21. Define the terms Unicasting, Multiccasting and Broadcasting?
If the message is sent from a source to a single destination node, it is called Unicasting.
If the message is sent to some subset of other nodes, it is called Multicasting.
If the message is sent to all the m nodes in the network it is called Broadcasting.
22. What is Multiplexing?
Multiplexing is the set of techniques that allows the simultaneous transmission of multiple signals across a single data link.
23. Name the categories of Multiplexing?
a. Frequency Division Multiplexing (FDM)
b. Time Division Multiplexing (TDM)
i. Synchronous TDM
ii. ASynchronous TDM Or Statistical TDM.
c. Wave Division Multiplexing (WDM)
24. What is FDM?
FDM is an analog technique that can be applied when the bandwidth of a link is greater than the combined bandwidths of the signals to be transmitted.
25. What is WDM?
WDM is conceptually the same as FDM, except that the multiplexing and demultiplexing involve light signals transmitted through fiber optics channel.
26. What is TDM?
TDM is a digital process that can be applied when the data rate capacity of the transmission medium is greater than the data rate required by the sending and receiving devices.
27. What is Synchronous TDM?
In STDM, the multiplexer allocates exactly the same time slot to each device at all times, whether or not a device has anything to transmit.
28. List the layers of OSI
a. Physical Layer
b. Data Link Layer
c. Network Layer
d. Transport Layer
e. Session Layer
f. Presentation Layer
g. Application Layer
29. Which layers are network support layers?
a. Physical Layer
b. Data link Layer and
c. Network Layers
30. Which layers are user support layers?
a. Session Layer
b. Presentation Layer and
c. Application Layer
