Leonard Kleinrock Leonard Kleinrock Professor, UCLA Computer - - PowerPoint PPT Presentation

  Leonard Kleinrock 1999

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

• f ‘computer utilities’, which, like present electric and
• f ‘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.”

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  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

September 1969

The Interface Message Processor IMP

  Leonard Kleinrock 1999

  Leonard Kleinrock 1999

1969 1969 The IMP The IMP

  Leonard Kleinrock 1999

  Leonard Kleinrock 1999

1969 1969 The IMP The IMP

  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. YEP! YEP!

• We sent an “O” - did you get the “O”?

We sent an “O” - did you get the “O”? YEP! YEP!

• We sent a “G” - did you get the “G”?

We sent a “G” - did you get the “G”?

• We sent an “L” - did you get the “L”?

We sent an “L” - did you get the “L”?

  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. YEP! YEP!

• We sent an “O” - did you get the “O”?

We sent an “O” - did you get the “O”? YEP! YEP!

• We sent a “G” - did you get the “G”?

We sent a “G” - did you get the “G”?

• We sent an “L” - did you get the “L”?

We sent an “L” - did you get the “L”?

UCLA UCLA SRI SRI

  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. YEP! YEP!

• We sent an “O” - did you get the “O”?

We sent an “O” - did you get the “O”? YEP! YEP!

• We sent a “G” - did you get the “G”?

We sent a “G” - did you get the “G”?

• We sent an “L” - did you get the “L”?

We sent an “L” - did you get the “L”?

UCLA UCLA SRI SRI

  Leonard Kleinrock 1999

What It Looked Like in 1969 What It Looked Like in 1969

September 1969 October 1969 November 1969 December 1969

The job is to The job is to stress the net stress the net to its breaking to its breaking point! point! UCLA serves UCLA serves the Network the Network Measurement Measurement Center Center

  Leonard Kleinrock 1999

  Leonard Kleinrock 1999

COMPUTER NET COMPUTER NET

INPUT INPUT

Response Time Response Time

T T

RESPONSE TIME RESPONSE TIME

CAPACITY CAPACITY

THROUGHPUT THROUGHPUT

Throughput Loss Loss

LOSS LOSS

  Leonard Kleinrock 1999

Flow Control

Output Output Input Input

IDEAL IDEAL

FREE-FLOW FREE-FLOW DEADLOCK DEADLOCK

CONSERVATIVE CONSERVATIVE DYNAMIC DYNAMIC

  Leonard Kleinrock 1999

BIG BIG DP DP SYS SYS FLOW CONTROL FLOW CONTROL

COMPUTER COMPUTER NET NET

PING ! PING !

  Leonard Kleinrock 1999

BIG BIG DP DP SYS SYS FLOW CONTROL FLOW CONTROL

COMPUTER COMPUTER NET NET

Whoa !! Whoa !!

  Leonard Kleinrock 1999

BIG BIG DP DP SYS SYS FLOW CONTROL FLOW CONTROL

COMPUTER COMPUTER NET NET

  Leonard Kleinrock 1999

Do you want Do you want to operate to operate here? here?

Response Time vs Throughput

Throughput Response Response Time Time

( ) T( )

Or here? Or here?

POWER = Throughput Response Time P =

T( )

1/P * Max Power Point =

  Leonard Kleinrock 1999

Response Time vs Throughput

Throughput Response Response Time Time

( ) T( )

POWER = Throughput Response Time P =

T( )

1/P

  Leonard Kleinrock 1999

Response Time vs Throughput

Throughput Response Response Time Time

( ) T( )

* Max Power Point

At Max Power At Max Power N N*

* = 1

= 1

  Leonard Kleinrock 1999

M/G/1 M/G/1

N*=1 N*=1

T( )

  Leonard Kleinrock 1999

T T

Only 1 customer Only 1 customer

= Min = Min Eff = Max Eff = Max

Use Your Intuition Use Your Intuition

Morale: Just keep the pipe full!

  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 A Brief History of Pkt Pkt Radio Radio

250 cu in 250 cu in 25 watts 25 watts 25 pounds 25 pounds

• 1970’s: ARPA

  Leonard Kleinrock 1999

  Leonard Kleinrock 1999

A Brief History of A Brief History of Pkt Pkt Radio Radio

10 cu in 10 cu in 1 watt 1 watt 1 pound 1 pound

• 1990’s: ARPA

  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]

• Choose R=R

Choose R=R*

* to minimize total delay

to minimize total delay

• dT(R)/dR = T(R)/R optimality condition

dT(R)/dR = T(R)/R optimality condition

  Leonard Kleinrock 1999

T(R) T(R) R R

dT(R)/dR = T/R dT(R)/dR = T/R

R R *

  Leonard Kleinrock 1999

Hit any key Hit any key to continue to continue No…….. No…….. Not that Not that

• ne!!!
• ne!!!

  Leonard Kleinrock 1999

Thank Thank You You

www.lk.cs.ucla.edu