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Networks - Computational Sciences - Lecture Slides, Slides of Computational Techniques
Computations Sciences course major topics are Bioinformatics, Cache Based Iterative Algorithms, Complex Domains, Computer Architecture, High Performance Computing, , Mpi and Openmpi, Nanotechnology, Networks. This lecture includes: Networks, Internet, Computational Science, Wan and Lan, Timeshared Computers, Circuit-Switching Image, Traffic, Packet Switching, Imp, Internetworking
Typology: Slides
2012/2013
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Networks
What is a Network?
z
Networks are defined as thetransmission of data over digital circuits.
z
Why Important? z Email, interactions z Remote Logins z Data transfers z Internet
z
WAN vs. LAN
History
z
The concept of networking began in theearly 1960's
z
Timeshared computers made usage bygeographically distributed users morepractical
z
How to best transmit informationbetween locations?
Circuit-Switching Image
Traffic
z
Most computer traffic is "bursty“ z i.e. has short periods of activity followed bylong periods of inactivity
z
This makes circuit-switching highlyinefficient z lots of inactive time during which the circuitsits idle
Packet Switching
Packet-Switching Cont.
z
Packet-switching was actually inventedat about the same time by three differentresearch groups. z Leonard Kleinrock at MIT z Paul Baran at the Rand Institute z Donald Davies and Ronald Scantlebury atthe National Physical Laboratory in England
IMP
Internetworking
z
The original ARPAnet was a single, closednetwork
z
By the mid-1970's, other packet-switchingnetworks had begun to show up, includingALOHAnet, Telenet, Tymnet, and Transpac
z
In 1974, Vinton Cerf and Robert Kahn coinedthe term "internetting" to describe the conceptof interconnecting multiple networks into asingle "network of networks"
Ethernet and Local Area Networks
z
Robert Metcalfe, motivated by the needto connect multiple PCs, printers, anddisks together, develops the basics ofthe Ethernet
z
Ethernet would later become the basisfor modern LANs
Ethernet
Speeds
z
DS-1 (56K Modem Category)
z
DSL & Cable ( Various Ranges)
z
T1 (1.5 Million bits/second)
z
T3 (45 Million bits/second)
z
OC-3 (155 Million bits/second)
z
OC-12 (4 x OC3)
z
Distributed Teragrid Facility (DTF) (10Gb/s)
z
Telecom and Network Speeds z
http://www.zytrax.com/tech/data_rates.htm
TeraGrid
z
40 gigabits per second—the fastest research networkon the planet.
z
5 Points
z National Center for Supercomputing Applications (NCSA) atthe University of Illinois, Urbana-Champaign z San Diego Supercomputer Center (SDSC) at the University ofCalifornia, San Diego z Argonne National Laboratory in Argonne z Center for Advanced Computing Research (CACR) at theCalifornia Institute of Technology in Pasadena z Pittsburgh Supercomputer Center (PSC) z Added after the original four centers z Added in October 2002