3 - switching and performance

3 - switching and performance - Last Lecture Nuts-and-bolts...

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
SUNY AT BUFFALO; CSE489/589 – MODERN NETWORKING CONCEPTS; Fall 2010; INSTRUCTOR: HUNG Q. NGO 1 Last Lecture Nuts-and-bolts description of the Internet ! The topology ! The core ! The edge ! The communication links
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
SUNY AT BUFFALO; CSE489/589 – MODERN NETWORKING CONCEPTS; Fall 2010; INSTRUCTOR: HUNG Q. NGO 2 This Lecture ! How to send data from end to end: two switching methods ! Circuit switching ! Packet switching ! Packet loss and delay in a packet switched network
Background image of page 2
How is data transferred through a network? SUNY AT BUFFALO; CSE489/589 – MODERN NETWORKING CONCEPTS; Fall 2010; INSTRUCTOR: HUNG Q. NGO 3 Two switching methods: 1. Circuit Switching : dedicated physical circuit is established, maintained, and terminated over a communication session (e.g. ISDN) 2. Packet Switching : data are transferred in packets (chunks of data of a fixed size), possibly go through different paths to reach the destination (e.g. ATM, X.25, Frame Relay, Internet)
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
1. Circuit Switching SUNY AT BUFFALO; CSE489/589 – MODERN NETWORKING CONCEPTS; Fall 2010; INSTRUCTOR: HUNG Q. NGO 4 Three step process o Source establishes connection to destination " Find path " Reserve resources o Data exchanged (no need for destination address) o Connection torn down " Resources released
Background image of page 4
SUNY AT BUFFALO; CSE 489/589 – MODERN NETWORKING CONCEPTS; Fall 2010; INSTRUCTOR: HUNG Q. NGO 5 Sharing a Link: Multiplexing ! To combine multiple signals (analog or digital) for transmission over a single line or medium. ! Multiplexing technologies: ! Frequency Division Multiplexing ( FDM ) : each signal is assigned a different frequency range (e.g. FM radio). ! Time Division Multiplexing ( TDM ) : each signal is assigned a fixed time slot in a “fixed” rotation. ! Statistical Time Division Multiplexing ( STDM ): time slots are assigned to signals dynamically to make better use of bandwidth. ! Wavelength Division Multiplexing ( WDM ) : each signal is assigned a particular wavelength; used in optical fiber.
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
SUNY AT BUFFALO; CSE 489/589 – MODERN NETWORKING CONCEPTS; Fall 2010; INSTRUCTOR: HUNG Q. NGO 6 Circuit Switching: FDMA and TDMA FDMA frequency time TDMA frequency time 4 users Example:
Background image of page 6
SUNY AT BUFFALO; CSE 489/589 – MODERN NETWORKING CONCEPTS; Fall 2010; INSTRUCTOR: HUNG Q. NGO 7 2. Packet Switching
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Packet Switching: Statistical Multiplexing Packets SUNY AT BUFFALO; CSE 489/589 – MODERN NETWORKING CONCEPTS; Fall 2010; INSTRUCTOR: HUNG Q. NGO 8
Background image of page 8
SUNY AT BUFFALO; CSE 489/589 – MODERN NETWORKING CONCEPTS; Fall 2010; INSTRUCTOR: HUNG Q. NGO 12 Packet Switching vs. Circuit Switching: In Theory ! Packet Switching ! CS wastes bandwidth when data is sporadic ! PS is statistically more efficient and less costly ! CS takes time to establish the circuit ! PS is simpler to implement ! Side Question: what about packet sizes? Small or Large? ! Circuit Switching ! PS is not suitable for real time application !
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 10
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 12/03/2010 for the course CS 489 taught by Professor Hungngo during the Fall '10 term at SUNY Buffalo.

Page1 / 31

3 - switching and performance - Last Lecture Nuts-and-bolts...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online