El protocol TCP/IP

a)IP de www.edu365.cat --> 85.192.66.11

b)La URL 173.194.45.24 és de www.google.com

Built a network

The bottleneck of my network is the cable ISDN line. 
Problem: The fast switch is using the network very heavily. This would probably cayse frequent problems in managing the flow of data across the network. Data transfer across the network might also stop altogether. 

TASCA. Tema: Xarxes

1. Esbrina les dades següents del teu accés a Internet:

Proveïdor d’accés a Internet (ISP)	Movistar
Velocitat de baixada nominal	920.9 Kb/s
Mesura de la velocitat de baixada	7,37 Mbps
Mesura de la velocitat de pujada	335 Kbps
IP del teu ordinador	192.168.1.146

2. Esbrina a quines URL corresponen les adreces IP següents:

Adreça IP	URL
http://212.73.198.167/	http://www.ara.cat/
http://212.58.244.68/	http://www.bbc.co.uk/

3. Si la velocitat de baixada d’una ADSL és de 10 Mbps, i el servidor que ens ofereix el servei de descàrrega suporta aquesta velocitat, quin serà el temps aproximat per baixar un fitxer de 100 Mbytes?

100MBàGBàTB

100MB · 1GB/1024MB · 1TB/1024GB= 0’09765625 TB

Temps= espai/velocitat= 0’09765625/1TB/s= 0’09 segons

4. Explica la funció d’un DNS i en quin context treballa.

El Domain Name System o DNS és un sistema de noms jeràrquic que funciona sobre una base de dades distribuïda. Permet que qualsevol sistema connectat a Internet o a una xarxa informàtica privada obtingui informació associada als noms de domini. El DNS ofereix un servei vital a Internet i sense ell la navegació seria molt complicada

5. Explica la diferència entre un concentrador (hub) i un commutador de xarxa (switch)

El hub rep un paquet de dades per un port, i el retransmet a tots els ordinadors i això provoca que es saturen les reds i, el switch rep l'adreça Mac de tots els ordinadors y envia el paquet de dades a l'ordinador que li correspon i això no satura la red.

Characteristics of networked

TYPES OF NETWORK

LAN (Local Area Network) is a computer network covering a small geographic area, like a home, office, school, or group of buildings. High speed (1000 mbps). One LAN can be connected to other LANs over any distance via telephone lines and radio waves. Network in an organization can be a LAN.

WAN (Wide Area Network) is a computer network that covers a broad area (e.g., any networkwhose communications links cross metropolitan, regional, or national boundaries over a long distance). Less speed (150 mbps). Internet is a good example of a WAN.

The client–server model is a  distributed application structure in computing that partitions tasks or workloads between the providers of a resource or service, called servers, and service requesters, called clients.


A peer-to-peer (P2P) network is a type of decentralized and distributed network architecturein which individual nodes in the network (called "peers") act as both suppliers and consumers of resources, in contrast to the centralized client–server model where client nodes request access to resources provided by central servers.



NETWORK TOPOLOGY(Is the arrangement of the various elements (links, nodes, etc.) of a computer network)

A bus network topology is a network topology in which a set of clients are connected via a shared communications line/cables, called a bus. There are several common instances of the bus architecture, including one in the motherboard of most computers.

Star networks are one of the most common computer network topologies. In its simplest form, a star network consists of one central switch, hub or computer, which act as a conduit to transmit messages. This consists of a central node, to which all other nodes are connected; this central node provides a common connection point for all nodes through a hub. In star topology, every node (computer workstation or any other peripheral) is connected to a central node called a hub or switch. The switch is the server and the peripherals are the clients.

What they are and what they are for computer networks (Summary)

What is a computer network? For many years computers have been isolated machines working independently and transfer of information is done for other physical media such as magnetic tapes, disks and diskettes. In the 80s if the computers were close, supporting data was transported easily, but if the location of the computers was very distant are complicated to used at perfection. Communication between computers began as a technical necessity in the process of implementation and expansion. One of the first solutions was using acoustic modems, which was an interface device for coupling electrical signals by Acoustical Means. Why computers could talk they share the same language or protocol of the comunicació.En grows the volume of data, computers need new features. The connection of networked computers has very important applications such features can be found in a network are: instant messaging system, email system, simultaneous work on the same document or database, centralized installation software, etc..

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Aquest es el meu blog d'informàtica d'aquest curs 2013/2014 de 4rt d'ESO. En aquest blog hi publicaré entrades sobre la informàtica del meu curs on podreu veure tot el que s'estudia en la informàtica.