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