Ch. 13-20 Flashcards
Multiplexer
Takes a circuit and combines it with a few hundred other circuits into a single complex circuit on one wire.
FDM
Frequency Division Multiplexing - process of keeping every separate call in its own unique frequency range.
Circuit Switching
Physically connecting two phones together on one circuit.
A repeater
Takes the entire digital signal and re-creates it out the other end.
Last Mile
The connection from a central office to individual users.
DS0
Digital Signal Rate - Converts analog sound into 8-bit chunks 8000 times a second creating a data stream.
Modem
A modulator takes a digital signal and converts it into an analog signal. A demodulator takes an analog signal and converts it into a digital signal. A modem does both.
T1 connection
A high-speed digital networking technology.
T1 Line
The specific, shielded, two-pair cabling that connects the two ends of a T1 connection.
CSU/DSU
Channel Service Unit/Digital Service Unit
DS1
Digital Signal 1 - A special signaling method. Uses a relatively primitive frame.
TDM
Time Division Multiplexing - The process of having frames that carry a portion of every channel in every frame on a regular interval.
T3 Line
Supports a data rate of about 4 Mbps on a dedicated telephone connection.
T1
24 channels, 1.544 Mbps
T3
672 channels, 44.736 Mbps
E1
32 channels, 2.048 Mbps
E3
512 channels, 34.368 Mbps
SONET
Synchronous Optical Network
SDH
Synchronous Digital Hierarchy
OC
Optical Carrier - standards denote the optical data-carrying capacity (in bps) of fiber-optic cables in networks conforming to the SONET standard.
WDM
Wavelength Division Multiplexing - enables an individual single-mode fiber to carry multiple signals by giving each signal a different wavelength.
DWDM
Dense Wavelength Division Multiplexing
STS
Synchronous Transport Signal - Consists of two parts: STS Payload and STS Overhead.
STS Payload
Carries data
STS Overhead
Carries the signaling and protocol information.
Packet Switches
Machines that forward and store packets using any type of packet switching protocol.
Frame Relay
An extremely efficient packet-switching standard, designed for and used primarily with T-carriers. Switches packets quickly, but without any guarantee of data integrity at all.
ATM
Asynchronous Transfer Mode - A network technology originally used for high-speed LAN’s. Integrated voice, video, and data on one connection, using short and fixed-length packets called cells to transfer information.
MPLS
Multiprotocol Label Switching - Adds an MPLS label that sits between the Layer 2 and Layer 3 information. Layer 3 is always IP, so MPLS labels sit between Layer 2 and the IP headers. Consists of four parts: Label, Cost of Service (CoS), S, Time to Live (TTL).
QoS
Quality of Service
FEC
Forwarding Equivalence Class - A group of devices that tend to send packets to the same place, such as a single broadcast domain of computers connected to a router.
LSR
Label Switching Router - Looks for and forwards packets based on their MPLS label.
LER
Label Edge Router - An MPLS router that has the job of adding MPLS labels to incoming packets that do not yet have a label.
LDP
Label Distribution Protocol - LSR’s and LER’s use the LDP to communicate dynamic information about their state.
BERT
Bit Error Rate Test - Verifies the T-connection from end to end.
Dedicated Lines
Are always off the hook, they never hang up on each other.
Dial-up Lines
Have phone numbers, must dial up to make connection.
PSTN
Public Switched Telephone Network - POTS (plain old telephone service). Regular phone line.
LEC
Local Exchange Carrier - The telephone company (telco) that provides local connections and usually the one that owns your local central office.
IXC
Interexchange Carrier - provides long distance
Baud
One analog cycle on a telephone line.
Baud Rate
The number of bauds per second.
NIU
Network Interface Unit - The small box on the side of a home that accepts the incoming lines from the telephone company and then splits connections used in businesses.
UART
Universal Asynchronous Receiver/Transmitter - Takes the 8-bit-wide digital data and converts it into 1-bit-wide digital data and hands it to the modem for conversion to analog. This process is reversed for incoming data.
CCITT
International Telegraph and Telephone Consultative Committee now known as ITU (International Telecommunication Union)
V Standards
Define the speeds at which modems can modulate. V.92 Standard is the current standard.
V.42
Error Checking
V.42bis
Data compression
V.44
Data compression
MNP5
Both error checking and data compression
ISDN
Integrated Services Digital Network - process of sending telephone transmission across fully digital lines end-to-end.
B Channels
Bearer Channels - carry data and voice information using standard DS0 channels.
D Channels
Delta Channels - Carry setup and configuration information at 16 Kbps.
BRI
Basic Rate Interface - Most common setup is two B/one D. Setup uses only one physical line, but each B channel sends 64 Kbps, doubling the throughput total to 128 Kbps.
PRI
Primary Rate Interface - Type of ISDN, A full T1 line, carrying 23 B channels.
TA
Terminal Adapter
SPID
Service Profile ID
DSL
Digital Subscriber Line - A fully digital, dedicated connection.
SDSL
Symmetric DSL - Expensive, equal upload and download speed
ADSL
Asymmetric DSL - less expensive
VDSL
Very High Bitrate DSL - most expensive
SOHO
Small Office and Home Office
DSLAM
DSL Access Multiplexer - connects multiple customers to the internet.
PPPoE
Point-to-Point Protocol over Ethernet
DOCSIS
Data Over Cable Service Interface Specification
802.16
Wireless Standard - WIMAX
MANs
Metropolitan Area Networks
LTE
Long Term Evolution
HSPA
High-Speed Packet Access - 3G, HSPA+ is 4G
PON
Passive Optical Network - uses single fiber to the neighborhood switch and then individual fiber runs to each final destination.
BPL
Broadband over Power Line
PLC
Powerline Communications
Remote Access
Uses WAN and LAN connections to enable a computer user to log onto a network from the other side of a city, a state, or even the globe.
Dial-up to the Internet
Using a dial-up connection to your ISP
Private dial-up
Using a dial-up connection to your private network.
Virtual Private Network
Using an Internet connection to connect to a private network
Dedicated Connection
Using a non-dial-up connection to another private network or the Internet.
Remote Terminal
Using a terminal emulation program to connect to another computer
VoIP
Voice over Internet
RAS
Remote Access Server
Remote Terminal
A Connection on a faraway computer that enables you to control that computer as if you were sitting in front of it, logged in.
ICA
Independent Computer Architecture
RDP
Remote Desktop Protocol
RDC
Remote Desktop Connection
RTP
Real-Time Transport Protocol
SIP
Session Initiation Protocol
H.323
A VoIP standard that handles the initiation, setup, and delivery of VoIP sessions.
Worldwide, most voice and data SONET rings use this cell-based packet switching standard.
ATM
Which of the following is NOT a version of DSL service?
DDSL
Which of the following is the DSL device that is located in a central office, connecting multiple DSL customers to the Internet?
DSLAM
What is the maximum distance between a user’s demarc and the central office for all versions of DSL?
18,000 feet
A common standard for VOIP is RTP.
True
DSSS
Direct Sequence Spread Spectrum
FHSS
Frequency Hopping Spread Spectrum
OFDM
Orthogonal Frequency Division Multiplexing
802.11
Wireless Standard
WAP
Wireless Access Point
Ad hoc mode
A wireless networking mode where each nodes in direct contact with every other node in a decentralized free-for-all. Ad hoc mode is similar to the mesh topology.
Infrastructure Mode
Mode in which wireless networks use one or more wireless access points to connect the wireless network nodes centrally. This configuration is similar to the star topology of a wired network.
CSMA/CD
Carrier Sense Multiple Access with Collision Detection
CSMA/CA
Carrier Sense Multiple Access with Collision Avoidance
POE
Power Over Ethernet
Network Threat
Any number of things that share one essential feature: the potential to damage network data, machines, or users.
NAC
Network Access Control
Fault Tolerance
The capability of any system to continue functioning after soem part of the system has failed. RAID is an example of a hardware device that provides fault tolerance for hard drives.
Malware
Any program or code (macro, script, and so on) that’s designed to do something on a system or network that you don’t want to have happen.
Virus
A program that can make a copy of itself without you necessarily being aware of it. Some viruses can destroy or damage files, and generally the best protection is always to maintain backups of your files.
Worm
A very special form of virus. Unlike other viruses, a worm does not infect other files on the computer. Instead, it replicates by making copies of itself on other systems on a network by taking advantage of security weaknesses in networking protocols.
Macro
A specially written application macro (collection of commands) that performs the same functions as a virus. These macros normally autostart when the application is run and then make copies of themselves, often propagating across networks.
Trojan
A virus that masquerades as a file with a legitimate purpose, so that a user will run it intentionally. The classic example is a file that runs a game, but also causes some type of damage to the player’s system.
Rootkit
A Trojan that takes advantage of very low-level operating system functions to hide itself from all but the most aggressive of anti-malware tools.
Adware
A program that monitors the types of Web sites you frequent and uses that information to generate targeted advertisements, usually pop-up windows.
Spyware
Any program that sends information about your system or your actions over the internet.
Social Engineering
The process of using or manipulating people inside the networking environment to gain access to that network from the outside.
Phishing
The attacker poses as some sort of trusted site, like an online version of your bank or credit card company, and solicits you to update your financial information, such as a credit card number.
Man in the Middle
A person inserts him into a conversation between two others, covertly intercepting traffic thought to be only between those other people.
DoS
Denial of Service attacks are the work of hackers whose only interest is in bringing a network to its knees by flooding the network with so manny requests that it becomes overwhelmed and ceses functioning.
Smurf Attack
When an attacker floods a network with ping packets sent to the broadcast address. The return address of the pings is spoofed to that of the intended victim.
DDoS
Distributed Denial of Service Attacks - Uses multiple computers under the control of a single operator to launch a devastating attack.
Zombie
A single computer under the control of an operator.
Botnet
A group of computers under the control of one operator.
Leeching
Using another person’s wireless network without that person’s permission.
Rogue Access Point
An unauthorized acces point (WAP) installed in a computer network.
Evil Twin
An attack that lures people into logging into a rogue access point that looks similar to a legitimate access point.
Internal Threats
All the things that a network’s own users do to create problems on the network. Examples include accidental deletion of files, accidental damage to hardware devices or cabling, and abuse of rights and permissions.
Authentication
A person can prove their identity.
Multifactor Authentication
A form of authentication where a user must use two or more factors to prove their identity.
Knowledge Factor
Something the user knows, like a password or personal identification number (PIN).
Ownership Factor
Something the user has, like an ID card or security token.
Inherent Factor
Something that is part of the user, like a fingerprint or retinal scan.
Two-factor Authentication
Typically some sort of physical token that, when inserted, prompts for a password. Using what she has and knows.
Passwords
A series of characters that enables a user to gain access to a file, a folder, a PC or program.
Smart Devices
Devices such as credit cards, USB keys, etc. that you insert into your PC in lieu of entering a password.
Biometric Devices
Devices that scan fingerprints, retinas, or even the sound of the user’s voice to provide a foolproof replacement for both passwords and smart devices.
Principle of Least Privilege
The control over what a legitimate account can do.
External Threats
Threats to your network through external means; examples include virus attacks and the exploitation of users, security holes in the OS, or the network hardware itself.
NAT
Network Address Translation
Port Filtering/Port Blocking
Preventing the passage of any TCP or UDP segments or datagrams through any ports other than the ones prescribed by the system administrator.
Stateless Filtering
.
Stateful filtering or Stateful inspection
.
MAC Filtering
.
Honeypot
A device (or set of functions within a firewall) that creates a fake network called a honeynet.
DMZ
Demilitarized Zone - A lightly protected network positioned between your firewall and the internet.
Intranet
A private, protected network.
NMAP
A utility program that scans a network to determine things like open ports, passive applications, and more.
