Methods and apparatus for interoperating communication networks

Abstract

PSTN functionality is enhanced by the addition of an external service bridging device (ESBD) between one or more devices, e.g., signal switching points (SSPs), and a service control point (SCP). The ESBD serves as a coupling device to one or more control devices, e.g., other SCPs or IP servers, in addition to the SCP. To support the passing of messages between the SS7 network and the control devices, the ESBD includes message reformatting capabilities. The ESBD monitors for messages directed to SCPs and/or replies to messages directed to an SCP. In response to detecting a message the ESBD checks to determine if the detected message is to be processed or simply forwarded to the SCP. Messages to be processed are intercepted, duplicated, modified, replaced, broadcast, redirected, etc. Replies to broadcast query messages are detected and processed so that a single reply, in the format of an SCP response, is returned.

1 . A method of providing enhanced telephone network capabilities, the method comprising:
 monitoring a communications link to detect messages of at least one of a first type and a second type, the first type of message being a message directed to a service control point, the second type of message being a reply to a message directed to a service control point;
 in response to detecting a message of either the first or second type: 
 determining if a message format conversion operation is required; and 
 in response to determining that a message format conversion operation is required, performing the required format conversion operation on the detected message. 
   
     
     
         2 . The method of  claim 1 , further comprising:
 wherein determining if a message format conversion operation is required is based on information on the message format required by a destination to which the message is directed.   
     
     
         3 . The method of  claim 1 , wherein the step of performing the required format conversion operation includes reformatting the detected message from an SS7 format to an IP format. 
     
     
         4 . The method of  claim 1 , wherein the step of performing the required format conversion operation includes reformatting the detected message from an IP format to an SS7 format. 
     
     
         5 . The method of  claim 1 , further comprising, in response to detecting a message of the second type:
 determining if message processing is to be suspended for a period of time, prior to determining if a message format conversion operation is required.   
     
     
         6 . The method of  claim 1 , wherein it is determined that message processing is to be suspended for a period of time when the detected message is the first detected reply to a broadcast query message. 
     
     
         7 . The method of  claim 6 , further comprising:
 discarding all but one detected reply to a broadcast query message.   
     
     
         8 . The method of  claim 7 , wherein a reply from a server is selected to be retained over a reply from a service control point when discarding all but one detected reply to a broadcast query message. 
     
     
         9 . The method of  claim 7 , wherein the step of performing the required format conversion operation includes reformatting the detected reply that was not discarded to appear as though it were from a service control point. 
     
     
         10 . A communications system comprising:
 a first device;   an external control device capable of controlling a telephone call processing operation;   a first service control point;   a bridging device coupled to said external control device, said first device, and said first service control point, said bridging device including:
 means for detecting at least one of a query message from said first device directed to said first service control point and a reply to a message directed to said first service control point; and 
 means for performing at least one of a message modification operation, a message redirection operation, and a message multicast operation on at least one detected message. 
   
     
     
         11 . The communication system of  claim 10 , wherein said bridging device further includes:
 means for reformatting said at least one message prior to transmitting said at least one message to said external control device.   
     
     
         12 . The communication system of  claim 11 , wherein said means for reformatting includes logic for reformatting an SS7 query message into an IP format. 
     
     
         13 . The communication system of  claim 10 , wherein said bridging device further comprises:
 means for selecting one of a plurality of reply messages received by said bridging device, in response to a multicast query message, to be returned to said first device;   means for reformatting the selected one of a plurality of reply messages from an IP format to an SS7 format.   
     
     
         14 . The communication system of  claim 10 , wherein said bridging device includes logic for determining if a detected message is to be subjected to a modification operation, a redirection operation or a multicast operation. 
     
     
         15 . The communications system of  claim 10 ,
 where said first device is a telephone switch;   where said external control device is an IP server; and   where said first service control point is a service control point in an SS7 network and which generates and receives SS7 compliant messages.   
     
     
         16 . A bridging device for use in a communications system including a first device, a control device capable of controlling a telephone call processing operation, and a first service control point, the bridging device comprising:
 a processor;   an interface coupled to said first device, said control device, and to said service control point; and   a memory including a module for controlling said processor to:
 detect at least one of a query message from said first device directed to said first service control point and a reply to a message directed to said first service control point; and 
 perform at least one of a message modification operation, a message redirection operation, and a message multicast operation on at least one detected message. 
   
     
     
         17 . The bridging device of  claim 16 , wherein said module further includes instructions for controlling said processor to:
 reformat said at least one message prior to transmitting said at least one message to said external control device.   
     
     
         18 . The bridging device of  claim 17 , wherein said module further includes instructions for controlling the processor to reformat an SS7 query message into an IP format. 
     
     
         19 . The bridging device of  claim 16 , wherein said module further includes instructions for controlling said processor to:
 select one of a plurality of reply messages received by said bridging device, in response to a multicast query message, to be returned to said first device; and   reformat the selected one of a plurality of reply messages from an IP format to an SS7 format.   
     
     
         20 . The bridging device of  claim 16 , wherein said module further includes:
 instructions for controlling the processor to determine if a detected message is to be subjected to a modification operation, a redirection operation or a multicast operation.