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(a)How does the Ethernet driver determine whether to use the IP or
the ARP module? [2 marks ]
The value of the type field in the Ethernet
frame determines whether the Ethernet frame is passed to the ARP or
the IP module (2)
(b)Discuss any two advantages of using hubs in Local Area Networks
[4 marks ]
Increases the bandwidth (1):Each device linked
to the network is directly connected to a central hub,within which
a high speed bus contention protocol operates to facilitate communication
between the devices (1) Simple and flexible network configuration
(1):
Switching in LAN hub are configurable through software,making network
reconfiguration more flexible and achieving high speed /performance
switching (1)
(c)ATM networks are less vulnerable to congestion than ethernet.Explain
why.
[4 marks ]
Uses a uniform cell structure for all types
of data (1) such as voice or video (1),so that no single type of data
is allowed to dominate the network (1) User can specify the speed
of transmission (1) required during the process of setting up the
connection.
(d)Explain the functions performed by the three layers in the ATM
protocol.[5 marks ]
ATM adaptation layer:Handles fragmentation
and reassemble of cells (1) Also
determines the quality of services a cell receive in the face of network
congestion (1)
ATM layer:Provides the addressing information for each cell,using
Virtual Path
Identifiers (1) and Virtual Channel Identifiers (1) to identify the
destination of each cell.
Physical layer:Deals with the transfer of information across the physical
switches (1)
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