Patent Publication Number: US-6907046-B1

Title: Communication system and device that provides service independent communication bridging

Description:
RELATED APPLICATIONS 
   Not applicable 
   FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
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   MICROFICHE APPENDIX 
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   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention is related to the field of communications, and in particular, to communication systems and devices that provide communication bridges under the control of a bridge agent. 
   2. Description of the Prior Art 
   A communication device transfers user communications between users. The communication device has a control system and a communication fabric. The communication fabric routes the user communications. The control system processes control information related to the communications to control the communication fabric. 
   A communication device provides a communication bridge by copying the user communications that are transferred to another user and transferring the copy to a third party. For example, consider that a communication device transfers user communications between User A and User B. The communication device can provide a communication bridge by transferring a copy of the user communications to an agent C. A communication device also provides a communication bridge by transferring third party communications to the users along with the user communications. In the above example, the communication device can provide a communication bridge by transferring agent C communications to User A and User B along with the user communications. 
   One example of communication bridging occurs when an operator must interrupt an on-going user communication to provide information to a user. For example, an operator may interrupt a voice communication to inform a user of an emergency. Another example of communication bridging occurs when a law enforcement agency directs a communication system to transfer a copy of user communications to them. For example, the Federal Bureau of Investigation (FBI) may require a communication system to provide the FBI with a voice tap—a live copy of user voice communications without the knowledge of the users. A tap is a passive one-way bridge, and the term “bridge” includes taps. 
   At present, bridge control protocols for communication devices are specific to the device manufacturer and are usually proprietary. Unfortunately, communication systems are increasingly comprised of different communication devices from diverse manufacturers. Thus, the communication system must have a complex bridge control system because the diverse array of communication devices use different bridge control protocols, such as SGCP, MGCP, or others. 
   In the computer field, peripheral devices, such as printers and modems, are connected to a computer. The computer is configured with an operating system and device drivers. The device drivers provide a software interface between the operating system and the peripheral devices. The peripheral devices must be able to interpret the instructions from the device drivers. Typically, the peripheral device manufacturer provides software device drivers that are compatible with their peripheral devices and also with commercial operating systems. In some cases, a peripheral device may automatically transfer their software driver to a common registry for use by any system that needs to control the peripheral device. Unfortunately, this device driver technology has not been effectively applied to provide better control of communication bridging. 
   SUMMARY OF THE INVENTION 
   The invention helps solve the above problems with communication systems, devices, and methods to implement bridges. The invention uses software applications to interface between a bridge agent and various communication devices. Advantageously, the software applications allow the bridge agent to use a common bridge request format that greatly simplifies bridge agent design and operation. The software applications translate the common bridge requests into various bridge commands that are customized to the various communication devices. Thus, the bridge agent uses a common request format, but the communication devices may retain their own proprietary command formats. 
   Some examples of the invention include a communication system and method of operation. A first communication device automatically transfers a first software application to the bridge agent in response to an operational control channel between the first communication device and the bridge agent. The bridge agent executes the first software application to translate a first bridge request into a first bridge command. The bridge agent transfers the first bridge command to the first communication device. The first communication device receives the first bridge command through a first physical port dedicated to bridge control. The first communication device processes the first bridge command to implement a first bridge. 
   The bridge agent executes a second software application to translate a second bridge request into a second bridge command. The bridge agent transfers the second bridge command from the bridge agent to a second communication device. The second communication device receives the second bridge command through a second physical port dedicated to bridge control. The second communication device processes the second bridge command to implement a second bridge. 
   The first bridge may copy all user communications transferred from a first user to a link and transfer the copies to the bridge agent. The first bridge may copy all user communications transferred from a link to a first user and transfer the copies to the bridge agent. The first bridge may transfer agent communications from the bridge agent to a first user. The first communication device and the second communication device may be from different manufacturers. The first bridge request and the second bridge request may have the same format, but the first bridge command and the second bridge command may have different formats. 
   Some examples of the invention include a communication device and method of operation. The communication device has a physical port dedicated to a bridge agent. The communication device has a bridge control coupled to the physical port and configured to automatically transfer a software application to the bridge agent in response to an operational control channel between the physical port and the bridge agent. The bridge control is configured to receive and process a bridge command to generate control signals. The communication device has a communication fabric configured to implement a bridge in response to the control signals. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The same reference number represents the same element on all drawings. 
       FIG. 1  illustrates a communication system in an example of the invention. 
       FIG. 2  illustrates a communication system in an example of the invention. 
       FIG. 3  illustrates a communication system in an example of the invention. 
       FIG. 4  illustrates communication system operation in an example of the invention. 
       FIG. 5  illustrates communication system operation in an example of the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   System Configuration— FIGS. 1-3   
     FIG. 1  illustrates communication system  100  in an example of the invention.  FIG. 1  illustrates a variety of possible communication bridges, and not all types of communication bridges are required in each example of the invention. Communication system  100  includes bridge agent  103  and communication device  110 . User  101  is coupled to communication device  110  by links  121  and  124 . User  102  is coupled to communication device  110  by links  122  and  123 . Bridge agent  103  is coupled to communication device  110  by links  141 - 144 . 
   The links may include switches, routers, protocol converters, or other communication devices. The links may include optical, wireless, metallic, or other types of transport media. The links may utilize time division multiplex, asynchronous transfer mode, internet protocol, synchronous optical network, code division multiple access, or other protocols. The links may be integrated together—for example, links  121  and  124  may be a single bidirectional link. 
   Communication device  110  transfers user communications from user  101  to user  102  over links  121 - 122 . Communication device  110  may provide bridge  131  to transfer a copy of the user communications to bridge agent  103  over link  141 . Communication device  110  may also transfer user communications from user  102  to user  101  over links  123 - 124 . Communication device  110  may provide bridge  133  to transfer a copy of these user communications to bridge agent  103  over link  143 . Communication device  110  may provide bridge  132  to transfer agent communications from bridge agent  103  over link  122  to user  102 . Communication device  110  may provide bridge  134  to transfer agent communications from bridge agent  103  over link  144  to user  101 . 
   Communication device  110  establishes bridges  131 - 134  in response to commands indicating the applicable links or users. The commands may include information that identify the links or users related to the bridge. This identifying information may include network addresses, user names, circuit identifiers, virtual connections, port numbers, and telephone numbers. Network addresses may include Internet addresses, MAC addresses, Ethernet addresses, e-mail addresses, or other such information. Bridges related to User  101  may be implemented by indicating identifying information for the users or links as illustrated in the following table. 
   
     
       
         
             
             
             
             
           
             
                 
             
             
               TRANSFER 
               TRANSFER 
               BRIDGE 
               BRIDGE 
             
             
               USER COM. 
               USER COM. 
               AGENT COM. 
               USER/AGENT 
             
             
               FROM 
               TO 
               FROM 
               COM. TO 
             
             
                 
             
           
          
             
               LINK 121 
               ANY LINK 
               NONE 
               LINK 141 
             
             
               ANY LINK 
               LINK 124 
               NONE 
               LINK 143 
             
             
               LINK 121 
               LINK 122 
               NONE 
               LINK 141 
             
             
               LINK 123 
               LINK 124 
               NONE 
               LINK 143 
             
             
               USER 101 
               ANY USER 
               NONE 
               LINK 141 
             
             
               ANY USER 
               USER 101 
               NONE 
               LINK 143 
             
             
               USER 101 
               USER 102 
               NONE 
               LINK 141 
             
             
               USER 102 
               USER 101 
               NONE 
               LINK 143 
             
             
               LINK 121 
               ANY LINK 
               LINK 142 
               ANY LINK 
             
             
               ANY LINK 
               LINK 124 
               LINK 144 
               LINK 124 
             
             
               LINK 121 
               LINK 122 
               LINK 142 
               LINK 122 
             
             
               LINK 123 
               LINK 124 
               LINK 144 
               LINK 124 
             
             
               USER 101 
               ANY USER 
               LINK 142 
               ANY USER 
             
             
               ANY USER 
               USER 101 
               LINK 144 
               LINK 124 
             
             
               USER 101 
               USER 102 
               LINK 142 
               LINK 122 
             
             
               USER 102 
               USER 101 
               LINK 144 
               LINK 124 
             
             
                 
             
          
         
       
     
   
     FIG. 2  illustrates communication system  200  in an example of the invention. Communication system  200  includes bridge agent  203  and communication device  210 . Bridge agent  203  is comprised of computer and communications systems that may have components located in different geographic areas and operated by different entities. Based on this disclosure, those skilled in the art will readily appreciate how to modify conventional computer and communication devices to arrive at bridge agent  203 . 
   Communication device  210  includes communication fabric  211 , communication control  212 , and bridge control  213 . Communication fabric  211  includes bridge fabric  215 , ingress fabric  216 , and egress fabric  217 . Based on this disclosure, those skilled in the art will readily appreciate how to modify conventional switches, routers, bridges, and other communication devices to arrive at communication device  210 . 
   Ingress fabric  216  is coupled to links  221 - 226 , and egress fabric  217  is coupled to links  231 - 236 . Bridge fabric  215  is coupled to links  241 - 242 . User  201  is coupled to links  223  and  231 . User  202  is coupled to links  226  and  234 . Bridge agent  203  is coupled to links  241  and  242 . The links may include switches, routers, protocol converters, or other communication devices. The links may include optical, wireless, metallic, or other types of transport media. The links may utilize time division multiplex, asynchronous transfer mode, internet protocol, synchronous optical network, code division multiple access, or other protocols. The links may be integrated together—for example, links  223  and  231  may be a single bidirectional link. 
   User  201  is coupled to communication control  212  over control channel  251 . Control channel  251  could be any media that transfers control information and could reside within links  223  and  231 . Communication control  212  receives commands over control channel  251 . Communication control  212  translates the commands into control signals for communication fabric  211 . Communication fabric  211  routes user communications from ingress fabric  216  to egress fabric  217  in response to the control signals. For example, the control signals may direct communication fabric  211  to route a communication packet from link  223  to link  234  based on a packet address. 
   Bridge agent  203  is coupled to bridge control  213  over control channel  261 . Communication device  210  includes a separate physical port for control channel  261 . The separate physical port may be important for security purposes. Control channel  261  could comprise any media that transfers control information—although control channel  261  typically uses a highly secure form of communication. 
   Bridge control  213  includes software application  214 . As indicated by the dashed lines, bridge control  213  is configured to transfer application  214  to bridge agent  203  over control channel  261 . This transfer could occur automatically in response to the establishment of control channel  261 . Software application  214  could be an Application Programming Interface (API) that translates bridge requests from a common format into bridge commands that have a unique format customized for communication device  210 . 
   Bridge agent  203  executes application  214  to transfer commands over control channel  261  to implement communication bridges in communication device  210 . Bridge control  213  receives and processes the bridge commands to generate control signals for communication fabric  211 . Communication fabric  211  may copy user communications from ingress fabric  216  to bridge fabric  215  in response to the control signals. For example, the control signals may direct communication fabric  211  to copy a communication packet routed from link  223  to link  234  and transfer the packet copy to bridge agent  203  through bridge fabric  215  and link  242 . 
   It may be desirable to logically or physically separate communication control  212  from bridge control  213 , and physical separation may be required by law. In this scenario, communication control  212  would remain ignorant of bridge operations and would not be aware of control channel  261 , bridge fabric  215 , and links  241 - 242 . Bridge control  213  would be unable to affect the operations of communication control  212 . Thus, neither communication control  212  nor bridge control  213  could interfere with the operation of the other. Different bridge agents would also be unaware of one another. This separation of control would help prevent improper control malfunctions in communication bridges and other services. 
     FIG. 3  illustrates communication system  300  in an example of the invention. Communication system  300  is comprised of bridge agent  303  and communication devices  371 - 373  that may all be configured to operate as described above. Communication devices  371 - 373  respectively include software applications  374 - 376  that are transferred to bridge agent  303  for execution. Each application translates bridge requests with a common format into bridge commands that are customized for their respective communication device. 
   Communication devices  371 - 373  are each from a different manufacturer, and thus, each communication device uses a different bridge control system that has proprietary bridge control commands. Applications  374 - 376  are different from one another in that they are customized to interface with their respective proprietary bridge control system. Advantageously, applications  374 - 376  are similar to one another in that they are standardized to interface in the same way with bridge agent  303 . As a result, bridge agent  303  can use the same format to generate bridge requests for communication devices  371 - 373 , and applications  374 - 376  translate these bridge requests into different bridge commands that have a unique format customized for each respective communication device  371 - 373 . 
   Communication system  300  may provide the same bridge agent interface specification to each manufacturer, and let each manufacturer provide an application that interfaces between bridge agent  303  and their own proprietary bridging systems. Thus, bridge agent  303  is simplified because it can have a single interface that executes the applications  374 - 376  to implement bridges among diverse communication devices  371 - 373 . If different communication devices deliver the same applications to bridge. agent  303 , then bridge agent  303  may discard redundant application code while maintaining separate state information for each device. 
   In  FIGS. 1-3 , the bridge agents and communication devices may use instructions that are stored on storage media. The instructions can be retrieved and executed by a processor. Some examples of instructions are software, script, program code, and firmware. Some examples of storage media are memory devices, tape, disks, integrated circuits, and servers. The instructions are operational when executed by the processor to direct the processor to operate in accord with the invention. The term “processor” refers to a single processing device or a group of inter-operational processing devices. Some examples of processors are computers, integrated circuits, and logic circuitry. Those skilled in the art are familiar with instructions, processors, and storage media. 
   System Operation— FIGS. 3-4   
     FIGS. 3-4  illustrate communication system operation in an example of the invention. Initially, the bridge control in a communication device transfers its bridging application to a bridge agent, possibly in response to the establishment of the bridge control channel. Based on the application, the bridge agent transfers a command to bridge control. Bridge control processes the command to transfer corresponding control signals to the communication fabric. The communication fabric configures itself to implement the desired bridge—in this case to bridge all user communications transferred between user A and user B to the bridge agent. 
   Subsequently, user A requests communication service from communication control in the communication device. Communication control processes the request to transfer corresponding control signals to the communication fabric. The communication fabric configures itself to provide the communication service in response to the control signals. User A sends a first communication to the communication fabric in the communication device. The communication fabric routes the first communication to user B. The communication fabric also transfers a copy of the first communication to the bridge agent. 
   User A may then request an end of the communication service from communication control. Communication control processes the request to transfer corresponding control signals to the communication fabric. The communication fabric configures itself to stop communication service for User A in response to the control signals. 
   Subsequently, user A again requests communication service from communication control in the communication device. Communication control processes the request to transfer corresponding control signals to the communication fabric. The communications fabric configures itself to provide the communication service in response to the control signals. User A sends a second communication to the communication fabric in the communication device. The communication fabric routes the second communication to user B. Because the bridge agent has not taken down the bridge, the communication fabric also transfers a copy of the second communication to the bridge agent. 
   The bridge agent then transfers a command to bridge control to take down the bridge. Bridge control processes the command to transfer corresponding control signals to the communication fabric. The communication fabric configures itself to take down the bridge. Subsequently, user A sends a third communication to the communication fabric in the communication device. The communication fabric routes the third communication to user B. Since the bridge is down, the communication fabric does not transfer a copy of the third communication to the bridge agent. 
   On  FIG. 4 , user A sends a fourth communication to the communication fabric in the communication device. The communication fabric routes the fourth communication to user B. Since the bridge is still down, the communication fabric does not transfer a copy of the fourth communication to the bridge agent. 
   The bridge agent then transfers a command to bridge control. Bridge control processes the command to transfer corresponding control signals to the communication fabric. The communication fabric configures itself to implement the desired bridge—in this case to bridge agent communications from the bridge agent to user B. The bridge agent transfers a fifth communication to the communication fabric. In response to the control signals, the communication fabric transfers the fifth communication to user B. 
   The bridge agent transfers another command to bridge control. Bridge control processes the command to transfer corresponding control signals to the communication fabric. The communications fabric configures itself to implement the desired bridge—in this case to bridge all user communications between users A and B to the bridge agent and to bridge agent communications from the bridge agent to users A and B. The bridge agent transfers a sixth communication to the communication fabric. In response to the control signals, the communication fabric transfers the sixth communication to both users A and B. User A sends a seventh communication to the communication fabric. The communication fabric routes the seventh communication to user B. The communication fabric also transfers a copy of the seventh communication to the bridge agent. User B sends an eighth communication to the communication fabric. The communication fabric routes the eighth communication to user A. The communication fabric also transfers a copy of the eighth communication to the bridge agent. 
   The communication system could provide required copies of user communications to law enforcement agencies. For example, the FBI may operate the bridge agent to tap user communications where probable cause exists for surveillance. The FBI may have the communication system operate some components of the bridge agent. 
   The communication system could provide an operator center with an interface to interrupt user communications. For example, an operator may desire to communicate with users in a busy line verification or interrupt operation. This typically occurs when users are busy communicating with one another and the immediate attention of one of the users is required to respond to an emergency. The operator interrupts the user communications to bring the emergency to the attention of the user. 
   Separate bridge agents could operate at the same time for law enforcement agencies and operator systems. Each bridge agent would have separate control channels and links. 
     FIGS. 1-5  and the above description depict specific examples of a communication system in accord with the present invention. Those skilled in the art will appreciate that some conventional aspects of the communication system have been simplified or omitted for clarity. Those skilled in the art will appreciate that the features described above could be combined in various ways to form multiple variations of the invention. Those skilled in the art will also appreciate variations of the communication system that fall within the scope of the invention. As a result, the invention is not limited to the specific examples described above, but only by the following claims and their equivalents.