Transport Layer Protocol
Q21.
For a host machine that uses the token bucket algorithm for congestion control, the token bucket has a capacity of 1 megabyte and the maximum output rate is 20 megabytes per second. Tokens arrive at a rate to sustain output at a rate of 10megabytes per second. The token bucket is currently full and the machine needs to send 12megabytes of data. The minimum time required to transmit the data is _____seconds.Q22.
Let the size of congestion window of a TCP connection be 32 KB when a timeout occurs. The round trip time of the connection is 100 msec and the maximum segment size used is 2kB. The time taken (in msec) by the TCP connection to get back to 32KB congestion window is ______Q23.
Which of the following statements are TRUE? S1: TCP handles both congestion and flow control S2: UDP handles congestion but not flow control S3: Fast retransmit deals with congestion but not flow control S4: Slow start mechanism deals with both congestion and flow controlQ24.
A TCP message consisting of 2100 bytes is passed to IP for delivery across two networks. The first network can carry a maximum payload of 1200 bytes per frame and the second network can carry a maximum payload of 400 bytes per frame, excluding network overhead. Assume that IP overhead per packet is 20 bytes. What is the total IP overhead in the second network for this transmission?Q26.
A layer-4 firewall (a device that can look at all protocol headers up to the transport layer) CANNOTQ27.
Consider a TCP connection between a client and a server with the following specifications; the round trip time is 6 ms, the size of the receiver advertised window is 50 KB, slow-start threshold at the client is 32 KB, and the maximum segment size is 2 KB. The connection is established at time t=0. Assume that there are no timeouts and errors during transmission. Then the size of the congestion window (in KB) at time t+60 ms after all acknowledgements are processed is _______Q30.
Consider a long-lived TCP session with an end-to-end bandwidth of 1 Gbps (= 10^{9} bits-per-second). The session starts with a sequence number of 1234. The minimum time (in seconds, rounded to the closest integer) before this sequence number can be used again is _______.