Leonard Kleinrock Leonard Kleinrock Professor, UCLA Computer Science Dept Professor, UCLA Computer Science Dept Founder & Chairman, Nomadix Inc Founder & Chairman, Nomadix Inc SIGCOMM Tutorial SIGCOMM Tutorial August 31, 1999 August 31, 1999 Leonard Kleinrock 1999
Leonard Kleinrock 1999 Leonard Kleinrock 1999
July 3, 1969 July 3, 1969 “UCLA will become the first station in a “UCLA will become the first station in a nationwide computer network…” nationwide computer network…” Leonard Kleinrock 1999 Leonard Kleinrock 1999
Leonard Kleinrock 1999
“As of now, computer networks are still in their infancy,” “As of now, computer networks are still in their infancy,” says Dr. Kleinrock, “But as they grow up and become says Dr. Kleinrock, “But as they grow up and become more sophisticated, we will probably see the spread more sophisticated, we will probably see the spread of ‘computer utilities’, which, like present electric and of ‘computer utilities’, which, like present electric and telephone utilities, will service individual homes telephone utilities, will service individual homes and offices across the country.” and offices across the country.” Leonard Kleinrock 1999
What It Looked Like in 1969 What It Looked Like in 1969 Before September 1969 Before September 1969 Leonard Kleinrock 1999 Leonard Kleinrock 1999
What It Looked Like in 1969 What It Looked Like in 1969 The Interface Message Processor IMP September 1969 Leonard Kleinrock 1999 Leonard Kleinrock 1999
The IMP The IMP 1969 1969 Leonard Kleinrock 1999 Leonard Kleinrock 1999
The IMP The IMP 1969 1969 Leonard Kleinrock 1999 Leonard Kleinrock 1999
Today Today Leonard Kleinrock 1999 Leonard Kleinrock 1999
What It Looked Like in 1969 What It Looked Like in 1969 October 1969 October 1969 Leonard Kleinrock 1999 Leonard Kleinrock 1999
Leonard Kleinrock 1999 Leonard Kleinrock 1999
Who Had the Foresight to Who Had the Foresight to Keep This Log? Keep This Log? Jon Postel Leonard Kleinrock 1999
Leonard Kleinrock 1999 Leonard Kleinrock 1999
First Message on the Internet - ever! Leonard Kleinrock 1999 Leonard Kleinrock 1999
But What WAS the First But What WAS the First Message Ever Sent on the Message Ever Sent on the Internet? Internet? • Was it “What hath God Wrought”? Was it “What hath God Wrought”? • • Was it “This is a Giant Step for Mankind”? Was it “This is a Giant Step for Mankind”? • • It was simply a LOGIN from the UCLA It was simply a LOGIN from the UCLA • computer to the SRI computer. computer to the SRI computer. • We sent an “L” - did you get the “L”? We sent an “L” - did you get the “L”? YEP! YEP! • YEP! • We sent an “O” - did you get the “O”? We sent an “O” - did you get the “O”? YEP! • • We sent a “G” - did you get the “G”? We sent a “G” - did you get the “G”? • Leonard Kleinrock 1999
But What WAS the First But What WAS the First SRI SRI Message Ever Sent on the Message Ever Sent on the Internet? Internet? UCLA UCLA • Was it “What hath God Wrought”? Was it “What hath God Wrought”? • • Was it “This is a Giant Step for Mankind”? Was it “This is a Giant Step for Mankind”? • • It was simply a LOGIN from the UCLA It was simply a LOGIN from the UCLA • computer to the SRI computer. computer to the SRI computer. • We sent an “L” - did you get the “L”? We sent an “L” - did you get the “L”? YEP! YEP! • YEP! • We sent an “O” - did you get the “O”? We sent an “O” - did you get the “O”? YEP! • • We sent a “G” - did you get the “G”? We sent a “G” - did you get the “G”? • Leonard Kleinrock 1999
But What WAS the First But What WAS the First SRI SRI Message Ever Sent on the Message Ever Sent on the Internet? Internet? UCLA UCLA • Was it “What hath God Wrought”? Was it “What hath God Wrought”? • • Was it “This is a Giant Step for Mankind”? Was it “This is a Giant Step for Mankind”? • • It was simply a LOGIN from the UCLA It was simply a LOGIN from the UCLA • computer to the SRI computer. computer to the SRI computer. • We sent an “L” - did you get the “L”? We sent an “L” - did you get the “L”? YEP! YEP! • YEP! • We sent an “O” - did you get the “O”? We sent an “O” - did you get the “O”? YEP! • • We sent a “G” - did you get the “G”? We sent a “G” - did you get the “G”? • Leonard Kleinrock 1999
What It Looked Like in 1969 What It Looked Like in 1969 UCLA serves UCLA serves the Network the Network Measurement Measurement Center Center The job is to The job is to stress the net stress the net to its breaking to its breaking December 1969 November 1969 September 1969 October 1969 point! point! Leonard Kleinrock 1999 Leonard Kleinrock 1999
Response Time Response Time Throughput Loss Loss RESPONSE TIME RESPONSE TIME T T INPUT THROUGHPUT INPUT THROUGHPUT CAPACITY CAPACITY 0 COMPUTER NET COMPUTER NET LOSS LOSS Leonard Kleinrock 1999
Flow Control Output Output 0 IDEAL IDEAL DYNAMIC DYNAMIC 0 CONSERVATIVE CONSERVATIVE FREE-FLOW FREE-FLOW DEADLOCK DEADLOCK 0 Input Input Leonard Kleinrock 1999
FLOW CONTROL FLOW CONTROL BIG BIG PING ! PING ! ! DP DP SYS SYS COMPUTER COMPUTER NET NET Leonard Kleinrock 1999
FLOW CONTROL FLOW CONTROL BIG BIG Whoa !! Whoa !! ! DP DP SYS SYS COMPUTER COMPUTER NET NET Leonard Kleinrock 1999
FLOW CONTROL FLOW CONTROL BIG BIG ! DP DP SYS SYS COMPUTER COMPUTER NET NET Leonard Kleinrock 1999
Response Time vs Throughput Throughput POWER = = P = Response Time T( ) Do you want Do you want to operate to operate Or here? Or here? here? here? T( ) Response Response Time Time Max Power Point 1/P ( ) 0 * Throughput Leonard Kleinrock 1999
Response Time vs Throughput Throughput POWER = Response Time P = T( ) T( ) Response Response Time Time 1/P ( ) 0 Throughput Leonard Kleinrock 1999
Response Time vs Throughput At Max Power At Max Power N * * = 1 N = 1 T( ) Response Response Time Time Max Power Point ( ) 0 * Throughput Leonard Kleinrock 1999
N*=1 N*=1 T( ) M/G/1 M/G/1 0 Leonard Kleinrock 1999
Use Your Intuition Use Your Intuition Only 1 customer Only 1 customer Morale: Just keep the = Min T = Min T pipe full! Eff = Max Eff = Max Leonard Kleinrock 1999
A Brief History of Radio A Brief History of Radio • Marconi 1890’s Marconi 1890’s • Leonard Kleinrock 1999
A Brief History of Radio A Brief History of Radio • Marconi 1890’s Marconi 1890’s • Leonard Kleinrock 1999
A Brief History of Pkt Pkt Radio Radio A Brief History of • 1970’s: ARPA 250 cu in 250 cu in 25 watts 25 watts 25 pounds 25 pounds Leonard Kleinrock 1999 Leonard Kleinrock 1999
A Brief History of Pkt Pkt Radio Radio A Brief History of • 1990’s: ARPA 10 cu in 10 cu in 1 watt 1 watt 1 pound 1 pound Leonard Kleinrock 1999 Leonard Kleinrock 1999
Leonard Kleinrock 1999
Leonard Kleinrock 1999
Leonard Kleinrock 1999
Giant Stepping Giant Stepping in Packet Radio in Packet Radio • Multihop Multihop • • Each hop covers distance R (Tx Radius) Each hop covers distance R (Tx Radius) • • Total distance to cover is D (D>>R) Total distance to cover is D (D>>R) • • Big R, more interference, fewer hops Big R, more interference, fewer hops • • Small R, less interference, more hops Small R, less interference, more hops • • Total Delay = T(R) Total Delay = T(R) [ D/R D/R ] • * to minimize total delay • Choose R=R Choose R=R * to minimize total delay • • dT(R)/dR = T(R)/R optimality condition dT(R)/dR = T(R)/R optimality condition • Leonard Kleinrock 1999
dT(R)/dR = T/R dT(R)/dR = T/R T(R) T(R) * R R R R Leonard Kleinrock 1999
Hit any key Hit any key to continue to continue No…….. No…….. Not that Not that one!!! one!!! Leonard Kleinrock 1999
Thank Thank You You www.lk.cs.ucla.edu Leonard Kleinrock 1999
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