$($a$).$A network connection $($see diagram $)$ between two routers operating at $10$Mps is to be shared by:

$1.$A real time live broadcast video service sending one stream of $20$ frames per second of video where each packet burst is $300$ kilobits per burst of streamed video data. This stream operates from Router A towards router B$.$

$2.$Up to $30$ telephone calls each telephone call being bidirectional and using $8000$ one byte samples per second in each direction aggregated into packets transmitted every $20$ms$.$

$3.$ The remaining bandwidth is available for ordinary best effort network traffic

Assuming a best effort service is provided for all these traffic types, roughly how many telephone calls can be made before the network link becomes congested? $[7].$

$($b$).$Suggest how to configure queuing in Router A for traffic to Router B so that that video and telephony services always work with a guaranteed quality of service and at the same time the TCP$/$UDP traffic is able to use any remaining bandwidth. Use a diagram to illustrate your answer. $[8]$