Enhanced overflow call processing

• US 6,330,323 B1
• Filed: 01/11/1996
• Issued: 12/11/2001
• Est. Priority Date: 01/09/1995
• Status: Expired due to Term

• Current Assignee: Shenzhen Technology Co. Ltd, Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Original Assignee: MCI Communications Corporation (Verizon Communications Inc.)
• Inventors: Engdahl, Roger P., Rogers, Wesley, Frazier, Cathleen, Gottlieb, Louis G.
• Primary Examiner(s): Tsang, Fan
• Assistant Examiner(s): Foster, Roland G.
• Application Number:
  US08/584,517
• Time in Patent Office: 2,161 Days
• Field of Search: 379/201, 379/207, 379/210, 379/211, 379/220, 379/221, 379/229, 379/230, 379/231, 379/265, 379/201.01, 379/201.02, 379/211.01, 379/211-2-2, 379/212.01, 379/219, 379/220.01, 379/221-1-2, 379/265.01, 379/265.02, 379/266.01, 379/266.04
• US Class Current: 379/220.01
• CPC Class Codes: H04Q 2213/13103 Memory
• CPC Class Codes: H04Q 2213/13144 Searching path through number of switching stages or nodes, e.g. revertive blocking
• CPC Class Codes: H04Q 2213/13145 Rerouting upon failure
• CPC Class Codes: H04Q 2213/13146 Rerouting upon blocking/overload, rearrangement
• CPC Class Codes: H04Q 2213/13344 Overflow
• CPC Class Codes: H04Q 2213/13353 Routing table, map memory
• CPC Class Codes: H04Q 3/66 Traffic distributors

Abstract

A system and method for Enhanced Overflow Call Processing redirects calls which cannot be completed to alternate terminations. An originating switch queries a network database for an alternate termination for the call each time the originating switch detects that the call cannot be completed to the current termination. The network database determines the alternate termination for each query using a hierarchical set of multi-branch overflow statements which are configured by the user. A set of overflow statements is selected by the network database based on the original termination of the call. The set of overflow statements is searched hierarchically until an active overflow statement is found. This overflow statement then controls all queries relating to that call. The reason the call was not completed is used to select either an alternate termination to which the call is to be routed or a particular treatment, such as a busy signal or network message, which is to be applied to the call. If an alternate termination is selected, the originating switch routes the call to the alternate termination. The process then repeats until either the call is completed, the overflow statement specifies a treatment is to be applied, or a predetermined number of completion attempts to alternate terminations have occurred.

Claims

1. A method of redirecting a telephone call from a first termination in a telecommunications network to a second termination in said telecommunications network, said telecommunications network including a plurality of interconnected switches, wherein said call enters the network at an originating switch, each of said terminations being coupled to a terminating switch, the method comprising the steps of:

a) routing said call from said originating switch to a first terminating switch coupled to said first termination;

b) after routing said call to said first terminating switch, determining, at said originating switch, whether said call is completed to said first termination;

c) upon determining that said call has not been completed, releasing said call from said first terminating switch and transmitting from said originating switch to a network database a request for an indication of a second termination, said request having an indication of said first termination and of the condition encountered;

d) using information relating to why said call was not successfully completed at said first termination and said condition encountered to select from at least one set of overflow statements providing instructions for overflow routing said second termination at said network database, wherein step d) further comprises the steps of;

selecting an overflow tree set from said set of overflow statements based on said original termination;

selecting an active overflow tree from said selected overflow tree set;

selecting a segment of said selected tree based on said original termination of said call;

comparing the condition encountered with a condition specified by said selected segment; and

selecting an action and an object specified by said selected segment, if said condition encountered matches said condition specified by said selected segment;

e) transmitting from said network database to said originating switch said indication of said second termination; and

f) upon receiving said indication of said second termination from said network database, routing said call to a second terminating switch coupled to said second termination.

2. The method of claim 1, further comprising the step of:

repeating steps c to f for each termination indicated by said network database until either said call is completed or said steps have been repeated a predetermined number of times.

3. The method of claim 1, wherein said object comprises an indicator of a termination;

and

wherein said action comprises the step of redirecting said call to the termination specified by said object.

4. The method of claim 1, wherein said object comprises an indicator of a treatment;

and wherein said action comprises the step of applying to said call the treatment specified by said object.

5. The method of claim 1, wherein at least one of said terminations comprises a telephone station.

6. The method of claim 1, wherein at least one termination comprises a customer premise equipment.

7. The method of claim 1, wherein the step of selecting an active overflow tree from said selected set further comprises the steps of:

selecting said active overflow tree to correspond to a dialed number of said call if there is an active overflow tree corresponding to the dialed number of said call;

selecting said active overflow tree to correspond to an outpulse number of said call if there is no active overflow tree corresponding to the dialed number of said call and if there is an active overflow tree corresponding to said outpulse number of the call; and

selecting a default overflow tree if there is no active overflow tree corresponding to either said dialed number of said call or said outpulse number of said call.

8. A system for redirecting a telephone call from a first termination in a telecommunications network to a second termination in said telecommunications network, said telecommunications network including a plurality of interconnected switches, wherein said call enters the network at an originating switch and each of said terminations is coupled to a terminating switch, the system comprising:

an originating switch having

an indicator of a first termination of said call;

a call router for selecting a terminating switch coupled to said indicated first termination and routing said call to said selected terminating switch;

a detector, coupled to said selected terminating switch, for detecting whether said routed call is completed from said selected terminating switch to said indicated termination, and for generating a condition encountered;

a call releasing device, coupled to said selected terminating switch and said detector, for releasing said call to said selected terminating switch, when in receipt from said detector an indication that said call has not been completed;

a request transmitter, coupled to a network database and said detector, for transmitting to said network database a request for an indication of said second termination when in receipt of said indication from said detector that said call has not been completed, said request including an indication of said first termination and of said condition encountered;

a response receiver, coupled to said network database, for receiving a response containing said indication of said second termination from said network database; and

an indicator updating device for updating said indicator to contain said indication of said second termination;

a terminating switch having

a call receiver for receiving said call from said originating switch; and

a call completion device, coupled to said call receiver and said original termination, for attempting to complete the call to said original termination; and

a network database having

a request receiver coupled to said originating switch, for receiving a request for a second termination for said call;

data store for storing information relating to selection of additional terminations for calls said information including at least one set of overflow statements providing instructions for overflow routing;

a selector, coupled to said request receiver and said data store, for using information received in said request for selecting one of said additional terminations as said second termination for said call from amongst the information relating to said additional terminations for calls; and

a response transmitter, coupled to said originating switch, for returning an indicator of said second termination to said originating switch, wherein said at least one set of overflow statements comprises;

an overflow tree having a plurality of overflow statements; and

wherein said selector of said network database further comprises;

an overflow statement selector, coupled to said message receiver, for selecting one of said overflow statements of said selected tree based on condition encountered at said original termination of said call.

9. The system of claim 8, wherein the information relating to selection of said second termination for said call comprises:

an overflow segment having respective indicators of a termination, a

condition and an indicator of an alternate termination; and

wherein said selector of said network database comprises;

a comparator, coupled to a message receiver, for comparing the condition encountered with a condition specified by said overflow segment;

an alternate termination selector, coupled to said comparator, for selecting said alternate termination indicated by said overflow segment if the condition encountered matches the condition specified by said overflow segment.

10. The system of claim 8, wherein the information relating to selection of said second termination for said call further comprises:

an overflow statement having a plurality of overflow segments; and

wherein said selector of said network database further comprises;

an overflow segment selector, coupled to said message receiver, for selecting one of said overflow segments that has an indicator of a termination corresponding to the termination of said call.

11. A system for redirecting a telephone call from a first termination in a telecommunications network to a second termination in said telecommunications network, said telecommunications network including a plurality of interconnected switches, wherein said call enters the network at an originating switch and each of said terminations is coupled to a terminating switch, the system comprising:

an originating switch having

an indicator of a first termination of said call;

a call router for selecting a terminating switch coupled to said indicated first termination and routing said call to said selected terminating switch;

a detector, coupled to said selected terminating switch, for detecting whether said routed call is completed from said selected terminating switch to said indicated termination, and for generating a condition encountered;

a call releasing device, coupled to said selected terminating switch and said detector, for releasing said call to said selected terminating switch, when in receipt from said detector an indication that said call has not been completed, a request transmitter, coupled to a network database and said detector, for transmitting to said network database a request for an indication of said second termination when in receipt of said indication from said detector that said call has not been completed, said request including an indication of said first termination and of said condition encountered;

a response receiver, coupled to said network database, for receiving a response containing said indication of said second termination from said network database; and

an indicator updating device for updating said indicator to contain said indication of said second termination;

a terminating switch having

a call receiver for receiving said call from said originating switch; and

a call completion device, coupled to said call receiver and said original termination, for attempting to complete the call to said original termination; and

a network database having

a request receiver coupled to said originating switch, for receiving a request for a second termination for said call;

data store for storing information relating to selection of additional terminations for calls said information including at least one set of overflow statements providing instructions for overflow routing;

a selector, coupled to said request receiver and said data store, for using information received in said request for selecting one of said additional terminations as said second termination for said call from amongst the information relating to said additional terminations for calls; and

a response transmitter, coupled to said originating switch, for returning an indicator of said second termination to said originating switch, wherein the information relating to selection of said second termination for said call further comprises;

an overflow tree set having a plurality of overflow trees, each of said overflow trees having an indicator of whether it is active; and

wherein said selector of said network database further comprises;

an overflow tree selector, coupled to said overflow tree set selector, for selecting an active overflow tree.

12. The system of claim 11, wherein said overflow tree set comprises a plurality of hierarchical levels each having a plurality of overflow trees;

and

wherein said overflow tree selector selects an active overflow tree from the highest hierarchical level containing an active overflow tree.

13. The system of claim 11, wherein said overflow tree set comprises three levels of hierarchy, said hierarchy having

a level corresponding to a dialed number of said call;

a level corresponding to an outpulse number of said call, and

a default level; and

wherein said overflow tree selector comprises;

a dialed number overflow tree selector, coupled to said overflow tree set selector, for selecting an active overflow tree corresponding to a dialed number of said call if there is an active overflow tree corresponding to said dialed number of said call;

an outpulse number overflow tree selector, coupled to said dialed number overflow tree selector, for selecting an active overflow tree corresponding to an outpulse number of said call if there is no active overflow tree corresponding to said dialed number of said call and if there is an active overflow tree corresponding to said outpulse number of the call; and

a default selector, coupled to said outpulse number overflow tree selector, for selecting a default overflow tree if there is no active overflow tree corresponding to either said dialed number of said call or said outpulse number of said call.

14. A system for redirecting a telephone call from a first termination in a telecommunications network to a second termination in said telecommunications network, said telecommunications network including a plurality of interconnected switches, wherein said call enters the network at an originating switch and each of said terminations is coupled to a terminating switch, the system comprising:

an originating switch having

an indicator of a first termination of said call;

a call router for selecting a terminating switch coupled to said indicated first termination and routing said call to said selected terminating switch;

a detector, coupled to said selected terminating switch, for detecting whether said routed call is completed from said selected terminating switch to said indicated termination, and for generating a condition encountered;

a call releasing device, coupled to said selected terminating switch and said detector, for releasing said call to said selected terminating switch, when in receipt from said detector an indication that said call has not been completed,

a request transmitter, coupled to a network database and said detector, for transmitting to said network database a request for an indication of said second termination when in receipt of said indication from said detector that said call has not been completed, said request including an indication of said first termination and of said condition encountered;

a response receiver, coupled to said network database, for receiving a response containing said indication of said second termination from said network database; and

an indicator updating device for updating said indicator to contain said indication of said second termination;

a terminating switch having

a call receiver for receiving said call from said originating switch; and

a call completion device, coupled to said call receiver and said original termination, for attempting to complete the call to said original termination; and

a network database having

a request receiver coupled to said originating switch, for receiving a request for a second termination for said call;

data store for storing information relating to selection of additional terminations for calls said information including at least one set of overflow statements providing instructions for overflow routing;

a selector, coupled to said request receiver and said data store, for using information received in said request for selecting one of said additional terminations as said second termination for said call from amongst the information relating to said additional terminations for calls; and

a response transmitter, coupled to said originating switch, for returning an indicator of said second termination to said originating switch, wherein said network database further comprises;

an overflow segment having respective indicators of a termination, a condition and an alternate termination;

an overflow statement having a plurality of overflow segments;

an overflow tree having a plurality of overflow statements; and

an overflow tree set having a plurality of hierarchical levels each including a plurality of overflow trees each having an indicator of whether it is active; and

wherein said selector of said network database comprises;

an overflow tree selector, coupled to said overflow tree set selector, for selecting an active overflow tree from the highest hierarchical level containing an active overflow tree;

an overflow statement selector, coupled to a message receiver, for selecting an overflow statement of a selected tree based on condition encountered at the original termination of said call;

an overflow segment selector, coupled to said message receiver, for selecting an overflow segment having an indicator of a termination corresponding to the termination of said call;

a comparator, coupled to said message receiver, for comparing the condition encountered with a condition specified by said selected overflow segment; and

an alternate termination selector, coupled to said comparator, for selecting said alternate termination indicated by said selected overflow segment if said condition encountered matches said condition specified by said selected overflow segment.