Computer networks Flashcards
LAN
Local Area Network
MAN
Metropolitan Area Network
WAN
Wide Area Network
PAN
Personal Area Network
client-server model
Distributed application structure that partitions workloads and tasks between the providers of a resource or service (server) and service requesters (client).
peer to peer (P2P)
P2P computing or networking is a distributed application architecture that partitions tasks and workloads between equipotent participants (peers). E.g. torrent.
circuit switching
A method of implementing a telecommunication network in which two network nodes establish a dedicated communications channel (circuit).
packet-switching
A type of network in which relatively small units of data (packets) are routed through a network based on the destination address contained within each packet. (connectionless communication)
ISO OSI layers
application,
presentation,
session,
transport,
network,
datalink,
physical
application
supporting network applications: ftp, smtp, http
transport
-reliable end-to-end communication
-creates the abstraction of an error-controlled, dlow controlled and multiplexed end-to-end link
TCP: error-control, flow control, multiplexing
UDP: only multiplexing
network
-logically concatenates a set of links to form the
abstraction of an end-to-end link
-routing of datagrams from source to destination: ip, routing protocols
-provide unique network-wide addresses
-both in end-systems and intermediate systems
link
-the first layer of software
-usually in a bundle with the physical layer in the hardware
-data transfer between neighbouring network elements: ppp, ethernet
Internet
-network layer is provided by the Internet Protocol (IP)
-found in all end-systems and intermediate systems
-provides abstraction of end-to-end link
-packet-fowarding, routing, scheduling
-unique IP-address
error control
GOAL:
-message reaches its destination despite packet loss, duplication and corruption
ACTION:
-retransmits lost packets
-detect, discard and retransmit corrupted packets
-detect and discard duplicated packets
flow control
Match transmission rate to the rate sustainable on the path to destination and at the destination.
twisted pair cable
Twisted pair cabling is a type of wiring used for communications in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility.
-two conductors, each with plastic insulation
-two types: shielded (STP), unshielded (UTP)
RJ
A registered jack (RJ) is a standardized telecommunication network interface for connecting voice and data equipment to a service provided by a local exchange carrier or long distance carrier.
-the most common UTP connector
-RJ45 male and RJ45 female
Coaxial cable
Coaxial cable is a type of electrical cable consisting of an inner conductor surronded by dielectric insulator and a concentric conducting shield.
-many have an outer protective plastic jacket/sheath
BNC connector
Bayone-Neill-Concelman connector
-the most common type of connector for coaxial cables
-types: BNC connector, BNC T connector, BNC terminator
-applications: TV cables, traditional LANs
optical fibre
Optical fibre is a transparent fibre made of silica. It’s mostly used for fibre-optic communications because they allow electromagnetic waves to travel long distances with small loss and interference.
-a dielectric waveguide that trasmits light along its axis due to internal refraction
parts:
-glass or plastic core
-cladding
-plastic buffer
-coating
-outer jacket
multimode fibre
-designed for small distances of transmission: LAN-systems, video surveillance
single mode fibre
-designed for larger distances of transmission: long distance telephony, multichannel television broadcast systems
unguided media
Unguided media (wireless communication) is the transport of electromagnetic waves without using a soild physical conductor.
The section of the electromagnetic spectrum called the radio communication is divided into 8 ranges (bands).
