CSE Department, University of Nevada - Reno 1 User’s View of Switched Network S S The network is...
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Transcript of CSE Department, University of Nevada - Reno 1 User’s View of Switched Network S S The network is...
CSE Department, University of Nevada - Reno1
User’s View of Switched Network
S
S
The network is generallyoperated by a service providercompany like Sprint or AT&T
Network applications sit at the end points.
CSE Department, University of Nevada - Reno4
1. Two or more computers/nodes/hosts
2. Links/Media that connect the nodes
What is a Network?
Guided mediaCableFiber Optics
Unguided media: (wireless)
Microwave frequencies (land, satellite)Radio Frequencies (RF)Infra Red Frequencies (IR)
C1
C2
CSE Department, University of Nevada - Reno5
What’s a layer? A bunch of rules, implemented by a program
A Protocol A protocol can be thought of as a black box /
function with two interfaces: Service interface Peer-to-peer interface
Host 1
Protocol
Host 2
Protocol
High-levelobject
High-levelobject
Peer-to-peer
interface
Send(Protocol, Message) Deliver(Object, Message)
Service interface
CSE Department, University of Nevada - Reno6
OSI Reference Model
User applications
Network applications
Presentation
Network
Session
Transport
Physical
Data Link
File transfer, electronic mail, document exchange, etc.(note: application layer is concerned with messages)
CSE Department, University of Nevada - Reno7
OSI Reference Model
User applications
Network applications
Presentation
Network
Session
Transport
Physical
Data Link
These next two are not well defined and most networks do not actually implement these as separate layers.
These next two are not well defined and most networks do not actually implement these as separate layers.
CSE Department, University of Nevada - Reno8
OSI Reference Model
User applications
Network applications
Presentation
Network
Session
Transport
Physical
Data Link
End-to-End error detection and correction (reliability),flow control, and connectivity.
Packetization (splitting messages into packets/segments; reassembling packets at the receiving end)
CSE Department, University of Nevada - Reno9
OSI Reference Model
User applications
Network applications
Presentation
Network
Session
Transport
Physical
Data Link
Routing: The process of choosing an optimal path through the network.
CSE Department, University of Nevada - Reno10
OSI Reference Model
User applications
Network applications
Presentation
Network
Session
Transport
Physical
Data Link Framing, error detection and correction (reliability),media access control, flow control
CSE Department, University of Nevada - Reno11
OSI Reference Model
User applications
Network applications
Presentation
Network
Session
Transport
Physical
Data LinkCoding and transmission of a bit stream (i.e. a bit pipe)
CSE Department, University of Nevada - Reno12
Layers at Intermediate Nodes
Application
Presentation
Session
Transport
End host
One or more nodes
within the network
Network
Data link
Physical
Network
Data link
Physical
Network
Data link
Physical
Application
Presentation
Session
Transport
End host
Network
Data link
Physical
CSE Department, University of Nevada - Reno13
Networking Research Goal: Improve the performance (e.g. faster) of
information exchange among separate entities. Social networks, the Internet, private and community
networks Methods: include all sane techniques!
Simulations(lots of coding)Visualization
(graph theory)
Experimentation(lots of fun!!)
Analysis & Modeling (lots of equations & math)
Measurement (lots of hacking)
CSE Department, University of Nevada - Reno14
Networking Research @ UNR
Wireless FSO-MANETs: Free-Space-Optical Mobile Ad-Hoc Networks ILLUMINICATION: ILLUMInation + commuNICATION Peer-to-peer wireless sharing
Wireline Topology measurement BigData Transfers Secure communications Network economics: neutrality, pricing
16
3-Transceiver Prototype
Circular 3 Transceiver
Design
Line Transceiver
PIC 12f615 Modulator Transceive
r Header
Programming Interface
Microcontroller
The design consists of 3 FSO transceivers connected to a circuit board with a microcontroller.
17
FSO Prototype: Mobility Experiment
Node-A
Node-B
A B
~19Kb/s
frame size 50B
alignment timer 500ms
18
3-D FSO Localization
Orientation-only localization with two localized neighbors: A third node can
triangulate using the advertised normals received from two other GPS-enabled nodes.
CSE Department, University of Nevada - Reno19
Illuminication
Illuminate and communicate
http://enpundit.com/nanolight-the-worlds-most-energy-efficient-and-stylish-lightbulb
http://www.ted.com/talks/harald_haas_wireless_data_from_every_light_bulb.html
CSE Department, University of Nevada - Reno20
Future Prospects CSE Upper level courses
CPE 401/601 Computer Networked Systems
CPE 701 Internet Protocol Design
CPE 400/600 Computer Communication Networks
Careers Candidate titles:
Network engineer Software engineer (in networking
companies) Research engineer
Major companies Cisco, AT&T, Sprint, Juniper, Nortel, Qwest,
… Intel, IBM, Microsoft, Sun
Application
Transport
Physical
Network
Data-Link
CSE Department, University of Nevada - Reno21
Contact
Computer Networking Lab (CNL)LMR 282/283
http://cnl.cse.unr.edu
Murat YukselSEM 237
Mehmet H. GunesSEM 230