SS7 gateway

#This invention relates to telecommunications and more particularly a method and system therefor of validating special service calls placed by a subscriber of a first telephone service provider in a geographical area, or a different country, where telephone services are provided by a different telephone service provider. This invention also relates to a gateway and a system for converting a first signaling protocol of a first telephone service provider to a second signaling protocol compatible with a different telephone service provider.

#Prior to the instant invention, when a subscriber of a particular telephone service provider, as for example a long distance carrier in the United States, were to travel to a foreign country such as for example Canada, if the subscriber wants to use a telephone card issued to him from his telephone service provider to make a special service call, such as for example an operator assisted call, he would hear a message from the local telephone service provider where he was placing the call that his telephone card could not be used. This is because the local telephone service provider has no means by which to check whether the account number entered by the subscriber is a valid number, as the database in which valid numbers (or invalid numbers) are stored for comparing with the subscriber's calling card number can only be accessed by the subscriber's telephone service provider. One of the reasons that there was no interaction between the different telephone service providers was that each telephone service provider may be using a different type of signaling protocol.

#There is prior art dealing with the conversion of different protocols. For example, in U.S. Pat. No. 5,182,748, there is disclosed a converter for converting an X.25 protocol to an X.32 protocol. However, this protocol conversion system does not deal with validation, but rather deals with coupling an X.25 terminal apparatus to a conventional telephone network, an ISDN, or a PBX system.

#The above mentioned objectives and advantages of the present invention will become apparent and the invention itself will be best understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

#FIG. 1 is an overall view of the system of the instant invention from the perspective of a telecommunications service provider to both its "domestic" and "foreign" calls;

#FIG. 2 is a simplified view of the present invention from the perspective of another telecommunications service provider in communication with the service provider of FIG. 1;

#With reference to FIG. 1, a caller or subscriber at 2 originates a call to a switch network 4 of a telecommunications service provider. The call is identified as a special service call, for example an operator assisted call, and gets routed to an operator network center (ONC) 6. At ONC 6, the operator identifies the call as either a calling card call or a third party bill etc. Switch network 4, in the meantime, prompts the caller to provide an authorization code which may for example be a number on a credit card or a telephone calling card.

#There are a number of consoles, designated 8, connected from ONC 6 to a ANSI SS7 network 10. For the FIG. 1 embodiment, the connection between network 10 and ONC 6 could be represented for example by a service switching point (SSP) 12.

#As is well known, the SS7 network, as its name implies, utilizes a SS7 protocol which consists of four basic sub-protocols. These sub-protocols are: message transfer part (MTP) which provides the function of basic routing of signaling messages between signaling points; a signaling connection control part (SCCP) which provides additional routing and management functions for transfer of messages other than call set-up between the signaling points; an integrated services digital network (ISDN) user part (ISUP) which transfers call set-up signaling information between signaling points; and a transaction capabilities part (TCAP) which transfers non-circuit related information between the signaling points.