Toll-free telephone number

From Academic Kids

A toll-free telephone number (or Freephone number in the UK) is a special telephone number, in which the calling party is not charged for the call by the telephone operator. Instead the called party pays all of the charges for the call to the telephone operator, usually based on factors such as the amount of usage the number experiences, the cost of the trunk lines to the facility, and possibly a monthly flat rate service charge. The called party usually recoups these charges in a number of ways:

  • they charge the calling party in another way, such as for technical support calls.
  • they make a sale following the call to the toll-free number.

Toll-free numbers in the North American Numbering Plan (known as WATS lines) are sometimes called "800 numbers" after the original area code which was used to dial them. They include the area codes 800, 888 (since 1995), 877 (since 1997), 866 (since 2000), 855 (since 2000 although not yet in heavy use), 844, 833 and 822 (the last three are not yet active but reserved).

A universal international freephone number (UIFN) is a worldwide toll-free "800 number" issued by the ITU. Like the 800 area code issued for the NANP in the U.S. and Canada, the call is free for the caller, and the receiver pays the charges. UIFN uses ITU country code 800, so that no matter where the caller is, only the international access code (IAC) and the 8-digit UIFN need to be dialed. Currently, about 30 countries participate in the UIFN programme.


How Toll-Free calls are handled by operators

In the US, both interexchange carriers (IXCs) such as Sprint, AT&T, and MCI, and Local Exchange Carriers (LECs) such as Verizon, Pacific Bell, and SBC offer toll free services.

The format of the toll-free number is called a non-geographic number, in contrast to telephone numbers associated with households which are geographic. In the latter case, it is possible to determine an approximate location of the caller from the dial code (e.g. New York or London). Toll-free numbers in contrast could be physically located anywhere in the country (or even abroad).

When a toll free number is dialed, the first job of the telephone operator is to determine where the actual physical destination is. This is achieved using the intelligent network capabilities embedded into the network.

In the simplest case, the toll-free number is translated into a regular geographic number. This number is then routed by the telephone exchange in the normal way. More complicated cases may apply special routing rules in addition such as Time of Day routing.

Technical Description of toll-free number routing in the U.S.

The IXCs generally handle traffic crossing boundaries known as LATAs (Local Access and Transport Areas). A LATA is a geographical area within the U.S. that delineates boundaries of the LEC. LECs can provide local transport within LATAs. When a customer decides to use toll free service, they assign a RESPORG to own and maintain that number. Usually the RESPORG is the IXC that is going to deliver the majority of the toll free services.

Taking a closer look, when a toll free number is dialed, each digit is analyzed and processed by the LEC. The toll free call is identified as such by the service switching point (SSP). The SSP is responsible for sending call information to the signal transfer point (STP). The STP asks the service control point (SCP) where to send the call.

The LEC will determine to which IXC that number is picked, based on the customer's choice. Toll free numbers can be shared among IXCs. The reason a customer might do this is for disaster recovery or for negotiating a better price among the carriers. For example, a customer may assign 50% of their traffic to Sprint and 50% to AT&T. It's all up to the customer.

Once the LEC determines to which IXC to send the call, it is sent to the IXCs point of presence (POP). The IXCs SCP must now determine where to send the call. When it comes to routing, the SCP is really the brains of the long distance network. The protocol used in this call control is known as Signaling System 7 (SS7). SS7 is a digital out-of-band method of transmitting information in the Public Switched Telephone Network (PSTN). SS7 is the protocol used to separate bearer control (the payload of the telephone call) from signaling control (setup and teardown of the call and services) in the AIN services network. Once the final determination of where the call is supposed to go is completed, the call is then routed to the subscriber's trunk lines. In a call center or contact center environment, the call is then typically answered by a telephone system known as an automatic call distributor (ACD) or private branch exchange (PBX).

The subsequent routing of the call may be done in many ways, ranging from simple to complex depending on the needs of the owner of the toll-free number. Some of the available options are:

  • Time-of-Day (TOD) Routing. One of the simplest ways to influence the destination of the call is by using time-of-day routing. An example of using TOD routing would be a company with a call center on the east coast and a call center on the west coast. TOD routing would enable Follow the Sun routing. The east coast center opens first and calls are sent to that destination earlier in the day. As the time changes across the country, expanded coverage would be offered by the call center in the west.
  • Day of Week (DOW) or Day of Year (DOY) Routing. Depending on the day of the week and business practices, not all call centers operate 24x7. Some centers may be closed for weekends or holidays. DOW routing allows alternate routing for calls that arrive on specific days. DOY routing allows for alternate routing on fixed holidays (example December 25th).
  • Area Code or Exchange Routing. Toll free traffic may also be routed depending upon the location of the caller. For instance, if a company has call centers in the north and in the south, they may express a preference to have their southern callers speak with people in the southern call centers. Companies may also wish to take advantage of the difference in interstate rates versus intrastate rates. For example, the cost of a telephone call across multiple states may be less expensive than a call within a state, and as a result, the ability to route a call originating in Michigan to a call center outside of Michigan can save a company substantial amounts of money.
  • Percentage Allocation Routing. If a company has multiple call centers, the company can choose to route calls across a number of call centers on a percentage basis. For example, an airline with ten call centers may choose to allocate 10% of all incoming traffic to each center.
  • All-Trunks-Busy Routing. If at a given time, a company's trunk facilities can no longer handle the incoming traffic, an alternate destination may be chosen. This assists companies handling unexpected call volumes or during crisis times.
  • Ring No Answer Routing. Some carriers have the ability to pull a call back into the network if the call is not answered. This provides for contingency routing for calls that ring and are not answered at the final destination.
  • Emergency or Disaster Routing. Companies usually have some type of disaster plan to deal with both natural (e.g. floods, fires and earthquakes) and man-made (e.g. bomb threats) emergencies. IXCs can provide alternate destinations should any of these situations occur.
  • Take Back and Transfer / Transfer Connect / Agent Redirect. If a company uses an ACD to facilitate the transfer, the ACD will remain in the call as long as the parties are on the phone. The drawback is that this uses up trunk capacity on the ACD (or VRU). This is called by a number of names including hairpinning or tromboning IXCs have the capability to allow a company to answer a call, provide a level of service, and then transfer the call to another location. These IXC features provide a level of transferring that is different from what is available via the ACD. There is usually a feature charge associated with this offering.

All of the above routing features are sometimes referred to as static routing features. These routes are put in place and are not usually changed. If changes are required, a customer usually has several options to make changes. A customer can call the IXC directly via a special toll free number to make changes, or a customer may be able to make changes through direct access to the network via a dedicated terminal provided by the IXC.

Toll-free numbers around the world

Countries around the world use different prefixes to denote toll-free services in their own networks. Some examples are:

  • In Australia, the prefix is "1800" for toll-free (or free call) numbers and are often referred to as "1-800 numbers". They used to be called "008 numbers".
  • In France and also in Belgium, the "0800" prefix is used for toll-free numbers.
  • In Hong Kong, toll-free numbers have "800" prefix.
  • In India, toll-free numbers begin with "1600".
  • In Sweden, the prefix is "020" for toll-free numbers.
  • In the UK, numbers starting "0800" or "0808" are free. The range 0808 570xxx, where xxx is any three digits, is set aside for use in TV and radio.
  • In Japan, the prefix "0120" is used for toll-free numbers and is often referred to as "free dial" (フリーダイヤル).
  • In Germany, the prefix "0130" is used for toll-free numbers.

See also

External links


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