JP4500831B2 - Communication system, control apparatus, router and communication method using network-based IP mobility protocol - Google Patents

Description

  The present invention relates to a communication technique using a network-based IP mobility protocol.

  In recent years, research and development of mobility support in the IP layer such as Mobile IPv6 (Internet Protocol version 6) has been active. Mobile IP is a network layer protocol that is the third layer in the OSI (Open Systems Interconnection) basic reference model established by ISO (International Organization for Standardization). This is a technology that conceals communication interruptions and continues communication.

  TCP / IP, which is a communication protocol generally used in the current Internet, means a position on a network as well as an IP address as an identifier. For this reason, when a node connected to a certain network is changed to another network, the IP address changes, and the session cannot be continued.

  Therefore, Mobile IP assigns a unique address to a node and replaces it with the IP address actually used in the TCP / IP stack. Provides a mechanism that makes it appear as if it is communicating (for example, see Non-Patent Document 1).

  The Mobile IP includes a mobile node (Mobile Node, mobile terminal, hereinafter referred to as “MN”), a home agent (Home Agent, hereinafter referred to as “HA”), a correspondent node (Correspondent Node, an opposite node, hereinafter, “CN”). ”)).

  The MN always has an invariable address called a home address (hereinafter referred to as “HoA”), and the node that manages the address is the HA. When the MN connects to a network other than the home link, which is a link of the HA, an address called a care-of address (care-of-address, hereinafter referred to as “CoA”) is actually used for communication. For example, it is obtained by router advertisement (Router Advertisement, hereinafter referred to as “RA”) with stateless address automatic setting or DHCP (Dynamic Host Configuration Protocol) v6 with stateful address automatic setting. The MN notifies the HA of the CoA obtained here with a message of a registration request (Binding Update, hereinafter referred to as “BU”).

  As a result, when a node (= CN) that wants to communicate with the MN transmits a packet to the HoA, the HoA is a link address managed by the HA, and therefore reaches the HA once. At that time, the HA transfers to the CoA associated with the HoA. As a result, the MN can always communicate with HoA. In the MN, an application operating on the MN always uses the IP address called HoA for communication.

  CoA is used as the source address or destination address of the actual IPv6 packet. Further, in order to conceal the movement from the upper application, techniques such as IPv6 in IPv6 encapsulation and mobility header are used. As a result, HoA is notified to the application, and the IPv6 address (CoA) actually used is concealed.

  In Mobile IPv6, when route optimization is performed for communication with a CN, after signaling for security called a test procedure (Return Routability, hereinafter referred to as “RR”), the MN performs BU for route optimization. Will be sent to CN. RR is a function in which the MN notifies the CN that the correspondence between HoA and CoA is correct.

  The RR is a message sent from the MN to the CN, a HoTI (Home Test Init) via the HA, a CoTI (Care of Test Init) sent directly to the CN, and a message sent back from the CN to the MN. , HoT (Home Test) via HA, and CoT (Care of Test) returned directly to MN. When this RR procedure ends normally, the MN transmits a BU to notify the CN of its own CoA. As a result, the CN can know the correct CoA of the MN, and can directly send the packet to the MN instead of the redundant route via the HA, that is, the route can be optimized.

  In other words, until this route optimization is completed, the communication between the MN and the CN passes through the HA, and the CN and the HA are sent with normal IPv6, and the packet between the HA and the MN is IPv6 in IPv6 encapsulated and delivered. The After route optimization, packets are directly delivered between the MN and CN, and HoA is described in the option header.

  MIPv6 and MIP-derived protocols are called host-based mobility protocols because they control mobility based on the MN. On the other hand, a network-based IP mobility protocol that performs mobility control on the network side and enables the MN to move without installing a special protocol for movement has been further proposed by IETF (Internet Engineering Task Force). (For example, refer nonpatent literature 2).

This eliminates the need for the MN to handle CoA, eliminates packet encapsulation by the MN, and eliminates signaling for movement by the MN.
The handover procedure of the first network-based IP mobility protocol will be described with reference to FIG.

  First, after the movement, in S601, the MN moves to the router and mobile access gateway (Mobile Access Gateway, hereinafter referred to as “MAG”) of the link of the destination denoted as “NewMAG” in FIG. A network configuration (network setting) request message such as a solicitation, a router request, hereinafter referred to as “RS”) or a DHCP request is transmitted.

MAG is a router that relays between a MN that has moved to a link and a root router, which is a control device that controls IP Mobile, and a local mobility anchor (hereinafter referred to as “LMA”). It is.
The LMA controls a plurality of MAGs connected via a network. The LMA manages the identifiers and IP addresses of the MN and MAG in the storage unit.
The MAG also manages the identifiers and IP addresses of the MN and LMA in the storage unit. Information managed by these MAGs can be acquired by communicating with the LMA.
Between MAG and LMA, packets are IPv6 in IPv6 encapsulated, and a header is attached with reference to information managed in the storage unit, so that tunneling can be performed and routing can be performed correctly.
In the network as described above, it is assumed that the MN transmits, for example, an RS here to the MAG of the same link at the movement destination.

  When MAG (NewMAG) receives RS from MN, it transmits location registration (location registration request) to LMA in S602.

  When the LMA receives the location registration, it detects that it is a handover, transmits a routing setup to the MAG (NewMAG) in S603, and sets up a tunnel path between the MAG (NewMAG) and the LMA.

  Here, the setting of the tunnel route means that the LMA encapsulates the packet for the MN and transmits the destination as the MAG, and the received MAG is set to remove the capsule and forward it to the MN.

  Upon receiving this routing setup, the MAG (NewMAG) transmits a confirmation routing setup Ack (Acknowledgement) to the LMA in S604.

  Also, the LMA that has received the location registration from the MAG (NewMAG) transmits a confirmation location registration Ack to the MAG (NewMAG) in S605.

  In step S606, the MAG (NewMAG) transmits RA to the MN, and the MN performs address configuration (address setting).

  Thereafter, in S607, the MN uses DAD (Duplicate Address Detection, hereinafter referred to as “DAD”) to NA (Neighbor Advertisement, hereinafter referred to as “NA”) to MAG (NewMAG). Confirm that the address is single and complete the address configuration. Further, the MAG (NewMAG) transmits an MN address setup to the LMA in S608, and in S609, the LMA transmits an MN address setup Ack to the MAG (NewMAG).

  As a result of completion of the LMA-MAG tunnel path setting and the MN address configuration, the packet can reach the MN. This is the handover method of the network-based mobility protocol. That is, since the packet addressed to the MN is sent via the LMA, the tunnel can be routed to the MN by completing the tunnel between the LMA and the MAG.

  In addition, a Proxy Mobile IP method using a network-based IP mobility protocol in which MAG performs a proxy (proxy) function of MN in Mobile IP using AAA (Authentication Authorization Accounting, authentication, authorization, and accounting) servers that perform authentication and the like is also proposed. (For example, see Non-Patent Document 3).

  A handover procedure according to the Proxy MobileIP system of the second network-based IP mobility protocol will be described with reference to the sequence diagram of FIG.

  First, in S701, the MN transmits authentication information including the MN-ID that is its own ID to the MAG (NewMAG) after movement.

  In step S702, the MAG that has received the authentication information from the MN (NewMAG) transmits the authentication information including the MN ID to the AAA server that is the authentication server for authentication.

The AAA server that has received the authentication information from the MAG (NewMAG) confirms the validity of the MN in S703, and returns a policy profile if it is determined to be valid.
This policy profile includes MN address configuration information such as information such as a home network prefix and a configuration method (stateless setting or stateful setting).

  The MAG (NewMAG) that has received the policy profile including the address configuration information from the AAA server can transmit the RA to the MN. In step S704, the RA is transmitted to the MN.

  The MN that has received the RA from the MAG (NewMAG) may configure this address and perform NA or DAD in S705.

When the MAG (NewMAG) transmits the RA, in order to generate a tunnel with the LMA, a proxy registration request (Proxy Binding Update) is transmitted to the LMA in S706.
This message includes the MN-ID, the home prefix of the MN, and the like.

  The LMA that has received the Proxy Binding Update returns a Proxy Binding Update Ack to the MAG (NewMAG) in S707.

  In this way, a bidirectional tunnel is generated between the LMA and MAG, and routing to the MN becomes possible.

In Mobile IPv4, a system that provides a function necessary for a CN as a proxy to a terminal that does not have the MIPv4 function for communicating with the MN is disclosed (for example, see Patent Document 1).
JP 2001-2224070 A Request for Comments (RFC) 3775, “Mobility Support in IPv6” Internet Draft “draft-gearetta-netlmm-dt-protocol” Internet Draft “draft-sgandave-mip6-proxymip6”

  However, when the mobile terminal of the first and second network-based IP mobility protocol communicates with the mobile terminal of Mobile IPv6 and attempts to optimize the route, signaling such as RR and BU is transmitted to the mobile terminal of the network-based IP mobility protocol. Fly away. Further, after route optimization, an option header is attached, and the overhead of the header becomes large. As a result, the band of the last one hop (in many cases, a radio link), which is the narrowest band, cannot be used efficiently.

  Further, even if the function of Patent Document 1 is extended for IPv6 and used for MAG, the network-based IP mobility protocol has a handover, and thus cannot be processed after the handover. This is because the MAG after the handover does not have the data for BC optimization, BC (Binding Cache), and cannot be used.

  The present invention has been made to solve the above-described problems, and its object is to provide the last one hop that is the narrowest band when communicating with a mobile terminal of Mobile IPv6 in the network-based IP mobility protocol. A communication system, a control device, a router, and a communication method thereof using a network-based IP mobility protocol that allows efficient use of the bandwidth of the network and enables communication with route optimization even after handover .

In view of such a situation, the communication system using the network-based IP mobility protocol according to the first invention uses the network-based IP mobility protocol, and data is transmitted from routers belonging to the same link by addresses uniquely assigned to mobile terminals. Is a communication system that switches communication under the control of a control device when the mobile terminal moves to another network.
The router stores a binding cache that is communication information about the mobile terminal for relaying using the Mobile IP protocol, and the router receives the mobile terminal and the Mobile IP protocol managed by the router. In the case of communication with a terminal to be used, the mobile terminal and the terminal using the Mobile IP protocol are relayed.

  In the communication system using the network-based IP mobility protocol according to the second aspect of the present invention, when the mobile terminal moves to another router network, the control device transfers the mobile terminal to the source router. A transfer instruction notification is transmitted so as to transfer the binding cache of the mobile terminal to the router to which the mobile terminal has moved.

  Further, in the communication system using the network-based IP mobility protocol according to the third invention, when the mobile terminal communicates with another terminal through a plurality of interfaces, the source router A forwarding policy (routing policy) is also transmitted to the destination router together with the binding cache.

According to a fourth aspect of the present invention, there is provided a control device that uses a network-based IP mobility protocol, and a mobile terminal performs communication by transmitting and receiving data from a router belonging to the same link using a uniquely assigned address. A control device that performs control to switch communication when a terminal moves to another network,
Communication means for receiving a notification including the identifier of the mobile terminal and the identifier or IP address of the router from the router in the network to which the mobile terminal is moving, and holding communication information regarding the router and the mobile terminal that perform relaying The storage means, and the mobile terminal's identifier included in the notification from the router, the communication information of the mobile terminal is referred to the storage means, and the information on the destination router and the data transfer between the routers is updated. Relaying by the mobile IP protocol and the mobile IP protocol including the identifier of the mobile terminal instructing the transfer of data to the destination router and the identifier of the destination router or the IP address of the destination router and the IP address. Binding cache which is communication information about the mobile terminal to perform Control means for generating a transfer instruction notification, wherein the communication means transmits the buffer transfer instruction notification and the binding / cache transfer instruction notification to the source router.

A router according to a fifth aspect of the invention is a router that uses a network-based IP mobility protocol and performs data transmission / reception with a mobile terminal belonging to the same link that performs communication using a uniquely assigned address under the control of a control device. And
Storage means for storing a binding cache, which is communication information related to the mobile terminal for relaying using the Mobile IP protocol, and the received data between the mobile terminal managed by itself and a terminal using the Mobile IP protocol In the case of communication, it is characterized by comprising control means for relaying between the mobile terminal and a terminal using the Mobile IP protocol.

  The router according to a sixth aspect of the invention transfers the binding cache to the destination router of the mobile terminal when the control means receives the binding cache transfer instruction notification from the control device. It is characterized by that.

  In the router according to the seventh invention, when the mobile terminal communicates with another terminal via a plurality of interfaces, the control means sends a transfer policy (routing) for each interface to the destination router. Policy) is also transferred together with the binding cache.

According to an eighth aspect of the present invention, there is provided a communication method using a network-based IP mobility protocol, causing a mobile terminal to transmit and receive data from a router belonging to the same link using a uniquely assigned address. When moving to a network, a communication method for causing a control device to perform control for switching communication of the mobile terminal,
When the received data is communication between the mobile terminal managed by the mobile station and a terminal using the Mobile IP protocol, the router relays the mobile terminal and the terminal using the Mobile IP protocol. the rows that have, in the case where the mobile terminal has moved to a network of other of said routers, said controller, to a mobile source of the router of the mobile terminal, to the mobile terminal for relaying the mobile IP protocol A transfer instruction notification is transmitted so as to transfer the binding cache as communication information to the router to which the mobile terminal has moved .

  By using the present invention, the router (MAG) performs the Mobile IP proxy function, so that the mobile terminal (MN) in the network-based IP mobility protocol domain does not need to receive packets such as RR and BU by Mobile IP signaling. In the last one hop, which is a narrow band, unnecessary signaling is skipped and header overhead is increased, and the control device (LMA) is directed to the destination router relative to the source router of the mobile terminal. Since the transfer instruction notification is transmitted so as to transfer the communication information (binding cache) related to the mobile terminal to be relayed, communication is possible with the route optimized even after the mobile terminal moves (handover).

  Hereinafter, embodiments of the present invention will be described together with illustrated examples.

[First Embodiment]
FIG. 1 is a diagram showing a schematic configuration of a network in the present embodiment.
FIG. 2 is a block diagram showing the configuration of the MAG in this embodiment.
FIG. 3 is a block diagram showing the configuration of the LMA in this embodiment.
FIG. 4 is a diagram illustrating an initial communication state according to the present embodiment together with a header example.
FIG. 5 is a sequence diagram showing a processing procedure in the present embodiment.

  As shown in FIG. 1, in the present embodiment, NetLMM-MN1 (a mobile terminal using a network-based IP mobility protocol) is described as being initially located on the MAGa2 link and moving to the MAGb3 link.

The MAG in FIG. 2 and the LMA in FIG. 3 will be described below.
As shown in FIG. 2, the MAGs 2 and 3 include a NetLMM communication unit 11, a network communication unit 12, a network-based IP mobility protocol processing unit 13 that performs control related to the network-based IP mobility protocol, and a proxy function related to Mobile IP. The mobile IP proxy processing unit 14 that performs the storage, and a storage unit 15 that includes a database unit and a temporary storage unit that can be temporarily stored.

  As shown in FIG. 3, the LMA 8 temporarily stores a NetLMM communication unit 16, a network communication unit 17, a network-based IP mobility protocol processing unit 18 that controls the network-based IP mobility protocol, and a database unit. And a storage unit 19 including a temporary storage unit capable of performing the above-described operation.

  NetLMM-MN1 is located in MIP-MN5 (currently located on the link of Router 6 which is a link not managed by HA4, that is, a foreign link (external link)), which is managed by HA4. Communication is started when MAGa2 is under control. Here, it is assumed that the processing of MAGa2 and LMA8 has been completed, and the tunnel for NetLMM-MN1 has been set between MAGa2 and LMA8.

When NetLMM-MN1 and MIP-MN5 start communication, communication is first performed via HA4.
That is, as shown in FIG. 4, communication between NetLMM-MN1 and MAGa2 is performed with normal IPv6 as the source address and NetLMM-MN1 as the destination address and HoA of MIP-MN5.

  Furthermore, between MAGa2 and LMA8, the tunnel base setting allows the MAGa2 or LMA8 network-based IP mobility protocol processing units 13 and 18 to add the header address outside the packet to be the addresses of MAGa2 and LMA8 for communication. Done.

  Further, the outer header is removed between LMA8 and HA4, and communication is performed as normal IPv6.

  Next, communication between HA4 and MIP-MN5 is performed by Mobile IP tunnel setting in which the address of the outer header is set to CoA between HA4 and MIP-MN5.

  When MIP-MN5 and NetLMM-MN1 start communication, MIP-MN5 first transmits HOTI and COTI to NetLMM-MN1 in S101, S102, and S103 for route optimization.

  The packet addressed to NetLMM-MN1, HOTI, arrives at MAGa2 via HA4 and LMA8 and COTI via LMA8.

FIG. 6 is a flowchart showing a procedure of Mobile IP proxy function processing in MAGs 2 and 3.
HOTI and COTI are received from the MAGa2 communication means 12, and these packets are output to the Mobile IP proxy processing unit 14. The Mobile IP proxy processing unit 14 of MAGa2 determines whether to perform Mobile IP proxy function processing according to the flowchart shown in FIG.

  First, in S201, the Mobile IP proxy processing unit 14 determines whether or not it is addressed to a terminal managed by itself. If “Yes” in S201, the process proceeds to S202, and if “No”, the process proceeds to S205.

  In S202, the Mobile IP proxy processing unit 14 determines whether or not the received packet is related to MIP. If “Yes” in S202, the Mobile IP proxy processing unit 14 performs MIP proxy processing in S203.

  If “No” in S202, the Mobile IP proxy processing unit 14 performs normal IP routing in S204.

  If “No” in S201, the Mobile IP proxy processing unit 14 proceeds to the process of S205, but determines whether or not the terminal is managed by itself.

  If “No” in S205, the Mobile IP proxy processing unit 14 performs normal IP routing in S208.

  If “Yes” in S205, in S206, the Mobile IP proxy processing unit 14 searches for whether or not the storage unit 15 has a BC related to the communication partner.

  If “No” in S206, the Mobile IP proxy processing unit 14 performs normal IP routing in S209.

  If “Yes” in S206, in S207, the Mobile IP proxy processing unit 14 provides the MIP proxy function.

  Here, since the destinations of the received HOTI and COTI are destined for NetLMM-MN1, the Mobile IP proxy processing unit 14 determines “Yes” in S201, and proceeds to S202. In S202, the Mobile IP proxy processing unit 14 determines that these packets are MIP-related packets, and thus “Yes”. The process proceeds to S203 and determines that Mobile IP proxy function processing is performed.

  Therefore, instead of NetLMM-MN1, Mobile IP proxy processing unit 14 generates HOT for HOTI and COT for COTI, generates the address of NetLMM-MN1 as a source address, and communication means. 12, the HOT is returned to the MIP-MN 5 via the LMA 8 and the HA 4 in S 104 and S 105, and the COT is returned to the MIP-MN 5 via the LMA 8 in S 106.

  Since the MIP-MN 5 has received the HOT and COT, a BU is generated based on the information in S107, and the BU is transmitted to the NetLMM-MN1.

  Upon receiving the BU, the Mobile IP proxy processing unit 14 of the MAGa2 determines whether to perform Mobile IP proxy function processing according to the flow of FIG. Here, the Mobile IP proxy processing unit 14 determines “Yes” because the BU destination is NetLMM-MN1 in the determination of S201, and determines “Yes” because the packet is related to MIP in S202. Then, the process proceeds to S203 to determine that Mobile IP proxy function processing is to be performed. Therefore, the Mobile IP proxy processing unit 14 of MAGa2 generates, for example, a BC as shown in FIG. 7 in the storage unit 15 based on the BU. Since this BC is for NetLMM-MN1, it is stored in association with the ID or IP address of NetLMM-MN1.

  If necessary, the Mobile IP proxy processing unit 14 returns a BA (Binding Acknowledgment, hereinafter referred to as “BA”) to the MIP-MN 5 instead of the NetLMM-MN 1 in S108. As a result of these processes, MAGa2 performs route optimization, holds BC in the storage unit 15, and can handle packets with an option header of the MIPv6 specification.

  A destination option header is attached to a packet addressed from MIP-MN 5 to NetLMM-MN 1 after route optimization. Upon receiving this packet via LMA 8, MAGa 2 determines whether to perform Mobile IP proxy function processing according to the flow of FIG.

  Since this packet is addressed to NetLMM-MN1, in step S201, the Mobile IP proxy processing unit 14 determines “Yes”. Further, since this packet has an MIP specification option header, the Mobile IP proxy processing unit 14 determines “Yes” in S202, and performs the Mobile IP proxy function processing in S203. In this packet, the CoA of MIP-MN5 is the source address, the destination address is NetLMM-MN-IP, and the destination option header is HoA of MIP-MN5.

  The Mobile IP proxy processing unit 14 compares these pieces of information with the BC searched in the storage unit 15 from the IP address of the NetLMM-MN 1 and determines whether the packet is related to the BC. If so, replace the header. That is, the Mobile IP proxy processing unit 14 has a source address MIP-MN-HoA, a destination option header NetLMM-MN, and a format without an option header in the same manner as a normal IPv6 header. Forward.

  A packet addressed from NetLMM-MN1 to MIP-MN5 reaches MAGa2 as a normal IPv6 packet. Here, MAGa2 determines whether to perform Mobile IP proxy function processing according to the flow of FIG.

  In S201, the Mobile IP proxy processing unit 14 determines that this packet is not addressed to NetLMM-MN1, and proceeds to the processing in S205. In S205, since the Mobile IP proxy processing unit 14 determines that the packet is from the NetLMM-MN1, the process proceeds to S206. Next, in S206, when the Mobile IP proxy processing unit 14 searches the storage unit 15 using the IP address of NetLMM-MN1 as a key, a BC as shown in FIG. 7 is found. In S207, Mobile IP proxy function processing is performed. .

  This proxy processing rewrites the header of a packet whose source address is NetLMM-MN-IP and whose destination address is MIP-MN-HoA. That is, according to MIPv6, the source address may be left as it is, and NetLMM-MN-IP is used. The Mobile IP proxy processing unit 14 of MAGa2 recognizes that the CoA of the MIP-MN-HoA is MIP-MN-CoA from the BC information of FIG. 7, and uses the MIP-MN-CoA as the destination address and performs routing. MIP-MN-HoA is stored as the option header TYPE 2 and the packet is transferred to the Internet network 7 via the LMA 8.

  As a result of these processes, NetLMM-MN1 can communicate with MIP-MN5 without losing the advantages of the network-based IP protocol while performing route optimization.

FIG. 8 is a sequence diagram illustrating an example of a procedure of processing after handover in the present embodiment.
An example in which NetLMM-MN1 is handed over from MAGa2 to MAGb3 will be described with reference to FIG.

  In S301, NetLMM-MN1 transmits a message including its own identifier NetLMM-MN-ID to MAGb3 according to a normal procedure.

  In S302, the network-based IP mobility protocol processing unit 13 of the MAGb 3 creates a location registration including the NetLMM-MN-ID and transmits it to the LMA 8.

  The network-based IP mobility protocol processing unit 18 of the LMA 8 that has received the location registration transmits a routing setup for tunnel creation with the MAGb 3 including the NetLMM-MN-IP in S303. At this time, the network-based IP mobility protocol processing unit 18 of the LMA 8 transmits a BC transfer instruction including the ID of the new MAG MAGb3 and the ID of the NetLMM-MN1 to the MAGa 2 in S304.

  In the MAGa2 network-based IP mobility protocol processing unit 13 that has received the BC transfer instruction, the NetLMM-MN-ID included in the message is output to the Mobile IP proxy processing unit 14, and the Mobile IP proxy processing unit 14 receives the NetLMM- The BC related to NetLMM-MN1 in the storage unit 15 is extracted from the MN-ID, and is output to the network-based IP mobility protocol processing unit 13. The network-based IP mobility protocol processing unit 13 obtains this BC information in MAGb3 in S305. Forward to. Also, the Mobile IP proxy processing unit 14 deletes this BC information from the storage unit 15.

  The network-based IP mobility protocol processing unit 13 of the MAGb 3 that has received the routing setup from the LMA 8 creates a bidirectional tunnel of packets related to the NetLMM-MN-IP between the LMA 8 and the MAGb 3, and returns the routing setup Ack to the LMA 8 in S306. To do.

  Also, the network-based IP mobility protocol processing unit 13 of MAGb 3 that has received the BC information from MAGa 2 outputs the information to the Mobile IP proxy processing unit 14, and the Mobile IP proxy processing unit 14 stores the BC in the storage unit 15. Store.

  The network-based IP mobility protocol processing unit 18 of the LMA 8 that has received the routing setup Ack from the MAGb 3 returns the location registration Ack to the MAGb 3 in S307.

  Upon receiving the location registration Ack from the LMA 8, the network-based IP mobility protocol processing unit 13 of the MAGb 3 transmits a message for configuring the NetLMM-MN address to the NetLMM-MN1 in S308. This message may be RA, DHCP-Advize, DHCP-Reconfigure, or the like.

  In this way, NetLMM-MN1 becomes communicable via MAGb3.

  Thereafter, the Mobile IP proxy processing unit 14 of MAGb3 performs processing according to the flow of FIG. 6 when receiving a packet, similarly to MAGa2. As a result, the Mobile IP proxy processing unit 14 processes the packet addressed to NetLMM-MN1 with the option header coming from MIP-MN5, and delivers it to NetLMM-MN1 as a normal IPv6 packet.

  Also, the Mobile IP proxy processing unit 14 processes the packet addressed to the MIP-MN-HoA received from the NetLMM-MN1 with reference to the BC of the storage unit 15 and performs the Mobile IP proxy function processing, thereby obtaining the Mobile IPv6 specification option header. And send it to the MIP-MN-CoA.

  In this way, even if a terminal having MIP function, a terminal using MIP-MN5 and a network-based IP mobility protocol, and NetLMM-MN1 communicate, NetLMM-MN1 does not reach MIP signaling, and Even if the packet with the option header does not arrive and the route is optimized, NetLMM-MN1 can perform communication even if it is handed over.

[Second Embodiment]
In the present embodiment, an example is shown in which a NetLMM-MN, which is a terminal that communicates with a terminal of MultipleCoA, which is a derived protocol of Mobile IP, and a normal MIP terminal, performs handover from MAGa to MAGb.

  MultipleCoA is a protocol for extending Mobile IP and realizing multi-home. The MN of MultipleCoA has a plurality of communication means, and can access the Internet from a plurality of networks. And CN can be registered. At this time, the BC registers the BID (Binding ID) assigned to each communication interface on the MN in association with the CoA. As a result, the CN can send a packet to any one of the plurality of CoAs of the MN with reference to the BC. Even if the packet arrives from any CoA, the BC verifies the matching with the HoA. It becomes possible.

FIG. 9 is a diagram showing a schematic configuration of a network in the present embodiment.
FIG. 10 is a diagram showing a communication state in the present embodiment.
FIG. 11 is a diagram showing addresses in the present embodiment.
FIG. 12 is a diagram showing BC held by MAGa in the initial state in the present embodiment.
FIG. 13 is a sequence diagram illustrating a processing procedure in the present embodiment.

In the present embodiment, paying attention to handover, the description of the part where MAGa shown in the first embodiment generates BC will be omitted.
As shown in FIG. 9, in the initial state, the NetGaM-MNa 22 and the NetLMM-MNb 23 are located on the MAGa 21 link.

  The LMA 24 manages MAGa 21 and MAGb 25. As a MultipleCoA terminal, an MCoA-MN 26 is located on the link of Router-a 27 and Router-b 28 and is connected to the LMA 24 via the Internet 29. In addition, an MIP terminal, MIP-MN 30 is located on the link of Router-c 31, and HAa 32 and HAb 33 exist as HA.

As shown in FIG. 10, NetLMM-MNa 22 makes a videophone call as indicated by MIP-MN 30 and type “GAME” while making a videophone call as indicated by types “Video” and “Voice” with MCoA-MN 26. It is in a state of being. The NetLMM-MNb 23 is in a state where a game is being played as indicated by the MIP-MN 30 and the type “GAME”.
Also, the IP address of each node shown in FIG. 9 is as shown in FIG.

  In the initial state, the MAGa 21 holds BC as shown in FIG. 12, and holds information as shown in FIG. 14 as a routing policy. FIG. 14 shows that in communication between NetLMM-MNa 22 and MCoA-MN 26, BID1 (that is, MCoA-MN-CoA1) is used for the video data stream, and BID2 (that is, MCoA-MN-CoA2) is used for the voice data stream. Is written to use. That is, BC relates to IP address information that can be used in the third layer of the OSI basic reference model, and the routing policy describes information related to the application and the IP address that is actually used.

  When the NetLMM-MNa 22 is handed over from the MAGa 21 to the MAGb 25 from the above state, first, in S401, the NetLMM-MNa 22 transmits a message including the NetLMM-MNa-ID that is its ID to the MAGb 25.

  In S402, the network-based IP mobility protocol processing unit 13 of the MAGb 25 transmits the location registration including the NetLMM-MNa-ID and the MAGb-ID that is the identifier of the MAGb 25 to the LMA 24.

  The network-based IP mobility protocol processing unit 18 of the LMA 24 that has received the location registration from the MAGb 25 transmits a routing setup to the MAGb 25 for generating the LMA 24-MAGb 25 tunnel in S403.

  In S404, the network-based IP mobility protocol processing unit 18 of the LMA 24 deletes the LMA 24-MAGa 21 tunnel (for NetLMM-MNa 22) from the MAGa 21 of the link where the NetLMM-MNa 22 is located before moving. Send a registration.

  Further, the network-based IP mobility protocol processing unit 18 of the LMA 24 transmits a buffer transfer instruction message to the MAGa 21 including the MAGb 25 ID, MAGb-ID, NetLMM-MNa22 ID, and NetLMM-MNa-ID. The BC transfer instruction message is also transmitted including the MAGb25 ID, MAGb-ID, NetLMM-MNa22 ID, and NetLMM-MNa-ID. These three messages (location deregistration, buffer transfer instruction, BC transfer instruction) may be combined and transmitted, or may be transmitted individually. At this time, the routing policy information is also transmitted together with the BC information.

  The network-based IP mobility protocol processing unit 13 of the MAGa 21 that has received these messages from the LMA 24 transmits the instruction information to the Mobile IP proxy processing unit 14 in S405, and the Mobile IP proxy processing unit 14 refers to the storage unit 15. Then, BC information related to NetLMM-MNa 22 (shown in FIG. 15 as part of FIG. 12) is extracted, output to the network-based IP mobility protocol processing unit 13, and transferred to the MAGb 25.

  Further, the network-based IP mobility protocol processing unit 13 of the MAGa 21 transmits a tunnel generation request message including the MAGa-ID and the NetLMM-MNa-ID to the MAGb 25. These two messages may be combined and transmitted, or may be transmitted individually.

  Upon receiving these messages from the MAGa 21, the network-based IP mobility protocol processing unit 13 of the MAGb 25 outputs the received BC information and routing policy regarding the NetLMM-MNa to the Mobile IP proxy processing unit 14, and the Mobile IP proxy processing unit 14 Stores the BC information and the routing policy in the storage unit 15.

  Further, the network-based IP mobility protocol processing unit 13 of the MAGb 25 performs tunnel setting between the MAGa 21 and the MAGb 25, and transmits a tunnel generation instruction and BC transfer Ack for confirmation to the MAGa 21 in S406.

  Thereafter, since the tunnel is set, the network-based IP mobility protocol processing unit 13 of the MAGa 21 starts to transfer the packets accumulated in the buffer addressed to the NetLMM-MNa 22 to the MAGb 25.

  The network-based IP mobility protocol processing unit 13 of the MAGb 25 that has received the routing setup from the LMA 24 sets a tunnel between the LMA 24 and the MAGb 25 and transmits the routing setup Ack to the LMA 24 in S407.

  The network-based IP mobility protocol processing unit 18 of the LMA 24 that has received the routing setup Ack from the MAGb 25 returns a location registration Ack to the MAGb 25 in S408.

  The network-based IP mobility protocol processing unit 13 of the MAGb 25 that has received the location registration Ack from the LAM 24 transmits a message for configuring (address setting) the address of the NetLMM-MNa 22 to the NetLMM-MNa in S409. This message may be RA, DHCP-Advize, DHCP-Reconfigure, or the like.

  In this way, NetLMM-MNa 22 is in a communicable state even after handover.

  The MAGb 25 that is in a state where the route optimization communication is possible by having the BC related to the MIP terminal performs processing according to the flow of FIG.

  As a result, for example, the Mobile IP proxy processing unit 14 of the MAGb 25 processes the packet addressed to the NetLMM-MNa 22 with the option header received from the MIP-MN 30 and performs the Mobile IP proxy function process to obtain the NetLMM-MNa 22 as a normal IPv6 packet. Will be delivered to.

  Further, the Mobile IP proxy processing unit 14 of the MAGb 25 performs Mobile IP proxy function processing on a packet addressed to the MIP-MN-HoA from the NetLMM-MNa 22, attaches an option header of the Mobile IPv6 specification, and MIP-MN- Send to CoA.

  Further, the Mobile IP proxy processing unit 14 of the MAGb 25 processes the packet addressed to the NetLMM-MNa 22 with the option header received from the MCoA-MN 26, and delivers the packet to the NetLMM-MNa 22 as a normal IPv6 packet.

  When the Mobile IP proxy processing unit 14 of the MAGb 25 receives a packet addressed to MCoA-MN-HoA from the NetLMM-MNa 22, it performs Mobile IP proxy function processing, attaches an option header of the Mobile IPv6 specification, and MCoA for the video stream. -For MN-CoA1, the Voice stream is transmitted to MCoA-MN-CoA2.

  The Mobile IP proxy process as described above is realized because the BC and the routing policy are transferred from the MAG before movement to the MAG of the movement destination.

  In this way, even in the embodiment in which the MIP-MN 30 and the MCoA-MN 26 communicate with the NetLMM-MNa 22, the MIP signaling does not reach the NetLMM-MNa 22, and the packet with the option header does not reach. The last one hop of the narrowest band can be effectively used, and communication is possible even if the NetLMM-MN is handed over after route optimization.

  By the way, even if the Proxy Mobile IP method described as the second network-based IP protocol of the prior art is applied to the present embodiment, the LMA controls the MAG and the MAG performs the Mobile IP proxy process. Similar effects can be obtained.

FIG. 16 is a sequence diagram when the Proxy Mobile IP method is applied to the handover of the present embodiment.
As shown in FIG. 16, when the NetLMM-MN moves to another MAG link, the destination MAG of the NetLMM-MN communicates with the AAA server for authentication, and the Proxy Binding Update is transmitted to the LMA. Send. In the subsequent processing, as in FIG. 13, under the control of the LMA, the BC, the buffer, etc. are transferred from the source MAG of the NetLMM-MN to the destination MAG, and the handover is completed.

  Note that the communication system, control device, router and communication method using the network-based IP mobility protocol of the present invention are not limited to the above-described illustrated examples, and may be variously within the scope of the present invention. Of course, changes can be made.

It is the figure shown about the schematic structure of the network in 1st Embodiment. It is the block diagram which showed the structure of MAG. It is the block diagram which showed the structure of LMA. It is the figure explaining the mode of the initial communication in 1st Embodiment with the example of the header. It is the sequence diagram which showed the procedure of the process in 1st Embodiment. It is the flowchart which showed the procedure of Mobile IP proxy function processing. It is an example of BC. It is the sequence diagram which showed the example of the procedure of the process in 1st Embodiment. It is the figure shown about the schematic structure of the network in 2nd Embodiment. It is the figure shown about the communication state in 2nd Embodiment. It is the figure shown about the address in 2nd Embodiment. It is the figure which showed BC which MAGa hold | maintains in the initial state in 2nd Embodiment. It is the sequence diagram which showed the procedure of the process in 2nd Embodiment. It is an example of a routing policy. It is an example of BC. It is a sequence diagram at the time of applying Proxy Mobile IP system to the handover of a 2nd embodiment. It is the sequence diagram which showed the procedure of the process of the hand-over of the conventional network base IP mobility protocol. It is the sequence diagram which showed the procedure of the process of the handover by the Proxy MobileIP system of the conventional network base IP mobility protocol.

Explanation of symbols

1,22,23 NetLMM-MN
2, 3, 21, 25 MAG
4, 32, 33 HA
5, 30 MIP-MN
6, 27, 28, 31 Router 7, 29 Internet 8, 24 LMA
11, 12, 16, 17 Communication means 13, 18 Network-based IP mobility protocol processing unit 14 Mobile IP proxy processing unit 15, 19 Storage unit 26 MCoA-MN

Claims (8)

Using a network-based IP mobility protocol, a mobile terminal performs communication by transmitting and receiving data from a router belonging to the same link using a uniquely assigned address. When the mobile terminal moves to another network, control is performed. A communication system for switching communication by controlling a device,
The router stores a binding cache that is communication information about the mobile terminal for relaying using the Mobile IP protocol,
When the received data is communication between the mobile terminal managed by the mobile station and a terminal using the Mobile IP protocol, the router relays the mobile terminal and the terminal using the Mobile IP protocol. A communication system using a network-based IP mobility protocol.   When the mobile terminal moves to a network of another router, the control device sends the binding cache of the mobile terminal to the router that is the source of the mobile terminal, and the destination of the mobile terminal The communication system using a network-based IP mobility protocol according to claim 1, wherein a transfer instruction notification is transmitted so as to be transferred to a router.   When the mobile terminal communicates with other terminals via a plurality of interfaces, the transfer source router has a transfer policy (routing policy) for each interface together with the binding cache and the transfer destination router. The communication system using the network-based IP mobility protocol according to claim 2, wherein: When a mobile terminal moves to another network in a system that uses a network-based IP mobility protocol and communicates by transmitting and receiving data from a router belonging to the same link using an address uniquely assigned to the mobile terminal. A control device that performs control for switching communication,
Communication means for receiving a notification including an identifier of the mobile terminal and an identifier or an IP address of the mobile terminal from the router in the network to which the mobile terminal is moved;
Storage means for holding communication information related to the router and the mobile terminal for relaying;
Refer to the storage means for communication information of the mobile terminal from the identifier of the mobile terminal included in the notification from the router, update the information on the destination router and data transfer between the routers, The router for instructing the router to transfer data to the destination router, the buffer transfer instruction notification including the identifier or IP address of the destination router, and the movement for relaying using the Mobile IP protocol Control means for generating a binding cache transfer instruction notification that is communication information related to the terminal,
The control apparatus, wherein the communication means transmits the buffer transfer instruction notification and the binding / cache transfer instruction notification to the source router. A router that transmits and receives data to and from a mobile terminal that belongs to the same link that communicates with a uniquely assigned address under the control of a control device using a network-based IP mobility protocol,
Storage means for storing a binding cache which is communication information related to the mobile terminal for relaying using Mobile IP protocol;
Control means for relaying between the mobile terminal and the terminal using the Mobile IP protocol when the received data is communication between the mobile terminal managed by the mobile terminal and a terminal using the Mobile IP protocol A router comprising:   The said control means transfers the said binding cache to the said router of the movement destination of the said mobile terminal, when the notification of a binding cache transfer instruction | indication is received from the said control apparatus. Router.   When the mobile terminal communicates with other terminals via a plurality of interfaces, the control means sends a forwarding policy (routing policy) for each interface to the destination router along with the binding cache. The router according to claim 6, wherein the router is forwarded. Using the network-based IP mobility protocol, the mobile terminal is made to transmit and receive data from a router belonging to the same link using a uniquely assigned address. When the mobile terminal moves to another network, the control device A communication method for performing control for switching communication of the mobile terminal,
When the received data is communication between the mobile terminal managed by the mobile station and a terminal using the Mobile IP protocol, the router relays the mobile terminal and the terminal using the Mobile IP protocol. is carried out for,
When the mobile terminal moves to another network of the router, the control device is a binding information that is communication information about the mobile terminal for relaying to the router that is the movement source of the mobile terminal using the Mobile IP protocol A communication method characterized by transmitting a transfer instruction notification so as to transfer the cache to the router to which the mobile terminal has moved .

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