PPT file - University of New Mexico

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©

Copyright 1997, The University of New Mexico


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Definitions


Architecture


Proprietary Systems


De facto Standards


Standards

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Copyright 1997, The University of New Mexico


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Definitions


Architecture:


The science, art, or profession of designing and constructing
buildings, bridges, etc.


Any framework, system, etc.


The design and interaction of components of a computer or
computer systems

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Copyright 1997, The University of New Mexico


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Definitions


Proprietary Systems


Privately owned and operated


Held under patented, trademark, or copyright by a private person
or company


De facto Standards


Existing or being such in actual fact though not by legal
establishment


Official recognition


Standards


Something established for use as a rule or basis of comparison in
measuring or judging capacity, quantity, content, extent, value,
quality, etc.

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Copyright 1997, The University of New Mexico


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Definitions


Rules and conventions for the exchange of
information


Open Systems


Who makes the rules and conventions?


Many local, regional, and international organizations


ISO, ITU, IEEE, ANSI, ECMA

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Copyright 1997, The University of New Mexico


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Definitions



Open Systems Interconnection Standards


Packet Switched Public Data Network (PSPDN)


Circuit Switched Public Data Network (CSPDN)


Public Switched Telephone Network (PSTN)


Integrated Services Digital Network (ISDN)


Local Area Network (LAN)

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Copyright 1997, The University of New Mexico


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Definitions


V
-
series


Connecting equipment to a Public Switched Telephone Network
(PSTN)


X
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series


Connecting equipment to a Public Switched Data Network (PSDN)


I
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series


Connecting equipment to an Integrated Services Digital Network
(ISDN)

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Copyright 1997, The University of New Mexico


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Internetworking Architecture
Models


OSI Model


3
-
Layer Model


TCP/IP Model

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Copyright 1997, The University of New Mexico


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OSI Model


International Organization for Standardization
(ISO)


Open System Interconnection (OSI) Model, provides a framework

Application

Presentation

Session

Transport

Network

Data Link

Physical

Boundary

Technology independent

Technology dependent

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Copyright 1997, The University of New Mexico


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OSI Model


Physical Layer (1)


deals with mechanical, electrical and procedural interfacing


provides collision detection


specifies cables, connectors, and other components


transmits raw information over communication channel


establishes, maintains, and disconnects physical links


includes software device drivers for communication interfaces

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Copyright 1997, The University of New Mexico


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OSI Model


Data Link Layer (2)


provides reliable transfer of data


breaks data (packets) into frames


adds bits for error detection/correction


manages access to and use of the channel


solve problems caused by lost, damaged, and duplicate frames


sends acknowledgments


adds flags to indicate beginning and end of message


connectionless or connection oriented services


IEEE MAC and LLC support

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Copyright 1997, The University of New Mexico


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OSI Model


Network Layer (3)


establishes, maintains and terminates connections


determines how packets are routed


divides transport messages into packets and reassembles them


performs congestion control, flow control


provides virtual circuit or datagram services


recognizes message priorities


sends messages in proper order


handles internetworking

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Copyright 1997, The University of New Mexico


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OSI Model


Transport Layer (4)


establishes reliable end
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to
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end transport session (error detection
and recovery), once path has been established


fragmentation of message into packets (if not handled by layer 3)


multiplexing of several sessions from same source and all going
to same destination


creates distinct network connections


monitors quality of service


disassembles and assembles session messages


flow control (if not done by layer 3)

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Copyright 1997, The University of New Mexico


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OSI Model


Session Layer (5)


establishes and controls system
-
dependent issues


establishes and terminates connections


accounting service


user interface into the network


authentication of users


controls dialogue, organizes and synchronizes

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Copyright 1997, The University of New Mexico


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OSI Model


Presentation Layer (6)


data encryption, security, compression and code conversion


make sure data is encoded in standard form (ASCII)


handles pass
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through of services from session to application
layer

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Copyright 1997, The University of New Mexico


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OSI Model


Application Layer (7)


login, password check


agreement on semantics for information exchange


file transfer, access and management


message handling, email


job transfer and manipulation


directory service


system management


industry protocols


database access and management


virtual terminals

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Copyright 1997, The University of New Mexico


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OSI Model


Application

Presentation

Session

Transport

Network

Data Link

Physical

Application

Presentation

Session

Transport

Network

Data Link

Physical

Data

Physical

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Copyright 1997, The University of New Mexico


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3
-
Layer Model


7
-
layer OSI to 3
-
layer mapping


System integrators approach

Application

Presentation

Session

Transport

Network

Data Link

Physical

Network Services

Network Protocols

Network
Infrastructure

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Copyright 1997, The University of New Mexico


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TCP/IP Model


TCP/IP Protocol Suite, ARPANET (DARPA)

Application

Transport (TCP,UDP)

Internet (IP)

Network Access

Physical

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Copyright 1997, The University of New Mexico


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OSI to TCP/IP Models


7
-
layer OSI and TCP/IP Protocol Architectures

Application

Presentation

Session

Transport

Network

Data Link

Physical

Transport (TCP,UDP)

Network Access

Application

Internet (IP)

Physical

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Copyright 1997, The University of New Mexico


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Internetworking Standards


Proprietary Systems


De facto Standards


Standards Based Solutions

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Copyright 1997, The University of New Mexico


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Internetworking Standards


Proprietary Systems


Hewlett
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Packard


DARPA TCP/IP


Sun Network Services


Novell NetWare


IBM/SNA


DEC/DECnet Phase IV


3Com


Xerox/XNS


IBM/SNA


Apple/AppleTalk


Banyan VINES

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Copyright 1997, The University of New Mexico


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Internetworking Standards


De facto Standards


TCP/IP


Ethernet V1 & V2


X
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Windows


Unix


WIN95


NT

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Copyright 1997, The University of New Mexico


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Internetworking Standards


Standards Based Solutions


IEEE: 802.3/CSMA/CD, 802.5/Token Ring, 802.2/LLC, etc.


ANSI: FDDI, etc.


CCITT: V.35, X.25, Frame Relay, etc.


ISO
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ITU: 8802/3, 8802/5, 9314, V.35, etc.


EIA: RS
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232, RS
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449, etc.


ATM Forum

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Copyright 1997, The University of New Mexico


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Network Terminology


Modems: OSI
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Layer 1 device. Modulator
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demodulator, device that converts digital and
analog signals, allows data to be transmitted
over voice grade telephone lines (PSTN).
Modem standards include: V.21, V.22 bis, V.32
bis, V.34, V.42 bis, etc.


Repeaters: OSI
-
Layer 1 device. Regenerates
and propagates electrical signals between two
network segments. Repeater standards include:
Ethernet, IEEE 802.3 (10Base5, 10Base2,
10BaseT, 10BaseFX), FDDI, ATM, etc.

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Copyright 1997, The University of New Mexico


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Network Terminology


Bridges: OSI Layer 2 device. Connects and
passes packets between network segments that
use similar and different communication
protocols. Bridge standards include: IEEE
802.1d, Transparent Source Routing,
Translational, etc.


Switches: OSI Layer 2 device. Very fast bridge.
Switch Standards include: ATM, Frame Relay,
SMDS, ISDN, etc.

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Network Terminology


Routers: OSI Layer 3 device. Forwards packets
from one network to another based on metrics
that will allow for optimum path. Router
standards include: RIP, OSPF, ISIS, BGP, EGP,
etc.


Gateways: OSI Layers 1
-
7 device. Special
-
purpose device that converts information from
one protocol stack to another.

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Copyright 1997, The University of New Mexico


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Network Terminology


4 types of equipment


Repeaters
-

layer 1


Bridges
-

layer 2


Routers
-

layer 3


Gateways
-

layers 1
-
7


All use functionality of lower layers

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Copyright 1997, The University of New Mexico


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Repeaters


Used to extend a LAN


Connects two cable segments


Amplifies and sends all electrical signals
between segments


Stations do not know whether a repeater
separates them


IEEE 802.3: max. 4 repeaters between any two
stations

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Copyright 1997, The University of New Mexico


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Repeaters

repeater

max. Ethernet segment

max. Ethernet segment

direct connection

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Copyright 1997, The University of New Mexico


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Bridges


Simplest form to extend a LAN


LANs can be of more than one type


Interconnect LAN and MAN


Past: used between LANs with identical
protocols (physical, MAC)


Present: used between LANs with different
protocols

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Copyright 1997, The University of New Mexico


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Bridges

bridge

stations

stations

standard connection

(same as computers)

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Copyright 1997, The University of New Mexico


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Switches


Switched LAN, single electronic device that
transfers frames among many stations


Hub: simulates a single shared medium


at most two computers can communicate at a time


max. possible bandwidth is R (rate a single computer can send
data)

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Copyright 1997, The University of New Mexico


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Switches


Switch: simulates a bridged LAN with one
station per segment


each computer is in a simulated LAN segment


as many as 1/2 of stations can send data at the same time (1/2
send, 1/2 receive)


max. possible bandwidth is RN/2, N is number of stations
connected

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Copyright 1997, The University of New Mexico


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Introduction to Transmission
Media & LAN Technologies


Transmission Media & Cabling Systems


LAN Technologies

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Copyright 1997, The University of New Mexico


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Introduction to
Transmission Media


Signals


Data Transmission


Transmission Media


Cabling Systems


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Copyright 1997, The University of New Mexico


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Introduction LAN
Technologies


10/100/1000 Mbps Ethernet


100 Mbps FDDI


155/620 Mbps ATM


4/10/45 Mbps Wireless