ATM%20Switch%20Architectures - PowerPoint PPT Presentation

About This Presentation
Title:

ATM%20Switch%20Architectures

Description:

ATM Switch Architectures Carey Williamson Department of Computer Science University of Calgary – PowerPoint PPT presentation

Number of Views:84
Avg rating:3.0/5.0
Slides: 20
Provided by: Carey61
Category:

less

Transcript and Presenter's Notes

Title: ATM%20Switch%20Architectures


1
ATM Switch Architectures
  • Carey Williamson

Department of Computer Science University of
Calgary
2
Introduction
  • ATM switches are categorized based on internal
    architectural characteristics
  • Example shared memory switch
  • Two key features of a switch design are the
    switch fabric and the buffer organization

3
A Classification Scheme
  • ATM switch designs can be classified as
    time-division or space-division switches
  • Time-division switches all cells pass through a
    common point within the switch en route to their
    output points, but do so at different times
  • Space-division switches all cells pass through
    the switch at the same time, but do so on
    different paths

4
Time Division Switches
  • The two most common types of time division
    switches are the shared memory switch and the
    shared medium switch

5
Time Division Switches (Contd)
  • Shared memory switch there is a common internal
    buffer in the switch, through which all cells
    pass en route to their output ports
  • Shared medium switch there is a common bus in
    the switch, over which all cells must pass en
    route to their output ports

6
Shared Memory Switch
Dual Ported Memory
Input Ports
Output Ports
7
Shared Memory Switch
  • All incoming cells multiplexed into a single
    stream (common memory)
  • Organized into output queues per output port
  • Cells retrieved sequentially
  • Central controller and memory bandwidth must be
    very fast (at least N times input port
    speed)

8
Shared Medium Switch
  • All incoming cells multiplexed across a common
    medium (bus)
  • Cells processed one at a time
  • Bus must be very fast (at
    least N times input port speed)

9
SHARED-MEDIUM PACKET SWITCH
OUTPUT 1
INPUT 1
AF
FIFO
S/P
OUTPUT 2
INPUT 2
S/P
AF
P/S
FIFO
TIME DIVISION BUS
...
...
...
...
...
...
INPUT N
OUTPUT N
S/P
AF
FIFO
10
Space Division Switches
  • Space division switches provide multiple
    concurrent paths from the input ports to the
    output ports
  • Cells coming in on different input ports and
    heading to different output ports can proceed
    through the switch simultaneously on these
    separate paths, without interfering with each
    other

11
Space Division Switches
  • There are many examples of space division
    switches
  • Crossbar switches
  • Multistage interconnection networks (MINs)
  • Banyan, Batcher-Banyan, Benes
  • delta, omega, perfect shuffle
  • Hypercube switches

12
4 x 4 Crossbar Switch
A1
A2
A3
A4
B1
B2
B3
B4
13
4 x 4 Crossbar Switch
A1
A2
A3
A4
B1
B2
B3
B4
14
4 x 4 Crossbar Switch
A1
A2
A3
A4
B1
B2
B3
B4
15
2 x 2 NETWORK
INPUT 0
OUTPUT 0
OUTPUT 1
INPUT 1
16
2 x 2 NETWORK
INPUT 0
OUTPUT 0
OUTPUT 1
INPUT 1
17
2 x 2 NETWORK
INPUT 0
OUTPUT 0
OUTPUT 1
INPUT 1
18
4 x 4 NETWORK
19
8 x 8 NETWORK
20
Summary
  • There is an extensive (and exhausting) set of
    literature on ATM switch architectures
  • Much of the real research activity took place
    five or more years ago
  • Most vendors have based their ATM switching
    products on the well-established good designs
    (e.g., banyan-based or shared memory)
Write a Comment
User Comments (0)
About PowerShow.com