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WorksheetsIntroduction to Networking Quiz
Total questions: 98
Worksheet time: 54mins
What is a protocol?
A set of rules that define the format and order of messages exchanged between network entities, and the actions taken on transmission and receipt.
A type of network topology
The physical medium used for data transmission
An Internet Service Provider
From a "nuts and bolts" view, the Internet is a collection of which of the following?
Only end systems
Only communication links
Packet switches, communication links, and end systems
Only protocols
What are the two key functions of the network core?
Packet switching and circuit switching
Forwarding and routing
Encoding and modulation
Multiplexing and demultiplexing
In packet switching, what can happen if the arrival rate to a link exceeds the link's transmission capacity?
Packets are immediately destroyed
The link's bandwidth is automatically increased
Packets will queue, waiting for transmission, and may be dropped if the queue fills up
The router will switch to circuit switching
What is the principal difference between circuit switching and packet switching?
Packet switching is older technology
Circuit switching requires a dedicated path and resources for the entire communication session
Circuit switching is used exclusively for data, while packet switching is for voice
Packet switching is less efficient
What are the two fundamental approaches to multiplexing in circuit-switched networks?
TCP and UDP
FDM and TDM
Packet and Datagram
HTTP and SMTP
The total nodal delay in a router is the sum of which four types of delay?
Transmission, propagation, processing, queuing
Sending, receiving, encoding, decoding
Serialization, deserialization, forwarding, routing
Access, core, Internet, LAN
The time required to push all of a packet's bits into the link is known as:
Propagation delay
Queuing delay
Transmission delay
Processing delay
The "traffic intensity" (La/R) is a measure used to predict what?
The bandwidth of a link
The likelihood of packet loss
The average queuing delay
The processing speed of a router
What happens if the traffic intensity La/R > 1?
The average queueing delay is small
The average queueing delay is infinite
The transmission rate decreases
The link's bandwidth doubles
Throughput, in the context of a communication session, is best defined as:
The speed of light in a fiber optic cable
The rate (in bits/time unit) at which bits are transferred from sender to receiver
The total capacity of a network link
The time it takes to send a packet
The end-to-end throughput of a connection is often constrained by the:
Fastest link in the path
Bottleneck link
Sender's application
Receiver's operating system
Which program provides delay measurements from source to router along an end-end Internet path?
Ping
Traceroute
Wireshark
Netcat
Packet loss in a router occurs primarily when:
The router's CPU is too slow
A packet's checksum is incorrect
The router's output buffer (queue) is full
The packet has an invalid IP address
The original vision of the Internet was a group of:
Commercial entities
Mutually trusting users attached to a transparent network
Government agencies
Competing ISPs
What is a common threat where an attacker overwhelms a resource with bogus traffic, making it unavailable to legitimate users?
IP Spoofing
Packet Sniffing
Denial of Service (DoS)
Encryption
Which of the following is NOT a common line of defense in network security?
Authentication
Confidentiality via encryption
Running all services with default settings (on-by-default)
Firewalls
Why is layering used in network protocol design?
To make networks more expensive
To add unnecessary complexity
To provide modularity, ease of maintenance, and a structured discussion model
To ensure all protocols are proprietary
What are the five layers of the Internet protocol stack?
Physical, Data Link, Network, Session, Application
Application, Transport, Network, Link, Physical
Application, Presentation, Session, Transport, Network
Physical, Network, Internet, Transport, Application
The process of keeping the network layers separate and having each layer rely on the services of the layer below is a key principle of:
Packet switching
Protocol layering
Circuit switching
Network security
In the context of the Internet, "hosts" are synonymous with:
Routers
Switches
End systems
Links
Which of the following is an example of a guided physical medium?
Radio
Satellite
Fiber optic cable
Bluetooth
Which of the following is an example of an unguided physical medium?
Twisted pair
Coaxial cable
Fiber optic cable
Wireless radio
What does DSL stand for?
Digital Satellite Link
Digital Subscriber Line
Data Switching Logic
Dedicated Service Line
In a home network, the box that combines the functions of a router, firewall, NAT, and wireless access point is often connected to a:
DSLAM
Cable modem or DSL modem
Ethernet switch only
Core router
A "base station" in a wireless access network is also known as a(n):
End system
Access point
Router
modem
The transmission rate of a link is also commonly referred to as its:
Propagation speed
Bandwidth
Length
Delay
The "store-and-forward" transmission method used by packet switches means the entire packet must be received before:
It is processed for errors
It can be transmitted on the next link
The checksum is calculated
The destination IP is read
The "network of networks" that forms the Internet is structurally complex due to being driven by:
A single global design
Economics and national policies
The original ARPANET blueprint
A single global ISP
At the center of the Internet's structure are a small number of well-connected large networks known as:
Access ISPs
Tier-1 ISPs and large content provider networks
Regional ISPs
Home networks
An IXP is an:
Internet Exchange Point
International X.25 Protocol
Internal Xerox Printer
Internet Exploitation Package
The concept of connecting each access ISP to every other access ISP directly is not used because it:
Is too secure
Doesn't scale (O(N^2) connections)
Is mandated by law
Uses too much wireless spectrum
The traditional telephone network is a classic example of:
Packet switching
Message switching
Circuit switching
Cell switching
In the caravan analogy, the time to push the entire caravan through a toll booth onto the highway is analogous to:
Propagation delay
Processing delay
Transmission delay
Queuing delay
In the caravan analogy, the time for the last car to propagate from the 1st toll booth to the 2nd is analogous to:
Propagation delay
Processing delay
Transmission delay
Queuing delay
A protocol defines the ________ of messages exchanged.
The organization that defines Internet standards through RFCs is the:
IEEE
IETF
ISO
ITU
From a "services" view, the Internet provides a(n) ________ for applications to send and receive data.
The "network edge" refers to:
The core routers of the Internet
Hosts (end systems) and access networks
Undersea cables
Satellite links
The "network core" refers to:
Home networks
The interconnected routers and network of networks
Mobile devices
Web browsers
HFC stands for:
High-Frequency Copper
Hybrid Fiber Coax
Home Fiber Connection
High-Fidelity Cable
Cable internet access is typically:
Symmetrical (same upstream/downstream rate)
Asymmetrical (higher downstream rate)
Full duplex only in theory
Only used for television
In a DSL network, data and voice are transmitted over the same line using:
Different packet switches
Different frequency bands
The same frequency band
Time division only
4G and 5G are examples of:
Wide-area cellular access networks
Local area wired networks
Home network protocols
Ethernet standards
A characteristic of a P2P architecture is:
There is an always-on server
Peers communicate directly with each other
It is easier to manage than client-server
It has no scalability
In the client-server model, the server is typically:
An intermittently connected host
An always-on host
A host with a dynamic IP address
A peer
A process is:
A physical device
A program running within a host
A network protocol
A type of cable
A socket is the interface between:
The application layer and the transport layer within a host
Two different hosts
The network layer and the link layer
The CPU and the memory
To identify a process on a host, one needs both the ________ and the ________.
IP address; MAC address
IP address; port number
MAC address; port number
Hostname; username
HTTP typically uses port number:
25
53
80
110
An application-layer protocol defines:
The voltage of signals on a wire
The types of messages, message syntax, semantics, and rules
The brand of router to be used
The physical layout of the network
A protocol that is defined in an RFC and allows for interoperability is called a(n) ________ protocol.
Open
Proprietary
Private
Secret
Skype and Zoom originally used ________ protocols.
Open
Proprietary
HTTP-based
SMTP-based
For a file transfer application, the most important service requirement is likely:
Timing
Throughput
Security
Loss tolerance
For an Internet telephony application, the most important service requirement is likely:
Timing (low delay)
High throughput
100% reliability
Security
TCP provides which of the following services?
Reliable, in-order delivery
Unreliable, unordered delivery
Timing guarantees
Bandwidth guarantees
UDP provides which of the following services?
Reliable, in-order delivery
Unreliable, unordered delivery
Flow control
Congestion control
Why would an application use UDP?
To have guaranteed delivery
To avoid connection setup delays and for finer control
Because it provides congestion control
Because it is more secure than TCP
TLS provides security at which layer?
Application layer
Physical layer
Network layer
Between the application and transport layers
A web page consists of:
A single object
Multiple objects, each addressable by a URL
Only text
Only the base HTML file
In the HTTP client-server model, the client is typically the:
Web server
Browser
DNS server
Mail server
HTTP uses which transport-layer protocol?
UDP
TCP
ICMP
FTP
HTTP is said to be "stateless" because:
It cannot maintain a TCP connection
Its servers maintain no information about past client requests
It only works in one state of the USA
It uses UDP
Non-persistent HTTP requires ________ RTTs per object.
1
2
4
It varies
Persistent HTTP:
Sends only one object per TCP connection
Leaves the TCP connection open for multiple requests/responses
Is slower than non-persistent HTTP
Is an older version of HTTP
The HTTP method used to request a resource is:
POST
PUT
GET
HEAD
The HTTP method used to upload data to a server (e.g., from a form) is:
POST
PUT
GET
HEAD
An HTTP response code of 200 means:
Moved permanently
Bad request
Not found
Request succeeded
An HTTP response code of 404 means:
Moved permanently
Bad request
Not found
Request succeeded
Cookies are used to:
Encrypt data
Increase transmission speed
Maintain state between HTTP transactions
Compress web pages
A "third-party cookie" often comes from:
The website you are directly visiting
An advertiser or tracker on the website you are visiting
Your own browser
Your ISP
A web cache (proxy server) acts as both a ________ and a ________.
Client; server
Router; switch
Browser; OS
Packet; datagram
The primary benefit of a web cache is to:
Reduce response time for clients and reduce traffic on an institution's access link
Make the Internet more complicated
Increase the load on origin servers
Store user passwords
A Conditional GET is used to:
Force a server to send an object
Check if a cached object is still up-to-date
Post new data to a server
Delete an object from a server
HTTP/2 aims to decrease delay by:
Using UDP instead of TCP
Mitigating head-of-line (HOL) blocking within a single TCP connection
Removing all headers
Slowing down transmission rates
The protocol used to send email messages between servers is:
HTTP
FTP
SMTP
DNS
The three major components of email are:
Browsers, clients, servers
User agents, mail servers, SMTP
TCP, IP, HTTP
POP, IMAP, HTTP
SMTP is a ________ protocol.
Pull (client retrieves when it wants)
Push (server sends immediately)
Peer-to-peer
Broadcast
Unlike HTTP, SMTP requires that message body be in:
7-bit ASCII
Binary
Encrypted format
HTML
Which protocol is used to retrieve email from a server, allowing management of messages on the server?
SMTP
HTTP
IMAP
FTP
DNS provides which service?
Hostname-to-IP-address translation
Email retrieval
Web page storage
Packet routing
DNS is a(n) ________ database.
Centralized
Distributed and hierarchical
Flat-file
Relational
The top of the DNS hierarchy is served by:
.com servers
Root name servers
Authoritative name servers
Local name servers
A company's own DNS server, providing authoritative mappings for its hosts, is called a(n):
Root server
TLD server
Authoritative server
Local server
The DNS record type "A" provides:
The canonical name for an alias
The IP address of a hostname
The mail server for a domain
The authoritative name server for a domain
The DNS record type "MX" provides:
The canonical name for an alias
The IP address of a hostname
The mail server for a domain
The authoritative name server for a domain
DNS caching is important because it:
Increases security
Improves response time and reduces DNS traffic
Makes records permanent
Is required by law
A DDoS attack on DNS would most likely target:
Individual user machines
Root or TLD servers
Web browsers
Ethernet cables
In a P2P architecture, scalability is achieved because:
Each peer is an always-on server
New peers bring new service capacity
There is a central authority
Peers have fixed IP addresses
BitTorrent uses a ________ strategy to encourage peers to upload.
First-come-first-served
Tit-for-tat
Random selection
Pay-to-play
In BitTorrent, a peer requesting chunks will typically ask for the ________ chunks first.
Largest
Smallest
Rarest
Most common
Video streaming often uses ________ to encode different versions of the same video at different rates.
DNS
SMTP
DASH
P2P
A CDN is a:
Content Distribution Network
Centralized Database Node
Cryptographic Data Notation
Client Device Network
The "enter deep" CDN strategy involves placing servers:
In a few large data centers
Deep into access networks, close to users
Only at the core of the Internet
On satellites
A socket is the door between:
Two different networks
The application process and the operating system's transport protocol
The client and server hardware
The router and the switch
For a simple request-reply application with low delay requirements and tolerance for loss, a developer might choose:
TCP
UDP
HTTP
SMTP
In socket programming with TCP, the server must first run and execute ________ to welcome client contact.
connect()
bind() and listen()
sendto()
close()
In socket programming with UDP, the sender must explicitly attach the ________ to each packet.
Destination's MAC address
Destination's IP address and port number
Source's port number only
Encryption key
