Question

Show flows for each set of devices and applications below by labeling each as either a unidirectional or bidirectional flow.

4. Client-server application: downstream (from server to client) – 1.2 Mb/s capacity; upstream (from client to server) – 15 kb/s capacity. ____________

5. Streaming video (UDP) from video server to a subscriber’s PC: 300 kb/s capacity, 40 ms delay (one-way). ____________

6. Downloading pages from the web: downstream - 250 kb/s capacity, 5 second download delay; upstream – 100 kb/s capacity. ____________

7. Transaction processing from point-of-sale machine to server: upstream (from PoS machine to server) – 30 kb/s capacity, 100 ms round-trip delay; downstream – 50 kb/s capacity. ____________

Answer 1

4. Bidirectional, since the traffic is from client and server both

5. Unidirectional, as the major traffic is from the video server sending the video to the destination

6. Bidirectional, as the client requests webpages (upstream traffic) and client downloads pages (downstream traffic)

7. Bidirectional, upstream traffic is pint of sale machine requesting the transaction to be processed and downstream traffic is acknowledgement that the transaction is processed from the server