Network Basics Flashcards
Host
A node that serves as the beginning or ending point of the communication.
Physical Network
A network of interface cards, network hardware, cables, and so on that you can see when you look around a building.
Logical Network
A virtual representation of a network that appears to the user as an entirely separate and self-contained network even though it might physically be only a portion of a larger network or a local area network.
Repeater
It allows a network cabling system to extend beyond its maximum allowed length and reduces distortion by amplifying or regenerating network signals.
Hub
A simple network device that lets you connect multiple nodes in a star configuration.
Bridge
A device that actively works to prevent collisions by making sure not to send data to a segment that’s already busy.
Translating Bridge
A device which joins segments using different link layer protocols, by translating frames from one format into the other, such as from Ethernet to Token Ring or Wi-Fi.
Digital Subscriber Line (DSL)
A family of related technologies which carry data as a separate, high-frequency signal over the same physical cables of a voice telephone or ISDN line, without interfering with the telephone service.
Node
Any device on the network that actively transmits and receives information. This could be a computer, a networked resource like a printer or storage device, or a network device like a switch or router.
Media
The physical path connecting the nodes. Most commonly media is either copper cables, fiber-optic cables, or radio transceivers, but anything that can carry information can be a network medium.
Data
The information carried by the media. Usually, data is digitally encoded in an electrical, optical, or radio signal.
Networking device
A node that functions as part of the network structure rather than as a host or resource.
Networking challenges - Availability
The ability of a network to maintain connectivity as consistently as possible, while avoiding outages. A broken connection is an example of reliability failure.
Networking challenges - Reliability
Not to be confused with availability, in network terms reliability means that the network is free of communication errors: every packet of data successfully arrives at its destination with its contents intact and unaltered.
Networking challenges - Serviceability
How easy it is to perform maintenance on a network, whether that means replacing cables, accessing network devices, or configuring network software.
Networking challenges - Performance
The network’s ability to rapidly convey traffic.
Networking challenges - Security
How hard it is for unauthorized users to access data on the network.
Networking challenges - Scalability
The network’s ability to grow to meet new demands.
Networking challenges - Compatibility
The ability of all of a network’s components to communicate successfully both physically and logically.
Networking challenges - Quality of Service (QoS)
The ability of a network to provide better service and connection quality to special kinds of network traffic.
What three conditions are needed to establish connectivity?
A physical connection must exist, the sender must be able to convey information to the recipient, and the recipient must be able to understand and act on it.
What is the difference between availability and reliability?
Availability is how seldom network outages occur, while reliability is how consistently the network ensures every packet reaches its destination intact.
Local Area Network (LAN)
A Local Area Network (LAN) is confined to a fairly small area, usually within a single building. Today you can find LANs wherever you go.
Wide Area Network (WAN)
A Wide Area Network (WAN) extends over a very large area, with nodes in multiple cities or countries. The Internet is the most familiar example of a WAN, but not the only one.
Personal area network (PAN)
personal area network (PAN), which covers only a very small area, of centimeters to a few meters across. Usually, a PAN is confined to a particular user’s devices, such as a computer and its peripherals.
Near Field Communication (NFC)
Near Field Communication (NFC) is used for short-distance communications between smartphones or other personal devices.
Campus Area Network (CAN)
Used to connect multiple buildings in a single campus
Metropolitan Area Network (MAN)
Used to connect all or part of a city
storage area network (SAN)
Used to connect computers to storage devices using network technology
What connection technologies are most common for modern LANs?
Ethernet for wired connections, and Wi-Fi for wireless networks.
Other than physical distance, what distinguishes a WAN from a LAN?
a WAN requires transmission technologies compatible with long distances, and usually involves leased lines owned by a third party.
peer-to-peer
In peer-to-peer, there is no central administration. Every host connects to the network as an equal, or peer, and can offer its own resources to the network.
client-server
In client-server, hosts are divided into two categories: the clients that request resources, and the servers that provide them. To access a network resource, a client requests it from the server.
What are the benefits and drawbacks of peer-to-peer networking?
The main benefit is lower initial expense due to less need for specialized hardware and technical knowledge. The drawbacks include increased maintenance, and reduced scalability and security.
What are the benefits and drawbacks of client-server networking?
The main benefits are increased central control, allowing more secure and scalable networks. The main drawback is that dedicated servers can be expensive and require more advanced technical knowledge to install and operate.
TCP/IP
TCP/IP consists of a stack of four vertical layers. Each layer contains its own protocols, and corresponds to certain functions and components on the network.
TCP/IP Layer - Network Interface
Also known as the Network Access Layer or Link Layer, this defines how nodes communicate on local network and adapter level; it corresponds to the NIC on any given node.
TCP/IP Layer - Internet
Controls the routing of packets across multiple logical networks; it corresponds to components in the protocol stack of the operating system.
TCP/IP Layer - Transport
Manages end-to-end communication between hosts, and breaks application data up into the segments or datagrams sent over the network; it also exists within the operating system’s protocol stack.
TCP/IP Layer - Application
Allows user level applications to access the other layers; it doesn’t correspond directly to user applications, but instead to the protocols those applications use to communicate to the network.
How do abstraction layers improve network compatibility?
You can change the implementation of a given layer, such as the network interface, without affecting protocols on other layers.
From top to bottom, what are the layers of the TCP/IP model?
Application, Transport, Internet, Network Interface.
Which TCP/IP layers have the widest variety of available protocols?
The Application and Network Interface layers. The Transport and Internet layers rely on a smaller number of core protocols.
How do the OSI model layers correspond to the TCP/IP model layers?
Layers 1-2 correspond to Network Interface, Layer 3 to Internet, Layer 4 to Transport, and Layers 5-7 to Application.
Which type of network covers only a very small area, of centimeters to a few meters across?
PAN
From smallest to largest, Name 4 network scopes.
PAN - LAN - MAN - WAN
The Application layer enables applications on a network node to request network services such as file transfers, email, and database access.
True
What networks still make frequent use of hubs and wired repeaters?
Hubs might still be found on legacy Ethernet networks that aren’t fully switched. Repeaters are usually found in CAN and WAN applications, where transmissions distances might be too great for a signal to carry clearly.
How are dial-up modems like broadband modems? How are they different?
They are alike since connect a computer or LAN to a WAN, and both modulate and demodulate digital signals into analog carrier waves. They are different since dial-up modems connect one place to another over analog telephone lines while broadband modems link into an ISP’s cable or DSL network.
What are the advantages and disadvantages of adding a wireless repeater to your Wi-fi network?
The advantage is that you can extend your coverage area without needing additional connections to the wired network. The disadvantage is that due to the nature of Wi-Fi it effectively halves your overall wireless bandwidth.
What is the difference between Ethernet over Power and Power over Ethernet?
Ethernet over Power lets you use power lines for networking where you don’t have existing network cables, while Power over Ethernet lets you use network cables to carry electrical power to remote network devices.
A bridge is a type of computer network device that provides interconnection with other networks that use the same protocol.
True
A cable modem is a peripheral device used to connect to the Internet.
True
Hub
A simple network device that connects multiple nodes in a star configuration
Bridge
A device that prevents collisions by ensuring not to send the data to a segment that is already busy
Router
A device that can read packets on the Internet layer to view their IP addresses and can communicate with others to find the best path through the network to any given host or subnet
Gateway
A device that enables the traffic to flow in and out of the network
Wired Internet Access - Dialup
Uses analog phone lines.
Wired Internet Access - ISDN
Uses digital phone lines.
Wired Internet Access - DSL
Carries data as a secondary signal on analog phone lines.
Wired Internet Access - Broadband Cable
Carries data over cable television lines.
Wired Internet Access - Fiber-optic
Uses optical cables.
FTTN
Fibre to the Neighbourhood
FFTC
Fibre to the Cabinet
FTTP
Fibre to the Premises
Describe - Cellular Data
Connections designed for mobile phones, but sometimes extended to other users.
Describe - Terrestrial Wireless
Other technologies using ground-based broadcasts, generally targeting home and business users.
Describe - Satellite Internet
Data connections using orbital satellites.
How many cellular networks are there and what are they called?
There are 6
1G, 2G, 2.5G-2.9G, 3G, 4G, 5G
What website measures the bandwidth and latency of the Internet connection?
Speed test site
What technology brings high-bandwidth information to homes and small businesses over ordinary telephone lines
DSL
What channel access method is used by various radio communication technologies?
CDMA
CDMA
Code Division Multiple Access is a more proprietary system.
GSM
Global System for Mobiles used more open standards created by an industry consortium, requiring interoperability between carriers.
What technology supports data rates up to 84Mbps downstream and 22Mbps upstream using MIMO transmission?
HSPA+
What is scalability?
Ability of a network to grow to meet new demands
What monitors network traffic and helps to detect malicious activities by identifying suspicious patterns in the incoming packets?
NIDS
What device provides an interface for connecting the computer to a network?
NIC
What network type is used to connect all or part of a city?
MAN
What technology carries data as a secondary signal on analog phone lines?
DSL
A PC with its connected Bluetooth devices is an example of what?
PAN
What describes the amount of traffic that can be passed through the network in a given time?
Throughput
What networking device lets you connect multiple nodes in a star configuration?
Hub
What is the Internet connection speed of the broadband cable?
384Kbps - 400Mbps
