Οκτ 2013 (πριν από 3 χρόνια και 9 μήνες)

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Network Technology

Foundations

©
2004 ProsoftTraining

All Rights Reserved

Lesson 1:

Introduction to Networking

Objectives


Identify and describe the
functions of servers,
workstations and hosts


Identify major network
operating systems and
their respective clients


Discuss packets and
describe packet creation,
and explain the OSI
reference model


Compare, contrast and
describe the functions of
network protocols,
including TCP/IP


Describe the basics of
LANs and WANs



Identify and describe
the function of NAPs


Describe transmission
media and types,
including cabling,
asynchronous and
synchronous, simplex,
half duplex, full
duplex, baseband and
broadband


Identify network
architectures, and
describe basic network
topologies and carrier
systems

Telephony Networking


PSTN: one of the oldest existing networks


Voice transmissions, which were once
carried over the PSTN, are now delivered in
digital form as packets of data using IP
instead of the circuit
-
switched lines of the
PSTN


PSTN: still an integral part of the Internet
infrastructure because it furnishes most of
the long
-
distance connections

Mainframes


Mainframe (centralized) computing
provided the first practical network solution


Retrieving information from mainframes


Mainframe liabilities


The future of mainframes

Mainframe

Networking Model

Client/Server Model


Client/server model (distributed computing)
divides processing tasks between the client and
the server


Client/Server Model
(cont’d)


Client/server advantages


Two
-
tier and three
-
tier computing


Advantages of three
-
tier computing

Two
-
Tier

Computing Architecture

Three
-
Tier

Computing Architecture

N
-
Tier

Computing Architecture

Network Operations

Center (NOC)


A specific location from which a network is
managed, monitored and maintained


Central point for network maintenance and
troubleshooting


Generally includes multiple, redundant network
connections and redundant power supplies


Many have dedicated phone lines from a separate
provider and cell phones to ensure
communication in an emergency

Networking

Categories


Peer
-
to
-
peer


Microsoft peer
-
to
-
peer


P2P


Centralized or decentralized


Server
-
based


Novell NetWare


UNIX/Linux


Microsoft LAN manger


Microsoft Windows NT/2000/2003 Server

Network

Topologies


Bus


Star


Ring


Hybrid


Mesh

Network Operating Systems


Interoperability


Microsoft Windows


UNIX/Linux


Novell NetWare

OSI Reference Model


Defined by the International Organization for
Standardization in 1983


Gives developers universal concepts so they can
develop and perfect protocols that can work with
operating system and network products
developed by other vendors


Explains the framework used to connect
heterogeneous systems


Describes the process of packet creation (how the
layers communicate)

OSI Model Layers


Client

Server

Packets


Packets consist of:


Header (OSI/RM
layer information)


Actual data


Trailer
(information that
validates the
packet)


CRC

Packet Creation

(
Adding Headers
)

OSI/RM Protocol Examples


Application layer


SMTP, POP3, IMAP, HTTP, SMB, NCP, NFS


Transport layer


TCP, SPX, NWLink, NetBEUI


Network layer


IP, IPX, NWLink, NetBEUI


Data link layer


Ethernet, Token Ring

Major

Networking Protocols


Connection
-
oriented (stateful)


Connectionless (stateless)


Routable


Nonroutable

TCP/IP


A collection of protocols


TCP


UDP


IP


An open standard

IPX/SPX


Consists of:


IPX


SPX


Frame types


Ethernet 802.2


Ethernet 802.3


Ethernet II


Token Ring


Token Ring SNAP

Additional

Networking Protocols


NetBEUI


NetBIOS


AppleTalk

Choosing and

Combining Protocols


Combining protocols


Binding protocols


Binding order

Local Area

Networks (LANs)


A group of computers connected within a
confined geographic area


Commonly used for intraoffice communication

Wide Area

Networks (WANs)


A group of computers connected over

an expansive geographic area

Network

Access Points (NAPs)


Internet backbones


Backbone Network

Service


Segments

Common

Network Components


NICs


Repeaters


Hubs


Bridges


Routers


Switches


Gateways


CSU/DSU


Modems


Patch panels


Firewalls

Transmission

Media


Twisted pair cable


Coaxial cable


Fiber
-
optic cable


Wireless media

Wireless Network Technologies


Wireless communications use spread spectrum
technologies


DSSS


FHSS


Wireless networking modes


Ad
-
hoc


Infrastructure


WAP


WAP security features


WEP


MAC address filtering

Transmission

Types


Synchronous transmission


Asynchronous transmission


Data transmission flow


Baseband/broadband transmission


Logical/physical topologies

IEEE LAN Standards


IEEE 802.2


Ethernet/IEEE 802.3


IEEE 802.3u


fast Ethernet


IEEE 802.3z and 802.3ab


gigabit Ethernet


IEEE 802.5


Token Ring


IEEE 802
-
12


100VG
-
AnyLAN

Additional

LAN Standards


Apple LocalTalk


FDDI

WAN

Standards


X.25


Fast packet switching


Frame relay


ATM

T
-
Carrier System

T
-
Carrier

Data Transfer
Rate

T1

1.544 Mbps

T2

6.312 Mbps

T3

44.736 Mbps

T4

274.176 Mbps

E
-
Carrier System

E
-
Carrier

Data Transfer Rate

E1

2.048 Mbps

E2

8.448 Mbps

E3

34.368 Mbps

E4

139.264 Mbps

E5

565.148 Mbps