US 5333185 System for processing calling party information for international communications services

ABSTRACT – A system for delivering originating country information for international toll-free calls to a subscriber includes three separate processes. The country code is extracted from billing and routing data forwarded by the caller’s national telephone network to the communication switching system of the destination country of the call, the originating country code is then inserted in either the calling party number or the destination number depending on subscriber’s terminating arrangement and finally, the originating country code is delivered to the international toll-free subscriber before the call is completed. Once received by the subscriber, the originating country information can be used to tailor customized services for the foreign caller such as directing calls to attendants fluent in caller’s language, or mapping the originating country code to the country name for display to attendants.


This invention relates to a system for processing calling party information relating to international telephone service, and more particularly to a system enabling automatic identification and delivery of information specifying the originating country of an incoming international call.


The explosive growth in international long distance telecommunications, coupled with the adoption and implementation of national and international signaling standards, such as Common Channel Signaling 7 Network Interconnect (CCS7 NI), Primary Rate Interface (PRI) and Basic Rate Interface (BRI) of Integrated Services Digital Network (ISDN), have provided the impetus for the creation of a wide variety of sophisticated international communications services offered by IntereXchange Carriers (IXC). These services include database-queried toll-free international calling which allows subscribers to be reached by customers beyond their national borders, usually at no cost to the caller except for a possible local access fee in a limited number of countries.

While toll-free subscribers in the United States have become accustomed to a variety of information forwarding features (such as calling party number forwarding), these features have not heretofore been available in the international arena. Thus, in contrast to the domestic market, international toll-free subscribers have not been able to receive background information regarding calls originating outside of areas that use the North American Numbering Plan. This background information could, for example allow the subscriber to distinguish between the needs of different callers and offer personalized services based upon the country or location of call origination.

One attempt to provide international toll-free subscribers with caller location information, involves the use of the Originating Country Information (OCI) which is part of the billing data exchanged between switching points at call setup time for some international calls. Unfortunately, this approach limits the scope of OCI usage to routing and billing functions exclusively. More importantly, this method lacks the required flexibility needed to permit OCI processing in any standard fashion to enable delivery of that information to the international toll-free subscriber. Thus, at the present time, international toll-free subscribers cannot target specific international market segments or tailor customized services for their foreign callers. This deficiency takes a special significance when one considers cultural and language barrier issues, as well as currency and measurement scale differences between calling and called parties located in different countries.

To remedy this limitation, consideration is being given to utilization of the ISDN User Part (ISUP) signaling standard that has been adopted by the CCITT, to transmit before call completion, OCI or more specifically, Calling Line Identity (CLI) information between switching points. CLI information is comprised of an Originating Country Code (OCC) which is a one to three digit number assigned to each country by CCITT, a trunk code (similar to the area code in the North American Dialing Plan) and a calling party national telephone number. CLI information can be passed between international and local exchange carrier digital switches only over international trunks rigidly adhering to stringent CCITT7 signaling standards that define protocols for the transmission of supervisory and out-of-band signaling information. Thus, even though future deployment of CCS7/ISUP or CCITT7/ISUP-compliant switching and transmission systems in calling and called parties’ countries will theoretically allow the called party to receive the CCITT-defined country code and the national telephone number of the calling party, a practical solution to the problem of OCI delivery to the international toll-free subscriber is not at hand in the foreseeable future. This conclusion stems from the fact that global implementation of the ISUP standards requires significant, costly and time-consuming enhancements to the switching and transmission systems of the worldwide telecommunications network. Furthermore, the practical implications of the strictness and stringency of the ISUP standards minimize the benefits of their full scale long-term implementation. The ISUP standards, for example, do not allow the international telecommunications network to forward only the Originating Country Code (OCC) portion of the CLI. Hence, until full CLI information can be forwarded from one country to another, no CLI information will be sent. The need for our invention takes greater importance when it is realized that partial implementation of the ISUP standards is unavailing since the presence of any non-ISUP compliant switches or non-CCITT7 compliant trunks in an international call path will prevent CLI forwarding.

Even if the ISUP standards are globally implemented, the problem of OCI delivery will still persist, because the ISUP standards specify a privacy option that enables the caller to prevent the display to the called party of his/her CLI information. Thus, the exercise of the privacy option by the caller prevents the calling party from receiving not only the calling party number, but also the OCC in the CLI, since only full CLI forwarding is allowed by the standards. Hence, even in the event of the future implementation of the ISUP standards, the problem of circumventing the undesirable side effects of the strictness of the standards still needs to be addressed.


In accordance with the present invention, a system is disclosed for identifying, forwarding and delivering to a called party, information regarding the originating country of a toll-free international call. The system does not depend on CLI availability nor does it require ISUP implementation. However, it takes advantage of ISUP signaling capability when available, in the destination country of the call. According to the invention, OCI forwarding to the toll-free subscriber involves three separate processes, namely, the identification of the originating country of the call, the formatting of the OCI, and, finally, the delivery of the originating country information to the subscriber.

The identification process is initiated by a foreign caller placing an international toll-free call which is recognized as an outbound international call by the calling party national telephone network based on the number dialed. The caller’s national telephone network then routes the call to its International Switching Center (ISC) also called an international gateway switch. As the point of exit for all international calls, the calling party ISC processes the call by converting the number dialed by the caller into billing and routing data to be forwarded to the called party ISC. The billing and routing data typically contains a code identifying the specific international toll-free subscriber to whom the call is destined. Embedded also in the billing and routing data is the CCITT-defined Originating Country Code (OCC) or equivalent information.

Upon receiving the billing and routing data from the calling party ISC, the called party ISC, sometimes called ISC Action Point or ISC/ACP, launches a query on its signaling network to locate the Adjunct Processor (AP) containing the database that stores the Call Processing Record (CPR) for the particular subscriber associated with the call. The ISC/ACP, then forwards the billing and routing data to the AP, which extracts the Originating Country Code (OCC) from the billing and routing data, thereby completing the OCI identification process.

The formatting process of our invention involves placing the Originating Country Code in parts of the routing and signaling message routinely processed by signaling or switching systems of the Interexchange Carrier, Local Exchange Carrier (LEC) and/or subscriber’s premises equipment. The following tasks are performed in a sequential manner in this process. The AP queries the database containing the Call Processing Record (CPR) to receive instructions on how to process the call. Information retrieved in the CPR by the database indicates to the AP the type of egress arrangement in use for the Subscriber’s Premises Equipment (SPE). Egress arrangements typically fall into two distinct categories, namely, dedicated and switched egress arrangements. In the dedicated egress category, the SPE is directly connected to the Interexchange Carrier network via ISDN or non-ISDN dedicated trunks. Conversely, in the switched egress arrangement, the SPE is connected to the Local Exchange Carrier (LEC) network via either trunks supporting or not supporting ISDN standards or ordinary (POTS) telephone lines. The type of egress arrangement and availability of ISDN signaling services dictate the course of the OCI formatting process.

If ISDN signaling services are available to the subscriber, the AP formulates a destination number and an Automatic Number Identification (ANI) parameter in which it inserts the Originating Country Code (OCC). The AP then forwards the ANI parameter and the destination number to the ISC/ACP which copies the value of the ANI into the Calling Party Number (CPN) parameter of the Initial Address Message (IAM), which is described in more detail below. The ISC/ACP then uses the destination number to forward the CPN parameter in the ISUP IAM, to the IXC terminating toll switch and to route the call to the same switch.

For non-ISDN subscribers, the AP inserts the Originating Country Code (OCC) in the non-exchange portion of the destination number that it forms. In addition, the AP formulates an ANI using the OCC. However, the ANI in this case is not used for OCI delivery purposes. The AP then forwards the destination number to the ISC/ACP which uses it to route the call to the IXC terminating toll switch. At this stage, the OCC is either formatted in the CPN parameter or embedded in the non-exchange portion of the destination number.

The delivery process allows communication of the OCI to the subscriber’s premises equipment. If ISDN signaling services are available, the terminating toll switch or the central office switch forwards the CPN parameter to the subscriber using the interworking features of ISUP and ISDN PRI or BRI signaling standard protocol. Alternatively, terminating switches can map the originating country code to the country’s name and deliver either one or both, to subscribers with an ISDN connection. For non-ISDN customers, the country code is forwarded to the subscriber in the destination number, using a standard signaling protocol such as the ground start/loop start protocol.

Once the Originating Country Information (OCI) is received by the SPE or station set, it can be used by the subscriber to tailor customized services for the foreign caller. Personalized services that can be offered include, for example, connecting callers from a given country to specialized attendants fluent in caller’s native language and familiar with his/her currency. In addition, a subscriber’s PBX can map the originating country code to the country’s name for display to attendants, if this function is not already performed in the network. In the case of data calls as opposed to voice calls, traffic can be directed to specialized processors capable of recognizing special characters such as Kanji, Chinese, Korean, Arabic, Greek, Hebrew and Cyrillic, to name a few. Furthermore, subscribers can perform traffic pattern analysis to determine distribution of calls by countries of origin. Other miscellaneous services such as billing, facsimile applications, and security services can also be offered. Finally, immediately after the call is terminated, the terminating toll switch sends a CCS7 message to the ISC/ACP indicating that the Originating Country Information was successfully delivered in order for the ISC/ACP to bill the subscriber for the service.

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