Automatic dialer for telephone network access control

• US 4,447,676 A
• Filed: 02/24/1983
• Issued: 05/08/1984
• Est. Priority Date: 02/24/1983
• Status: Expired due to Fees

• Current Assignee: Shawmut Bank of Boston NA A National Banking Association
• Original Assignee: Telelogic Software Singapore Pte Limited (International Business Machines Corporation)
• Inventors: Harris, William J., Petty, David C., Jackson, Joseph M.
• Primary Examiner(s): Schreyer, Stafford D.
• Application Number:
  US06/469,277
• Time in Patent Office: 439 Days
• Field of Search: 179/90 BD, 179/18 AG, 179/18 B, 179/18 EB, 179/90 BB, 179/90 B, 179/18 EA, 179/18 BA
• US Class Current: 379/199
• CPC Class Codes: H04M 1/2746 Sorting, e.g. according to history or frequency of use
• CPC Class Codes: H04M 1/27485 Appending a prefix to or inserting a pause into a dialling sequence

Abstract

An automatic dialer for controlling access to a long-distance telephone network. The automatic dialer includes a read/write memory. Each time the user attempts to call through the network a telephone number inaccessible via the network, an entry representing the area code and/or exchange of that telephone number is made in the memory. Prior to calling the network, the dialer compares the destination telephone number with the entries in the memory; the call is placed via the network only if the area code and exchange of the destination number do not match any of the entries. The entries in the memory are ordered according to recency of attempts by the user to access a telephone number within the groups of telephone numbers represented by the entries; when the memory is filled, the oldest entry is deleted to make room for the newest entry. Memory entries may be erased manually or automatically, by the network control station, without human intervention, to remove entries corresponding to areas added to the network. Automatic erasure is accomplished by the network sending an appropriate command, using tone signalling, as part of a message that the user has attempted to call a location not covered by the network.

Claims

1. An automatic telephone dialer for use in accessing a long-distance telephone network, comprising:

(a) a memory having a plurality of locations, each location being suitable for storing an entry indicating a group of telephone numbers not accessible via the long-distance network;

(b) means for comparing a telephone number being called with the entries in the memory and, responsive to such comparison, routing the call to the long-distance network if the number being called is not within a group of telephone numbers represented by the entries in the memory; and

(c) means for writing into said memory an indication of a telephone number called on the long-distance network when that number is found to be inaccessible via that network, whereby the directory may be compiled in said memory in response to failed attempts to access the network.

2. Apparatus for controlling access to a long-distance telephone network, connection to which is accomplished through an interconnected local telephone system, comprising:

(a) an automatic telephone dialer;

(b) means for providing to the telephone dialer a representation of a telephone number being called, responsive to user selection of said telephone number; and

(c) the automatic telephone dialer including

(i) a memory having a plurality of locations, each location being suitable for storing an entry indicating a group of telephone numbers not accessible via the long-distance network,

(ii) means for comparing a telephone number being called with the entries in the memory and, responsive to such comparison, routing the call to the long-distance network if the number being called is not within any group of telephone numbers represented by the entries in the memory, and

(iii) means for writing into said memory an indication of a telephone number called on the long-distance network when that number is found to be inaccessible via that network, whereby a directory may be compiled in said memory in response to failed attempts to access the network.

3. The apparatus of claim 2 wherein at least a portion of the entries in the memory are organized in order according to recency of attempts by the user to dial telephone numbers within the respective groups of numbers represented by the entries, and further including:

(a) means for modifying the order of the directory entries in said portion to maintain the order according to recency of attempt to access the long-distance network; and

(b) the means for writing into the memory being adapted to delete the least recent entry therein and substitute a new entry therefor when the memory is full and a failed attempt to access the network results in the generation of a new entry.

4. The apparatus of claim 3 further including means responsive to signals from the long-distance network for modifying the contents of the directory by removing therefrom the indication for a group of telephone numbers previously not accessible via the long-distance network but which have become accessible via that network.

5. Apparatus for controlling access to a subscription long-distance telephone network, connection to which is accomplished through an interconnected local telephone system, comprising:

(a) an automatic telephone dialer;

(b) means for providing to the telephone dialer a representation of a telephone number being called, responsive to user selection of said telephone number; and

(c) the automatic telephone dialer including

(i) a directory of long-distance network dialing restrictions, termed a "splash back list," the splash back list containing entries indicating of groups of telephone numbers not accessible via the long-distance network,

(ii) at least a portion of the entries in said splash back list being organized in chronological order according to recency of attempt by the user to access a telephone number within the group of numbers represented by the entry,

(iii) means for comparing a telephone number being called with the contents of the directory and, responsive to such comparison, routing the call to the long-distance network if the number being called is not within a group of telephone numbers represented by the directory entries and otherwise routing the call over a different path, and

(iv) means for modifying the chronological order of said portion of the directory entries to maintain the ordering according to recency of attempt to access the long-distance network.

6. The apparatus of claim 5 wherein the automatic dialer includes a memory for containing the entries of the directory and means for writing into said memory an indication of a telephone number called on the long-distance network which is found to be inaccessible via that network, whereby the directory may be compiled in said memory in response to failed attempts to access the network.

7. The apparatus of claim 6 wherein the memory is of finite capacity and further including means for eliminating from the memory the entry corresponding to the user'"'"'s least recent attempt to access the long-distance network when the memory is full and an attempt is made to access a telephone number inaccessible via that network and such number is not already indicated in the memory as being inaccessible.

8. The apparatus of claim 7 further including means responsive to signals from the long-distance network for modifying the contents of the directory by removing therefrom the indication for a group of telephone numbers previously not accessible via the long-distance network but which have become accessible via that network.

9. The apparatus of claim 5 further including means responsive to signals from the long-distance network for modifying the contents of the directory by removing therefrom the indication for a group of telephone numbers previously not accessible via the long-distance network but which have become accessible via that network.