Describe why an application developer might choose to run an application over UDP rather than TCP. correct answers An application developer may not want
... [Show More] its application to use TCP's congestion control, which can throttle the application's sending rate at times of congestion. Often, designers of IP telephony and IP videoconference applications choose to run their applications over UDP because they want to avoid TCP's congestion control. Also, some applications do not need the reliable data transfer provided by TCP.
Is it possible for an application to enjoy reliable data transfer even when the application runs over UDP? If so, how? correct answers Yes. The application developer can put reliable data transfer into the application layer protocol. This would require a significant amount of work and debugging, however.
In our rdt protocols, why did we need to introduce sequence numbers? correct answers Sequence numbers are required for a receiver to find out whether an arriving packet contains new data or is a retransmission.
Suppose Host A sends two TCP segments back to back to Host B over a TCP connection. The first segment has sequence number 90; the second has sequence number 110.
a. How much data is in the first segment?
b. Suppose that the first segment is lost but the second segment arrives at B. In the acknowledgment that Host B sends to Host A, what will be the acknowledgment number? correct answers The acknowledgement number is the sequence number of the next byte the receiver expects to receive. The receiver ack'ing sequence number x acknowledges receipt of all data bytes less than (but not including) byte number x.
Discuss why each input port in a high-speed router stores a shadow copy of the forwarding table. correct answers With the shadow copy, the forwarding decision is made locally, at each input port, without invoking the centralized routing processor. Such decentralized forwarding avoids creating a forwarding processing bottleneck at a single point within the router.
Suppose that an arriving packet matches two or more entries in a router's forwarding table. With traditional destination-based forwarding, what rule does a router apply to determine which of these rules should be applied to determine the output port to which the arriving packet should be switched? correct answers A router uses longest prefix matching to determine which link interface a packet will be forwarded to if the packet's destination address matches two or more entries in the forwarding table
Three types of switching fabrics are discussed in Section 4.2 . List and briefly describe each type. Which, if any, can send multiple packets across the fabric in parallel? correct answers Switching via memory: Fabric switching with the use of Crossbar, and Switching with use of Bus. [Show Less]