Call forwarding
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Call forwarding (or call diverting), in telephony, is a feature on some telephone networks that allows an incoming call to a called party, which would be otherwise unavailable, to be redirected to a mobile telephone or other telephone number where the desired called party is situated. In North America usually (though not always) the forwarded line rings once, to remind the customer using Call forwarding that the call is being redirected. More consistently, the forwarded line indicates its condition by stutter dial tone.
In Europe, most networks indicate that unconditional call forwarding is active with a special dial tone. When the phone is picked up it is immediately apparent that calls are being forwarded.
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[edit] How to Use
Special types of call forwarding can be activated only if the line is busy, or if there is no answer, or even only for calls from selected numbers. In North America, the NANP generally uses the following vertical service codes to control call forwarding:
| Forward service | Activation | Deactivation | Number change |
|---|---|---|---|
| All calls | *72 | *73 | |
| On busy or no answer | *68 | *88 | |
| From select callers | *63 | *83 | |
| On ISDN | *56 | ||
| Customer-programmable features (where available): | |||
| Busy line | *90 | *91 | *40 |
| No answer | *92 | *93 | *42 |
Most EU fixed-line carriers use the following codes based on CEPT and ETSI standards developed in the 1970s on both POTS and ISDN lines: (There may be some variation to these, but the unconditional code *21*, is very much universally standard on EU telephone lines.) The general syntax for all European service codes always follows the pattern below:
| Forward service | Activate | Cancel & Deregister | Cancel & Retain | Status | Reestablish |
|---|---|---|---|---|---|
| Unconditional forwarding: | |||||
| All Calls (Unconditionally) | *21*[phone number]# | #21# | #21# | *#21# | *21# |
| Conditional forwarding: | |||||
| If Busy | *69*[phone number]# or *67*[phone number]# | #69# or #67# | #69# or #67# | *#69# or *#67# | *69# or *67# |
| If Not Answered | *61*[phone number]# | #61# | #61# | *#61# | *61# |
For GSM/3GSM (UMTS) Phones, GSM standard defines the following forward codes These were developed by ETSI and are based on standard European diversion codes and are similar to those used on most landlines in the EU:
| Forward service | Activate | Cancel & Deregister | Cancel & Retain | Status | Reestablish |
|---|---|---|---|---|---|
| Unconditional forwarding: | |||||
| All Calls | *21*[phone number]# | ##21# | #21# | *#21# | *21# |
| Conditional forwarding: | |||||
| If Busy | *67*[phone number]# | ##67# | #67# | *#67# | *67# |
| If Not Answered | *61*[phone number]# | ##61# | #61# | *#61# | *61# |
| If Out of Reach | *62*[phone number]# | ##62# | #62# | *#62# | *62# |
| Simultaneous forwarding: | |||||
| All Forwards | *002*[phone number]# | ##002# | #002# | *#002# | *002# |
| All Conditional Forwards | *004*[phone number]# | ##004# | #004# | *#004# | *004# |
Some carriers use *71 for conditional forwarding despite the fact that this is not to standards.
Sometimes, to deactivate a call forwarding, *720 will work on cellphones.
[edit] When and Why to Use it
Diverting calls can increase one's availability to a caller. The main alternative is an answering machine or voicemail, but some callers do not wish to leave a recorded message, suspecting that the party will delay returning their messages.
Some businesses find that the human touch can improve contact, thus sales, but traditional wired answering services are expensive, so they have their calls forwarded to a call center, so the client can reach an operator instead of an answering machine or voice mail.
Some services offer international call forwarding by allocating for the customer a local virtual phone number which is forwarded to any other international destination.
