midterm 1
If the ACK value is 200, then byte _______ has been received successfully.
b) 199
TCP assigns a sequence number to each segment that is being sent. The sequence number for each segment is number of the __________ byte carried in that segment.
first
Bluetooth is an example of
personal area network
Application layer protocol defines:
a) types of messages exchanged, message format, syntax and semantics, rules for when and how processes send and respond to messages
What is the size of the sequence number field in TCP segment structure?
32 bits
DNS server uses port
53
1 GBps is equivalent to
8 Gbps (wat) byte -> bit?
The transport layer protocol serving HTTP for web browsing is
TCP
What is the difference between TCP congestion control and flow control?
TCP congestion control makes sure the network bandwidth/capacity is not overwhelmed by the sender's transmission rate while TCP flow control makes sure the receiver buffer is not overwhelmed by the sender's transmission rate.
What does the phrase non-authoritative answer in the nslookup output mean?
The information in the output was obtained from a server cache
Multicasting communication is
When a packet is sent from a single source to multiple destinations
DNS databases contain
name server records, hostname-to-address records, hostname aliases
In the transfer of file between server and client over four hops (links), if the transmission rates along the path is 40Mbps, 30Mbps, 20Mbps, 10Mbps, the throughput of the connection between server and client is
10Mbps
If a packet size is 1500 bits and the rate at which a router can pump out packets is 10Mega bits per second, then the transmission delay is:
150 microseconds
TCP segment has mandatory ________________ bytes long header.
20
By default, what type of query does nslookup do for a domain?
A
Assume a client is establishing communication with a server through a 3-way TCP handshake protocol. In this connection establishment phase, when the server is responding, which of the six flags (U, A, P, R, S, F) will be set by the server?
A and S
What is the difference between iterative and recursive DNS query?
Iterative: Burden of name resolution on local DNS server Recursive: Burden of name resolution on contacted name server (either local or root or TLD or authoritative based on who is contacted)
In the layer hierarchy as the data packet moves from the upper to the lower layers, headers are
Added
Which of the following 5 components must be part of reliable data transfer protocol?
Checksum, Timer, Sequence number, Acknowledgement and Pipelining
In TCP, the size of the transmission window is the ________ of rwnd and cwnd.
Minimum
The time required to examine the packet's header and determine where to direct the packet is part of
Nodal Processing delay
A set of rules that governs data communication is known as
Protocols
Which of the following is NOT a correct statement?
Routers examine packets at application layer.
For the following event at receiver, what would be TCP receiver's action?Event: arrival of out-of-order segment higher-than-expect seq. # . Gap detected.
Send duplicate ACK, indicating seq. # of next expected byte.
The domain name system is maintained by
distributed database system
What is NOT true about persistent HTTP connection?
downloading multiple objects must require multiple TCP connections
Which one of the following protocol delivers/stores mail to receiver server?
simple mail transfer protocol
In the congestion detection algorithm, if detection is by a time-out, a new _______ phase starts.
slow start
Which one of the following is NOT part of the network protocol stack?
synchronization layer