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    • How to Dial International Phone Numbers

      How to Dial International Phone Numbers

      With the expansion of Voice over IP and cellular phone technologies over the past decade, it has never been more cheaper to call international phone numbers. A common barrier for consumers trying to call friends, family, or business contacts that live abroad is determining how to dial international phone numbers from your country. International Dialing 

    • Numbers that always Ring Busy

      Numbers that always Ring Busy

      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

    • How to Change my PIN and PUK

      How to Change my PIN and PUK

      A PIN, or Personal Identification Number, is a number that is used on some SIM cards to prevent unauthorized use of the cell phone it is located in. PINs are not used by all SIM cards and may need to be setup before they can be used. A PIN is generally between 4 and 8

    • Blue Box

      Blue Box

      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

    • Milliwatt Test Line

      Milliwatt Test Line

      A “Milliwatt (102 Type) Test Line” is a signal generated from an Access Service Provider end office to the customer’s location for the purposes of transmission measurement, that is, testing the line quality and loss of transmission. The generated signal is a 1004 Hz tone at 0 dBm, which is the equivalent of 1 milliwatt

    • CLEC (Competitive Local Exchange Carrier)

      CLEC (Competitive Local Exchange Carrier)

      A CLEC, or Competitive Local Exchange Carrier, is a type of telecommunications provider that was formed after the breakup of AT&T. CLECs are usually smaller telecommunications providers that compete with ILECs, or Incumbent Local Exchange Carriers, which were already in place before AT&T’s separation. While CLECs generally provide the same services as ILECS for less,

    • How to Block Incoming Calls

      How to Block Incoming Calls

      Blocking incoming calls can sometimes be quite important for many reasons. Someone may be troubling you over the phone, harassing you, giving blank calls and you just want to avoid a specific person. A simple way to do this is to block an incoming call of a specific person. That is, whenever that person calls

    • IS-95: CDMA

      IS-95: CDMA

      IS-95 is a standard for CDMA (Code Division Multiple Access) Digital Cellular. Mobile Frequency Range Rx: 869-894; Tx: 824-849 Multiple Access Method CDMA/FDM Duplex Method FDD Number of Channels 20 (798 users per channel) Channel Spacing 1250kHz Modulation QPSK/OQPSK Channel Bit Rate 1.2288Mb How CDMA Works In a CDMA system, your encoded voice is digitized

    • How to Unlock a BlackBerry

      How to Unlock a BlackBerry

      Many wireless providers across the globe, including AT&T/Cingular, T-Mobile, Vodafone, and Verizon sell Blackberries. When these companies sell a BlackBerry, they do so at a discount in order to attract customers. The providers then make up the lost profits over the lifetime of their contract with the customer. To protect those profits, the wireless providers

    • TL1 (Transaction Language 1)

      TL1 (Transaction Language 1)

      TL1 (Transaction Language 1) is an element management protocol used primarily in the telecommunications industry. TL1 was designed by Bellcore (now Telecordia) in 1984 for use with its OSS (Operations Support System), NMA. TL1 is an MML (Man Machine Language), which means that TL1 messages should be readable and writeable by humans as well as

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