| Local Area Networks (LANs) are able to deliver
data quickly and reliably over short distances. Various different topologies are
available.
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| (a) | Describe four factors to be considered
in selecting a topology for a LAN.
|
[4] |
| (b) | A particular open-plan office is being equipped
with a new LAN. Network sockets are to be arranged in a 3 x 3 grid, as follows:
The vertical/horizontal distance between sockets is 4 m; the diagonal distance is therefore 5.7 m. What is the minimum length of cable that will be needed if the LAN is to be |
[6] |
| (i) a ring, | ||
| (ii) a bus | ||
| (iii) a star. State any assumptions you make. You may find it useful to draw a diagram in each case, showing how the nodes are connected.
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| (c) | What is the IEEE's standard for token passing
ring networks? Describe with the aid of a diagram, the operation of this type of media
access technique.
|
[8] |
| (d) | Which layer of the OSI reference model is concerned with the specification of cable topologies? Describe one function of this layer which is independent of the actual medium used. | [2] |
