WorksheetsNWC 241-260 1
Total questions: 20
Worksheet time: 10mins
In TCP connection management, which of the following statements are true
Select initial sequence numbers (ISN) to protect against segments from prior connections
High bandwidth connection pose a problem
Use global clock to select ISN sequence number
Time for clock to go through a full cycle should be less than the maximum lifetime of a segment
In phases of congestion behavior, when arrival rate is greater than outgoing line bandwidth
Knee
Congestion onset
Light traffic
Congestion collapse
Which of the following services are provided by UDP
IP
De-multiplexing
Error Checking
All of the above
When a TCP client initiates a three-way handshake with a sequence number x, what will be the acknowledgement number when the TCP server replies?
x
x + 1
x + y (where y is the sequence number proposed by TCP server)
None of the above
TCP header has a field called window size. What value is the value window size set to?
Advertised window size for congestion control
Round-trip delay
Advertised window size for flow control
None of the above
In general, there are three phases of congestion behavior, i.e., light traffic, knee, congestion collapse. Which phase does TCP congestion avoidance maps to?
Light traffic
Knee
Congestion collapse
None of the above
When three duplicate acknowledgements arrive before timeout expires, what will TCP congestion control algorithm reset congestion threshold to for fast re-transmission and fast recovery?
Reset congestion threshold to 1
Reset congestion threshold to half of the current congestion window size
Reset congestion threshold to the current congestion window size
None of the above
Assume a TCP source writes a 1200-byte message in one write. Which of following is possible for the destination to receive the message?
It receives three reads of 400 bytes each
It receives two reads of 600 bytes each
It receives a 1200-byte message in one read
All of the above
The process of combining multiple outgoing protocol streams at the Transport and Network layers in TCP/IP is called Multiplexing
t
f
TIMELY provides a framework for rate control that depends on transport layer protocol for reliability
t
f
The operation of TCP congestion control can be divided into three phases, which phase requires that the congestion window size be increased by one segment upon receiving an ACK from receiver
Congestion avoidance
Slow start
Congestion
None of the above
In a router, the control of the transmission rate at the sender's side such that the router's buffer will not be over-filled is called _________ if sender is transmitting too fast
Network under-utilization
Host flooding
Network congestion
None of the above
Congestion control is associated with the window size field
t
f
Which of following protocol allows a host to signal its multicast group membership to its attached routers?
ICMP
IGMP
OPSF
None of the above
Which of following statements most accurately describes the reverse-path broadcasting?
It assumes that the shortest path from the source to a given router should be the same as the shortest path from the router to the source
Each link in the network to be symmetric
Each packet is forwarded by a router exactly once
All of the above
Which class of IP address does the reverse-path broadcasting uses?
Class A
Class B
Class C
Class D
Attackers attempt to gain unauthorized access to server. What type of network security threat it imposes?
Client imposter
Server imposter
Man-in-Middle
None of the above
In mobile IP, when a home agent wants to send a packet to a mobile host in a foreign network, each IP packet at the home agent will be encapsulated with an outer IP header. What is the destination IP address in the outer IP header?
Care-of address
Mobile host's address
Home agent's address
None of the above
An IP address associated with a mobile node while visiting a foreign link
Handover address
Home address
Care of address
Home link
TCP SYN flood attack exploits the TCP three-way handshake
t
f
