Method and apparatus for enhancing the operating capabilities of a telephone switching system

• US 4,782,519 A
• Filed: 05/22/1986
• Issued: 11/01/1988
• Est. Priority Date: 05/22/1986
• Status: Expired due to Fees

• Current Assignee: Network Access Corp.
• Original Assignee: Network Access Corp.
• Inventors: Miller, Charles C., Binford, Donald D. Jr., Yang, Yeong-Haw, Cheng, Zye-Kong, Patel, Rajendra, Lauffenburger, Kenneth A., Coley, Gerald K., Thorn, David W.
• Primary Examiner(s): Brown, Thomas W.
• Application Number:
  US06/866,165
• Time in Patent Office: 894 Days
• Field of Search: 379/221, 379/207, 379/113, 379/230, 379/112, 379/269, 379/244, 379/246, 379/275, 340/827, 370/58
• US Class Current: 379/201.05
• CPC Class Codes: H04Q 3/42 Circuit arrangements for indirect selecting controlled by common circuits, e.g. register controller, marker
• CPC Class Codes: H04Q 3/665 Circuit arrangements therefor

Abstract

A method and apparatus is described for providing extended subscriber features, e.g., equal access, to otherwise non-conforming central offices of a telephone switching system. According to the invention, a register module is interposed between the subscriber line and an input of the central office for intercepting digits from the subscriber line intended for the central office and for receiving subscriber information from the central office identifying the subscriber line. The register module includes a memory having a plurality of address locations and a control circuit for analyzing the intercepted digits to determine whether processing of the subscriber call requires an extended subscriber feature. If so, the intercepted digits are processed to generate a coded signal, the coded signal including the address location where the stored digits and the subscriber information resides in the memory. The coded signal is then used by the marker in the central office to select an appropriate outgoing trunk to complete the subscriber call. An associated trunk module interposed between the switch element of the central office and the outgoing trunks receives the coded signal and in response thereto polls the register module to request transmission of the digits and the subscriber information. Upon receipt of this data, the trunk module outputs a signal to the selected trunk.

Claims

1. An apparatus for enhancing the operation of a central office in a telephone switching system to provide one or more extended subscriber features, the central office including a switch element for connecting a subscriber line to one of a plurality of outgoing trunks and control means for controlling the switch element, comprising:

a register module interposed between the subscriber line and the control means of the central office, said register module receiving subscriber signals from the subscriber line intended for the central office and including;

(a) a line identification receiver connected to receive line information from the control means identifying the subscriber line and for translating the line information into automatic number identification and pre-subscription information,

(b) a memory for storing the subscriber signals, the automatic number identification and the pre-subscription information at one of a plurality of addressable locations,

(c) a central processing unit for analyzing the subscriber signals to determine whether processing of the subscriber signals requires an extended subscriber feature and for generating a coded signal if processing of the subscriber signals requires an extended subscriber feature, the coded signal including the address location in the memory where the subscriber signals, the automatic number identification and the pre-subscription information resides,

(d) means for connecting the coded signal to the control means and the switch element;

a trunk module interposed between the switch element and the plurality of outgoing trunks for receiving the coded signal from the switch element; and

communication management means connected between the register module and the trunk module for routing the subscriber signals, the automatic number identification and the pre-subscription information to the trunk module in response to receiving the coded signal from said trunk module to thereby select an outgoing trunk.

2. The apparatus for enhancing the operation of a central office as described in claim 1 wherein the trunk module comprises:

means for polling the memory for storing to request transmission of the subscriber signals, the automatic number identification, and the pre-subscription information; and

means for receiving the subscriber signals, the automatic number identification, and the pre-subscription information and in response thereto outputting a signal in a predetermined format.

3. The apparatus for enhancing the operation of a central office as described in claim 2 wherein the signal output from the means for receiving includes the subscriber signals, the automatic number identification, and the pre-subscription information.

4. The apparatus for enhancing the operation of a central office as described in claim 1 further including file management means connected to said communication management means for storing data, subscriber information and billing information used by the telephone switching system.

5. The apparatus for enhancing the operation of a central office as described in claim 1 further including maintenance means connected to said communication management means for inputting information for maintaining the central office.

6. The apparatus for enhancing the operation of a central office as described in claim 1 further including:

means responsive to the control means for determining when a subscriber has gone off-hook; and

means responsive to the subscriber going off-hook for transmitting a dialtone to the subscriber prior to receiving subscriber signals from the subscriber line.

7. A method for enhancing the operation of a central office in a telephone switching system to provide one or more extended subscriber features such as equal access, the central office including a switch for connecting a subscriber line to one of a plurality of outgoing trunks and control means for controlling the switch, comprising the steps of:

receiving in a register module line information identifying the subscriber following seizure of the control means by the subscriber line;

intercepting in the register module subscriber signals from the subscriber line intended for the central office;

translating in the register module the line information into subscriber information, the subscriber information including a subscriber'"'"'s identifying number and an interexchange carrier;

storing in the register module the subscriber signals and the subscriber information in a memory having a plurality of address locations;

analyzing in the register module the subscriber signals to determine whether processing of the subscriber signals requires an extended subscriber feature;

if processing of the subscriber signals requires an extended subscriber feature, generating a coded signal including the address location of the stored subscriber signals and the subscriber information;

connecting the coded signal from the register module to the control means and the switch of the central office;

transmitting the coded signal from the switch to a trunk module interposed between the switch and the plurality of outgoing trunks; and

routing data including the subscriber signals and the subscriber information through a communication management means connected between the register module and the trunk module in response to the coded signal transmitted to the trunk module.

8. The method for enhancing the operation of a central office as described in claim 7 further including the step of:

transmitting a dialtone to the subscriber following seizure of the control means and prior to intercepting the subscriber signals from the subscriber line.

9. A method for routing data between nodes of a network, each of the nodeshaving one or more ports associated therewith, comprising the steps of:

compiling a primary routing table at each node for identifying a port of the node from which a data message should be sent to reach each node of the network via a shortest possible path;

generating at a node a data message to be routed, the data message including a first portion to control routing of the data message and a second portion for identifying a destination node where the data message is to be routed; and

using the information in the first and second portions of the data message to identify the port of the node from which the message should be routed to reach the destination node over the shortest possible path.

10. The method for routing data between nodes of a network as described in claim 9 further including the steps of:

determining whether a valid route exists for the data message; and

if a valid route exists for the data message, determining whether the data message is to be routed between nodes of the network.

11. The method for routing data between nodes of a network as described in claim 10 further including the steps of:

if the data message is to be routed between nodes of the network, sending the data message to the identified port; and

if the data message is not to be routed between nodes of the network, sending the data message to an operating system at the node generating the message.

12. The method for routing data between nodes of a network as described in claim 9 further including the step of:

compiling a secondary routing table at each node for identifying a port of the node from which the data message should be sent to reach each other node of the network via a next shortest possible path.

13. The method for routing data between nodes of a network as described in claim 12 further including the step of:

using the information in the first and second portions of the data message to identify the port of the node from which the message should be routed to reach the destination node over the next shortest possible path.

14. The method for routing data between nodes of a network as described in claim 13 further including the steps of:

determining whether a valid secondary route exists for the data message; and

if a valid secondary route exists, determining whether the data message is to be routed between nodes of the network.

15. The method for routing data between nodes of a network as described in claim 14 further including the steps of:

if the data message is to be routed between nodes of the network, sending the data message to the identified port; and

if the data message is not to be routed between nodes of the network, sending the message to an operating system of the node generating the message.

16. A method for routing data between nodes of a network, each of the nodes having one or more ports associated therewith, comprising the steps of:

(a) compiling a primary routing table at each node for identifying a port of the node from which a data message should be sent to reach each other node of the network via a shortest possible path;

(b) generating at a node a data message to be routed, the data message including a first portion for storing information to control routing of the data message and a second portion for identifying a destination node where the data message is to be routed;

(c) determining whether the information in the first portion of the data message has a first predetermined value; and

(d) if the information in the first portion of the data message has a first predetermined value, using the information in the second portion of the data message as an index to the primary routing table to identify the port of the node from which the message should be routed to reach the destination node over the shortest possible path.

17. The method for routing data between nodes of a network as described in claim 16 further including the steps of:

(e) determining whether the data message is to be routed internally in the node generating the message;

(f) if the data message is to be routed internally in the node generating the message, setting a first flage to a first predetermined value and setting a second flag to a second predetermined value;

(g) if the data message is not to be routed internally in the node generating the message, determining whether the port identified in step (d) is a valid port of the node;

(h) if the port identified in step (d) is a valid port of the node generating the message, setting the first and second flags to the second predetermined value; and

(i) if the port identified in step (d) is not a valid port of the node generating the message, setting the second flag to the first predetermined value.

18. The method for routing data between nodes of a network as described in claim 17 further including the step of:

(j) compiling a secondary routing table at each node for identifying a port of the node from which the data message should be sent to reach each other node of the network via a next shortest possible path.

19. The method for routing data between nodes of a network as described in claim 18, further including the steps of:

(k) if the information in the first portion of the data message does not have a first predetermined value, determining whether the information in the first portion of the data message has a second predetermined value; and

(l) if the information in the first portion of the data message has a second predetermined value, using the information in the second portion of the data message as an index to the secondary routing table to identify the port of the node from which the message should be routed to reach the destination node over the next shortest possible path.

20. The method for routing data between nodes of a network as described in claim 19, further including the steps of:

(m) determining whether the data message is to be routed internally in the node generating the message;

(n) if the data message is to be routed internally in the node generating the message, setting the first flag to the first predetermined value and setting the second flag to the second predetermined value;

(o) if the data message is not to be routed internally in the node generating the message, determining whether the port identified in step (1) is a valid port of the node;

(p) if the port identified in step (1) is not a valid port of the node, repeating steps (d) through (i);

(q) if the port identified in step (1) is a valid port of the node, setting the information in the first portion of the data message to the first predetermined value; and

(r) setting the first and second flags to the second predetermined value.

21. A method for routing data between nodes of a network, each of the nodes having one or more ports associated therewith, comprising the steps of:

generating at a node a data message to be routed, the data message including;

a first portion to control routing of the data message;

a second portion for identifying a destination node where the data message is to be routed;

a third portion for identifying a source node from which the data message originates; and

a fourth portion for storing the data to be routed in the data message; and

routing the data message from the port of the node at which the message was generated to reach the destination node over the shortest possible path.

22. The method for routing data between nodes of a network as described in claim 21 wherein the data message further includes:

a fifth portion for identifying a task in the destination node to which the data message is intended to be routed; and

a sixth portion for identifying a task in the source node from which the message originates.

23. The method for routing data between nodes of a network as described in claim 21 wherein the data message further includes:

a seventh portion including information for establishing a link between the source and destination nodes; and

an eighth portion identifying the length of the data message.

24. The method for routing data between nodes of a network as described in claim 23 wherein the data message further includes:

a ninth portion for identifying a start of the data message; and

a tenth portion for identifying an end of the data message.

25. A method for routing data between nodes of a network, each of the nodes having one or more ports associated therewith, comprising the steps of:

generating at a node a data message to be routed, the data message including;

a class field to control routing of the data message;

a destination node field for identifying a destination node where the data message is to be routed;

a source node field for identifying a source node from which the data message originates;

a destination task field for identifying a task at the destination node to which the data message is intended to be routed;

a source task field for identifying a task at the source node from which the data message originates; and

at least one message field for storing the data to be routed in the data message; and

routing the data message fro a port of the node at which the message was generated to reach the destination node over the shortest possible path.

26. The method for routing data between nodes of a network as described in claim 25 wherein the data message further includes:

a start-of-message byte field for identifying a start of the data message;

a control byte field for storing information used to establish a link between the source and destination nodes; and

a check sum byte field for identifying an end of the message.