An IXC (Inter-eXchange Carrier) is a telephone company that is responsible for handling long distance telephone calls. A long distance telephone call refers to any call made to an area outside of the caller’s LATA (Local Access and Transport Area), which the caller’s local telephone company usually handles. While local telephone companies may forward a long distance call to an IXC, which will then forward the call to a phone company in the recipient’s LATA, most telephone companies serve as both local and long distance carriers. How IXC Works If Read More

IS-54 and IS-136 are standards for TDMA American Digital Cellular. Mobile Frequency Range Rx: 869-894; Tx: 824-849 Multiple Access Method TDMA/FDM Duplex Method FDD Number of Channels 832 (3 users per channel) Channel Spacing 30Khz Modulation DQPSK Channel Bit Rate 48.6Kb IS-54 and IS-136: TDMA Security IS-54 and IS-136 use the CAVE (Cellular Authentication, Voice Privacy and Encryption) algorithm for authentication and the CMEA (Cellular Message Encryption Algorithm) for encryption. CAVE and CMEA are documented in Common Cryptographic Algorithms and Interface Specification for Common Cryptographic Algorithms. David Wagner, Bruce Schneier Read More

This "mosquito ringtone" is the original "secret ringtone." A secret ringtone is any ringtone which is recorded above 15Khz. Most adults are unable to hear frequencies above 15Khz due to age-related hearling loss known as presbycusis. Because of this, secret ringtones such as the mosquito ringtone can usually only be heard by people up to their mid twenties. This sound was originally developed by Howard Stapleton of Compound Security Systems as a way to prevent young people from loitering around businesses. That product was named the Mosquito, because the sound Read More

A 66 block is a punch-down block used to connect wiring for telephone systems and other low-speed low-voltage wiring applications. A punch-down tool is used to force solid wire into metal slots on the 66 block. The 25-pair standard non-split 66 Block encloses 50 rows; each row has four columns of clips that are electrically linked. Each row contains four clips, but the left two clips are electrically isolated from the right two clips. Blocks may be punched down manually, or purchased already wired at the factory. The newer 110 Read More

To understand what an unlocked cell phone is, it is important to first understand what a locked cell phone is. A locked cell phone is one that can only be used with one cellular service provider. In contrast, an unlocked cell phone can be used with any cellular service provider. When a cell phone is locked, it only recognizes a SIM (Subscriber Identification Module) card that the cellular service provider that the cell phone is locked to (a SIM card is a microchip that stores data and provides cellular service Read More

Blue boxes use a 2600hz tone to size control of telephone switches that use in-band signaling. The caller may then access special switch functions, with the usual purpose of making free long distance phone calls, using the tones provided by the Blue Box. To quote Karl Marx, blue boxing has always been the most noble form of phreaking. As opposed to such things as using an MCI code to make a free phone call, which is merely mindless pseudo-phreaking, blue boxing is actual interaction with the Bell System toll network. Read More

Mobile software refers to software that can be stored and executed on a mobile device such as a cell phone, PDA, smart phone, or similar device. Mobile software can range in its capabilities as some simply change the virtual appearance of the device while others provide important features such as menu layouts and password protection. ScreenLocker, for instance, can lock unauthorized users out of a mobile device while Opera Mini is a mobile browser. This article will go over a number of mobile programs that can greatly enhance the user’s Read More

A reverse telephone directory is a type of directory used in telephony to identify a person and his/her address by entering his/her phone number. A reverse telephone directory is the opposite of traditional telephone directories, such as Yellow Pages or caller ID, which allow a user to search for a person’s phone number by entering his/her name or address. Reverse telephone directories can be useful in situations in which a phone number is available, via caller ID or another source, but a name is not. Although many commercial reverse telephone Read More

In the following listings, "xxx" means that the same number is used as a constantly busy number in many different prefixes. In most of these, there are some exchanges that ring busy and some exchanges that are in normal use. ALWAYS test these numbers at least three times during normal business hours before using as a constantly busy number. NPA Telephone Number Geography 213 xxx-1117 Los Angeles, CA 213 xxx-1118 Los Angeles, CA 213 xxx-1119 Los Angeles, CA 213 xxx-9198 Los Angeles, CA 216 xxx-9887 Akron/Canton, Cleveland, Lorain, and Youngstown, Read More

Blackberry is a wireless handheld smartphone created by the Canada based company Research In Motion. It was first introduced in 1999 in the form of a two way pager. The first Blackberry smartphone was released in 2002. Blackberry smartphones work together with mobile service providers to transmit information or data through their wireless networks. Blackberry is the second largest selling smartphone in the world, accounting for about 21% of global smartphone sales. Apart from conventional mobile telephony, Blackberry smartphones offer the following features and services: Blackberry Enterprise Server The Blackberry Read More