IT-215 Course Study Material: Key Concepts in Computer Networking

In client/server processing, processing is done on the ________.

Neither client nor server

server

client

Both client and server

Both client and server

In P2P applications, most processing is done on the ________.

client (Who plays sometimes as a server!)

Peer-to-peer (P2P) applications

Clients provide service to each other.

- Made possible by growing PC processing power.

Cloud Computing

Resources are outsourced to a provider who is accessed entirely via a network.

- Users only need a PC or other intelligent device.

- Company does not need to maintain servers or applications.

kilobits per second (KBps)

1,000 bps

megabits per second (MBps)

1,000,000 bps

gigabits per second (GBps)

1,000,000,000 bps

Terabits per second (Tbps)

1,000,000,000,000 bps

47,000,000 bps is ________.

47 Mbps

Which of the following uses packet switching?

Neither Dial-up telephone circuits nor Leased line circuits

Breaking down a message into many packets is done on the _______ while the reassembly of packets into a message is done on the _______.

source host, destination host

A ________ is the path that a packet takes across a single switched network and its src and dst physical addresses stay unchanged.

data link

When a packet passes through seven switches between the source and destination hosts (no routers), the number of physical links is ______, while the number of data links is ____.

Eight, One

If two hosts are separated by seven networks, how many packets will there be along the way when a host transmits a packet to another host?

1.

How many data links will there be if a frame passes from a computer through two switches, then through a router, then through two more switches, and then to the destination computer?

Two

In binary, the decimal 13 is equivalent to 1101. What is 14?

1110

Inside a computer, data is represented as

Binary

____________ data sent in discrete "chunks" (packets); each has a path chosen for it.

Packet Switching

Frequency division multiplexing (FDM) is an example of sharing bandwidth under

Circuit Switching

Any home TV must be a " Network Host" ?

False

You need to store your "Data" on a remote server to be able to access it from any place in the world. You are using "Cloud Computing" for your data.

false

A network is a system that permits networked applications on different hosts to work together.

True

Which of the following has greater resistance to transmission errors

Binary signaling.

For bursty data, packet switching is desirable because it ________.

makes transmission more efficient

Packets are carried inside frames.

True

Which standard places packets that arrive out of order in order?

TCP

Ethernet addresses are ________.

48 bits long

Messages (segments, packets or frames) always have data fields.

False

Which of the following have explicit openings and closings?

Connection-oriented protools(TCP)

An 8-bit field can represent ________ alternatives.

256

After the internet "Network" layer process does encapsulation, it passes the IP packet to the ________ layer process.

data link

After the side wishing to close a TCP connection sends a FIN message, it will

only send ACK segments

An HTTP message is encapsulated at the transport layer to become a TCP _____, which in turn is encapsulated at the internet layer to become an IP_____ , which in turn it's encapsulated at the data link layer to become an Ethernet _____.

Segment, Packet Frame

B7-22-DD-6F-C8-AB is a/an ________ address.

Ethernet

Converting application messages (consist of characters) into bits is called ________.

encoding

IP version 6 addresses are ________.

128 bits long

Ethernet detects errors but does not correct them. Therefore, Ethernet is reliable.

False

Headers usually are divided into fields.

True

Host P transmits a SYN to Host Q. If host Q is willing to open the connection, it will transmit a/an ________ segment.

SYN, ACK

How a message is organized is its ________.

syntax

How long are IP (version 4) addresses?

32 bits.

If the destination host receives a segment that is incorrect, it will

it will typically discard the segment and wait for retransmission

(TCP)If the destination host receives a segment that is incorrect, it will

prompting the sender to retransmit the data after a timeout or upon receiving duplicate acknowledgments for the previous segment.

Transport port fields are found in

Both UDP headers and TCP headers

MAC Addresses are ______________octets (bytes).

6

The tool used for network protocol analyzer is called ______________.

Wireshark

The meaning of a message is referred to as the message's ________.

semantics

What is (are) the well-known port number(s) for FTP?

20 and 21.

UDP checks messages for errors but does not correct them. UDP is ________.

unreliable

Which layer process does NOT do encapsulation when an application layer process transmits a message?

Physical.

________ is placing a message in the data field of another message.

Encapsulation

Routing

he route taken by packets from source to destination (involvesall routers)

Forwarding

(aka Switching): the movement of packets from an input interface to an appropriate output interface (involves a single router)

Application-layer protocols

define when and how messages are sent

Network-layer protocols

deliver data from one end-system to another. on every end-system and router

Transport-layer protocols

deliver data between processes on different end-systems. only on end systems

Buffering

required when data grams arrive from fabric faster than the transmission rate

Scheduling discipline

chooses among queued datagrams for transmission

Queuing

if data grams arrive faster than forwarding rate into switch fabric

IP: Internet Protocol (version 4):

transfer IP packets from one host to another. One of the most common protocols today. This is what the Internet is built around.

IPv6: Internet Protocol (version 6)

ICMP: Internet Control Message Protocol (version 4)

This is a protocol toreport common errors and events in the IP, TCP and UDP protocols.

ICMPv6: Internet Control Message Protocol (version 6):

This is a protocolto report common errors and events in the IPv6, TCP and UDP protocols.

IGMP

IP multicasting

HTTP

is connectionless.- Every request-response cycle is independent.

TCP

is connection-oriented.- There is a formal opening of the connection.- Within the connection, messages are sequenced,acknowledged, and retransmitted if necessary.- There is a formal closing of the connection.8

Field lengths may be measured in

bits or bytes

Another name for byte is

octet

MAC addresses

48 bits

Data Field (dozens, hundreds, or thousands of bits)

Often contains a TCP segment

What does the IP packet never have?

Trailer

Where are trailers found?

Layer 2 frames

Do all Layer 2 frames have trailers?

No, many Layer 2 frames do not have trailers

The trailer contains

Frame Check Sequence field for error detection.

IP address

32-bit identifier for host or router interface

Interface

connection betweenhost or router and a physicallink

IP addresses are associated with an

interface, not the host or router

A network (subnet)

the set of hosts reachable without having to traverse a router

Netmask

32-bit number to identify which bits are network prefix inthe IP address

Physical Layer

•Is the physical connection between the sender and the receiver.

•It includes all the hardware devices (computers, modems, and hubs) and physical media (cables and satellites).

•This layer specifies the type of connection and the electrical signals, radio waves, or light pulses that pass through it.

Data Link Layer

•Is responsible for moving a message from one computer to the next computer in the network path from the sender to the receiver. This layer has 3 functions:

-Control the physical layer by deciding when to transmit messages over the media.

-Format the messages by indicating where they start and end.

-Detects and corrects any errors that have occurred during transmission.

Network Layer

-Routing, selecting the next computer to which the message should be sent.

-

-Find the address of that computer if it doesn't already know it.

Transport Layer

-It is responsible for linking the application layer software to the network and establishing end-to-end connections between the sender and receiver when such connections are needed.

-

-It breaks long messages into several smaller messages to make them easier to transmit.

-

-Detect lost messages and request that they be resent.

Application Layer

-This is the application software used by the network user.

-With this layer the user defines what messages are sent over the network.

-Examples of this layer are the internet explorer and web pages.