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Introduction to Networking
V.T. Raja, PhDJames R. Coakley, PhD
BA 572 – Advanced Information Systems
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Outline
5-layer Network Model A theoretical framework for our day-to-day
interactions on the Internet Protocol stack
Network Design and Topology
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Theoretical Framework: 5-layer network model
Application Layer (Layer-5)Transport LayerNetwork LayerData Link LayerPhysical Layer (Layer-1)
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Five-Layer Network ModelMajor Functions
Application Layer User interface with application software Example: user types web/e-mail address
Transport Layer Packetizing
Breaking large messages into smaller packets at source Reassembling packets at final destinationCreates/appends TCP header
Packet # Source/Destination Port ID
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Five-Layer Network ModelMajor Functions – cont’d
Network Layer: Addressing and Routing. Internet Protocol prepares IP header - contents include:
Source/Destination IP Address and Routing Information Addressing
DHCP Server (Dynamic Host Control Protocol Server) Assigns IP addresses to client machines requesting an IP address
DNS Server (Domain Name Service Server) Similar to directory assistance – used for finding destination IP
addresses. Routing
Routing tables; Routers (Tracert); Routing Protocols
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Five-Layer Network ModelMajor Functions – cont’d
Data Link Layer Media Access Control (Handling message collisions) Error Detection/Error Correction Message Delineation (Identifying beginning and ending
of packets – since all computer transmissions go out as 0s and 1s over the physical layer)
DL layer appends a DL header and DL Trailer Physical Layer (Layer-1)
Transmission of data
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Five-Layer Network ModelProtocols and Addresses
HTTP (Hyper Text Transfer Protocol) Operates at the Application Layer Example of an application layer address:
www.bus.oregonstate.eduTCP (Transmission Control Protocol)
Operates at the Transport Layer Example of a transport layer default port
address/port ID: 80 (Web)25 (E-mail)
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Five-Layer Network ModelProtocols and Addresses – cont’d
IP (Internet Protocol) Operates at the Network Layer. Example of an IP address: 128.192.64.224
Ethernet operates at the data link layer. Example of a DLL address: 00-B0-D0-B4-54-13
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Layer 1 - Physical Layer
Wired Media/Wireless Media: Examples Twisted pair; Coaxial; Fiber Optic Cables Wireless
Wireless Access PointsMicrowave (radio) towersCellular network towers Satellites (GEOS/MEOS/LEOS) http://www.orbitaldebris.jsc.nasa.gov/index.html
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Some Network Topologies
Physical versus logical topologyStar topologyMesh topologyBus topologyRing topologyPhysical versus logical topology
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Ethernet vs. Token RingLocal Area Network
LAN Protocols Ethernet: Bus with CSMA/CD
Carrier Sense Multiple Access/Collision Detection Token Ring FDDI
Fiber Distributed Data InterfaceToken Ring on fiber
Fast Ethernet (100 mbps) Gigabit Ethernet
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
FDDI
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
FDDI (Continued)
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Network DesignHow to support full connectivity?
Design the most economic internetwork between “end-user nodes” and an existing WAN
Usernode
Usernode
Usernode
Usernode Usernode
Usernode
Usernode
Usernode
UsernodeUsernode
WAN
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Network DesignFind an economic internetworking solution
Usernode
Usernode
Usernode
Usernode
UsernodeUsernode
A direct connection toa WAN backbone node
Usernode
Usernode
Usernode
Usernode
Usernode
Usernode
Connection viamultiplexers
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Some Network Design IssuesMajor Cost Components
Acquisition and installation costs of a MUXCost of high bandwidth link between MUX
and WAN (Internet)Cost of low bandwidth link between end-user
node and MUX
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Network Design ManagementHow to design a feasible and economical
internetwork?
Find an optimal number of MUXs to interconnect all given user nodes to some existing WAN such that ... All user nodes are connected User communication requirements are satisfied Capacity constraints on each MUX is not violated Total internetworking costs are minimized Topology issues are considered
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Example 1
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Example 2
V.T. Raja & James R. Coakley BA 572 – Advanced Information Systems
Example 3
