JP2005072817A - Ip phone system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an IP telephone system capable of maintaining telephone call and carrying and the like, even at the occurrence of a fault, by optimizing routing of an RTP packet. <P>SOLUTION: A SIP server 100 informs a VoIP address converter 101 for each calling about address conversion information, the address converter converts a SIP message from a private IP network 104 side into an IP address of a global IP network 105 side and converts a SIP message from the global IP network side into an IP address of the private IP network, and the IP phone system is configured, such that when communication between IP phone terminals 108 connected to the same private IP network is conducted, the terminals make direct communication via a single address converter, and in the case of communication between the terminals connected over a plurality of the private IP networks, the terminals make direct communication via a single address converter or the terminals make communication via a global network by a plurality of address converters interconnected to each other. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an IP telephone system, and more particularly to an IP telephone system in which an SIP server and a VoIP address translation device cooperate to control RTP packets.

  An IP telephone system between a global network and a private network subscriber in a conventional VoIP (Voice Over IP) network includes a SIP (Session Initiation Protocol) server and an address translation device (NAT (Network Address Translation) or NAPT (Network Address Port Translation). ) Router having a function) and an IP telephone terminal.

  In the conventional IP telephone system having such a configuration, the address translation device has a static address translation pattern and performs fixed RTP (Realtime Transport Protocol) packet routing. Also, the address translation device to be used is fixed for each IP telephone terminal.

  However, the conventional IP telephone system has the following problems.

  First, since an RTP packet for voice is also a UDP (User Datagram Protocol) data packet, a network policy prohibiting data transfer between adjacent data terminals, such as a cable television network, can use a personal computer or the like. In a network where data transfer between data terminals is prohibited, there has been a problem that RTP packets cannot be directly transmitted and received between IP telephone terminals.

  Here, in order to solve the above-described problem, once all RTP packets are transmitted / received via the address translation device, the packet traffic of the network increases in the vicinity of the address translation device, so that the network can be used efficiently. There was a problem that I could not.

  Second, in SIP, the communication port for RTP packets is variable for each call. Therefore, if an address translation pattern is statically set for all communication ports that may be used, the security of the private network There are problems that make it vulnerable, and it takes time to configure. Further, if the control is performed for each call, a mechanism at the same level as that of the SIP server is required, and the processing speed is reduced. Therefore, when a failure occurs in the address translation device, it is difficult to maintain a call during communication. There was a problem.

  Thirdly, since the MIDCOM (Middlebox Communication) protocol for remotely operating the address translation device for each call from the SIP server is not compatible with VLAN (Virtual LAN), when the address translation device is remotely operated from the SIP server, However, there is a problem that a plurality of private networks cannot be accommodated in a single address translation device by VLAN. As a result, the private network assigns a closed IP address to that network, so when communicating with another private network, there is a possibility that the address will be duplicated. Connection is made after changing to an IP address. In such connection, since a plurality of address translation devices are installed, there is a problem that the cost of the address translation device increases when an IP telephone network spanning a plurality of private networks is constructed. .

  Therefore, the present invention has been made in view of the problems in the conventional IP telephone system described above, and can optimize the route of the RTP packet, maintain the call even in the event of a failure, An object of the present invention is to provide an IP telephone system capable of controlling address translation information dynamically from a SIP server even when connected.

  To achieve the above object, the present invention provides a SIP server connected to a global IP network, a VoIP address translator connected to the global IP network and the private IP network, the global IP network, and the private IP network. In the IP telephone system configured with an IP telephone terminal connected to the IP telephone terminal, the SIP server notifies the address conversion information to the VoIP address conversion apparatus for each call, and the VoIP address conversion apparatus transmits the private IP A SIP message from the network side is converted to an IP address on the global IP network side, a SIP message from the global IP network side is converted to an IP address on the private IP network side, and connected to the same private IP network When communicating between IP phone terminals, a single VoIP When the IP telephone terminals are set to directly communicate with each other via the address conversion apparatus and communicate with each other between the IP telephone terminals connected across a plurality of private IP networks, the single VoIP address conversion apparatus The IP telephone terminals communicate directly with each other, or a plurality of the VoIP address translators are linked to communicate with each other via the global network.

  And according to the present invention, when communicating between IP telephone terminals connected to the same private IP network, and when communicating between IP telephone terminals connected across a plurality of private IP networks, It is possible to communicate directly through a single VoIP address translator, or to link two or more VoIP address translators and communicate with each other via IP telephone terminals via the global network.

  In the IP telephone system, when the private IP network is a network having a policy prohibiting data transfer between terminals, the single VoIP address translation device is configured to wrap an RTP packet. Can do.

  As a result, even within a network where data transfer between personal computer terminals is prohibited, an IP telephone terminal can make a call and the SIP server and the VoIP address translator cooperate with each other to recognize the IP terminal accommodation form. Therefore, the route of the RTP packet can be optimized for each call in the IP telephone network extending over the private network.

  In the previous IP telephone system, the protocol for controlling the address translation information can be adapted to VLAN. As a result, even when connected to the VLAN, the address translation information can be controlled dynamically from the SIP server.

  The present invention also provides a SIP server connected to a global IP network, a plurality of VoIP address translators connected in parallel to the global IP network and the private IP network, the global IP network, and the private IP network. In the IP telephone system configured with an IP telephone terminal connected to the IP telephone terminal, the SIP server notifies the address conversion information to the VoIP address conversion apparatus for each call, and the VoIP address conversion apparatus transmits the private IP A SIP message from the network side is converted to an IP address on the global IP network side, a SIP message from the global IP network side is converted to an IP address on the private IP network side, and connected to the same private IP network When communicating between IP telephone terminals, a single VoIP add If one of the plurality of VoIP address translators is abnormal, the address translation information is sent to another VoIP address translator. It is characterized by forwarding and diverting a call.

  According to the present invention, by cooperating the SIP server and the VoIP address translation device, the VoIP address translation device and the line connected to the device are checked for life and death, and the address translation information of the call during the call is dynamically obtained. Since the call can be bypassed by transferring to the VoIP address translator, even if the VoIP address translator used for the call fails, the call is switched to another normal VoIP address translator. The call can be maintained.

  Furthermore, the present invention is a VoIP address translation device connected to a global IP network and a private IP network, based on address translation information for each call notified from a SIP server connected to the global IP network. The SIP message from the private IP network side is converted into an IP address on the global IP network side, the SIP message from the global IP network side is converted into an IP address on the private IP network side, and the same private IP network When communication is performed between IP telephone terminals connected to the IP telephone terminal, the IP telephone terminals are set to communicate directly with each other via a single VoIP address translation device, and are connected across a plurality of private IP networks. When communicating with other IP telephone terminals, the IP address is transferred via a single VoIP address translation device. Or so as to communicate directly talking between terminals to tie together the VoIP address translation device, via said global network, characterized in that to communicate with the IP telephone terminal to each other. By coordinating this VoIP address translator and the SIP server, as described above, when communicating between IP telephone terminals connected to the same private IP network, and across multiple private IP networks In the case of communication between connected IP telephone terminals, direct communication is performed via a single VoIP address translation device, or a plurality of the VoIP address translation devices are linked together to perform IP communication via the global network. Communication between telephone terminals is possible.

  In the VoIP address translation device, when the private IP network is a network having a policy prohibiting data transfer between terminals, the single VoIP address translation device is configured to wrap an RTP packet. can do. As a result, even within a network in which data transfer between personal computer terminals is prohibited, IP telephone terminals can talk with each other, RTP control can be performed in consideration of the accommodation form of the IP terminals, and a private network can be used. In the straddled IP telephone network, the route of the RTP packet can be optimized for each call.

  The present invention is also a VoIP address translation system comprising a plurality of VoIP address translation devices connected in parallel to a global IP network and a private IP network, the SIP server being connected to the global IP network The SIP message from the private IP network side is converted into an IP address on the global IP network side based on the address conversion information for each call notified from the network, and the SIP message from the global IP network side is converted to the private IP network. When the IP address is converted to an IP address on the side, and one of the plurality of VoIP address translators is abnormal, the address translation information is transferred to another VoIP address translator to divert the call. To do. By linking this VoIP address translation device and the SIP server, the VoIP address translation device and the line connected to the device are checked for life and death, and the address translation information of the call during the call is dynamically used for VoIP. Since the call can be bypassed by transferring to the address translation device, even if the VoIP address translation device used for the call fails, the call is switched to another normal VoIP address translation device. Can be maintained.

  Furthermore, the present invention provides a SIP server connected to a global IP network, and notifies address conversion information to each VoIP address translator connected to the global IP network and the private IP network. Features. By coordinating this SIP server with the VoIP address translator, etc., it becomes possible to optimize the route of the RTP packet.

  As described above, according to the present invention, the route of the RTP packet can be optimized, the call can be maintained even in the event of a failure, and even when connected to the VLAN, the SIP server dynamically An IP telephone system capable of controlling address translation information can be provided.

  FIG. 1 shows a first embodiment of an IP telephone system according to the present invention, and this IP telephone system includes a SIP server 100 for controlling a SIP call and a VoIP address translator 101. The SIP server 100 is connected to the global IP network 105, and the VoIP address translation device 101 is connected to the global IP network 105 and the private IP network 104. The SIP server 100 and the VoIP address translation device 101 implement the MIDCOM protocol. Further, the VoIP address translation device 101 has a function of analyzing a SIP message. An IP telephone terminal 108 is connected to each of the global IP network 105 and the private IP network 104.

  The VoIP address translator 101 converts a SIP message from the private IP network 104 side to an IP address on the global IP network 105 side, and converts a SIP message from the global IP network 105 side to an IP address on the private IP network 104 side. To do. The SIP server 100 notifies the address translation information 106 to the VoIP address translation device 101 for each call using the MIDCOM protocol.

  Next, the overall operation of the IP telephone system having the above configuration will be described in detail with reference to FIG.

(1) Registration of IP telephone terminal 108 (1-1) Operation at the time of registration of IP telephone terminal 108 to SIP server 100 In SIP server 100, "global IP address after conversion + port number" Register as an address. At that time, the registered address translation information 106 for the IP telephone terminal 108 (the private IP address of the IP telephone terminal 108 and the translated global IP address + port number) is sent from the SIP server 100 to the VoIP address translation apparatus 101. Notification is made using the MIDCOM protocol. Here, it is assumed that the translated global IP address = the IP address on the global IP network 105 side of the VoIP address translator 101. By this operation, address translation information 106 for SIP signaling that can be used only for the registered IP telephone terminal 108 is dynamically set in the VoIP address translation apparatus 101. The above operation is performed every time the IP telephone terminal 108 is registered in the SIP server 100.

(1-2) Setting of IP Telephone Terminal 108 The IP telephone terminal 108 registers the IP address on the private IP network 104 side of the VoIP address translator 101 as the address of the SIP server 100.

(2) Signal between IP telephone terminal 108 and SIP server 100 (2-1) Signal from IP telephone terminal 108 of private IP network 104 toward SIP server 100

  Since the signal transmitted from the IP telephone terminal 108 of the private IP network 104 registered by the previous operation has the address of the VoIP address translator 101 registered as the address of the SIP server 100, the VoIP address translator 101.

  The VoIP address translation device 101 uses the address translation information 106 notified from the SIP server 100 at the time of registration of the IP telephone terminal 108 to convert all the IP header of the signal and the IP address information in the SIP message on the global IP network 105 side. The IP address is converted and a signal is transmitted to the SIP server 100.

(2-2) Signal from the SIP server 100 toward the IP telephone terminal 108 in the private IP network 104 In the SIP server 100, the “global IP address after conversion + port number” is registered as the address of the IP telephone terminal 108. Therefore, in order to transmit a signal from the SIP server 100 to the IP telephone terminal 108, the signal is transmitted to a specific port number of the VoIP address translator 101.

  Upon receiving the signal from the SIP server 100, the VoIP address translation device 101 converts all of the IP header of the signal and the IP address information in the SIP message into the IP address on the private IP network 104 side in the reverse ethics of (2-1). The data is converted and transmitted to the corresponding IP telephone terminal 108.

(3) RTP packet path change The RTP packet path is changed by operating “c =” of the SDP information in the SIP message by the SIP server 100. In “c =” of the SDP information, a reception address of a packet for media (voice) is stored.

(4) RTP packet route setting logic (4-1) Network having policy for prohibiting data transfer between terminals A single VoIP address translation device 101 performs setting for returning an RTP packet. The SDP information “c =” is used as the IP address on the private network 104 side of the VoIP address translation device 101, and the IP header is changed in the VoIP address translation device 101 so that the RTP packet is not divided. Realization of wrapping.

(4-2) Calls in the same private network 104 of other forms of network are set to directly communicate with each other. The address of the partner terminal is used as it is for “c =” in the SDP information.

(4-3) Calling over the private network 104 of another form of network is set to select an appropriate VoIP address translation device 101 with free traffic. This is realized by managing the number of RTP packet sessions that are being transferred by each VoIP address translator 101 and the usage status of each call in the SIP server 100. The connection in the form (4-1) is selected as long as the number of sessions allows. Only when a session that can be used for connection in the form (4-1) cannot be secured, RTP packet transfer via the global network 105 is performed by linking two VoIP address translators 101 together. In this case, “c =” of the SDP information sets the global network 105 side address of each VoIP address translator 101.

(5) Address translation information setting for RTP packet The address translation information 106 for RTP packet is set in the VoIP address translation device 101 using the MIDCOM protocol immediately after the SIP server 100 receives the SIP message including the SDP information. And do it. In a normal SIP message, since SDP information is included in INVITE and 200 OK, these signals are performed when the SIP server 100 receives these signals.

  When receiving the INVITE signal, the address translation information from the called terminal to the calling terminal is set in the VoIP address translator 101 when receiving the 200 OK signal. Address translation becomes possible. These address translation information is deleted by a notification from the SIP server 100 using the MIDCOM protocol at the end of the conversation.

  FIG. 2 shows a second embodiment of the IP telephone system according to the present invention, which comprises a SIP server 100 for controlling SIP calls and a plurality of VoIP address translators 101. . The SIP server 100 is connected to the global IP network 105, and a plurality of VoIP address translators 101 are connected in parallel at the boundary between the global IP network 105 and the private IP network 104. Each of the plurality of VoIP address translators 101 operates in a hot standby state. The plurality of VoIP address translators 101 can be seen from the IP telephone terminal 108 by the floating IP mechanism as the same address. The SIP server 100 has a life / death monitoring function 107 of the VoIP address translation device 101. The SIP server 100 and the VoIP address translation device 101 implement the MIDCOM protocol. Further, the VoIP address translation device 101 has a function of analyzing a SIP message. An IP telephone terminal 108 is connected to each of the global IP network 105 and the private IP network 104.

  When the VoIP address translation device 101 is normal, signals are transmitted and received by a predetermined combination of the IP telephone terminal 108 and the VoIP address translation device 101.

  When the SIP server 100 detects an abnormality of the VoIP address translation device 101 by the life and death state monitoring function 107 or the MIDCOM protocol message, as shown in FIG. The address translation information 106 is transferred according to the protocol to bypass the call.

  Next, the operation of the IP telephone system having the above configuration will be described in detail with reference to FIGS.

(1) Registration of IP telephone terminal 108 (1-1) Operation at the time of registration of IP telephone terminal 108 to SIP server 100 When the SIP telephone 100 registers the IP telephone terminal 108, The conversion information of the private IP address and the global IP address + port is notified by the MIDCOM protocol. This operation is performed every time the IP telephone terminal 108 is registered in the SIP server 100. Since a plurality of VoIP address translation devices 101 are connected, distribution is appropriately made to each address translation device according to the configuration of the subordinate private network 104. This distribution logic allocates the IP address translation information of the IP telephone terminal 108 to the same VoIP address translation device 101 in a network having a policy prohibiting data transfer between terminals. In another form of network, the IP address translation information of the IP telephone terminal 108 is uniformly allocated to each VoIP address translation device 101.

(1-2) Setting of IP Telephone Terminal 108 The IP telephone terminal 108 registers the floating IP address of each VoIP address translation device 101 as the address of the SIP server 100.

(2) Signal between IP telephone terminal 108 and SIP server 100 (2-1) Signal from IP telephone terminal 108 of private IP network 104 toward SIP server 100

  A router on the private network 104 side that bundles a plurality of VoIP address translators 101 is set to multicast SIP signaling (port 5060) to all connected VoIP address translators 101.

  The signal transmitted from the IP telephone terminal 108 of the private network 104 registered by the previous operation is multicast to each VoIP address translator 101 by the router. Only the VoIP address translator 101 that receives the address translation information of the IP telephone terminal 108 from the SIP server 100 translates the signal into a global address (discards in the other VoIP address translators 101), and is addressed to the SIP server 100. Send a signal to As a result, the IP telephone terminal 108 can operate without being aware of the IP addresses of the VoIP address translators 101 installed in parallel.

  The SIP server 100 that has received the signal obtains the optimum route of the RTP packet from the accommodation information of the IP telephone terminal 108 of the connection destination and rewrites the SDP information of the SIP signal. In the network having a policy prohibiting data transfer between terminals, the SDP information rewrite logic is different between terminals in a call within the same private network 104 in other forms, such as being returned by a single VoIP address translation device 101. In the case of a call straddling the private network 104 so that direct communication is performed, the VoIP address translation device 101 with free traffic is selected.

  When the route of the RTP packet of the IP telephone terminal 108 is a route passing through the VoIP address translation device 101, the address translation information is notified to each corresponding VoIP address translation device 101 by the MIDCOM protocol.

(2-2) Signal from the SIP server 100 toward the IP telephone terminal 108 in the private IP network 104 After the route of the optimum RTP packet is determined, the SIP server 100 sends an IP telephone terminal 108 in the destination private network 104 to the IP telephone terminal 108 Then, a signal is transmitted via the VoIP address translation device 101 assigned at the time of terminal registration. At this time, the address information of the signal is converted into a private IP address by the VoIP address translator 101. At the response of the called terminal, processing is performed in the reverse flow.

(3) Operation when VoIP Address Translation Device 101 Fails When the VoIP address translation device 101 detects a failure of its own device, the failure information is notified to the SIP server 100 by the MIDCOM protocol. In some cases, the SIP server 100 may detect a failure of the VoIP address translation device 101 using the monitoring function 107 in a life / death state. The SIP server 100 that has received or detected the failure notification selects another normal VoIP address translation device 101 and first transfers the address translation information 106 to the selected VoIP address translation device 101 using the MIDCOM protocol. Next, a Re-INVITE signal for switching the transmission destination of the RTP packet is transmitted to the IP telephone terminal 108 in communication.

  FIG. 4 shows a third embodiment of the IP telephone system according to the present invention. This IP telephone system includes a plurality of private networks 109 to 111 on the private network 104 side of the address translation apparatus 101 in FIG. Are connected to the VLAN 112 in an aggregated form. The SIP server 100 that controls SIP calls and the VoIP address translator 101 are implemented by extending the MIDCOM protocol to support VLAN tags.

  Next, the operation of the IP telephone system having the above configuration will be described with reference to FIG.

  The difference between the present embodiment and the second embodiment is that the private networks 109 to 111 of the VoIP address translator 101 are VLANs. In the MIDCOM protocol in which the address translation information is transmitted from the SIP server 100 to the VoIP address translation device 101, the address translation information is represented by an IP address + port number. This makes it impossible to assign duplicate IP addresses in each of the private networks 109 to 111, so the MIDCOM protocol is extended to support VLAN. The element indicating the address translation information is VLAN tag + IP address + port number.

It is a block diagram which shows the structure of 1st Embodiment of the IP telephone system concerning this invention. It is a block diagram which shows the structure before the address translation apparatus switching of 2nd Embodiment of the IP telephone system concerning this invention. It is a block diagram which shows the structure after the address translation apparatus switching of 2nd Embodiment of the IP telephone system concerning this invention. It is a block diagram which shows the structure of 3rd Embodiment of the IP telephone system concerning this invention.

Explanation of symbols

100 SIP server (call processing device)
101 VoIP address translation device (NAPT device)
104 Private network 105 Global network 106 Address translation information 107 Life / death monitoring function 108 IP telephone terminals 109 to 111 Private network 112 VLAN

Claims (8)

A SIP server connected to a global IP network; a VoIP address translator connected to the global IP network and the private IP network; and an IP telephone terminal connected to the global IP network and the private IP network. IP phone system
The SIP server notifies the address translation information to the VoIP address translation device for each call,
The VoIP address translator converts a SIP message from the private IP network side to an IP address on the global IP network side, and converts a SIP message from the global IP network side to an IP address on the private IP network side And
When communicating between IP phone terminals connected to the same private IP network, set to communicate directly between IP phone terminals via a single VoIP address translation device,
When communicating between IP telephone terminals connected across a plurality of private IP networks, the IP telephone terminals communicate directly with each other via a single VoIP address translation device, An IP telephone system, wherein IP address terminals communicate with each other via the global network in cooperation with VoIP address translators.   2. The RTP packet is set to be turned back by the single VoIP address translator when the private IP network is a network having a policy prohibiting data transfer between terminals. IP phone system.   3. The IP telephone system according to claim 1, wherein a protocol for controlling the address translation information corresponds to a VLAN. SIP server connected to global IP network, a plurality of VoIP address translators connected in parallel to global IP network and private IP network, and IP telephone connected to global IP network and private IP network In an IP telephone system composed of terminals,
The SIP server notifies the address translation information to the VoIP address translation device for each call,
The VoIP address translator converts a SIP message from the private IP network side to an IP address on the global IP network side, and converts a SIP message from the global IP network side to an IP address on the private IP network side And
When communicating between IP phone terminals connected to the same private IP network, set to communicate directly between IP phone terminals via a single VoIP address translation device,
An IP telephone system, wherein when one of the plurality of VoIP address translators is abnormal, the address translation information is transferred to another VoIP address translator to divert the call. A VoIP address translator connected to a global IP network and a private IP network,
Based on the address translation information for each call notified from the SIP server connected to the global IP network, the SIP message from the private IP network side is converted into an IP address on the global IP network side, and the global IP network A SIP message from the side is converted into an IP address on the private IP network side,
When communicating between IP phone terminals connected to the same private IP network, set to communicate directly between IP phone terminals via a single VoIP address translation device,
When communicating between IP telephone terminals connected across a plurality of private IP networks, the IP telephone terminals can communicate directly with each other via a single VoIP address translation device, A VoIP address translation device, wherein IP address terminals communicate with each other via the global network in cooperation with a VoIP address translation device.   6. If the private IP network is a network having a policy prohibiting data transfer between terminals, the single VoIP address translation device is configured to wrap an RTP packet. VoIP address translation device. A VoIP address translation system comprising a plurality of VoIP address translation devices connected in parallel to a global IP network and a private IP network,
Based on the address translation information for each call notified from the SIP server connected to the global IP network, the SIP message from the private IP network side is converted into an IP address on the global IP network side, and the global IP network A SIP message from the side is converted into an IP address on the private IP network side,
A VoIP address translation system characterized in that, when one of the plurality of VoIP address translation devices is abnormal, the address translation information is transferred to another VoIP address translation device to divert the call.   A SIP server connected to a global IP network, wherein the address conversion information is notified for each call to a VoIP address translator connected to the global IP network and the private IP network.

Images