Internet service provider

Internet service provider

An Internet service provider (abbr. ISP, also called Internet access provider or IAP) is a business or organization that provides consumers or businesses access to the Internet and related services. In the past, most ISPs were run by the phone companies. Now, ISPs can be started by just about any individual or group with sufficient money and expertise. In addition to Internet access via various technologies such as dial-up and DSL, they may provide a combination of services including Internet transit, domain name registration and hosting, web hosting, and colocation.

ISPs employ a range of technologies to enable consumers to connect to their network. For "home users", the most popular options include dial-up, DSL (typically ADSL), Broadband wireless access, Cable modem, and ISDN (typically BRI). For customers who have more demanding requirements, such as medium-to-large businesses, or other ISPs, DSL (often SHDSL or ADSL), Ethernet, Metro Ethernet, Gigabit Ethernet, Frame Relay, ISDN (BRI or PRI), ATM, satellite Internet access and SONET are more likely. With the increasing popularity of downloading music and online video and the general demand for faster page loads, higher bandwidth connections are becoming more popular.

Just as their customers pay them for Internet access, ISPs themselves pay upstream ISPs for Internet access. In the simplest case, a single connection is established to an upstream ISP using one of the technologies described above, and the ISP uses this connection to send or receive any data to or from parts of the Internet beyond its own network; in turn, the upstream ISP uses its own upstream connection, or connections to its other customers (usually other ISPs) to allow the data to travel from source to destination.

In reality, the situation is often more complicated. For example, ISPs with more than one point of presence (PoP) may have separate connections to an upstream ISP at multiple PoPs, or they may be customers of multiple upstream ISPs and have connections to each one at one or more of their PoPs. ISPs may engage in peering, where multiple ISPs interconnect with one another at a peering point or Internet exchange point (IX), allowing the routing of data between their networks, without charging one another for that data - data that would otherwise have passed through their upstream ISPs, incurring charges from the upstream ISP. ISPs that require no downstream and have only customers and/or peers, are called Tier 1 ISPs, indicating their status as ISPs at the top of the Internet hierarchy. Routers, switches, Internet routing protocols, and the expertise of network administrators all have a role to play in ensuring that data follows the best available route and that ISPs can "see" one another on the Internet.

Internet service providers in India

Tata Indicom, Sify, Airtel, Reliance, Asianet, Bsnl, etc

Anti-virus

Antivirus

Virus{Definition}

Though it is unclear even within the anti-virus industry what actually constitutes a virus, one known element is that it is a program designed to replicate. Spread is achieved by infecting other files within a system. Viruses can also incorporate a payload, which is often malicious. The first PC virus was discovered in-the-wild in 1986, and today, there are over 54,000 viruses that are currently known. About 200 of the viruses that exist at any time are in-the-wild threats. Viruses have been made even more effective by being combined with worms and Trojans, to do more damage to a system while spreading faster.

Anti-virus

A software or hardware designed to identify and remove a known or potential computer virus, worm, or trojan horse. Or Program used to stop or prevent your computer being infected by a computer virus. A computer virus essentially acts like a biological virus and most usually gets into a computer system through unsolicited email.

Anti-virus is the term used for the technology and software that acts to detect malicious codes, prevent these codes or files from infecting and damaging your system, and to also remove any malicious codes that have gotten through. Anti-virus vendors, share information and keep in constant contact to make sure any malicious code outbreaks are quickly reported and dealt with. Anti-virus vendors also usually participate in independent tests to check and certify their products for speed and thoroughness when detecting and disinfecting viruses. The original versions of anti-virus software look through files for malicious code as they enter the system, or as the user requests it (manually). More recent versions of antivirus programs, such as NOD 32, often depends on integrity checking, and sometimes behavior blocking to prevent files from unauthorized modifications, or to stop various sequences of code from changing anything internally.

Antivirus software.

Antivirus software is a term used to describe a computer program that attempts to identify, neutralize or eliminate malicious software. This type of software is so named because the earliest examples were designed exclusively to combat computer viruses; however most modern antivirus software is now designed to combat a wide range of threats, including worms, phishing attacks, rootkits, trojan horses and other malware.

Antivirus software typically uses two different techniques to accomplish this:

Examining (scanning) files to look for known viruses matching definitions in a virus dictionary

Identifying suspicious behavior from any computer program which might indicate infection. Such analysis may include data captures, port monitoring and other methods.

Most commercial antivirus software uses both of these approaches, with an emphasis on the virus dictionary approach. { A utility that searches a hard disk for viruses and removes any that are found. Most antivirus programs include an auto-update feature that enables the program to download profiles of new viruses so that it can check for the new viruses as soon as they are discovered.

Anti-Spam

Anti-Spam

There’s a lot of argument as to which “anti-spam” techniques are legitimately so called. In this article, I’d like to consider what constitutes an anti-spam technique in an ideal sense, then consider the various practiced approaches to spam mitigation in that light, drawing conclusions as to how we should frame the “anti-spam” discussion. An ideal anti-spam system rejects messages which are both bulk and unsolicited, letting pass those messages which are of specific personal relevance to the recipient (not “bulk"), and those which the recipient has expressly requested (not “unsolicited"). When phrased in these terms, spam filtering is obviously a task for a well-informed intelligent agent of immense sophistication—quite beyond our current ability to construct. Anything less is a weak approximation at best.

The system described so far is ideal in the sense that it keeps spam out of a recipient’s inbox, but it says nothing of network and computing resources consumed in the process. A system that accepts all mail and then discards the portion which is spam wastes significant resources on mail that will ultimately be discarded. This is the hidden cost of spam, and it can be arbitrarily large, since it depends on how much spam other parties send to the recipient. An ideal system must address this cost: it must not only be perfectly accurate, but also perfectly efficient. In the ideal case, each incoming spam is rejected at no cost to the recipient. Only under these conditions is the system guaranteed to scale under increasing spam load.

To address this, the hypothetical intelligent agent could operate at the sender’s system, preventing unwanted data from entering the network at all. Unfortunately this seems practically untenable for several obvious reasons, not the least of which is the cost of replicating the agent at every prospective sender. But in order for the agent to operate from the recipient’s system without the waste inherent in the “accept then drop” approach, it would need to engage with each potential sender in a very light-weight protocol for determining whether a candidate message is personally relevant or requested, prior to accepting the actual text. I can’t even imagine how a protocol would meet these requirements, let alone be reliable in the face of a hostile sender. The situation seems intractable.

If an ideal anti-spam system is technically possible at all, it’s firmly in the realm of science fiction for now.

How ANTI-SPAM works

This page has fifty randomly generated email addresses (refresh and new ones will appear). At the bottom of the page is a link to this page again, essentially reloading it for programs to collect more fake email addresses. Email collecting programs (spam bots) will be sent into an infinite loop by following the link at the bottom of the page and will get more and more fake email addresses stuck in their databases.

Spam is the electronic world's biggest problem. A fool proof method of filtering out spam does not yet exist, but we don't have to sit back and take it. Anti-Spam pages like this one make spamming less profitable and is our way to help FIGHT SPAM.

Anti-Spam Software

A spam filter is a program that is used to detect unsolicited and unwanted email and prevent those messages from getting to a user's inbox. Like other types of filtering programs, a spam filter looks for certain criteria on which it bases judgments. For example, the simplest and earliest versions (such as the one available with Microsoft's Hotmail) can be set to watch for particular words …

A spam filter is a program that is used to detect unsolicited and unwanted email and prevent those messages from getting to a user's inbox. Like other types of filtering programs, a spam filter looks for certain criteria on which it bases judgments. For example, the simplest and earliest versions (such as the one available with Microsoft's Hotmail) can be set to watch for particular words in the subject line of messages and to exclude these from the user's inbox. This method is not especially effective, too often omitting perfectly legitimate messages (these are called false positives) and letting actual spam through. More sophisticated programs, such as Bayesian filters or other heuristic filters, attempt to identify spam through suspicious word patterns or word frequency.