CONNECTION CONTROLLER FOR MANAGING MEDIA PATHS BETWEEN TERMINAL DEVICES RESIDING IN DIFFERENT NETWORK DOMAINS

Abstract: A terminal proxy for a PBX. The terminal proxy manages the flow of media signals originating or arriving at a terminal device residing in a packet switched network. The terminal proxy has a first interface for communicating with the terminal device using a terminal device protocol, and a second interface for communicating with a media path server using a media path server protocol and an interoperation functional unit. The interoperation functional unit effects manipulations on signaling information received by said first interface and by said second interface, to allow the terminal device and the media path server to interoperate for effecting management of the flow of media signals originating or arriving at the terminal device. The invention also provides a PBX that has a call manager and a connection controller. The connection controller is responsible for the management of media paths during call sessions between terminal devices set-up by the call manager. The call manager sends signaling information to the connection controller that is independent of the connection type of the terminal devices.

Description: TITLE: Connection controller for managing media paths between terminal devices residing in different network domains FIELD OF THE INVENTION The invention relates to communication devices, in particular to a connection controller for the management of media paths. The invention also extends to a terminal proxy useful for controlling the flow of media signals originating or arriving at a terminal device residing"in a communications network. BACKGROUND OF THE INVENTION Circuit switching and packet switching are different and well-known methods for establishing a connection between two terminal devices to permit the exchange of voice or data signals. In the dial-up telephone network, for example, a caller's line goes to a switching center or switch, where the actual connection is made to the called party. In the case of a circuit-switch network, a permanent connection is set-up and maintained for the duration of the call. In contrast, the packet-switched network does not establish a permanent connection, rather the information to be transmitted is assembled in packets that are sent over a channel dedicated to the connection only for the duration of the packet transmission. Communications systems that are currently available in the marketplace, that support both circuit-switched and packet-switched domains, use call processing and media path management logic that is very much dependent upon the nature of the terminal devices involved in the call. This is obviously undesirable since the call processing logic must be designed to support a variety of signaling protocols to accommodate a wide range of terminal devices. Against this background it clearly appears that a need exists in the industry to develop a communications system that supports both circuit-switched and packet- switched domains where the call processing and/or media path management logic is de-coupled from the specific signaling protocols of the individual terminal devices. SUMMARY OF THE INVENTION In a broad aspect, the invention provides a terminal proxy for controlling media signals originating or arriving at a terminal device residing in a packet switched network domain. The proxy server has a first interface for communicating with the terminal device using a terminal device protocol, a second interface for communicating with a remote entity using a protocol other than the terminal device protocol, and an interoperation functional unit in communication with the first interface and with the second interface. The interoperation functional unit is operative to effect manipulations on signaling information received by the interfaces from the terminal device and the remote entity, respectively, to allow the terminal device and the remote entity to interoperate for effecting management of the flow of media signals originating or arriving at the terminal device. The terminal proxy presents an advantage in that it allows de-coupling the management of the media signals from the signaling protocol of the terminal device. In a specific and non-limitative example of implementation, the remote entity with which the terminal proxy communicates is a media path server. • The media path server can set-up a media path between two or more terminal devices residing in a packet switched network. A terminal proxy is associated with each terminal device. The media path server communicates with each terminal proxy by using a common protocol. In particular, when a media path is to be set between two terminal devices remote from one another, the media path server sends signaling information to the terminal proxies of the respective terminal devices. In turn, the terminal proxies manipulate or convert the signaling information to allow the media path server and the terminal devices to interoperate. For the purpose of this specification, the expression terminal device" should be given a broad interpretation, and should not be limited to a communication device, such as a telephone, that a user would normally employ to communicate with a remote party. "Terminal device" can include any device capable of providing telephony-related services to a user, a gateway that connects two different network domains, such as a gateway between a Private Branch Exchange (PBX) and the Public Switched Telephone Network (PSTN) or a gateway between two packet switched networks, or a media gateway that forms a point of interaction between a packet switched network domain and a circuit switched network domain. "Terminal device" can also include the device that is the point of interaction between two PBX systems, among many other possibilities. Under a second broad aspect, the invention provides a connection controller for the management of- media paths between two or more terminal devices. These devices can be in the same switching domain or reside in different switching domains. For example, one terminal could reside in a packet switched network and another terminal device could reside in a circuit switched network. The connection controller includes an input for receiving signaling information indicative of a need of a media path between two or more terminal devices. The connection controller also includes one or more packet switched subsystems responsive to the signaling information to effect management of the packet switched network leg, and one or more circuit switched sub-system also responsive to the signaling information to effect management of the circuit switched network leg. Under a third broad aspect, the invention includes a PBX that has a call manager and a connection controller. The connection controller is responsible for the management of media paths during call sessions between terminal devices set-up by the call manager. The call manager sends signaling information to the connection controller that is independent of the connection type of the terminal devices. "Connection type" refers to where or how terminal devices are connected or reside. The terminals can be connected to or reside on one of multiple circuit-switched networks or one of multiple independent packet switched networks . BRIEF DESCRIPTION OF THE DRAWINGS A detailed description of examples of implementation of the present invention is provided hereinbelow with reference to the following drawings, in which: Figure 1 is a block diagram of a PBX that spans two different network domains. In the block diagram the arrows in solid lines represent logic signaling paths. The arrows in dashed lines represent media paths. Figure 2 is a detailed block diagram of a connection controller of the PBX shown in Figure 1; Figure 3 is a detailed block diagram of a terminal proxy shown in Figure 2; and Figure 4 is a block diagram of a terminal proxy in accordance with a variant. In the drawings, embodiments of the invention are illustrated by way of example. It is to be expressly understood that the description and drawings are only for purposes of illustration and as an aid to understanding, and are not intended to be a definition of the limits of the invention. DETAILED DESCRIPTION An example of implementation of the present invention is illustrated in figure 1 that depicts a PBX system 10 associated with terminal devices residing in a circuit- switched network and terminal devices residing in a packet-switched network. More particularly, the PBX system 10 has four main functional units, namely a call manager 12, a connection controller 14, an array of media gateways 16 (individual media gateways are designated by 16a, 16b, 16c, etc.) and a time switch 18. It should be noted that a plurality of time switches 18 can be provided if a single time switch cannot provide enough resources in terms of switching capacity. Also, a plurality of time switches 18 can be provided to support circuit switched devices residing in different circuit switched networks to which the PBX 10 connects. The PBX system 10 spans two types of network domains that differ from one another by the manner in which a connection between terminal devices involved while a call session is made. The first domain is a circuit-switched domain, while the second domain is a packet-switched domain. The PBX system 10 is associated with a number of terminal devices that reside in a circuit-switched network 15 that is part of the circuit-switched domain. It should be appreciated that the PBX system 10 can be associated with several independent circuit-switched networks, all being part of the circuit-switched domain. For example, Figure 1 shows five typical terminal devices, namely three devices 35, 37 and 39 that provide telephony related services to users, a gateway 43 that forms a point of interaction between the PBX 10 and the PSTN and a point of interaction 45 between the PBX 10 and another PBX system. The PBX 10 is also associated with a plurality of terminal devices 38, 40, 41 and 47 that reside a packet- switched network 34 that forms part of the packet-switched network domain. As mentioned above in connection with the circuit-switched domain, the PBX system 10 can be associated with several independent packet-switched networks, all being part of the packet-switched domain. The terminal devices 38, 40 and 41 provide telephony- related services to users. The terminal device 47 is a gateway that forms a point of interaction between the packet switched network 34 and another packet-switched network. Finally, note that the media gateways 16a, 16b, 16c, etc., also constitute terminal devices that are controlled by the PBX. The time switch 18 is an entity that routes media signals properly to complete the media signal paths during a call session between terminal devices that involves the circuit-switched network 15. As mentioned earlier, the PBX system 10 may be provided with an array of time switches 18 to augment the resources of the PBX 10 when required, or to service independent circuit-switched networks. The media gateways 16a, 16b, 16c, etc., form points of interaction between the circuit-switched network 15 and the packet-switched network 34. A media gateway 16a, 16b, 16c, etc., is responsible for performing the necessary media signal conversions such that parties involved in a call session terminating in different network domain types can hear what each other is saying. For example, media signals into the circuit-switched network 15 are in the form of Pulse Coded Modulation (PCM) signals. When such PCM signals are delivered to a media gateways 16a, 16b, 16c, etc., they are converted into discrete data packets that are sent to the packet-switched network 34 for delivery to the terminal device 38, 40, 41 or 47 that terminates the call session in the packet-switched network 34. Advantageously, the media gateway 16a, 16b, 16c, etc., will encode the audio information to compress it in order to reduce the bandwidth requirements. Any suitable encoding algorithm can- be used for this purpose. For media signals- into the reverse direction, the media gateway 16a, lβb, 16c, etc., converts data packets into a suitable encoding algorithm for circuit switched connections, for example PCM, that is passed to the circuit-switched network 15. If the media signals into the reverse direction are encoded, the media gateway 16a, 16b, 16c, etc., will decode them into a suitable encoding algorithm for circuit switched connections, for example, PCM format. The call manager 12 includes a call . processing functional unit 42 and a plurality of terminal agents 44. A distinct terminal agent 44 is associated with each terminal device 35, 37, 39, 43, 45, 38, 40, 41 and 47. The call processing functional unit 42 is software implemented and performs high level call processing services such as call set-up, feature invocation, voice mail, among many others. The terminal agents 44 are software implemented entities that manage the operations of the terminal devices 35, 37, 39, 43, 45, 38, 40, 41 and 47. For example, the terminal agent 44 of the terminal device 38 could be designed to track call states, feature states and the user interface operation of the terminal device 38. Although Figure 1 shows the call manager 12 as a single entity, it should be appreciated that the call manager 12 could be designed as a distributed architecture system where the different components, such as the call processing functional unit 42 and the terminal agents 44, are remote from one another. Individual Call Processing Functional Units can also be linked to form to form a larger distributed system. The connection controller 14 is responsible for managing media paths involving the terminal devices 35, 37, 39, 43, 45, 38, 40, 41, 47 and 16a, 16b, 16c, etc., during call sessions handled by the call manager 12. The call manager 12 controls the operation of the connection controller 14 by sending signaling information to the connection controller. This signaling information is independent upon the connection type of terminal device being controlled. Figure 2 illustrates in greater detail the structure of the connection controller 14. The connection controller 14 includes a central connection unit 48, a circuit-switched sub-system 50 and a packet-switched subsystem 52. In the example shown, each sub-system 50, 52 is associated with a corresponding network, namely circuit-switched network 15 and the packet-switched network 34. When the PBX 10 connects to devices residing in different or independent networks under the same domain type, for instance two or more circuit-switched networks, the connection controller may be provided with a plurality of sub-systems, each sub-system associated with a corresponding network. Accordingly, it should be understood that the connection controller 14 is not limited to only a single sub-system per network domain type. The central connection unit 48 has an input 46 through which signaling information sent from the call manager 12 is received. The central connection unit 48 has an overall controlling responsibility for the operation of the connection controller 14. The purpose of the circuit-switched sub-system 50 is to manage the portion of the media path during a call session that resides in the circuit-switched network 15. Similarly, the purpose of the packet-switched sub-system 52 is to manage the portion of the media path during a call session that resides in the packet-switched network 34. During a call session" where the terminal devices reside in the same network, only the sub-systems 50-52 associated with that network will be activated. The other sub-systems 50-52 will remain inactive. The packet-switched sub-system 52 includes a media path server 54 and a plurality of terminal proxies 56. Each terminal proxy 56 is associated with a terminal device that resides in the packet-switched network 34. In the example shown in the drawings, there is one terminal proxy 56 for each terminal device 38, 40, 41, 47 and 16a, 16b, 16c etc. The media path server communicates with the terminal proxies 56 by using a common protocol. This signaling is done independently of the specific signaling protocols of the terminal devices 38, 40, 41, 47 and 16a, 16b, 16c etc. One of the functions of the media path server 54 is to mediate with various terminal devices that are to be connected by a media path such as to allow the media signals to be properly exchanged. For example, when terminal devices exchange encoded voice information, and each terminal device can implement a plurality of encoding/decoding algorithms, one of the functions of the media path server is to designate for each terminal device the encoding/decoding algorithm to use such that there is compatibility. It should be noted that the connection controller 14 could include a plurality of media path servers, each media path server controlling a set of terminal proxies. Also, the connection controller 14 may have a distributed architecture such that its various components are remote from one another. The components of the connection controller 14 are software implemented. As such these components can be executed on computing platforms that are remote from one another without departing from the spirit of the invention. Figure 3 illustrates a terminal proxy 56 in greater detail. The terminal proxy 56 includes an interface 58 that communicates with the media path server 54 by using any suitable signaling protocol. The media path server 54 communicates with each terminal proxy 56 by using the same signaling protocol. For the purpose of convenience, the signaling protocol between the media path server 54 and the terminal proxy 56 will be referred to as "media path server signaling protocol". The terminal proxy 56 includes an interface 60 that communicates with the terminal devices 38, 40, 41, 47 and 16a, 16b, 16c etc., by using signaling protocols that are terminal device specific. The terminal proxy 56 further includes an interoperation functional unit 62 whose task, broadly stated, is to effect the necessary manipulations on data exchanged between the entities (media path server 54, terminal devices 38, 40, 41, 47 and 16a, 16b, 16c etc.,) such that the two entities can functionally interoperate. For example, the interoperation functional unit 62 can perform some basic signaling information translation such that signaling information received in the media path server protocol is converted into signaling information in the protocol of the specific terminal devices 38, 40, 41, 47 and 16a, 16b, 16c, etc. It should be expressly noted that "interoperation" is not limited to signaling information translation as it can encompass a number of other functions. For the purpose of this specification, "interoperation" implies conversion of data, either protocol conversion or logical conversion such as to allow messages from one entity to be understood and/or implemented by another entity. Although not essential, it is advantageous to provide the interoperation functional unit 62 with the capability to either query the terminal devices 38, 40, 41, 47 and 16a, 16b, 16c etc., for information such as what are its specific functionalities or capabilities, or store a profile that holds this information. The profile as to the specific functionalities or capabilities of the terminal devices 38, 40, 41, 47 and 16a, 16b, 16c, etc., can be transmitted to the media path server 54 that can use this information in setting up the media path leg in the packet switched network 34. The terminal proxies 56 can be software implemented. As indicated earlier, the terminal proxies 56 abstract the media path server functions from the terminal device specific signaling protocols. The terminal proxies 56 can be designed to be generic or terminal device specific. A generic terminal proxy 56 has an interoperation functional unit 62 that has the capability to effect signaling information translation from the media path server protocol into a variety of possible terminal device specific protocols. Also, the terminal device interface 60 is designed to communicate with a variety of possible terminal devices that use different signaling protocols. In contrast, a terminal proxy 56 that is terminal device specific can work with a specific terminal device . ' Figure 4 illustrates- a variant of the terminal proxy 70. The terminal proxy 70 can perform the functions of the terminal proxy 56 described earlier. In addition, it can also perform translation of signaling information directed/received from a terminal device, that is used for purposes other than media signals control. Such signaling information can be used for call processing functions, for example. This feature allows the terminal proxy 70 to interoperate with the terminal agents 44, to abstract the operations of the call manager 12 from the terminal device specific signaling protocols. The terminal proxy 70 has, in addition to the components of the terminal proxy 56, a call manager interface to communicate with the call manager 12 using a call manager protocol. An interoperation functional unit 66 performs the necessary data manipulations such that signaling information from the call manager can be made compatible with the signaling protocol of the terminal device, and vice-versa. The interoperation functional unit 66 communicates with the terminal device ' interface 60. In a possible variant, a single interoperation functional unit can be provided to handle signaling information for both media path management and call processing functions. The following detailed examples will help to illustrate the operation of the PBX system 10 in greater detail . 1) Example 1 (call session between terminal devices in the circuit-switched network) : a) A user at terminal 35 wants to call a user at terminal device 39; b) The user at terminal device 35 goes off-hook or performs another action (such as depressing a button on the terminal device 35) that indicates that a call ■ session is desired; c) The terminal agent 44 detects the off-hook condition (or other action) and starts collecting information input by the user identifying the remote party to be called. Such information can be the directory number dialed on the terminal device 35; d) The terminal agent 44 communicates with the call processing functional unit 42 and then with the terminal agent 44 of the terminal device 39 to signal that a call session with the terminal device 35 is desired; e) The terminal agent 44 of the terminal device 39 signals to the terminal agent 44 of the terminal device 35 that the call session is accepted; f) The call manager 12 then signals the connection controller 14 to set-up a media path to connect the terminal devices 35 and 39. This signaling information is independent of the connection type of the terminal devices 35 and 39, accordingly immediately after the signaling information is received " the connection controller 14 does not "know" that the terminal devices 35 and 39 are both in the circuit-switched network 15; g) Based on the identifiers of the terminal devices 35 and 39 transmitted by the call manager 12, the connection controller determines their connection type. For instance, the connection controller 14 may query the terminal devices 35 and 39 (or their terminal proxies) involved in the call session to determine where they reside. Alternatively, the connection controller 14 communicates with another entity in the PBX or even external to the PBX that can indicate the type of terminal devices based on their identifiers; h) Under this example, the connection controller 14 determines that both terminal devices 35 and 39 reside in the circuit-switched network 15. i) The central connection unit 48 signals to the circuit-switched sub-system 50 to establish a media path between the terminal devices 35 and 39; j) The circuit-switched sub-system 50 signals the time switch 18 to set-up a media path between the terminal devices 35 and 39; k) During the call session the packet-switched subsystem 52 is idle. 2) Example 2 (call session between one terminal device in the circuit-switched network and one terminal device in the packet-switched network) . Steps (a) to (f) are the same as above except that the call session is to be established between the terminal device 35 and the terminal device 38: g) Based on the identifiers of the terminal devices 35 and 38 transmitted by the call manager 12, the connection controller determines their connection type; h) Under this example, the connection controller 14 determines that terminal device 35 resides in the circuit switched network 15 and terminal device 38 resides in the packet-switched network 34; i) The packet-switched sub-system 52 allocates a media gateway, say media gateway 16a; j) The central connection unit 48 signals to the circuit-switched sub-system 50 to establish a media path leg between the terminal device 35 and the media gateway 16a; k) The central connection unit 48 signals to the packet- switched sub-system to establish a media path- leg between the media gateway 16a and the terminal device 38; 1) The media path server 54 sends signaling information to the terminal proxy 56 of the media gateway 16a to inquire about its capabilities; m) The signaling message in (1) above is converted by the terminal proxy 56 associated with the media gateway 16a, in a message that the media gateway 16 can understand; n) The media gateway 16a issues a response message and that message is converted by the terminal proxy 56 associated with the media gateway 16a such that the media server can understand the message; o) The steps (1) to (n) are repeated with the terminal proxy 56 associated with the terminal device 38; p) Assume that the media path server 54 has been advised that the media path server can encode/decode voice signals according to algorithms A, B, and C, while the terminal device can encode/decode voice signals according to algorithms C and E; q) -The media path server 54 selects encoding/decoding protocol C for compatibility; r) The media path server 54 sends signaling information to the terminal proxies 56 of the media gateway 16a and of the terminal device 38 such as to set the media gateway 16a and the terminal device 38 to use the encoding/decoding algorithm C. Alternatively, the logic of the media path server 54 and the logic of the terminal proxies 56 can be configured such that it is the terminal proxies 56 that perform the actual selection of the encoding/decoding algorithm. The media path server in this case acts as a go-between mostly re-transmitting messages from one terminal proxy 56 to another terminal proxy 56. s) At this point, the media path between the terminal device 35 and the terminal device 38 is ready. The various components of the PBX, such as the connection controller 14, and the terminal proxies 56, are implemented in software. More particularly, the software is a program element contained on a computer readable storage medium. The program element is executable on a suitable computing platform to provide the functionality of the connection controller 14 and the functionality of one or more terminal proxies 56. Alternatively, the connection controller 14 and a terminal proxy 56 can be implemented in hardware or a combination software/hardware, without departing from the spirit of the invention. Although various embodiments have been illustrated, this was for the purpose of describing, but not limiting, the invention. Various modifications will become apparent to those skilled in the art and are within the scope of this invention, which is defined more particularly by the attached claims.

Claims: CLAIMS : 1) A terminal proxy for managing the flow of media signals originating or arriving at a terminal device residing in a packet switched network, comprising: a) a first interface for communicating with the terminal device using a terminal device protocol; b) a second interface for communicating with a remote entity using a protocol other than the terminal device protocol; and c) an interoperation functional unit in communication between said first interface and said second interface, operative to effect manipulations on signaling information received by said first interface and by said second interface, respectively, to allow the terminal device and the remote entity to interoperate for effecting management of the flow of media signals originating or arriving at the terminal device. 2) A terminal proxy as defined in claim 1, wherein said second interface receives signaling information in said protocol other than the terminal device protocol for controlling media signals originating or arriving at the terminal device. 3) A terminal proxy as defined in claim 2, wherein the terminal device is a first terminal device, the remote entity is a media path server for controlling media signals exchanged between the first terminal device and a second remote terminal device. 4) A computer readable storage medium containing a program element for execution by a processor to implement a terminal proxy for managing the flow of media signals originating or arriving at a terminal device residing in a packet switched network, said terminal proxy comprising: a) a first interface for communicating with the terminal device using a terminal device protocol; b) a second interface for communicating with a remote entity using a protocol other than the terminal device protocol; and c) an interoperation functional unit in communication between said first interface and said second interface, operative to effect manipulations on signaling information received by said first interface and from said second interface, respectively, to allow the terminal device and the remote entity to interoperate for effecting management of the flow of media signals originating or arriving at the terminal device. 5) A connection controller for the management of a media path between one terminal device residing in a packet switched network and another terminal device residing in a circuit switched network, said connection controller including: a) an input for receiving first signaling data indicative of a need of a media path between the one and the another terminal devices, the media path including a packet switched network leg and a circuit switched network leg; b) a packet switched sub-system responsive to the signaling information at said input to generate second signaling data to effect management of the packet switched network leg; and c) a circuit switched sub-system responsive to the signaling information at said input to generate third signaling data to effect management of the circuit switched network leg. 6) A connection controller as defined in claim 5, wherein said packet switched sub-system includes a media path ■ server and a plurality of terminal proxies in communication with said media path server, each terminal proxy suitable to communicate with a known terminal device residing in the packet switched network that can potentially be involved in a media path managed by said connection controller. 7) A connection controller as defined in claim 6, wherein each terminal proxy includes: a) a first interface for communicating with the terminal device associated with the terminal proxy using a terminal device protocol; b) a second interface for communicating with said media path server using a media path server protocol; and c) an interoperation functional unit in communication between said first interface and said second interface, operative to effect manipulations on signaling information received by said first interface and by said second interface, respectively, to allow the terminal device associated with the terminal proxy and said media path server to interoperate for effecting management of the flow of media signals originating or arriving at the terminal device associated with the terminal proxy. 8) A connection controller as defined in claim 7, wherein said media path server protocol is common to said plurality of terminal proxies. 9) A connection controller as defined in claim 8, wherein the media path server protocol is independent the terminal device protocol. 10) A connection controller as defined in claim 9, wherein each terminal proxy is operative to generate signaling data directed to a terminal device associated with the terminal proxy, the second signaling data comprising the signaling data generated by the terminal proxy and directed to the terminal device associated therewith. 11) A connection controller as defined in claim 10, wherein the third signaling data is suitable to control a time switch. 12) A connection controller as defined in claim 11, wherein said connection controller includes a central connection unit, said central connection unit comprising said input. 13) A connection controller as defined in claim 12, wherein said central connection unit is operative to issue commands to said media path server. 14) A connection controller as defined in claim 13, wherein the media path includes a media gateway between the packet switched network leg and the circuit switched network leg, said packet switched sub-system including a terminal proxy for communicating with the media gateway. 15) A computer readable storage medium containing a program element for execution by a processor to implement a connection controller for the management of a media path between one terminal device residing in a packet switched network and another terminal device residing in a circuit switched network, said connection controller including: a) an input for receiving first signaling data indicative of a need of a media path between the one and the other terminal devices, the media path including a packet switched network leg and a circuit switched network leg; b) a packet switched sub-system responsive to the signaling information at said input to generate second signaling data to effect management of the packet switched network leg; and c) a circuit switched sub-system responsive to the signaling information at said input to generate third signaling data to effect management of the circuit switched network leg. 16) A PBX comprising a plurality of terminal proxies, each terminal proxy being as defined in claim 1. 17) A PBX comprising the connection controller as defined in claim 5. 18) A PBX comprising: a) a call manager for providing call processing functions for establishment of a call session between a first terminal device residing in a circuit switched network and a second terminal device in a packet-switched network; b) a connection controller in communication with said call manager, said connection controller being responsive to signaling information received from said call manager to effect management of a media path between the first terminal device and the second terminal device during the call session set-up by the call manager; and c) said signaling information being independent of the connection type of the first terminal device and of the second terminal device. 19) A terminal proxy for managing the flow of media signals originating or arriving at a terminal device means residing in a packet switched network, comprising: a) first interface means for communicating with the terminal device using a terminal device protocol; b) second interface means for communicating with a remote entity means using a protocol other than the terminal device protocol; and c) interoperation functional means in communication between said first interface means and said second interface means, operative to effect manipulations on signaling information received by said first interface means and by said second interface means, respectively, to allow the terminal device means and the remote entity means to interoperate for effecting management of the flow of media signals originating or arriving at the terminal device means . 20) A method for users residing at respective first and second terminal devices to communicate with one another, the first terminal device residing in a circuit-switched network and the second terminal device residing in a packet-switched network, said method comprising: a) implementing a call processing function to initiate establishment of a call session between the first terminal device and -the second terminal device; b) generating signaling information that is independent of the connection type of the first terminal device and of the second terminal device, the signaling information being indicative of a need of a media path between the first and the second terminal devices; and c) in response to the signaling information setting up a media path between the first terminal device and the second terminal device during the call session.

Inventors: MCINTYRE STEPHEN J, MEIJER FRANK F, MCINTYRE, STEPHEN, J., MEIJER, FRANK, F.
Applicants: MCINTYRE STEPHEN J, MEIJER FRANK F, NORTEL NETWORKS LTD, MCINTYRE, STEPHEN, J., MEIJER, FRANK, F., NORTEL NETWORKS LIMITED
Application year: 2001
Main classification: H04L29
IPC codes: H04L12, H04M7, H04Q3