3rd long exam

Question 1

is responsible for process-to-
process delivery—the delivery of a packet, part of a
message, from one process to another.

Answer 1

transport layer

Question 2

3 types of data deliveries

Answer 2

node to node - data link
host to host - network
process to process - transport

Question 3

T/F
a process on the local host (client) needs
services from a process usually on the
remote host (server)

Answer 3

True

Question 4

T/F
Operating systems today support both multiuser and
multiprogramming environments.

Answer 4

True

Question 5

___can run several server programs at the same time

Answer 5

remote computer

Question 6

___can run one or more client programs at the same time

Answer 6

local computers

Question 7

Whenever we need to deliver something to one specific

destination among many, we need an _____

Answer 7

address

Question 8

At the Data Link layer, we need a ________ to choose one node among several nodes if the connection is not point to point

Answer 8

MAC address

Question 9

A ____ in the data
link layer needs a destination MAC address for delivery and a
_____ for the next node’s reply.

Answer 9

frame

source address

Question 10

At the Network layer, we need an _____ to choose one host among millions

Answer 10

IP address

Question 11

A _____ in the network layer needs a destination IP address for delivery and a ______ for the destination’s reply

Answer 11

datagram

source IP address

Question 12

____ address of processes running in the destination host

Answer 12

port number

Question 13

T/F
in the Internet model, port numbers are 16-bit
integers that ranges from 0 to 65,532

Answer 13

True

Question 14

____ chosen randomly by the transport layer software

running in the client host

Answer 14

ephemeral port number

Question 15

T/F
ephemeral port number is n short-lived; created when there is a request for
available port

Answer 15

True

Question 16

____ server process can not choose random numbers;

universal port numbers for servers

Answer 16

well-know port number

Question 17

T/F
IP addresses and port numbers play different
roles in selecting the final destination of data.

Answer 17

True

Question 18

The _____ defines the host among the different hosts in the

world.

Answer 18

destination IP address

Question 19

After the host has been selected, the _____ defines one of the
processes on this particular host

Answer 19

port number

Question 20

what does IANA stand for?

Answer 20

Internet Assigned Numbers Authority

Question 21

IANA RANGES:

ranges from 0-1023, controlled and assigned by IANA

Answer 21

well-known ports

Question 22

IANA RANGES:

1024 - 49,151, not assigned and controlled by IANA

Answer 22

registered ports

Question 23

IANA RANGES:

49,152 - 65,536, neither controlled nor registered.

ephemeral ports

Answer 23

dynamic ports

Question 24

____ needs two identifiers, IP address and the port number, at each end to make a connection.

Answer 24

process to process delivery

Question 25

The combination of an IP address and a port number is called a ______

Answer 25

socket address

Question 26

____ selects one analog or digital input signal among several and sends the selection to the single-line output

Answer 26

multiplexer

Question 27

_____ single input; sends the signal to one of the several output lines

Answer 27

demultiplexer

Question 28

packets are sent from one party to another with no need for | connection establishment or connection release

Answer 28

Connectionless service

Question 29

a connection is first established between the sender and the | receiver

Answer 29

connection-oriented service

Question 30

difference between connectionless service and connection-oriented service

Answer 30

connectionless - packets are sen from one party to another with no need for connection establishment. Packets are not numbered; may be delayed or lost or may arrive out of sequence. No acknowledgement. connection-oriented - connection is first established between the sender and the receiver. Data are transferred. at the end, connection is released.

Question 31

Reliable transport layer protocol

Answer 31

implements flow and error control at the transport layer

Question 32

____ and ____ are connection-oriented and reliable

Answer 32

transmission control protocol (TCP) and stream control transmission protocol (SCTP)

Question 33

___ application progrm uses its own flow and error control mechanism or it needs fast service

Answer 33

Unreliable Transport Layer protocol

Question 34

______ is connectionless and unreliable

Answer 34

User datagram Protocol (UDP)

Question 35

provide process-to-process communication instead of host-to-host communication.

Answer 35

User datagram Protocol (UDP)

Question 36

T/F | UDP is a very simple protocol using a minimum of overhead.

Answer 36

TRUE

Question 37

T/F If a process wants to send a small message and does not care much about reliability, it can use UDP.

Answer 37

TRUE

Question 38

T/F | Sending a small message by using UDP takes much less interaction between the sender and receiver than using TCP or SCTP

Answer 38

TRUE

Question 39

In UNIX, the well-known ports are stored in a file called _____

Answer 39

/etc/services.

Question 40

Simple Network Management Protocol (SNMP) uses ____ port numbers

Answer 40

2 (161 and 162)

Question 41

UDP jacket is called ____

Answer 41

User Datagram

Question 42

T/F | UDP length = IP length – IP header’s length

Answer 42

TRUE

Question 43

T/F UDP datagram is encapsulated in IP datagram. * At the UDP layer, the IP header is dropped

Answer 43

True

Question 44

each user datagram can travel on a ____

Answer 44

different path

Question 45

Only those processes sending ___ should use UDP

Answer 45

short messages

Question 46

There is no error control mechanism in UDP except for the ____. ** means sender does not know if a messafe has been lost or duplicated

Answer 46

checksum

Question 47

what is checksum?

Answer 47

sequence of numbers | and letters used to check data for errors

Question 48

what will happen When the receiver detects an error through the checksum

Answer 48

user datagram is silently discarded

Question 49

________ encapsulates and decapsulates messages in an IP datagram

Answer 49

UDP protocol

Question 50

is a connection-oriented protocol; it creates a | virtual connection between two TCPs to send data

Answer 50

TCP (Transmission control protocol)

Question 51

TCP uses ______ mechanisms | at the transport level.

Answer 51

flow and error control mechanisms

Question 52

TCP SERVICES

Answer 52

process to process communication sream delivery service

Question 53

provides process-to-process communication using port numbers.

Answer 53

process to process communication

Question 54

___ allows the sending process to deliver data as a stream of bytes and allows the receiving process to obtain data as a stream of bytes.

Answer 54

stream delivery service

Question 55

why do TCP needs buffers for storage?

Answer 55

Because the sending and the receiving processes may not write or read data at the same speed

Question 56

T/F The IP layer, as a service provider for TCP, needs to send data in packets, not as a stream of bytes.

Answer 56

True

Question 57

At the transport layer, TCP groups a number of bytes together into a packet called a _____

Answer 57

segment