ITEC45_MIDTERM Flashcards
is a set of connected devices.
is a set of nodes that are interconnected to permit the exchange of information.
is a collection of computers, servers, mainframes, network devices, peripherals, or other devices connected to one another to allow the sharing of data.
Network
refers to the way in which the end points, or stations, attached to the network are interconnected.
refers to the shape of a network, or the network’s layout
may define both physical and logical aspect of the network.
Topology
is either a redistribution point or a communication endpoint.
any system or device connected to a network is also called a _____.
Node
is the arrangement with which computer systems or network devices are connected to each other.
Network topology
is the simplest topology that connects two nodes directly together with a common link.
networks contains exactly two hosts such as computer, switches, routers, or servers connected back to back using a single piece of cable.
If the hosts are connected point-to-point logically, then may have multiple intermediate devices. But the end hosts are unaware of underlying network and see each other as if they are connected directly.
Point to Point
all devices are connected to a central cable, called the bus or backbone.
all devices share single communication line or cable.
In bus topology there is a main cable and all the devices are connected to this main cable through drop lines.
There is a device called tap that connects the drop line to the main cable.
Since all the data is transmitted over the main cable, there is a limit of drop lines and the distance a main cable can have.
Each end of the cable is terminated using a special terminator.
In this type of topology, if one workstation goes faulty all workstations may be affected as all workstations share the same cable for the sending and receiving of information.
Bus Topology
is a connector that either splices into the main cable or punctures the sheathing of a cable to create a contact with the metallic core.
Tap
is a connection running between the device and the main cable.
Drop line
uses a central hub through which, all components are connected.
Central hub
is the host computer, and at the end of each connection is a _______.
Terminal
is the host computer, and at the end of each connection is a terminal.
Central Hub
As in Bus topology, hub acts as single point of failure. If hub fails, connectivity of all hosts to all other hosts fails.
Every communication between hosts takes place through only the hub.
is not expensive as to connect one more host, only one cable is required and configuration is simple.
Star topology
all devices are connected to one another in the shape of a closed loop, so that each device is connected directly to two other devices, one on either side of it
When one host tries to communicate or send message to a host which is not adjacent to it, the data travels through all intermediate hosts.
Failure of any host results in failure of the whole ring.
Thus, every connection in the ring is a point of failure. There are methods which employ one more backup ring.
Ring topology
In this type of topology, a host is connected to one or multiple hosts.
This topology has hosts in point-to-point connection with every other host or may also have hosts which are in point-to-point connection with few hosts only.
Mesh topology
All hosts have a point-to-point connection to every other host in the network. Thus for every new host n(n-1)/2 connections are required. It provides the most reliable network structure among all network topologies.
Full Mesh
Not all hosts have point-to-point connection to every other host. Hosts connect to each other in some arbitrarily fashion. This topology exists where we need to provide reliability to some hosts out of all.
Partially Mesh
The pattern of connection resembles a tree in which all branches spring from one root.
is a hybrid topology, it is similar to the star topology but the nodes are connected to the secondary hub, which in turn is connected to the central hub
Tree Topology
A network structure whose design contains more than one topology is said to be hybrid topology
inherits merits and demerits of all the incorporating topologies.
Hybrid Topology
Kinds of network Topologies
Point to point topology
Bus Topology
Star topology
Ring topology
Mesh topology
Tree Topology
Hybrid Topology
Devices in Bus topology ( 2)
Tap
drop line
Feature of Bus topology
- it transmits data only in one direction
- Every device is connected to a single cable
The transmission is unidirectional, but it can be made bidirectional by having 2 connections between each Network Node, it is called ____ ____ ________.
Dual Ring Topology
Features of Mesh topology
- Fully connected
- Robust
Feature of Tree Topology
- Ideal if workstations are located in groups
- Used in Wide Area Network
Advantage of Tree Topology
- Extension of bus and star topologies
- Expansion of nodes is possible and easy.
- Easily managed and maintained
- Error detection is easily done
Disadvantage of Hybrid Topology
- Complex design
- Costly
is smallest network which is very personal to a user.
this may include Bluetooth enabled devices or infra-red enabled devices.
has connectivity range up to 10 meters.
may include wireless computer keyboard and mouse, Bluetooth enabled headphones, wireless printers, and TV remotes.
Personal Area Network (PAN)
a computer network spanned inside a building and operated under single administrative system is generally termed as _____ _____ _______
it covers an organization offices, schools, colleges or universities. Number of systems connected in LAN may vary from as least as two to as much as 16 million.
are composed of inexpensive networking and routing equipment. It may contains local servers serving file storage and other locally shared applications. It mostly operates on private IP addresses and does not involve heavy routing.
it works under its own local domain and controlled centrally.
Local Area Network (LAN)
LAN can be wired, wireless, or in both forms at once.
( true/false)
true
LAN uses either Ethernet or Token-ring technology.
(true/false)
true
is most widely employed LAN technology and uses Star topology, while Token-ring is rarely seen.
is a family of computer networking technologies commonly used in local area networks, metropolitan area networks and wide area networks.
Ethernet
generally expands throughout a city such as cable TV network. It can be in the form of Ethernet, Token-ring, ATM, or Fiber Distributed Data Interface (FDDI).
is a service which is provided by ISPs. This service enables its users to expand their Local Area Networks.
is high-capacity and high-speed fiber optics. MAN works in between Local Area Network and Wide Area Network. MAN provides uplink for LANs to WANs or internet.
Metropolitan Area Network (MAN)
covers a wide area which may span across provinces and even a whole country.
Generally, telecommunication networks are Wide Area Network. These networks provide connectivity to MANs and LANs. Since they are equipped with very high speed backbone, WANs use very expensive network equipment.
may use advanced technologies such as Asynchronous Transfer Mode (ATM), Frame Relay, and Synchronous Optical Network (SONET). WAN may be managed by multiple administration.
Wide Area Network (WAN)
A network of networks is called an ___________
is the largest network in existence on this planet.
The internet hugely connects all WANs and it can have connection to LANs and Home networks. Internet uses TCP/IP protocol suite and uses IP as its addressing protocol. Present day, Internet is widely implemented using IPv4. Because of shortage of address spaces, it is gradually migrating from IPv4 to IPv6.
enables its users to share and access enormous amount of information worldwide. It uses WWW, FTP, email services, audio, and video streaming etc. At huge level, internet works on Client-Server model.
Internet uses very high speed backbone of fiber optics. To inter-connect various continents, fibers are laid under sea known to us as submarine communication cable.
Internet is widely deployed on World Wide Web services using HTML linked pages and is accessible by client software known as Web Browsers.
Internetwork
Internet is widely deployed on World Wide Web services using HTML linked pages and is accessible by client software known as ____ ________
Web Browsers
In layered architecture of Network Model, one whole network process is divided into small tasks. Each small task is then assigned to a particular layer which works dedicatedly to process the task only. Every layer does only specific work.
In layered communication system, one layer of a host deals with the task done by or to be done by its peer layer at the same level on the remote host. The task is either initiated by layer at the lowest level or at the top most level.
If the task is initiated by the topmost layer, it is passed on to the layer below it for further processing. The lower layer does the same thing, it processes the task and passes on to lower layer. If the task is initiated by lowermost layer, then the reverse path is taken.
Layered task
