9. Network Basics Flashcards
What is the purpose of Power over Ethernet (PoE)?
It allows an Ethernet connection to be used as both a network and power connection
Which technology allows voice data to be transmitted over a company’s computer network
Voice over IP (VoIP)
Which hardware device can connect similar networks and can separate the network traffic on each segment?
bridge
Which two details can you use to access a router’s configuration page through a web browser
The router’s IP address and the router name
Which hardware device operates at the Physical layer (Layer 1) of the Open Systems Interconnection (OSI) model to provide connectivity to network computers?
a hub
Which hardware device operates at the Data Link Layer of the Open Systems Interconnection (OSI) model to provide connectivity to network computers
switch
Which device is used to extend the range of an existing wireless network
wireless repeaters
Which devices are used to connect workstations in a 100-BaseT network
routers, switches, and hubs
Which device is the combination of a bridge and a router
brouter
Which hardware device routes data from a local area network (LAN) to a phone line or other network connection
router
How many network cards are required in each computer when internet access is shared via a router
one network card in each computer
To which port on the router or switch should you connect a computer to access the internet
to the local area network (LAN) port
What device must be isntalled in a comptuer to conenct the computer to other computers or a network
a network adapter
What does the acronym ISP denote
Internet Service Provider
DNS
Domain Name System
AP
Access Point
Which intenet connection has a line of sight requirement
satellite
Which type of wireless network interference is caused by competing wireless signals
radio frequency interference (RFI)
Which type of wireless network interference is caused by electrical devices such as fluorescent lights
electromagnetic interference (EMI)
Maximum speed limit supported by T1 line
1.544 Megabits per second (Mbps)
DSL
Digital Subscriber Line
Bridge
a device that actively works to prevent collisions by making sure not to send data to a gement that’s already busy
Digital Subscriber Line (DSL)
family of 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.
Hub
A simple network device that lets you connect multiple nodes in a star configuration
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 extened beyond its maximum allowed length and reduces distortion by amplifying or regenerating network signals
Translating Bridge
A device which joins segments using different link layers protocols, by translating frames from one format into the other, such as from Ethernet to Token Ring or Wi-Fi
Physical network
The network of interface cards, network hardware, cables, etc
Node
Any device on the network that actively transmits and receives information
Host
A node that servers as the beginning or ending point of communication
Media
The physical path connecting the nodes
Data
The information carried by the media
Networking device
A node that functions as part of the network structure rather than as host or resource
Availability
The ability of a network to maintain connectivity as consistently as possble, while avoiding outages
Reliablity
Means the network is free of communication errors : every packet of data successfully arrives at is destination with its contents intact and unaltered.
Serviceability
How easy it is to perform maintenance on a network
Performance
The network ability rapidy convey traffic
Security
How hard it is for unauthorized users to access data on the network
Scalability
The network’s ability to grow to meet new demands
Compatibility
The ability of all of a network’s components to communicate successfully both physically and logically
Quality of Service (QoS)
Overall connection quality as seen by users of the network, especially as connected to some expected baseline. This generally includes performance, reliability, and availablity.
QoS
Quality of Service
Most common network scope
- LAN
- WAN
LAN
Local Area Network
Local Area Network
usually confined to a fairly small area, usually within a single building
WAN
Wide Area Network
Wide Area Network (WAN)
extends over a very large ara, with nodes in multiple cities of countries
PAN
Personal Area Network
Personal Area Network
- Covers only a very small area
- Centimeters to a few meters across
- Usually confined to a user’s devices, such as computer and its peripherals
CAN
Campus Area Network
Campus Area Network (CAN)
Used to connect multiple buildings in a single campus
MAN
Metropolitan Area Network
Metropolitan Area Network (MAN)
- used to connect all or part of a city
- intermediate in size between a LAN and a WAN
SAN
Storage area network
Storage Area Network
specialized type of LAN which connects computers to storage devices using network technology
not actually a scope
Two resource-sharing models
- Peer-to-peer model
- Client-Server model
Peer-to-peer model
- 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 Model
hosts are divided into two categories: the clients that request resources and the servers that provide them.
Two primary reference models
- OSI model
- TCP/IP model
7 layers of the OSI layer
- Layer 7: Application
- Layer 6 : Presentation
- Layer 5: Session
- Layer 4: Transport
- Layer 3: Network
- Layer 2: Data Link
- Layer 1: Physical
Four Layers of the TCP/IP model
- Application Layer
- Transport Layer
- Internet Layer
- Network Interface Layer
Application Layer:
- Allows user level application to access the other layers
- Doesn’t correspond directly to uer applications, but instead to the protocolos used by said applications use to communicate to the network
- Corresponds to OSI Layers 5-7
Transport Layer
- Manages end-to-end communication betwen hosts
- breaks application data up into the segments or datagrams sent over the network
- exists within the OS’s protocol stack
- Corresponds to OSI Layer 4
- Primary protocols on this level are TCP and UDP
- TCP is more stable
- UDP is simpler and quicker
Internet Layer
- Controls the routing of packets across multiple logical networks
- Coresponds to components in the protocol stack of the OS
- Corresponds to OSI layer 3
Network Interface Layer
- Also known as the Network Access Layer or Link Layer
- Defines how nodes communicate on the local network and adapter level
- corresponds to the NIC on any given node
- Corresponds to the OSI layers 1 and 2.
Most basic devices for network infrastructure fall into three levels of sophistication
- Repeaters and hubs
- Bridges and switches
- Routers and gateways
Repeaters
device made to enable connections over longer distances.
Hub
A simple network device that lets you connect multiple nodes in a store configuration.
Passive hub and active hub
Active or repeater hub
whenever it received a signal on one port, it regenerates it and broadcasts on all the others (more or less a repeater with more ports)
passive hub
Functionally just splits the cable in multiple directions
Bridge
similar to a repeater except instead of blinding regenerating signals and passing it on, it actively works to prevent collections by making sure not to send data to a segment that’s already busy.
translating bridges
- Can join two network segments of different types
- Can even join segements using different link layer protocols
Switches
A bridge with four or more ports
multilayer switches
capable of examining frame payloads to understand them on the internet layer or even higher to the application layer
Routers
- Sits at the boundaries within the large network and separate it into smaller networks called subnets
- The can read packets on the internet layer to view their IP addresses and can communicate with other routers to find the best path through the network to any give host or subnet.
- Works like a bridge or switch, but since it operates on the interney layer it tracks logical addresses and subnets.
Intrusion Detection System (IDS)
passive monitoring systems designed to alert administrators when something suspicious happens, but take no action on their own
Intrusion Prevention Systems (IPS)
active protection systems which can block traffic, disconnect users, or take other corrective actions against an attack
VPN
virtual private network
Dialup Speed
< 56Kbps
ISDN speed
64-128Kbps
DSL speed
128Kbps-100Mbps
Broadband cable
384Kbps-400Mbps
Fiber-optic speed
up to 1Gbps
ISDN
Integrated Services for Digital Network
ISDN types
- Basic Rate Interface (BRI): the most common ISDN type.
- gross data rate of 144kbps
- consists of two 64kbps bearer channels for user data and one 16kbps delta channel for control
- Primary Rate Interface (PRI)
- connects directly to the digital carrier lines
- more bearer channels and a larger delta channel
- Typically uses T-1 carrieirs with a 1.544Mbps gross bit rate and 23 B channels (in the US and Japan)
- Typically uses E-1 carriers with 2.048 Mbps data rate and 30B channels
DOCSIS
Data Over Cable Service Interface Specification
Approaches to Fiber Optic connections
- Fiber to the Neighborhood (FTTN)
- Fiber to the Curb (FTTC)
- Fiber to the premises (FTTP)
- Conists of Fiber to the Home (FTTH)
- or Fiber to the Building (FTTB)
Cellular network generations
- 1G: Original analog cellular network used from the early 1980s to the early 1990s
- 2G: Early digital ceullar networks ued in the 1990s and early 2000s. Available speeds under 50kbps
2.5G-2.9G: Marketing terms for 2G services desiged for faster and more efficient data operations while 3G was establishing. Faster variants, Enhanced Data rates for GSM Evolution (EDGE)
3G: Standard complied with IMT2000 created by ITU. Speeds of at least 200kbps
4G LTE: Long Term Evolution Supports vocie and data using TCP/IP protocols and can reach data speeds of 1Gbps down and 500 Bbps upstream. Many networks fall back to 3G network for voice calls
5G: Supports speeds of 20Gbps.
Two ceullar radio technologies
- GSM
- CDMA
GSM
Global System for Mobiles
More popular standard worldwide
used more open standards, requiring interoperability between carriers
CDMA
Code Division Multiple Access
More proprietary system
Initially it had higher perforamnce but also higher licensing fees
