CPE 041 DATACOM P3 Flashcards
Computer communication
Data Communications
Protocol
Sysntax
Semantics
Timing
Standards
De Facto
De Jure
Market Driven Standards
De Facto
Legislated by organized body
De Jure
Standards Organization
IEEE
ITU-T
TIA
EIA
ANSI
IEEE Standard Organization
8021 Bridging and Management
80.2.2 logic Link Control
802.3. Ethernet-CSMA/CD Access Method
802. 4 Token Passing Bus Access Method
802.5 Token Ring Access Method
802.6 Distributed Queue Dual Bus Access Method
802.7 Broadband LAN
802.8 Fiber Optic
802.9 Integrated Services LAN
802.10 Security
802.11 Wireless LAN
802 12 Demand Priority Access POZ. 14 Medium Access Control 802.15 Wireless Personal Area Network
802.16 Broadband Wireless Metro Area Network
802.17 Resilient Packet Ring
Network Criteria
Performance
Reliability
Security
Four Fundamentals Characteristics of Data Communications
Delivery
Accuracy
Timeless
Jitter
Transmission Mode
Simplex
Half-Duplex
Full-Duplex
one direction
Simplex
both direction but not same time
Half-Duplex
both direction at the same time
Full-Duplex
acts as the source of destination
Data Terminal Equipment
used to establish, maintain, and terminate communication network
sessions between a data source and it’s destination
Data Communications Equipment
a device used to convert serial digital data from a transmitting terminal to a signal suitable for transmission over a telephone channel, or to reconvert the transmitted signal to a serial digital data for acceptance at the receiving terminal
Modem (modulator-demodulator)
Advantages of Modems
-easier to multiplex
-easier to integrate in to a switching system
-easy to interface with other digital equipment
-noise immunity
-better performance monitorability
-easy to encode, decode, encrypt, and scramble
Disadvantages of Modems
-large bandwidth
-need for synchronization
-need for additional equipment
- not compatible with existing system
-need for AD/DA conversion
-restriction in wired topology
concerns with the physical configuration of the devices and the cable that it connects. It is the architecture or physical layout of the network
Data Network Topology
consists of nodes string together in series with each node connected to a long cable or bus; many nodes can tap into the bus and begin communication with all other nodes on that cable segment
Bus Topology
-bucket or token passing
-signals are transmitted in a rotating fashion
-tokens give stations the “right to transmit” messages
Ring Topology
-how the nodes are connected
Physical Topology
-how data is transmitted
Logical Topology
-features a central controller to which all nodes are connected
Star Topology
-variation of star topology, it contains multiple bus
Tree Topology
- the devices are connected redundantly with each other
Mesh Topology
formula to know how many cables should be use
C=(N(N-1))/2
Network Breadth
Local Area Networks (LAN) Metropolitan Area Networks (MAN) Wide Area Networks (WAN) Global Area Networks (GAN)
collection of independent computers which can communicate with one another over a shared medium, usually conf to a small geographical area, such as a single building or a college campus
Local Area Network (LAN)
PAN
SAN
VPN
EPN
PAN - Personal Area Network
SAN - Storage Area Network
VPN- Virtual Private Network
EPN - Enterprise Private Network
-consists of a computer networks across an entire city, college campus or small region
Metropolitan Area Network (MAN)
-occupies a very large area, such as an entire country or the entire world
Wide Area Network
a global computer network that connects thousands of networks together allowing them to exchange files, send messages, download, graphics and text, and share other resources
Internet
-categories and identifiers the pointer or number of location
Network Configuration
-provides a dedicated link between two devices
Point-to-Point
-more that two specific devices share a single link
Multipoint
Data Transmission
Serial
Parallel
-sends only one bit at a time
Serial
-chunk of data is sent at the same time
Parallel
Serial Transmission
Synchronous
Asynchronous
- eliminates the need for start and stop bits
Synchronous
-one character is transmitted at a time
-transmission is controlled by start and stop bits at the beginning and end of each character
Asynchronous
In serial transmission ______is faster than ___________
Synchronous
Asynchronous
-transmission in which data are sent at a fixed rate, with the receiver and transmitter synchronized
-synchronized transmission eliminates the need for start and stop bits
Synchronous
is the transmission of information from one or more source to one more destination over the same transmission medium
Multiplexing
splits the available bandwidth for a given communication link into a number of chanels
Frequency Division Multiplexing
splits up the capacity of the line by assigning each user a particular timeslot
Time Division Multiplexing
Different kind of Multiplexing
Frequency Division Multiplexing
Time Division Multiplexing
Synchronous / Statical TDM
Asynchronous / Statical TDM
Frequency Hopping Spread Spectrum
Direct Sequence Spread Spectrum
Seven OSI Layer
Physical Layer
Data Link Layer
Network Layer
Transport Layer
Session Layer
Presentation Layer
Application Layer
File Transfer :File Transfer Protocol (FTP)
Email: Simple Mail Transfer Protocol (SMTP)
Web Browsing: Herpertext Transfer Protocol (HTTP)
Application Layer
Data Encryption/Decryption
Data Compression
-lossing
-lossless
Presentation Layer
Authentication
-username
-password
Authorization
Session Layer
Transmission Control Protocol (TCP)
*connection oriented services
-request
-acknowledge
-send data
User Datagram Protocol
*connection services
-send data
-send data
-send data
Transport Layer
routing, networking, logical / IP addressing
Network Layer
-error-free data transfer
Data Link Layer
-composed of 6-two digit hexadecimal number
Media Access Control (Mac)
responsible for physical connections
Physical layer
A
P
S
T
N
D
P
Application Layer
Presentation Layer
Session Layer
Transport Layer
Network Layer
Physical Layer
