Cyberspace Internet Components

With this presentation we intend to present the different components/equipments that allow us to connect and browse the Web. Internet connection equipment Transmission Means Communication protocols

Transmission Means A physical means of transmission in a computer network is the communication channel, by which, computers send and receive signals that encode information. The most currently used is the wireless. Electric cables Optical cables Wireless Home

Electric cables The copper cable transmit electrical signals at a high frequency to relatively long distances. They are vulnerable to external electromagnetic interference. Copper cables are composed of four pairs of copper wires that are twisted together, protecting transmissions from outside interference. Transmission Means Home Main conductor Copper wire Shield Copper wire webbing Dielectric Solid plastic Externel protection Anti-fire flexible polyvinyl chloride Electric versus Optical cables

Optical cables The optical fiber cables using the phenomenon of total internal refraction of light beams to pass over long distances. A very thin glass core, made of silica with high purity is surrounded by a layer (also silica) with refractive index lower cladding call, which causes the light transmitted by the fiber core is reflected the inner walls of the cable. Home Electric versus Optical cables Transmission Means

Electric Cables Vs Optical Cables AdvantagesDisadvantages Optical Cables Thickness allows the inclusion of a large volume of wire in one cable. Immune to electromagnetic interference. High transmission rate. Carry digital signals without loss. Expensive material. More susceptible to external interference. Electric Cables Cheap material. Good resistance to external interference. Loss of transmission signal over long distances. Vulnerable to electro- magnetic interference. Home Transmission Means

Wireless It is a technology that don’t uses wires to transmit data to another device. Examples of wireless technologies: – Bluetooth Bluetooth – InfraredInfrared – Wi-FiWi-Fi Home Transmission Means

Bluetooth Bluetooth is a communication protocol that allows the connection via a radio frequency at short ranges, between devices such as mobile phones, laptops, computers, printers, digital cameras and game consoles. Home Transmission Means Back

Infrared Another type of wireless transmission medium is based on infrared light. Basically functions as the communication system using optical fiber, but the beam is transmitted through free space (light waves) instead of fiberglass. The signal is converted to digital format and transmitted through free space. Home Transmission Means Back

Wi-Fi Bluetooth is a communication protocol that allows the connection via a radio frequency at short ranges, between devices such as mobile phones, laptops, computers, printers, digital cameras and game consoles. Home Transmission Means Back

Internet evolution Introduction of modems that allowed the connection of terminals to central computers The need for transferring large files and graphics led to the introduction of faster modems The speeds increased to 56kbps modems The high-speed services or broadband becomes necessary. Use of transmission media (twisted pair, coaxial cable, wireless or fiber optic). Modem Switch Bridge Router Home

Modem Modem electronic equipment is one which has the function, modulation and demodulation (through which digital signals to recover the originally built). There are certain characteristics that distinguish each other's modem: Bps: (Bytes per second) The more bps modem to allow the faster the transmission and receipt of information. Voice/data: Transmission and reception of audio signals. This is a mixture of the modem with the sound card. Auto-answer: Allows the computer to receive calls without the user. Internet connection equipment Home Back

Modem There are two common types of modem: Broadband modems: The broadband modems are connected to a cable or DSL (Digital Subscriber Line) and provide access to high-speed Internet. Dial-up modems: Dial-up modems are connected to the Internet using a telephone line, usually at much lower than that of broadband modems. Home Back

Switch A switch is a device used in computer networks to forward frames. The switch functions are performed more quickly by sending multiple packets simultaneously. Internet connection equipment Home

Bridge Bridge is the term used in computing to describe a device that connects two or more networks that use different protocols or equal to two segments of the same network using the protocol memo. Bridges are used to interconnect two networks, such as connection of a network of a building to another. Internet connection equipment Home

Router The Router is a device that a packet switching network information, is responsible for forwarding these from its origin to its destination. Routing is a function associated with the network layer in a simple model of network programming, the OSI (Open Systems Interconnection). For home and office computers that have a fast connection to the Internet via cable, satellite or DSL, the router can function as a hardware firewall. Internet connection equipment Home Back

Communication protocols In computer networks, a protocol is an objective set of specifications that computers understand. Technically, it is a standard set of rules that characterize the format, timing, sequence, and also the detection of errors and failures in the transmission of information between computers. Thus, two or more computers to communicate over a network, must speak the same language, ie using the same protocol. For communication to exist there must be at least one channel, a transmitter and a receptor and ensure that both have the option of using a common protocol. Home HTTP/HTTPS STMP FTP POP

Communication protocols HTTP/HTTPS: – The HyperText Transfer Protocol is an application responsible for processing requests and responses between client and server on the World Wide Web. – He arose from the need to distribute information over the Internet and that this distribution was possible was necessary to create a standardized way of communication between clients and Web servers and understood by all computers connected to the Internet. – The main idea is to create an HTTPS secure channel over an insecure network. This ensures reasonable protection of persons who perform illegal wiretaps (called eavesdroppers) attacks and man-in-the-middle (man-in-the-middle), since the encryption has been properly used and that the server certificate is verified and reliable. Home Back

Communication protocols FTP – File Transfer Protocol (FTP) is a standard network protocol used to transfer files from one host to another host over a TCP-based network, such as the Internet. – It is often used to upload web pages and other documents from a private development machine to a public web-hosting server. – FTP is built on a client-server architecture and uses separate control and data connections between the client and the server. Home Back

Communication protocols POP – Post Office Protocol (POP) is an application-layer Internet standard protocol used by local clients to retrieve from a remote server over a TCP/IP connection. Home Back

Communication protocols STMP – Simple Mail Transfer Protocol (SMTP) is the standard protocol for sending s over the Internet. – It is a relatively simple protocol, based on plain text, where one or more recipients of a message are specified (and in most cases verified to exist) and then, the message transferred. Home Back