JP5225300B2 - Route control method for mobile IP via private network, mobile router, and program - Google Patents

Description

  The present invention relates to a mobile IP (Internet Protocol) route control technique.

  Mobile IP is a layer 3 protocol that allows a mobile terminal to access using a unique IP address regardless of the network to which it is actually connected. A mobile terminal can connect to a mobile router via a mobile network and move together. According to the mobile IP, a fixed home agent is required, and the destination of the mobile terminal or the mobile router is managed and the packet transfer is relayed.

  Conventionally, there is a technique for transmitting and receiving packets between a mobile router and a home agent via a bidirectional tunnel (see, for example, Patent Document 1). According to this technique, a mobile router in IPv6 acquires a care-of address associated with an address configuration and registers the care-of address with a home agent.

  In addition, the mobile router uses the communication attribute table to identify whether the packet flow is a client-server type communication that does not require the mobile IP or the packet flow of the peer-to-peer (P2P) type communication that should use the mobile IP. However, there is a technique for controlling the route according to the packet flow (see, for example, Patent Document 2). According to this technology, a received packet for client / server communication with a short session can be transferred to the server through a direct route without overhead, and a unique IP address is applied to the received packet for P2P communication. A communication service based on mobile IP can be provided.

  FIG. 1 is a system configuration diagram in which mobile IP is applied in a private network.

  According to the system of FIG. 1, a mobile terminal (MNN: Mobile Network Node) 2 is connected to a mobile router (MR: Mobile Router) 1 via a mobile network (MNW: Mobile Network) 53. The mobile router 1 manages a mobile network address that is an address space of the mobile network. The mobile router 1 communicates with a counterpart terminal (CN) 4 via a communication carrier network 5.

  The telecommunications carrier network 5 is a private network and is configured by, for example, an interconnection between the access network 51 and the satellite communication network 52 and the core network 50 according to FIG. The access network 51 is, for example, a mobile phone network or a wireless LAN (Local Area Network). The satellite communication network 52 is a network via a communication satellite such as iridium, for example. The communication carrier network 5 is interconnected to the external Internet 6 via a gateway. According to FIG. 1, the counterpart terminal 4 may be connected to the communication carrier network 5 or may be connected to the Internet 6.

  According to FIG. 1, a home agent (HA) 3 is arranged in a private network as a carrier network. Here, since the mobile router 1 and the home agent 3 exist in the private network, the address (for example, care-of address) of the mobile router 1 is recognized from the counterpart terminal 4 connected to the external network (for example, the Internet). It is not possible.

  FIG. 2 is a sequence diagram of packets transmitted from a mobile terminal in the prior art.

(S201) First, it is assumed that a data packet is transmitted from the mobile terminal 2 to the counterpart terminal 4. For example, it may be a VoIP (Voice over IP) call message. This data packet is received by the mobile router 1 via the mobile network 53. This data packet has the following header:
Source address: mnn (IP address of mobile terminal)
Destination address: cn (IP address of partner terminal)

(S202) The mobile router 1 associates an arbitrary port number with the transmission source address mnn, and converts the transmission source address mnn in the data packet into the home address HoA (NAT (Network Address Transform)). The home address is an address assigned to the mobile terminal in the home network to which the mobile terminal was originally connected.

(S203) The mobile router 1 passes the data packet through the IP tunnel established for the home agent 3. The data packet is encapsulated and transferred, and has the following header.
Encapsulated source address: CoA (care-of address)
Destination address: HA (IP address of home agent)
Source address: HoA (home address)
Destination address: cn (IP address of partner terminal)
When the mobile router 1 has two communication paths (via an access network or satellite communication network), a different care-of address CoA is assigned to each communication path.

(S204) The home agent 3 decapsulates the received data packet and transfers it to the counterpart terminal 4. This data packet has the following header.
Source address: HoA (home address)
Destination address: cn (IP address of partner terminal)

(S211) In response to this, the counterpart terminal 4 returns a data packet to the mobile terminal 2. For example, a confirmation message for a VoIP call message. This data packet is received by the home agent 3 via the management router. This data packet has the following header.
Source address: cn (IP address of the partner terminal)
Destination address: HoA (home address)

(S212) The home agent 3 passes the data packet through the IP tunnel established for the mobile router 1. The data packet is encapsulated and transferred, and has the following header.
Encapsulated source address: HA (IP address of home agent)
Destination address: CoA (care-of address)
Source address: cn (IP address of the partner terminal)
Destination address: HoA (home address)

(S213) The mobile router 1 decapsulates the received data packet. Then, for the data packet, the home address HoA is converted into the source address mnn.

(S214) The mobile router 1 transmits the data packet to the mobile terminal 2. This data packet has the following header.
Source address: cn (IP address of the partner terminal)
Destination address: HoA (home address)

JP 2005-510122 A JP 2006-050035 A

  However, as shown in FIG. 1, when Mobile IP is applied in a private network, there arises a problem that data packets cannot be received from an external counterpart terminal to a mobile terminal in the private network.

  FIG. 3 is a sequence diagram of a packet transmitted from a counterpart terminal in the prior art.

(S301) The counterpart terminal 4 transmits a data packet to be transmitted to the mobile terminal 2 toward the communication carrier network. For example, a VoIP call message. This data packet has the following header:
Source address: cn (IP address of the partner terminal)
Destination address: mnn (IP address of mobile terminal)
This data packet is transferred to the home agent 3 by the management router in the carrier network. However, when the location registration from the mobile router 1 is not performed, the home agent 3 does not know the destination address (care-of address for the mobile router) in the data packet. Eventually, the data packet is discarded.

(S310) Here, it is assumed that the network administrator registers the location of the mobile network address of the mobile terminal 2 and the care-of address for the mobile terminal 2 in the home agent 3. Further, it may be based on a location registration request from the mobile router 1.

(S311) The counterpart terminal 4 attempts to transmit a data packet to the mobile terminal 2. Here, when the counterpart terminal 4 is connected to the Internet 6, even if the IP address mnn (for example, 192.168.0.100) of the mobile terminal is included as the destination address, the data packet cannot be transmitted. On the other hand, when the counterpart terminal 4 is connected to the carrier network 5, this data packet is transferred to the home agent 3 by the management router of the carrier network. This data packet has the following header:
Source address: cn (IP address of the partner terminal)
Destination address: mnn (IP address of mobile terminal)

(S312) The home agent 3 passes the data packet through the IP tunnel established for the mobile router 1. The data packet is encapsulated and transferred, and has the following header.
Encapsulated source address: HA (IP address of home agent)
Destination address: CoA (care-of address)
Source address: cn (IP address of the partner terminal)
Destination address: mnn (IP address of mobile terminal)

(S313) The mobile router 1 decapsulates the received data packet. Then, the data packet is transmitted to the mobile terminal 2. This data packet has the following header.
Source address: cn (IP address of the partner terminal)
Destination address: mnn (IP address of mobile terminal)

(S321) In response to this, the mobile terminal 2 returns a data packet to the counterpart terminal 4 to the mobile router 1 via the mobile network. For example, a confirmation message for a VoIP call message. This data packet has the following header:
Source address: mnn (IP address of mobile terminal)
Destination address: cn (IP address of partner terminal)

(S322) The mobile router 1 converts the source address mnn in the received data packet into the home address HoA.

(S323) The mobile router 1 passes the data packet through the IP tunnel established for the home agent 3. The data packet is encapsulated and transferred, and has the following header.
Encapsulated source address: CoA (care-of address)
Destination address: HA (IP address of home agent)
Source address: HoA (home address of mobile terminal)
Destination address: cn (IP address of partner terminal)

(S324) The home agent 3 decapsulates the received data packet and transmits it to the counterpart terminal 4. This data packet has the following header.
Source address: HoA (home address of mobile terminal)
Destination address: cn (IP address of partner terminal)

  However, in the counterpart terminal 4, the destination address of the data packet transmitted in S311 is the IP address mnn of the mobile terminal, whereas the source address of the data packet received in S324 is the home address HoA of the mobile terminal. . For this reason, the counterpart terminal 4 discards the received data packet.

  Thus, the data packet transmitted from the counterpart terminal 4 cannot be received by the mobile terminal 2. Specifically, an incoming call cannot be received from an external VoIP terminal to a mobile terminal in the private network. This problem is based on the fact that mobile routers and home agents that construct mobile IP are arranged in a private network.

  Therefore, the present invention provides a routing method, a mobile router, and a mobile router that can cause a mobile terminal to receive a data packet transmitted from a partner terminal outside the private network even when the mobile IP is built in a private network. And to provide a program.

According to the present invention, a home agent and a mobile router are arranged in a private network, and a mobile terminal connects a data packet transmitted from a partner terminal outside the private network to a system connected to the mobile router via the mobile network. A mobile router route control method for receiving an incoming call to a mobile terminal,
The mobile router has a function of mutually converting the node address of the mobile terminal and the home address for the mobile terminal for data packets encapsulated and exchanged with a private network,
A first step in which a mobile router stores a mobile network address for a mobile terminal;
A second step in which the mobile router decapsulates the data packet received from the home agent and forwards the data packet to the mobile terminal via the mobile network;
A third step of receiving a data packet from a mobile terminal via a mobile network and determining whether the source address of the data packet is included in the stored mobile network address;
And a fourth step of encapsulating the data packet without performing address translation when it is determined to be true, and transmitting the data packet to the home agent via the private network. .

According to another embodiment of the mobile router routing method of the present invention,
The destination address of the first data packet transmitted from the counterpart terminal includes the node address of the mobile terminal,
For the third step, it is also preferable to receive a second data packet in response to the first data packet from the home agent.

According to another embodiment of the mobile router routing method of the present invention,
Regarding the second step, the data packet received from the home agent is the first data packet transmitted from the counterpart terminal, and the first data packet includes the node address of the mobile terminal as the destination address. And
Regarding the third step, it is also preferable that the data packet received from the mobile terminal is a second data packet that is a reply to the first data packet.

  According to another embodiment of the mobile router routing method of the present invention, the private network is a carrier network, and the carrier network includes an access network and / or a satellite communication network in the core network. preferable.

According to the present invention, a home agent and a mobile router are arranged in a private network, and a mobile terminal transmits a data packet transmitted from a counterpart terminal outside the private network to a system connected to the mobile router via the mobile network. A mobile router that performs route control for incoming calls to mobile terminals,
Network address conversion means for mutually converting the node address of the mobile terminal and the home address for the mobile terminal for data packets encapsulated and exchanged with the private network,
Setting information storage means for storing a mobile network address;
Downlink packet transfer means for decapsulating a data packet received from a home agent and transmitting the data packet to a mobile terminal via a mobile network;
An uplink packet transfer means for encapsulating a data packet received from a mobile terminal via a mobile network and transmitting the data packet to a home agent via a private network;
Address determination means for determining whether or not the source address of the data packet is included in the mobile network address set in the setting information storage means for the upstream packet transfer means;
And an address translation control unit that instructs the network address translation unit not to perform address translation when it is determined to be true by the address judgment unit.

According to another embodiment of the mobile router of the present invention,
The destination address of the first data packet transmitted from the counterpart terminal includes the node address of the mobile terminal,
The address translation control means preferably instructs not to perform address translation on the second data packet returned in response to the first data packet.

According to another embodiment of the mobile router of the present invention,
It further has a location registration means for requesting location registration to the home agent,
The setting information storage means preferably stores the mobile network address whose location is registered by the location registration means.

  According to another embodiment of the mobile router of the present invention, the private network is preferably a carrier network, and the carrier network preferably includes an access network and / or a satellite communication network in the core network.

According to the present invention, a home agent and a mobile router are arranged in a private network, and a mobile terminal connects a data packet transmitted from a partner terminal outside the private network to a system connected to the mobile router via the mobile network. A program for causing a computer installed in a mobile router to perform route control to be received by a mobile terminal,
Network address conversion means for mutually converting the node address of the mobile terminal and the home address for the mobile terminal for data packets encapsulated and exchanged with the private network,
Setting information storage means for storing a mobile network address;
Downlink packet transfer means for decapsulating a data packet received from a home agent and transmitting the data packet to a mobile terminal via a mobile network;
An uplink packet transfer means for encapsulating a data packet received from a mobile terminal via a mobile network and transmitting the data packet to a home agent via a private network;
Address determination means for determining whether or not the source address of the data packet is included in the mobile network address set in the setting information storage means for the upstream packet transfer means;
An address translation control means for instructing the network address translation means not to perform address translation when it is determined to be true by the address judgment means;
And making the computer function .

  According to the route control method, mobile router, and program of the present invention, even when Mobile IP is built in a private network, a data packet transmitted from a partner terminal outside the private network is received by the mobile terminal. be able to.

1 is a system configuration diagram in which a mobile IP is applied in a private network. It is a sequence diagram of the packet transmitted from the mobile terminal in a prior art. It is a sequence diagram of the packet transmitted from the other party terminal in a prior art. It is a sequence diagram of a packet transmitted from a counterpart terminal in the present invention. It is a functional block diagram of the mobile router in this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 4 is a sequence diagram of a packet transmitted from the counterpart terminal in the present invention.

  According to FIG. 4, the mobile router 1 and the home agent 3 are arranged in the private network 5. The mobile terminal 2 connects to the mobile router 1 via the mobile network 53. With respect to such a system, according to the present invention, path control is performed so that the data packet transmitted from the counterpart terminal 4 outside the private network 5 is received by the mobile terminal 2.

  The private network 5 is a telecommunications carrier network. Further, the communication carrier network may be a network in which a core network and an access network and / or a satellite communication network are interconnected. In this case, the mobile router 1 may include a communication interface for the access network and a communication interface for the satellite communication network. When the mobile router 1 and the mobile terminal 2 via the mobile network move together, a handover can be performed between different communication networks operated by the same carrier.

(S401) The mobile router 1 transmits a location registration request message (BU: Binding Update) to the home agent 3. The location registration request message includes the following addresses.
Mobile terminal home address: HoA
Care-of address of mobile router 1: CoA
Network address of mobile network 53: MNW
(S402) Based on the location registration request message, the home agent 3 registers the home address HoA and the network address MNW in association with the care-of address CoA.
(S403) Then, the home agent 3 returns a location registration confirmation message (BA: Binding Acknowledge) to the mobile router 1.
A VPN (Virtual Private Network) is established between the mobile router 1 and the home agent 3 through S401 to S403.

(S410) Here, according to the present invention, the mobile router 1 sets the location-registered mobile network address MNW to cancel NAT translation. That is, it is set not to execute the conversion from the IP address of the mobile terminal to the home address of the mobile terminal as in S322 in FIG.

(S411) The counterpart terminal 4 transmits a data packet to the mobile terminal 2. This data packet is transferred to the home agent 3 via the management router of the carrier network. This data packet has the following header:
Source address: cn (IP address of the partner terminal)
Destination address: mnn (IP address of mobile terminal)

(S412) The home agent 3 passes the data packet through the IP tunnel established for the mobile router 1. The data packet is encapsulated and transferred, and has the following header.
Encapsulated source address: HA (IP address of home agent)
Destination address: CoA (care-of address)
Source address: cn (IP address of the partner terminal)
Destination address: mnn (IP address of mobile terminal)

(S413) The mobile router 1 decapsulates the received data packet. Then, the data packet is transmitted to the terminal 2. This data packet has the following header.
Source address: cn (IP address of the partner terminal)
Destination address: mnn (IP address of mobile terminal)

(S421) In response to this, the mobile terminal 2 returns a data packet for the counterpart terminal 4 to the mobile router 1 via the mobile network 53. This data packet has the following header:
Source address: mnn (IP address of mobile terminal)
Destination address: cn (IP address of partner terminal)

(S422) The mobile router 1 determines whether or not the transmission source address of the received data packet is included in the mobile network address stored in S410. According to FIG. 4, the source address mnn is included in the mobile network address MNW. Therefore, no address translation is performed on the data packet.

  Here, when the transmission source address mnn of the received data packet is not included in the mobile network address MNW, a sequence similar to FIG. 2 described as the conventional technique is executed. That is, it can be considered that the data packet of the transmission source address not set in the mobile network address MNW is transmitted from the mobile terminal 2 to the counterpart terminal 4. That is, the operation of canceling the NAT conversion in the present invention is directed to the uplink data packet that is a reply to the downlink data packet transmitted from the counterpart terminal 4 to the mobile terminal 2.

(S423) The mobile router 1 passes the data packet through the IP tunnel established for the home agent 3 without performing NAT conversion on the received data packet. This data packet has the following header.
Encapsulated source address: CoA (care-of address)
Destination address: HA (IP address of home agent)
Source address: mnn (IP address of mobile terminal)
Destination address: cn (IP address of partner terminal)

(S424) The home agent 3 decapsulates the received data packet. Then, the data packet is transmitted to the counterpart terminal 4. This data packet has the following header.
Source address: mnn (IP address of mobile terminal)
Destination address: cn (IP address of partner terminal)

  According to FIG. 4, in the counterpart terminal 4, the destination address of the data packet transmitted in S411 is the IP address mnn of the mobile terminal, and the source address of the data packet received in S424 is also the IP address mnn of the mobile terminal. is there. Therefore, the counterpart terminal 4 can receive the data packet.

  FIG. 5 is a functional configuration diagram of the mobile router in the present invention.

  According to FIG. 5, the mobile router 1 has a carrier network interface 101 and a mobile network interface 102. In addition, the mobile router 1 includes a location registration unit 111, an uplink packet transfer unit 112, a downlink packet transfer unit 113, and a network address conversion unit 114. Furthermore, the mobile router 1 according to the present invention includes a setting information storage unit 121, an address determination unit 122, and an address conversion control unit 123. These functional components excluding the communication interface are realized by executing a program that causes a computer mounted on the mobile router to function.

  The location registration unit 111 transmits a location registration request message to the home agent and receives a location registration response message. The processes of S401 to S403 in FIG. 4 are executed. Here, the mobile network address MNW whose location is registered is output to the setting information storage unit 121.

  The setting information storage unit 121 stores the mobile network address whose location is registered by the location registration unit 111. The process of S410 in FIG. 4 is executed. The IP address of the mobile terminal included in this mobile network address is set so as to cancel NAT conversion in the uplink packet returned to the downlink packet.

  The downlink packet transfer unit 113 decapsulates the data packet received from the home agent, and transmits the data packet to the mobile terminal via the mobile network. The process of S413 in FIG. 4 is executed.

  The address determination unit 122 determines whether the transmission source address of the uplink data packet is included in the mobile network address set in the setting information storage unit 121. The process of S422 in FIG. 4 is executed. The determination result is output to the address translation control unit 123.

  The address translation control unit 123 instructs the network address translation unit 114 not to perform address translation when it is determined to be true by the address determination unit 121. The process of S422 in FIG. 4 is executed.

  The network address conversion unit 114 has a function of mutually converting the node address of the mobile terminal and the home address for the mobile terminal for the data packet to be transmitted to the private network. The network address conversion unit 114 switches the presence / absence of network address conversion based on the control from the address conversion control unit 123. The process of S423 in FIG. 4 is executed.

  The upstream packet transfer unit 112 encapsulates the data packet output from the network address conversion unit 114 and transmits the data packet to the home agent 3 via the private network 5.

  As described above in detail, according to the route control method, mobile router, and program of the present invention, even when the mobile IP is built in the private network, it is transmitted from the counterpart terminal outside the private network. Data packets can be received by the mobile terminal.

  Various changes, modifications, and omissions of the above-described various embodiments of the present invention can be easily made by those skilled in the art. The above description is merely an example, and is not intended to be restrictive. The invention is limited only as defined in the following claims and the equivalents thereto.

DESCRIPTION OF SYMBOLS 1 Mobile router 101 Network operator network interface 102 Mobile network interface 111 Location registration part 112 Up packet transfer part 113 Down packet transfer part 114 Network address conversion part 121 Setting information storage part 122 Address determination part 123 Address conversion control part 2 Mobile terminal 3 Home agent 4 Partner terminal 5 Private network, carrier network 50 Core network 51 Access network 52 Satellite communication network 53 Mobile network

Claims (9)

A home agent and a mobile router are arranged in a private network, and a mobile terminal receives a data packet transmitted from a partner terminal outside the private network for the system connected to the mobile router via the mobile network. A route control method for a mobile router,
The mobile router has a function of mutually converting a node address of the mobile terminal and a home address for the mobile terminal for data packets encapsulated and exchanged with the private network,
A first step in which the mobile router stores a mobile network address for the mobile terminal;
A second step in which the mobile router decapsulates a data packet received from the home agent and forwards the data packet to the mobile terminal via the mobile network;
A third step of receiving a data packet from the mobile terminal via the mobile network and determining whether a source address of the data packet is included in a stored mobile network address;
And a fourth step of encapsulating the data packet without performing address translation when it is determined to be true, and transmitting the data packet to the home agent via a private network. The mobile router routing control method. Regarding the second step, the data packet received from the home agent is a first data packet transmitted from the counterpart terminal , and the first data packet includes a destination address of the mobile terminal. Node address is included,
The mobile router according to claim 1, wherein in the third step, the data packet received from the mobile terminal is a second data packet that is a reply to the first data packet. Route control method. Before the first step, requesting the home agent for location registration;
The mobile router path control method according to claim 1 or 2, characterized in that the mobile network address whose location is registered is stored in the first step. The private network is a carrier network;
4. The mobile router path control method according to claim 1, wherein the communication carrier network includes an access network and / or a satellite communication network in a core network. A home agent and a mobile router are arranged in a private network, and a mobile terminal receives a data packet transmitted from a partner terminal outside the private network for the system connected to the mobile router via the mobile network. A mobile router that executes routing control,
Network address conversion means for mutually converting a node address of the mobile terminal and a home address for the mobile terminal for data packets encapsulated and exchanged with the private network;
Setting information storage means for storing the mobile network address;
A downlink packet transfer means for decapsulating a data packet received from the home agent and transmitting the data packet to the mobile terminal via a mobile network;
An uplink packet transfer means for encapsulating a data packet received from the mobile terminal via a mobile network and transmitting the data packet to the home agent via a private network;
Address determination means for determining whether the source address of the data packet is included in the mobile network address set in the setting information storage means for the uplink packet transfer means;
A mobile router comprising: an address translation control unit that instructs the network address translation unit not to perform address translation when it is determined to be true by the address determination unit. The destination address of the first data packet transmitted from the counterpart terminal includes the node address of the mobile terminal,
6. The mobile router according to claim 5, wherein the address translation control unit instructs not to perform address translation on the second data packet returned in response to the first data packet. A location registration means for requesting location registration to the home agent;
The mobile router according to claim 5 or 6, wherein the setting information storage unit stores a mobile network address whose location is registered by the location registration unit. The private network is a carrier network;
The mobile router according to any one of claims 5 to 7, wherein the communication carrier network includes an access network and / or a satellite communication network in a core network. A home agent and a mobile router are arranged in a private network, and a mobile terminal receives a data packet transmitted from a partner terminal outside the private network for the system connected to the mobile router via the mobile network. A program for causing a computer mounted on a mobile router to execute routing control to function,
Network address conversion means for mutually converting a node address of the mobile terminal and a home address for the mobile terminal for data packets encapsulated and exchanged with the private network;
Setting information storage means for storing the mobile network address;
A downlink packet transfer means for decapsulating a data packet received from the home agent and transmitting the data packet to the mobile terminal via a mobile network;
An uplink packet transfer means for encapsulating a data packet received from the mobile terminal via a mobile network and transmitting the data packet to the home agent via a private network;
Address determination means for determining whether the source address of the data packet is included in the mobile network address set in the setting information storage means for the uplink packet transfer means;
An address translation control means for instructing the network address translation means not to perform address translation when determined to be true by the address judgment means;
A program for a mobile router characterized by causing a computer to function as

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