Q $2($c$)$

$[12$ Marks$]$

Suppose we wish to implement a DiffServ Architecture as follows.

There are three classes of traffic

The first class should be allocated at least $80\%$ of available bandwidth

The second class should be allocated at least $15\%$ of the available bandwidth

The third class should receive the rest.

Additionally, streams for the classes transmit at different rates.

The first class transmits at $2$ Mbps$.$

The second class transmits at $0\mathrm{.}5Mbps$

The third class transmits at $10kbps$

i$)$ Suggest a Weighted Fair Queuing policy to enforce the bandwidth allocation requirement for the system.

$(4$ marks$)$

ii$)$ What guarantees does a weighted fair queuing policy offer to individual traffic streams?

$(2$ marks$)$

iii$)$ Suppose the overall system bandwidth is $10Mbps.$ What is the maximum number of streams of each traffic class that are guaranteed to be supported? $(4$ marks$)$

iv$)$ Under what circumstances might additional streams of a traffic class be supported?

$(2$ marks$)$

$[$End of Question $2]$