Introductory Topics EE 122 TAs past and present

  • Slides: 16
Download presentation
Introductory Topics EE 122 TAs past and present

Introductory Topics EE 122 TAs past and present

Comprehension • How fast is my speech? – ~1000 ft/s (speed of sound) –

Comprehension • How fast is my speech? – ~1000 ft/s (speed of sound) – ~125 words/minute • What about Steve Woodmore? – ~1000 ft/s (speed of sound) – ~640 words/minute (maybe) propagation delay transmission delay • How long would it take: – to hear me or Steve, if we shout “Help” (very loudly) from Stanford? (~40 miles [~200, 000 feet] away) – me or Steve to dictate War and Peace? (~600, 000 words) N. B. If-I-am-actually-speaking-far-too-fast o r w a y t o o s l o w l y, let me know!

Transmission Delay

Transmission Delay

Transmission Delay Time taken to push data onto link § Measured from § when

Transmission Delay Time taken to push data onto link § Measured from § when the first bit of data is pushed onto the link to § when the last bit of data is pushed onto the link § Limited by the Bandwidth of the link

Propagation Delay

Propagation Delay

Propagation Delay Time taken by data to traverse a link § Limited by the

Propagation Delay Time taken by data to traverse a link § Limited by the speed of light § Latency of a link is the propagation delay to traverse the link

Transmission and Propagation Delay A B Propagation delay Transmission delay A Packet B

Transmission and Propagation Delay A B Propagation delay Transmission delay A Packet B

Queuing Delay

Queuing Delay

Queuing Delay Time a packet spends in a buffer/queue of a switch / router

Queuing Delay Time a packet spends in a buffer/queue of a switch / router § Only when arrival rate > service rate § Especially when packet arrivals are bursty

Bursty

Bursty

Not Bursty

Not Bursty

Queuing Delay A B C Transmission delay doubles Queuing delay Brown packet waits for

Queuing Delay A B C Transmission delay doubles Queuing delay Brown packet waits for half the trans. delay of blue packet

No Queuing Delay A B C Transmission delay doubles Brown packet does not have

No Queuing Delay A B C Transmission delay doubles Brown packet does not have to wait

End-to-End Delay Sum of all delays Propagation delay Transmission delay Queuing delay Processing delay

End-to-End Delay Sum of all delays Propagation delay Transmission delay Queuing delay Processing delay End-to-End Delay +

Round Trip Time (RTT) Time for packet to reach a destination AND a response

Round Trip Time (RTT) Time for packet to reach a destination AND a response to return A B Packet Response

Worksheet A B Propagation delay Physical distance / Speed of light Transmission delay Size

Worksheet A B Propagation delay Physical distance / Speed of light Transmission delay Size of transfer / Bandwidth of link A B

Introductory Topics EE 122 TAs past and presentIntroductory Topics EE 122 TAs past and present
Introductory Topics EE 122 TAs past and presentIntroductory Topics EE 122 TAs past and present
Reliable Transport EE 122 TAs Past and PresentReliable Transport EE 122 TAs Past and Present
CS 168 and EE 122 TAs past andCS 168 and EE 122 TAs past and
Past Tenses Simple Past Past continuous and PastPast Tenses Simple Past Past continuous and Past
PAST SIMPLE AND PAST CONTINUOUS PAST SIMPLE PastPAST SIMPLE AND PAST CONTINUOUS PAST SIMPLE Past
PAST TENSES PAST SIMPLE PAST CONTINUOUS AND PASTPAST TENSES PAST SIMPLE PAST CONTINUOUS AND PAST
PAST CONTINUOUS Past Continuous Past Simple Past ContinuousPAST CONTINUOUS Past Continuous Past Simple Past Continuous
PAST SIMPLE PAST CONTINUOUS PAST PERFECT PAST SIMPLEPAST SIMPLE PAST CONTINUOUS PAST PERFECT PAST SIMPLE
Past Tenses Past Simple Past Perfect Past ContinuousPast Tenses Past Simple Past Perfect Past Continuous
PAST SIMPLE Vs PAST CONTINUOUS PAST SIMPLE PASTPAST SIMPLE Vs PAST CONTINUOUS PAST SIMPLE PAST
Esau Past Present and Future Esau Past PresentEsau Past Present and Future Esau Past Present
Esau Past Present and Future Esau Past PresentEsau Past Present and Future Esau Past Present
Past Continuous Past Simple Past Continuous Present timePast Continuous Past Simple Past Continuous Present time
Past Indefinite Past Continuous Past Perfect Present IndefinitePast Indefinite Past Continuous Past Perfect Present Indefinite