Arrangement for serving a telephone office code from two switching systems
First Claim
1. A method of establishing a telephone call from a caller to a customer, said customer'"'"'s plain old telephone service (POTS) number comprising an office code assigned to a first switch but served by a second switch, comprising the steps of:
- receiving in a third switch of a public switched network, said POTS number assigned to said first switch;
in said third switch, translating the office code of said POTS number to determine whether POTS numbers of said office code are served from two other switches;
if said translating step indicates that said office code is served from two other switches, transmitting a query message, comprising said POTS number, from said third switch of said public switched network to a database shared by a plurality of switches;
responsive to receiving said query, translating in said database to determine information for use in routing said call to said second switch, and transmitting a message comprising said information to said third switch; and
responsive to receiving said information, using said information for routing said call from said third switch to said second switch.
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Accused Products
Abstract
This invention relates to a method and apparatus for establishing connections over a public switched telephone network to a customer whose telephone number is in a block associated, for routing purposes, with a first telephone switching system, but who is actually served by a second telephone switching system. The facility for carrying out this method is desirable in order to serve customers who need the advanced functions of a digital switching system, who are currently served by an analog switching system, and do not wish to have their telephone number changed when they switch to being served by the digital switching system. In accordance with the invention, a centralized database is queried to find the identity of the switch serving the called customer. The database returns a routing index for routing the call to that switch.
134 Citations
10 Claims
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1. A method of establishing a telephone call from a caller to a customer, said customer'"'"'s plain old telephone service (POTS) number comprising an office code assigned to a first switch but served by a second switch, comprising the steps of:
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receiving in a third switch of a public switched network, said POTS number assigned to said first switch; in said third switch, translating the office code of said POTS number to determine whether POTS numbers of said office code are served from two other switches; if said translating step indicates that said office code is served from two other switches, transmitting a query message, comprising said POTS number, from said third switch of said public switched network to a database shared by a plurality of switches; responsive to receiving said query, translating in said database to determine information for use in routing said call to said second switch, and transmitting a message comprising said information to said third switch; and responsive to receiving said information, using said information for routing said call from said third switch to said second switch. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A switching system comprising:
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means for translating an office code of a plain old telephone service (POTS) number of a received call to determine if POTS numbers of said office code are served from two other switching systems; means, responsive to an indication from said means for translating that numbers of said office code are served from one other switching system, for extending said call to a destination switch specified in translation information of said switching system; means, responsive to an indication from said means for translating that numbers of said office code are served from two other switching systems, for transmitting a query message to a database shared by a plurality of switching systems, said query message comprising said POTS number; and means, responsive to receiving a response from said database, for using said POTS number and information of said response message for extending said call toward a particular destination switch for establishing said call. - View Dependent Claims (8, 9, 10)
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Specification