DTEs and DCEs

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Figure 6-6
DTEs and DCEs
Sensor
Display
DTE Data Terminal Equipment DCE Data
Circuit-Terminating Equipment
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Figure 6-19
Modem
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Multiplexing
4

Figure 8-1
Multiplexing vs. No Multiplexing
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Figure 8-2
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Figure 8-3
FDM
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Figure 8-4
FDM, Time Domain
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Figure 8-6
Demultiplexing, Time Domain
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Figure 8-5
Multiplexing, Frequency Domain
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Figure 8-7
Demultiplexing, Frequency Domain
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Figure 8-8
TDM
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Figure 8-9
Synchronous TDM
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Figure 8-10
TDM, Multiplexing
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Figure 8-11
TDM, Demultiplexing
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Figure 8-14
Asynchronous TDM
1
1
2
3
5
1
3
1
5
3
4
5
1
4
5
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Figure 8-15
Frames and Addresses
a. Only three lines sending data
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Figure 8-15-continued
Frames and Addresses
c. All five lines sending data
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Switching
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Figure 14-1
Switched Network
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Q. Under what circumstances should the
interconnection of a set of computers be based
on switching?

• multiple devices
• need of one-on-one comminication

Q. Give examples of other means of communication.
Star topology
Mesh topology
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Q. Suppose a set of 4 computers are fully
interconnected, i.e. eachcomputer is connected
to every other one by a dedicated link. How many
links are necessary?
6 links
(N-1)
N
/ 2 links

• Q. How many links are necessary if the number of
  interconnectedcomputers is
• 8
• 16
• 32
• 64
• 128
• 256?

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N computers ? N (N-1) / 2 links

• 8 computers ? 8 7 / 2 28 links
• 16 computers ? 16 15 / 2 120 links
• 32 computers ? 32 31 / 2 496 links
• 64 computers ? 64 63 / 2 2,016 links
• 128 computers ? 128 127 / 2 8,128 links
• 256 computers ? 256 255 / 2 32,640 links

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Figure 14-2
Packet switching
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Figure 14-3
Circuit-Switched Network
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Figure 14-9
Switching Path
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Figure 14-9-continued
Switching Path
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Figure 14-13
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Figure 14-14
Datagram Approach
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Figure 14-16
Switched Virtual Circuit
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Figure 14-16-continued
Switched Virtual Circuit
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Figure 14-16-continued
Switched Virtual Circuit
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