The present invention relates to managing network services between networks and in particular to managing voice-over-IP (VoIP) service in a Network Address Translation (NAT)-enabled private network environment.
Data is transmitted over a network through paths in digital data packets that traverse routers in the network to arrive at a desired destination over IP protocols. Often, data streams must be delivered from a public network to a local node or device in a private network and vice versa. In these situations, any IP-based services are delivered to or from a local node or device through an entry or exit point of a local network. This entry/exit point functions as a gateway for data such that the public network recognizes a single address for the private network. Typically, Network Address Translation (NAT) is employed to present the private network to the Internet or other public network with one address. In this way, the NAT translates individual IP addresses for each device in the private network for the public network such that the private individual IP addresses are concealed from the public network. This results in conservation of addresses and added efficiency of the network interfaces.
Messages or data being transmitted in networks contain a header and payload. The header is the portion of a message or data that contains information that guides the message to the intended destination. Information contained in the header may include the address of the sender, the address of the receiver, precedence level, routing instructions, etc. Transmitted messages or data further contain a payload portion. The payload portion is in the data portion of the IP packet. An interface between the private network and the public network or Internet must know the mapping between a local node or device and its specific IP address and User Data Protocol (UDP) port to correctly route data to the proper destination. The Network Address Translation (NAT) at the gateway is such an interface. It establishes the said mapping between the private and public networks to interpret address data in the IP headers and delivers any incoming data to the desired local node or device.
However, VoIP protocols sometimes contain address information in the payload (i.e., data portion of the IP packet). One example of such a VoIP protocol is MGCP/NCS (Media Gateway Controller Protocol/Network-based Call Signaling protocol). MGCP/NCS protocol is used for call processing signaling control to provide Voice-over-IP (VoIP) services. In situations where specific IP address information and/or port number information is contained in the payload, the NAT, which only interprets data in the IP header, is unable to properly translate the address information or port number information. As a result, data is not properly delivered to the desired destination in the private network.
Further, the actual voice stream is carried by the Real-Time Transport Protocol (RTP). The IP address and port number information for the RTP packets are defined by the Session Description Protocol (SDP) included in the MGCP/NCS payload and need to be translated properly. In addition, the voice stream, i.e., the RTP packets, need to be routed properly to the intended destination. Therefore, the mapping information is necessary at the gateway for proper routing of data to the correct final destination within the private network. The data packet is delivered to the gateway of the private or local network and the gateway must then route the data to the intended destination within the private or local network. The NAT does not have address mapping information and therefore cannot properly route data to the desired destination node.
Therefore, there exists a need in the art to properly translate address and/or port number information such that VoIP signaling packets are delivered to the desired destination node within a private or local network and public network.
Further, there exists a need in the art to provide address mapping information and actually perform the routing if necessary for delivery of VoIP voice packets to the desired destination node within a private or local network and public network.
In one exemplary embodiment of the present invention, a method is provided for managing network services between a plurality of networks comprising receiving an Internet Protocol data packet with a corresponding address from a first network source, wherein the Internet Protocol data packet comprises a header and a payload and the payload of said Internet Protocol data packet contains at least a portion of a destination address; translating the destination address; and delivering the Internet Protocol data packet to a destination node on a second network based on said translating.
a illustrates message flow of a Restart in Progress (RSIP) in an exemplary embodiment of the present invention.
b is a flowchart illustrating an exemplary method of RSIP message flow.
c is a flowchart illustrating an exemplary method of RSIP message flow with RestartMethod being “graceful” or “forced” or “disconnected”.
a illustrates an exemplary embodiment of message flow in client registration.
b is a flowchart illustrating an exemplary method of RSIP message flow; the voice proxy server 100 receives a RSIP message with EndpointID=“*@VC” and RestartMethod=“restart”.
c is a flowchart illustrating an exemplary method of RSIP message flow with RestartMethod—“graceful”, “forced”, or “disconnected”.
a illustrates an exemplary embodiment of message flow in Notification Request (RQNT).
b illustrates an exemplary embodiment of message flow in Notification Request (RQNT) wherein EndpointID is a wild card.
c is a flowchart illustrating an exemplary method of RQNT message flow with EndpointID and NotifiedEntity specified.
a illustrates an exemplary embodiment of message flow for Notifications (NTFY).
b is a flowchart illustrating an exemplary method of NTFY message flow.
a illustrates an exemplary embodiment of message flow for Create Connection (CRCX).
b is a flowchart illustrating an exemplary method of CRCX message flow where EndpointID is a single endpoint.
a illustrates an exemplary embodiment of message flow for Create Connection (CRCX) where EndpointID is a wild card.
b is a flowchart illustrating an exemplary method of CRCX message flow where EndpointID is a wild card.
a illustrates an exemplary embodiment of message flow for Modify connection (MDCX).
b is a flowchart illustrating an exemplary method of MDCX message flow where EndpointID is a single endpoint and NotifiedEntity is specified.
a illustrates an exemplary embodiment of message flow for Delete Connection (DLCX) from a call agent.
b is a flowchart illustrating an exemplary method of DLCX message flow where EndpointID is a single endpoint and Notifiedentity is specified.
a illustrates an exemplary embodiment of message flow for Delete Multiple Connections from a call agent where ConnectionID is not specified.
b is a flowchart illustrating an exemplary method of Delete Multiple Connections message flow.
a illustrates an exemplary embodiment of message flow for Delete Multiple connections from a call agent where CallID and ConnectionID are not specified.
b is a flowchart illustrating an exemplary method of Delete Multiple connections message flow.
a illustrates an exemplary embodiment of message flow for Delete Connection (DLCX) from a voice client.
b is a flowchart illustrating an exemplary method of DLCX message flow.
a illustrates an exemplary embodiment of message flow for Audit Endpoints (AUEP).
b is a flowchart illustrating an exemplary method of AUEP message flow.
a illustrates an exemplary embodiment of message flow for Audit Multiple Endpoints.
b is a flowchart illustrating an exemplary method of Audit Multiple Endpoints where EndpointID=*@VPS.
c is a flowchart illustrating an exemplary method of Audit Multiple Endpoints where MaxEndpointIDs are specified.
d is a flowchart illustrating an exemplary method of Audit Multiple Endpoints where MaxEndpointIDs and SpecificEndpointIDs are specified.
e is a flowchart illustrating an exemplary method of Audit Multiple Endpoints where SpecificEndpiontIDs are specified.
a illustrates an exemplary embodiment of message flow for Audit Connection (AUCX).
b is a flowchart illustrating an exemplary method of AUCX message flow where EndpointID is a single endpoint.
The present invention relates to a method and system of properly routing data, such as packets associated with Voice-over-IP (VoIP) service between networks. When data packets are transmitted through a network, specific IP address and/or port number information may be located in the payload. The NAT can only translate addresses in the IP header and those applications that use IP addresses in the IP payload will break at the NAT environment. Protocols that provide the VoIP service, for example, the Media Gateway Controller Protocol/Network-based Call Signaling Protocol (MGCP/NCS) provide VoIP messages, such as MGCP/NCS messages, that are carried in a UDP/IP message. In other words, the MGCP/NCS message is in the payload portion of a UDP/IP message. The MGCP message comprises a specific IP address and port number which are in the IP payload and cannot be translated by the NAT. Therefore, VoIP service cannot be provided in a NAT-enabled private network. The present invention provides a solution to support VoIP service that may co-exist with the NAT and provide a method and system of translating the address information of the message in the header and payload such that the data packet may be routed properly to the desired destination from a public network source to a local destination node in a private network and vice versa. Additionally, the invention also supports the routing of the incoming voice packets to the desired destination in the private network.
In an exemplary embodiment of the present invention, the MGCP/NCS protocol is used for call processing signaling control to provide VoIP services. It should be appreciated that the invention is not so limited, as a variety of IP protocols may be used without deviating from the scope or spirit of the present invention. For example, Session Initiation Protocol (SIP) may also be used and the system and method of the present invention may properly translate IP address and/or port number information.
MGCP messages are carried in the data portion (payload) of the UDP/IP packets with the header containing the identifier of the endpoints. An “endpoint” is a network element or component at the end of the network, such as a transmitter or receiver or an originating or terminating device, and may be represented by an endpoint identifying parameter, for example, an EndpointID. The endpoint identifying parameter comprises specific information to identify a particular network element or component. An example of a typical form of an endpoint identifying parameter, such as an EndpointID of an endpoint, is local-name@domain-name or an IP address. There are many parameters in the message header and many of these parameters require specific names, specific IP addresses and/or port numbers which may be all located in the IP payload.
For proper delivery of data packets to the desired node in a private network, a gateway may be utilized for receiving the data packets from the public network, such as the Internet for example, and routing the data packets to the desired node in the private network. Within the gateway, a voice proxy server (VPS) operates as the intermediary. Like the NAT, the VPS establishes an IP address/port mapping table when the VoIP clients in the private network initiate their contacts to the VoIP call agent in the public network. In addition, the VPS translates any address/port information in the IP payload before relaying the IP packets to a public network. The VPS then uses mapping information to deliver data packets from the public network to the desired destination within the private network as well as to deliver data packets from a node in a private network to the desired destination in the public network. For VoIP protocols wherein essential IP address or port number data is located in the payload, the VPS may properly translate the data for routing to the desired destination.
When a call is placed from a local node, for example, a call signaling path is set up by the call agent (CA) 105. In one example, the call originates at the VC 101 and an off-hook signal is received at the VPS 100 and relayed to the CA 105. The CA 105 responds through the VPS 100 back to the VC 101 with a dial tone. The response from the CA 105 is returned to the address of the VPS 100, in this example, because the public network where the CA 105 resides need only recognize the one address of the VPS 100 rather than each and every local node in the private network.
As an example, the user inputs a destination number (e.g., phone number) which is relayed through the VPS 100 to the CA 105, then to the VoIP gateway 104 and to the Public Switched Telephone Network (PSTN) 106. Thus, the CA 105 manages call signaling. In this example, the private network nodes such as the VC 101, VC 102 or VC 103 each have unique private addresses and each communicates with the VPS 100. The CA 105 need only recognize the globally unique registered address of the VPS 100 in the public network. In this way, the VPS 100 acts as an embedded client to the CA 105 with several access lines. Each of the access lines corresponds to a real line in a node in the private network, such as the VC 101. At the same time, the VPS 100 acts as a “call agent” to the local nodes in the private network since the address of the CA 105 need not be recognized by the local nodes. Instead, the local nodes need only recognize the address of the VPS 100. In this exemplary embodiment, therefore, the public network need only recognize one address for all of the local nodes in a private network which is the address of the VPS 100.
As illustrated in this exemplary embodiment, the VPS 100 resides at a gateway which is on the edge of a broadband private network and functions as an entry/exit point to the public network. IP-based services, such as Voice-over-IP (VoIP), can be delivered to a private network through the VPS 100. VoIP data is received in data packets using VoIP protocols. One example of a commonly used VoIP protocol is Media Gateway Controller Protocol/Network-based Call Signaling protocol (MGCP/NCS). In such VoIP protocols, specific IP address information or port number information is contained in the payload of the message. The VPS 100 effectively translates the address or port number information in the payload of the message to route the data to the desired destination within the private network.
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a-5c illustrate another exemplary application of the VPS 100 of the present invention. In this example as illustrated in
In another illustrative application depicted in
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a and 7b illustrate another exemplary application of the VPS 100 of the present invention. In this example, the VPS 100 receives a Notify (NTFY) message from the voice client (step 701). A NotifiedEntity parameter may also be specified. After receiving the NTFY message, the VPS retrieves the logical line number from the line mapping table (step 702) according to the EndpointID specified in the NTFY command. The EndpointID parameter is replaced with a new identifier (i.e., aaln/LN@VPS) (step 703) and the NotifiedEntity parameter is replaced with a previously saved identifier (step 704). The NTFY command is delivered to the restored NotifiedEntity (step 705), which corresponds to the call agent 105. The VPS 100 sends the response received to the voice client 101 (step 706).
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c illustrates another exemplary application of the VPS 100 of the present invention. In this example, the VPS receives an AUEP message from a call agent with EndpointID=*@VPS and a parameter associated with the maximum number of Endpoints such as the MaxEndPointIDs specified (step 1610). The VPS 100 retrieves all the local voice clients from the line mapping table (step 1611) and sends the AUEP command with EndpointID parameter=*@vc to each of the retrieved voice clients (step 1612). Once responses are received from the voice clients, the VPS updates the line mapping table accordingly (step 1613) and when all the responses are received, the VPS may have N logical lines corresponding to the physical lines at the voice clients (step 1614). If N is less than or equal to MaxEndPointIDs, the VPS sends one response to the call agent with a list of N endpoints (step 1615). If not, the VPS sends one response to the call agent including a list of endpoints, the number of endpoints being equal to the value of MaxEndPointIDs, along with the total number of endpoints, NumEndPoints=N (step 1616).
d illustrates another exemplary application of the VPS 100 of the present invention. In this example, the VPS receives an AUEP message from a call agent with EndpointID=*@VPS and the MaxEndPointIDs and a parameter indicating a specified endpoint identifying parameter such as the SpecificEndPointID are specified (step 1620). The VPS calculates the number of endpoints (“M”) after the SpecificEndPointID (step 1621). If M is less than or equal to MaxEndPointIDs (step 1622), then the VPS sends one response to the call agent with a list of M endpoints, the first endpoint being the endpoint immediately following the SpecificEndPointID (step 1623)—i.e., the remaining list of endpoints. If M is greater than MaxEndPointIDs, then the VPS sends one response to the call agent with a list of endpoints, the list containing a number of endpoints equal to the value of MaxEndPointIDs and the first endpoint being the endpoint immediately following the SpecificEndPointID (step 1624)—i.e., the next block of endpoints. In this case, the VPS may also send the number of the total number of endpoints, N, as NumEndPoints.
e illustrates another exemplary application of the VPS 100 of the present invention. In this example, the VPS receives an AUEP message from a call agent with EndpointID=*@VPS and the SpecificEndPointID is specified (step 1630). The VPS sends one response to the call agent with a list of endpoints (step 1631). The list of endpoints starts at a first endpoint, the first endpoint being the endpoint immediately after the SpecificEndPointID. In this way, the VPS sends the remaining list of endpoints.
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It is understood that the present invention can take many forms and embodiments. The embodiments shown herein are intended to illustrate rather than to limit the invention, it being appreciated that variations may be made without departing from the spirit of the scope of the invention.
Although illustrative embodiments of the invention have been shown and described, a wide range of modification, change and substitution is intended in the foregoing disclosure and in some instances some features of the present invention may be employed without a corresponding use of the other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
This application is a continuation of and claims priority to U.S. Pat. No. 7,406,043, filed Apr. 10, 2007, which is a continuation of U.S. Pat. No. 7,203,166, filed Oct. 28, 2005, which is a continuation of and claims priority to U.S. Pat. No. 7,006,436, filed Nov. 13, 2001, each of which is incorporated herein by reference in its entirety.
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Number | Date | Country | |
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Parent | 11733641 | Apr 2007 | US |
Child | 12181623 | US | |
Parent | 11260163 | Oct 2005 | US |
Child | 11733641 | US | |
Parent | 10054135 | Nov 2001 | US |
Child | 11260163 | US |