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Virtual private network

Virtual private network
VPN connectivity overview A virtual private network connection across the Internet is similar to a wide area network (WAN) link between sites. From a user perspective, the extended network resources are accessed in the same way as resources available within the private network.[2] VPNs allow employees to securely access their company's intranet while traveling outside the office. Similarly, VPNs securely connect geographically disparate offices of an organization, creating one cohesive network. Types[edit] Early data networks allowed VPN-style remote connectivity through dial-up modems or through leased line connections utilizing Frame Relay and Asynchronous Transfer Mode (ATM) virtual circuits, provisioned through a network owned and operated by telecommunication carriers. VPNs can be either remote-access (connecting an individual computer to a network) or site-to-site (connecting two networks together). VPN systems may be classified by: Security mechanisms[edit] Authentication[edit]

Brute-force attack The EFF's US$250,000 DEScracking machine contained over 1,800 custom chips and could brute-force a DES key in a matter of days. The photograph shows a DES Cracker circuit board fitted on both sides with 64 Deep Crack chips. When password guessing, this method is very fast when used to check all short passwords, but for longer passwords other methods such as the dictionary attack are used because of the time a brute-force search takes. When key guessing, the key length used in the cipher determines the practical feasibility of performing a brute-force attack, with longer keys exponentially more difficult to crack than shorter ones. Brute-force attacks can be made less effective by obfuscating the data to be encoded, something that makes it more difficult for an attacker to recognize when he/she has cracked the code. Brute-force attacks are an application of brute-force search, the general problem-solving technique of enumerating all candidates and checking each one. Unbreakable codes[edit]

Internet Protocol Suite The Internet protocol suite is the computer networking model and set of communications protocols used on the Internet and similar computer networks. It is commonly known as TCP/IP, because its most important protocols, the Transmission Control Protocol (TCP) and the Internet Protocol (IP), were the first networking protocols defined in this standard. Often also called the Internet model, it was originally also known as the DoD model, because the development of the networking model was funded by DARPA, an agency of the United States Department of Defense. TCP/IP provides end-to-end connectivity specifying how data should be packetized, addressed, transmitted, routed and received at the destination. The TCP/IP model and related protocol models are maintained by the Internet Engineering Task Force (IETF). History[edit] Early research[edit] Diagram of the first internetworked connection Specification[edit] Adoption[edit] Key architectural principles[edit] Abstraction layers[edit] Link layer[edit]

IMI: Los beneficios de una herramienta World Class y una rápida implementación con SAP y TFC « TFC Soluciones Controlar todo el negocio, en sus diferentes áreas, capacidad a la que es posible acceder a través de un ERP, fueron las razones que llevaron a IMI a implementar un sistema de este tipo. La solución llegó de la mano de SAP Business One y la compañía implementadora TFC, elegidas principalmente por las características World Class de esta herramienta y la eficiente metodología de implantación del proveedor. Al respecto, profundiza Jean Pierre Segovia, Administrador General de IMI. Ingeniería y Mantenimiento Industrial (IMI) se vio enfrentada a la necesidad de llevar un control más exhaustivo de su negocio, más allá de limitarse sólo a ámbito contable, pudiendo contar, por ejemplo, con detalles de los productos o materiales adquiridos, a qué proveedor corresponden y su precio. La velocidad de implementación fue otro de los factores que llevaron a la firma a escoger esta propuesta, pues el proveedor TFC cuenta con una metodología propietaria que destaca por esta característica. Volver

Krebs on Security Telemetry An expendable dropsonde used to capture weather data. The telemetry consists of sensors for pressure, temperature, and humidity and a wireless transmitter to return the captured data to an aircraft. Telemetry is the highly automated communications process by which measurements are made and other data collected at remote or inaccessible points and transmitted to receiving equipment for monitoring.[1] The word is derived from Greek roots: tele = remote, and metron = measure. Systems that need external instructions and data to operate require the counterpart of telemetry, telecommand.[2] Although the term commonly refers to wireless data transfer mechanisms (e.g., using radio, ultrasonic, or infrared systems), it also encompasses data transferred over other media such as a telephone or computer network, optical link or other wired communications like phase line carriers. A telemeter is a device used to remotely measure any quantity. History[edit] Applications[edit] Meteorology[edit]

CIO. Chief Information Officer Introducción Las organizaciones, desde el punto de vista de la teoría de los sistemas, puede ser considerara como un sistema abierto y por esta razón , la organización estará expuesta a los diversos cambios que se producen el medio ambiente que la rodea. El éxito o fracaso de una organización, cualquiera sea su rubro, dependerá de la capacidad que tenga la misma para adaptarse a tales cambios. Teniendo en cuenta el concepto anterior, podemos afirmar que existen diversas empresas que ante la necesidad de un cambio o adaptación en el área de informática (manejo de tecnología e información), han implementado un nuevo encuadre para el líder de la tecnología de información, es decir un cambio en la visión y misión que traen durante una larga trayectoria los profesionales de sistemas(en particular los gerentes del centro de cómputos). En este resumen, se detallara esa nueva visión y como consecuencia el surgimiento de un cargo denominado CIO. ¿ Cómo nace el termino CIO? El Papel Que cambia

How to protect your PC against devious security traps Securing your PC against the malicious wilds of the Web isn’t as simple as just keeping your antivirus software of choice up-to-date. In fact, the pervasiveness of security software has forced the bad guys to turn to increasingly clever tricks in their quest to “pwn” your PC. But fear not! Those sneaky tricks are most effective if victims are unaware of the danger. Phishing Let’s start with the devious attack you’re most likely to encounter during your day-to-day computing. Phishing websites mimic the look of another site in an attempt to lure you into entering your personal and account information. One simple tell gives away a phishing site: The URL doesn’t match the URL of the website you think it is. Beyond that, most social media and banking websites use HTTPS encryption by default. Malicious email Scammers and hackers love email. Okay, that’s not quite true. Though not all malicious email messages originate from foreign lands and contain spelling and grammar mistakes, many do. OMG hax

IEC 61131-3 IEC 61131-3 is the third part (of 8) of the open international standard IEC 61131 for programmable logic controllers, and was first published in December 1993 by the IEC. The current (third) edition was published in February 2013. Part 3 of IEC 61131 deals with programming languages and defines two graphical and two textual PLC programming language standards: Data types[edit] (Considering byte size 8 bits) Variables[edit] Variable attributes: RETAIN, CONSTANT, AT GlobalDirect (local)I/O Mapping - Input, Output, I/OExternalTemporary Configuration[edit] Resource - Like a CPUTasks - Can be multiple per CPU.Programs - Can be executed once, on a timer, on an event. Program organization units[edit] Functions Standard: ADD, SQRT, SIN, COS, GT, MIN, MAX, AND, OR, etc.CustomFunction Blocks Standard:Custom - Libraries of functions can be supplied by a vendor or third party.Programs Configuration, resources, tasks[edit] Configuration - processing resources, memory for IO, execution rates, number of tasks.

RFID Chile | Radio Frequency Identification Serial communication In telecommunication and computer science, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels. Serial communication is used for all long-haul communication and most computer networks, where the cost of cable and synchronization difficulties make parallel communication impractical. Serial computer buses are becoming more common even at shorter distances, as improved signal integrity and transmission speeds in newer serial technologies have begun to outweigh the parallel bus's advantage of simplicity (no need for serializer and deserializer, or SerDes) and to outstrip its disadvantages (clock skew, interconnect density). The migration from PCI to PCI Express is an example. Cables that carry serial data[edit] Serial buses[edit] Serial versus parallel[edit] See also[edit]

The Open Source Initiative | Open Source Initiative Parallel communication In telecommunication and computer science, parallel communication is a method of conveying multiple binary digits (bits) simultaneously. It contrasts with serial communication, which conveys only a single bit at a time; this distinction is one way of characterizing a communications link. The basic difference between a parallel and a serial communication channel is the number of electrical conductors used at the physical layer to convey bits. Parallel communication implies more than one such conductor. For example, an 8-bit parallel channel will convey eight bits (or a byte) simultaneously, whereas a serial channel would convey those same bits sequentially, one at a time. Examples of parallel communication systems[edit] IBM System/360 Direct Control Feature (1964).[1]:p.18. Comparison with serial links[edit] Before the development of high-speed serial technologies, the choice of parallel links over serial links was driven by these factors: References[edit] See also[edit]

ACTI How Ethernet Works" Bridges can reduce congestion by allowing multiple conversations to occur on different segments simultaneously, but they have their limits in segmenting traffic as well. An important characteristic of bridges is that they forward Ethernet broadcasts to all connected segments. This behavior is necessary, as Ethernet broadcasts are destined for every node on the network, but it can pose problems for bridged networks that grow too large. When a large number of stations broadcast on a bridged network, congestion can be as bad as if all those devices were on a single segment. Routers are advanced networking components that can divide a single network into two logically separate networks. While Ethernet broadcasts cross bridges in their search to find every node on the network, they do not cross routers, because the router forms a logical boundary for the network. See How Routers Work for a detailed discussion of this technology.

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