Connecting to the Internet

PSTN (Public Switches telephone network)
Plain old telephone service (POTS)
USENET
A dial-up connection uses POTS for data transfer, and gets its name because the connection is established by actually dialing a phone number
Modulator/Demodulator
Baud rate
A measurement of how many bits can be passed across a phone line in a second
14.4 kbps

Broadband
Any connectivity technology that isn’t dial-up internet
T-carrier technologies
originally invented by AT&T in order to transmit multiple phone calls over a single link
T-Carrier technologies
DSL
Cable broadband
Fiber connections
Transmission System 1

Cable Communications Policy Act
TV frequency
Phone frequency
Cable broadband
Shared bandwidth technology
Central office
Cable Modem
The device that sits at the edge of a consumer’s netwrok and connects it to the cable modem termination system, or CMTS
Cable Modem termination system(CMTS)
Connects lots of different cable connections to an ISPs core network

FTTX (Fiber To THe X)
Fiber To The Neighborhood(FTTN)
Fiber To The Building (FTTB)
FTTB is a setup where fiber techonogies are used for data delivery to an individual building.
FTTH(Fiber To The Home)
FTTP (Fiber To The Premises)
Optical Network terminator(ONT)
Converts data from protocols the fiber network can understand, to those that more traditional, twisted-pair copper netwroks can understand

Wide Area Networks (WAN)
Acts like a single network, but spans across multiple physical locations

Wireless networking
A way to network without wires
IEEE 802.11 standards
802.11 family
WiFi
Frequency band A certain section of the radio spectrum that’s been agreed upon to be used for certain communications
In North America, FM radio transmissions operate between 88 and 108 MHz
FM broadcast band
2.4 Ghz and 5Ghz
802.11b, 802.11a, 802.11g, 802.11n, 802.11ac
802.11 = physical and data link layers
Frame control field Is 16 bits long and contains a number of subfields that are used to describe how the frame itself should be processed
Duration field It specifies how long the total frame is, so the receiver knows how long it should expext to have to listen to this transmission
Sequence control field Is 16 bit long and mainly contains a sequence number used to keep track of the ordering of frames
Data payload Has all the data of the protocols further up the stack
Frame check sequence field Contains a checksum used for a cyclical redundancy check, just like how ethernet does it

Channels
Individually, smaller sections of the overall frequency band used by a wireless network
Collision domain
Any one network segment where one computer can interrupt another
Avoid collision domains wherever you can

Wired Equivalent Privacy (WEP)
An encryption technology that provides a very low of privacy
WiFi Protected Access
128 bits
WPA2
256 bits
MAC filtering
You configure your access points to only allow for connections from a specific set of MAC addresses belonging to devices you trust