Firewall (computing) An illustration of where a firewall would be located in a network. In computing, a firewall is a software or hardware-based network security system that controls the incoming and outgoing network traffic by analyzing the data packets and determining whether they should be allowed through or not, based on applied rule set. A firewall establishes a barrier between a trusted, secure internal network and another network (e.g., the Internet) that is not assumed to be secure and trusted.[1] Firewall technology emerged in the late 1980s when the Internet was a fairly new technology in terms of its global use and connectivity. The predecessors to firewalls for network security were the routers used in the late 1980s:[3] The first paper published on firewall technology was in 1988, when engineers from Digital Equipment Corporation (DEC) developed filter systems known as packet filter firewalls. Packet filters act by inspecting the "packets" which are transferred between computers on the Internet.
IEEE 802.11 IEEE 802.11 is a set of media access control (MAC) and physical layer (PHY) specifications for implementing wireless local area network (WLAN) computer communication in the 2.4, 3.6, 5 and 60 GHz frequency bands. They are created and maintained by the IEEE LAN/MAN Standards Committee (IEEE 802). The base version of the standard was released in 1997 and has had subsequent amendments. The standard and amendments provide the basis for wireless network products using the Wi-Fi brand. While each amendment is officially revoked when it is incorporated in the latest version of the standard, the corporate world tends to market to the revisions because they concisely denote capabilities of their products. As a result, in the market place, each revision tends to become its own standard. The LinksysWRT54G contains a router with an 802.11b/g radio and two antennae General description[edit] History[edit] 802.11 technology has its origins in a 1985 ruling by the U.S. Protocol[edit] 802.11b[edit]
Proxy server Communication between two computers (shown in grey) connected through a third computer (shown in red) acting as a proxy. Note that Bob doesn't know whom the information is going to, which is why proxies can be used to protect privacy. Types of proxy[edit] A proxy server may reside on the user's local computer, or at various points between the user's computer and destination servers on the Internet. Forward proxies[edit] A forward proxy taking requests from an internal network and forwarding them to the Internet. Forward proxies are proxies in which the client server names the target server to connect to.[2] Forward proxies are able to retrieve from a wide range of sources (in most cases anywhere on the Internet). The terms "forward proxy" and "forwarding proxy" are a general description of behavior (forwarding traffic) and thus ambiguous. Open proxies[edit] An open proxy forwarding requests from and to anywhere on the Internet. Reverse proxies[edit] Uses of proxy servers[edit] Translation[edit]
Tech Know: CHoosing an e-reader Technology continues to advance day after day to become one of the most important aspects of a person's life. Get tips on tech and learn about choosing better equipment from eHow's Tech Know. Choosing an E-Book Reader A good E-Book reader will allow you to take not just your favorite book but your entire collection with you wherever you go. Get tips on choosing an E-Book reader with help from an expert in this free video clip. Take Better Smart Phone Photos Just because your smart phone has a great camera doesn't mean you can expect every last picture to come out perfect. Selecting a Cell Phone Plan That Meets Your Needs Choosing a cell phone plan that works for you requires careful consideration for both budget and features. What You Need in a Digital Camera Picking the right digital camera for you can be a tricky exercise. Get Online: Wireless Ways to Change Your Life Communications today require constant exchange of information between people at different locations instantaneously.
Samsung Galaxy S: 15 Free Android Applications iBangle puts the iPod on the wrist by Mark R When it comes to iPods and other MP3 players, not much has changed about them in the past few years. Sure, the memory is getting better all the time, but the design is the same: they clip on the belt and the obligatory wired earplugs. This iBangle design concept is a little bit daring as the design fits right on your wrist instead of clipping to your belt. As for the earphones, forget about it! Now, if only it had a way to play video files. Too bad this iBangle remains only a concept from designer Gopinath Prasana. Source
Wireless Earbuds For iPod If you are looking for wireless earbuds for your iPod maybe this article will make you decide which earbuds are good for you. This wireless earduds are perfect if you want to run in a park or any other sport activates because you can listen to your favorite music without cord or wires. <-300x250 Medium Rectangle - center-> If you are looking for wireless earbuds you should know that there are 2 types: the ones that connect directly to your iPod and the ones that connect to your iPod through an iPod adapter. Most of the wireless earbuds for iPod use the Bluetooth protocol to connect to your iPod and some of them use other wireless protocol. The fist wireless earbuds we are going to present are the Sennheiser MX W1 Totally Wireless Earphones. This earbuds don’t connect directly to your iPod and they come with a small transmitter that connects to your player. You can find the Sennheiser MX W1 Totally Wireless Earphones on amazon.com at a price of $499.95.
Polk Audio UltraFit 500 headphones Polk Audio, one of the classic manufacturers of high-end room speakers, have taken their first step into headphone-land with their recent UltraFit line of sports headphones. The ergonomic fit of some exercise-specific headphones can sometimes be difficult and too often we find the earpieces won't stay correctly in the ears when actively exercising and jumping about. While the fit design of the UltraFit 500 doesn't technically fall too far outside of "difficult", once you figure it out, they'll fit very securely and feel like they would stay perfectly in place through even the most aggressive of work-outs. The earpiece fit into the ear is fairly shallow which allows you to remain at least somewhat aware of your ambient environs when jogging city streets, for example. The overall fit ergonomics remain very stable due to the flexible ear loops securing the headphones to your noggin.
Best Headphones For Running and Exercise- 2011 Gear Guide Best Headphones for Indoor or Outdoor Exercise Anyone who hits the gym or runs knows that awesome music is a huge asset to any exercise routine. After all, nothing can get you motivated for a hard workout quite like your favorite tunes. Best Headphones for the Gym In ear headphones are excellent for workouts since they can isolate you from all the ambient gym noise and distractions. Best Headphones for Running or Jogging Perhaps amongst the very best choice for dedicated running or jogging headphones are the recent Polk Audio series.
ISM band The industrial, scientific and medical (ISM) radio bands are radio bands (portions of the radio spectrum) reserved internationally for the use of radio frequency (RF) energy for industrial, scientific and medical purposes other than telecommunications.[1] Examples of applications in these bands include radio-frequency process heating, microwave ovens, and medical diathermy machines. The powerful emissions of these devices can create electromagnetic interference and disrupt radio communication using the same frequency, so these devices were limited to certain bands of frequencies. In general, communications equipment operating in these bands must tolerate any interference generated by ISM equipment, and users have no regulatory protection from ISM device operation. Despite the intent of the original allocations, and because there are multiple allocations, in recent years the fastest-growing uses of these bands have been for short-range, low power communications systems. ISM bands[edit]
Frequency allocation United States radio spectrum frequency allocations chart as of 2011 United States radio spectrum frequency allocations chart as of 2003 Use of radio frequency bands of the electromagnetic spectrum is regulated by governments in most countries, in a Spectrum management process known as frequency allocation or spectrum allocation. Radio propagation does not stop at national boundaries. Giving technical and economic reasons, governments have sought to harmonise the allocation of RF bands and their standardization. A number standards bodies work on standards for frequency allocation, including: These standards bodies have assigned frequency bands in three types of allocation: High-demand sections of the electromagnetic spectrum may sometimes be allocated through auctions. Daily impact[edit] Every day, users rely on allocation of frequencies for efficient use of such devices as: Power levels vary widely (from 1 milliwatt in a Bluetooth node to 1 kilowatt in a microwave oven). the Americas, Region 1
Bluetooth Bluetooth is a wireless technology standard for exchanging data over short distances (using short-wavelength UHF radio waves in the ISM band from 2.4 to 2.485 GHz[2]) from fixed and mobile devices, and building personal area networks (PANs). Invented by telecom vendor Ericsson in 1994,[3] it was originally conceived as a wireless alternative to RS-232 data cables. It can connect several devices, overcoming problems of synchronization. Bluetooth is managed by the Bluetooth Special Interest Group (SIG), which has more than 19,000 member companies in the areas of telecommunication, computing, networking, and consumer electronics.[4] Bluetooth was standardized as IEEE 802.15.1, but the standard is no longer maintained. Name and logo[edit] Bluetooth logo The Bluetooth logo is a bind rune merging the Younger Futhark runes (Hagall) (ᚼ) and (Bjarkan) (ᛒ), Harald's initials. Implementation[edit] Bluetooth operates in the range of 2400–2483.5 MHz (including guard bands). Uses[edit] Bluetooth vs.