JP2005073271A - System and method for enabling mobile ipv6 communication over network containing ipv4 components using isatap, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow a mobile dual stack node to engage in IPv6 communication while roaming within an IPv4-only network. <P>SOLUTION: First, the node determines that it has moved and obtains a new IPv4 address. After determining that the visited network contains no IPv6-enabled components, the node uses in IPv6 connect agent to engage in IPv6 communication. The node configures its MIPv6 care-of address using the IPv6 connect agent's routing information and the node's newly-obtained IPv4 address. In one embodiment, the node and the connect agent optimize the handoff when the node has moved but still uses the same connect agent, thereby reducing packet loss. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates generally to Internet protocol communications, and more particularly to techniques that enable Mobile IPv6 over networks with IPv4 using ISATAP and Mobile IPv6 handover optimization.

  This application claims priority based on the following provisional US patent application, which application is incorporated herein by reference. That is, this application is serial number 60/497743, entitled “Use of an extension to ISATAP to enable MIPv6 communication over networks with IPv4 components” filed on August 25, 2003, Serial number 60/5033641, entitled "Optimized Mobile IPv6 Extension (Optimized ISATAP-MIPv6 Service Architecture) in ISATAP IPv6-enabled Network", filed September 16, 2003, May 2003 Serial number 60/474794 entitled "Detection of Automatic IPv6 Connection Agent Using DNS" filed on 29th, and Serial entitled "ISP IPv6 Connection Service" filed on 21st February 2003 Main priority based on the number 60/448957 And these applications are incorporated herein by reference.

  Internet Protocol version 6 (IPv6) is a new version of the Internet protocol and was designed as a successor to Internet Protocol version 4 (IPv4). IPv6 does not support mobility, and packets destined for a mobile IPv6 node (a node that dynamically changes the access point to the Internet) will reach that node when it is away from its home link I can't. Mobile IPv6 (MIPv6) has been devised to support mobile IPv6 nodes. MIPv6 allows mobile IPv6 nodes to remain reachable while traveling in an IPv6 network.

  However, there are two versions currently in use, one is the widely used but old Internet Protocol version 4 (IPv4) and the other is the less used but new Internet Protocol version 6 (IPv6). ). If a mobile IPv6 node moves to an IPv4-only network, the mobile IPv6 node cannot continue to communicate with its corresponding IPv6 peer. This is because the source Mobile IPv6 node must first communicate with an IPv4-only node, and that IPv4-only node must communicate with the terminating IPv6. This is not supported by either IPv6 or MIPv6. IPv6 is expected to gradually replace IPv4, but the two versions will coexist for years during the transition period. Therefore, enabling Mobile IPv6 nodes to connect to communications with other IPv6 nodes, even when Mobile IPv6 is in an IPv4-only network, is an important concern among Internet users.

  What is needed is a method and system for a mobile IPv6 node in an IPv4-only network to connect to IPv6 communications through an IPv4-only network. The method and system should not require an IPv4-only network upgrade.

  In order to connect to IPv6 communication through a network that does not have an IPv6-enabled component, the mobile dual-stack node configures a new mobile IPv6 care-of address using an IPv6 connection.

  The mobile dual stack node determines that it has moved. This node then obtains a new IPv4 address. This node determines that the visited network does not have an IPv6-compatible component. This node finds an IPv6 connection agent such as an ISATAP router that allows this node to connect to IPv6 communications through an IPv4-only network. This node then performs mobile IPv6 handover and configures the MIPv6 care-of address using information from the IPv6 connection agent. In one embodiment, the new MIPv6 care-of address is in the ISATAP format. Then, the MIPv6 binding update (MIPv6 binding update) is transmitted to the MIPv6 home agent of the node and the corresponding peer.

  In one embodiment, nodes and connection agents optimize handoffs. This node detects that it has moved but is still using the same connection agent. The node then sends a binding update to the connection agent with the node's old MIPv6 care-of address and the new one. The connection agent receives the binding update and, in one embodiment, stores the binding update in a binding cache that maps the old MIPv6 care-of address to the new MIPv6 care-of address. The connection agent then receives a packet directed to the node's previous MIPv6 care-of address, which forwards the packet to the node's current MIPv6 care-of address, thereby reducing packet loss. .

  The features and advantages described in this summary and the following detailed description are not all-inclusive, and in particular, many additional features and advantages are considered in view of the drawings, specification, and claims of this application. It will be clear to the contractor. Further, the language used herein is selected primarily for readability and explanatory purposes, and is not selected to delineate or limit the subject matter of the invention; It should be noted that it depends on the claims necessary to determine the subject matter.

  FIG. 1A is a block diagram illustrating a high-level overview of a mobile dual stack node in an IPv6 section of an IPv4 and IPv6 mixed network connected to IPv6 communication over an IPv6 network according to one embodiment of the present invention.

  FIG. 1B is a block diagram illustrating a high-level overview of a mobile dual stack node in an IPv4 section of an IPv4 and IPv6 mixed network connected to IPv6 communication over an IPv6 network according to one embodiment of the present invention.

  FIG. 2 is a block diagram of a stack enabled by a mobile dual stack node according to an embodiment of the present invention.

  FIG. 3 is a flowchart illustrating steps for connecting to IPv6 communication after a mobile dual stack node moves to an IPv4-only network according to an embodiment of the present invention.

  FIG. 4 is a flowchart illustrating steps for a mobile dual stack node and an IPv6 connection agent to optimize handoff when a node moves in an IPv4-only network according to an embodiment of the present invention.

  The drawings represent embodiments of the invention for purposes of illustration only. Those skilled in the art will readily appreciate from the following description that alternative embodiments of the arrangements and methods described herein may be employed without departing from the principles of the invention described herein. Will.

  FIG. 1A is a block diagram illustrating a high level overview of a mobile dual stack node in an IPv6 section of an IPv4 and IPv6 mixed network connected to IPv6 communication over an IPv6 network according to one embodiment of the present invention. The illustrated embodiment comprises a mixed network 100, a communication network 150, and an IPv6 device 190. In the illustrated embodiment, the mixed network 100 and the IPv6 device 190 are connected to a communication network 150.

  The mixed network is a network having both an IPv4-only component and an IPv6-enabled component. In the illustrated embodiment, the mixed network 100 comprises an IPv4 only section (Ipv4-only section) 105 and an IPv6 enabled section (Ipv6-enabled section) 110. The IPv4 dedicated section 105 includes one IPv4 dedicated node (Ipv4-only node) 115, and the IPv6 compatible node 110 includes one IPv6 compatible node 120 and one mobile dual stack node 125. A dual stack node is a node with both an IPv4 stack and an IPv6 stack and can therefore be connected to both IPv4 and IPv6 communications. This illustrated architecture is used only as an example. Although FIG. 1A illustrates one IPv4 dedicated node 115 in the IPv4 dedicated section 105, the present invention is applicable to any architecture that includes one or more IPv4 dedicated nodes 115 in the IPv4 dedicated section 105. In addition, although FIG. 1A illustrates one IPv6 enabled node 120 and one mobile dual stack node 125 in the IPv6 enabled node section 110, the present invention supports one or more IPv6 enabled in the IPv6 enabled section 110. It can be applied to any architecture including node 120 and one or more dual stack nodes 125.

  Communication network 150 may comprise a plurality of processing systems and may be a local area network (LAN), a wide area network (WAN; eg, the Internet), and / or any other device with which a plurality of devices can communicate. Of interconnected data paths. In the illustrated embodiment, the communication network 150 comprises one IPv6 connection agent 130. This architecture is used as an example only. Although FIG. 1A illustrates one IPv6 connection agent 130, the present invention is applicable to any architecture with zero or more IPv6 connection agents 130. If more than one IPv6 connection agent 130 is available, the mobile dual stack node 125 has the right to select which IPv6 connection agent 130 to use. In addition, although the illustrated embodiment shows an IPv6 connection agent 130 located outside the network with mobile dual stack node 125, in other embodiments, the IPv6 connection agent 130 is mobile dual It is arranged in a network having a stack node 125.

  The IPv6 connection agent 130 has a function necessary to enable the mobile dual stack node 125 residing in the IPv4 dedicated section 105 (or the IPv4 dedicated network) of the mixed network 100 to connect to IPv6 communication through the network. The IPv6 connection agent 130 will be further described below with reference to FIG. 1B.

  As shown in FIG. 1A, the mobile dual stack node 125 is located in the IPv6-capable section 110 of the mixed network 100. Since the mobile dual stack node 125 is located in the IPv6 capable section 110, the mobile dual stack node 125 can use MIPv6 to receive and transmit packets while away from its home network. . In this embodiment, an IPv6 connection agent is not used.

  FIG. 1B shows a high-level overview of a mobile dual stack node in the IPv4 section of an IPv4 and IPv6 mixed network that connects to IPv6 communications over an IPv6 network according to one embodiment of the present invention. FIG. 1B is similar to FIG. 1A except that the mobile dual stack node 125 has moved from the IPv6-capable section 110 to the IPv4-only section 105 within the mixed network 100.

  As described above, MIPv6 can receive and transmit packets only when the IPv6-compatible node 125 remains in the IPv6-compatible network (or within the IPv6-compatible node of the mixed network). To. MIPv6 does not allow communication when the mobile IPv6-compatible node 125 is located in an IPv4 dedicated network (or in an IPv4 dedicated section of a mixed network). Accordingly, the IPv6 connection agent 130 performs IPv6 communication between the mobile dual stack node 125 and the IPv6 entity 190 when the mobile dual stack node 125 is located in the IPv4 dedicated network (or the IPv4 dedicated section of the mixed network). Needed to make possible.

  In one embodiment, the IPv6 connection agent 130 implements Intra Site Automatic Tunneling and Addressing Protocol (ISATAP). ISATAP requires a static dual-stack node residing in an IPv4 dedicated network or a static dual stack node residing in an IPv4 dedicated section of a mixed network to connect to IPv6 communications on an IPv4 dedicated or mixed network Enable. Specifically, an ISATAP-compatible device such as a router or a server enables a source dual stack node to tunnel a packet to an IPv6 next-hop address through an IPv4 dedicated network. . In other words, the IPv4 dedicated network is treated as a link layer for IPv6. ISATAP is known to those skilled in the relevant arts, and “Intra-Site Automatic Tunnel Addressing Protocol (ISATAP)” (Internet-Draft) by F. Templin, T. Gleeson, M. Talwar, D. Thaler. , October 2003 ".

  ISATAP allows IPv6 communication over IPv4-only or mixed networks, but ISATAP can only be used with a static originating node, not a mobile source node. Mobile IPv6 does not support moving source nodes with different access points to the network 150. As described above, MIPv6 allows a mobile IPv6-enabled node to maintain a reachable state while moving around an IPv6-enabled network. In MIPv6, each mobile node is always identified by its MIPv6 home address, regardless of the current point of attachment to the network. While far away from its home, the mobile node is also associated with a MIPv6 care-of address, which provides information about the current location of the mobile node. An IPv6 packet addressed to the mobile node's MIPv6 home address is transparently routed to that MIPv6 care-of address. In MIPv6, an IPv6-capable node stores a binding between a mobile node's MIPv6 home address and its MIPv6 care-of address in a cache, and any packet destined for the mobile node is of the MIPv6 care-of address. Allows direct transmission. All IPv6-capable nodes can communicate with mobile nodes, whether mobile or fixed. MIPv6 is known to those skilled in the relevant arts and is described in more detail in “Mobility Support in Ipv6” (Internet-Draft), June 2003 by D. Johnson, C. Perkins, J. Arkko. Has been.

  To overcome the limitations of ISATAP and MIPv6, in one embodiment, the mobile dual stack node 125 is an ingenious that allows the mobile dual stack node 125 to move to an IPv4 dedicated network and connect to IPv6 communications. Includes software components. The methods and systems described herein allow an IPv4-only element or IPv4-only network of mixed network 100 to be upgraded to IPv6 to allow mobile dual stack node 125 to connect to IPv6 communications. Please pay attention to the point which is not necessary.

  FIG. 2 is a block diagram of a stack that enables a mobile dual stack node according to an embodiment of the present invention. The stack 200 includes an IPv4 stack 205 and an IPv6 stack 210. The IPv4 stack 205 includes an IPv4 movement detection module 215 and an IPv4 dynamic address configuration module 220. The IPv6 stack 220 includes an ISATAP client module 225, an MIPv6 client module 230, an IPv6 address configuration and ISATAP establishment module 235, and an IP layer type detection module 240.

  The IPv4 movement detection module 215 determines that an IPv4-compatible node has moved from one access point to another in the network. Specifically, the IPv4 movement detection module 215 detects that a node is detached from a subnetwork or network and attached to another subnet or network, thereby using a different router. To do. If a node uses a wireline connection, the IPv4 movement detection module 215 detects that the node physically disconnected itself from the network. If a node uses a wireless connection, the IPv4 movement detection module 215 detects that the node has stopped using a particular wireless access point. Methods for detecting network detachment and attachment are known to those skilled in the relevant art and are described in more detail in “IP Mobility Support” (RFC2002), October 1996 by C. Perkins. Has been.

  The IPv4 dynamic address configuration module 220 obtains an IPv4 address for the IPv4-compatible node. Methods for dynamically obtaining IPv4 addresses, such as DHCP (Domain Host Control Protocol) or PPP (Point-to-Point Protocol), are known to those skilled in the art.

  The IP layer type detection module 240 determines whether the node is in a network with IPv6-enabled components. In one embodiment, the network comprises an IPv6-enabled component if a node in the network receives an IPv6 router advertisement. This node may receive an IPv6 router advertisement or may request an IPv6 router advertisement by sending an IPv6 router advertisement.

  The IPv6 connection agent discovery module 245 determines the IPv4 address of the IPv6 connection agent. In one embodiment, this is implemented by sending an IPv4 anycast broadcast. In another embodiment, this is a domain name system (as described in US patent application serial number 10/729257, filed December 4, 2003 entitled "Automatic Ipv6 Connect Agent Discovery using DNS"). DNS), which is incorporated herein in its entirety by reference.

  The ISATAP client module 225 implements ISATAP so that a dual stack node can send and receive IPv6 communications over an IPv4-only or mixed network using an ISATAP-compatible connection agent.

  The MIPv6 client module 230 implements MIPv6 to register and update the mode's MIPv6 care-of address.

  The ISATAP setup module 250 notifies the IPv6 connection agent 130 of the IPv4 address of the node.

  FIG. 3 is a flowchart illustrating steps for connecting to IPv6 communication after a mobile dual stack node moves to an IPv4-only network according to an embodiment of the present invention. In the first step, the IPv4 movement detection module 215 determines that the node 125 has moved (step 310). Then, the IPv4 dynamic address configuration module 220 dynamically acquires a new IPv4 address (step 320), thereby configuring the IPv4 connection of the node.

  Then, the IP layer type detection module 240 determines whether or not the surrounding network includes an IPv6 compatible component (step 330). If the network includes one or more IPv6-capable components, node 125 connects to IPv6 communications through an IPv6-capable component (not shown). If the network does not include an IPv6-compatible component, the IPv6 connection agent discovery module 245 determines the IPv4 address of the IPv6 connection agent 130 (step 340).

  Next, the MIPv6 client module 230 configures the MIPv6 care-of address of the node using the routing information of the IPv6 connection agent and the newly acquired IPv4 address of the node (step 350). Then, the ISATAP establishment module 250 notifies the IPv6 connection agent 130 of the MIPv6 care-of address of the node. The node 125 then uses the IPv6 connection agent 130 to communicate with the IPv6 entity 190 over the IPv4 dedicated network, as shown in FIG. 1B.

  In one embodiment, the handover that occurs when the mobile dual stack node 125 moves within the IPv4 private network 105 is optimized. The mobile dual stack node 125 in the IPv4 dedicated network 105 accesses the network using an IPv4 router. When node 125 moves within IPv4-only network 105, it uses another IPv4 router to access the network. Node 125 sends a binding update to the MIPv6 home agent and the corresponding node to receive the packet at the new location, binding the old MIPv6 care-of address to the new MIPv6 care-of address. By the time the binding update is received, packets already sent to the old MIPv6 care-of address of the node may be lost.

  FIG. 4 is a flowchart illustrating steps for a mobile dual stack node and an IPv6 connection agent to optimize handoff when a node moves in an IPv4 dedicated network according to an embodiment of the present invention. In this embodiment, packet loss is reduced by modifying the configuration of the IPv6 connection agent 130 so that the IPv6 connection agent 130 automatically forwards the packet to the node's current MIPv6 care-of address. As described above, the mobile dual stack node 125 in the IPv4 dedicated network uses the IPv6 connection agent 130 to connect to IPv6 communication on the IPv4 dedicated network. In the first step, the mobile dual stack node 125 detects that it has moved within the IPv4 private network but is still using the same IPv6 connection agent 130 (step 410). Next, the node 125 transmits a binding update to the IPv6 connection agent 130 (step 420). This binding update binds the node's old MIPv6 care-of address to the node's new MIPv6 care-of address. The IPv6 connection agent 130 receives the binding update (step 430). As a result, when the IPv6 connection agent 130 receives a packet directed to the node's previous MIPv6 care-of address (step 440), the IPv6 connection agent 130 forwards the packet to the node's current MIPv6 care-of address. (Step 450).

  In one embodiment, this is accomplished by adding a binding cache to the IPv6 connection agent 130 and adding an extended binding update module to the mobile dual stack node 125. In MIPv6, an entry in the binding cache maps a node's MIPv6 home address to its MIPv6 care-of address. In contrast, the present invention uses a binding cache entry that maps a node's previous MIPv6 care-of address to its current MIPv6 care-of address. In one embodiment, another nature of the binding update is indicated by setting a flag in the message with the binding update. In other embodiments, the binding update is in the same format as a standard MIPv6 binding update, but when sent to the IPv6 connection agent 130 comprises the node's old MIPv6 care-of address rather than the node's MIPv6 home address. .

  The extended binding module detects when a node has moved in the IPv4 network but is still using the same IPv6 connection agent 130. When this happens, the customized binding module sends a binding update to the IPv6 connection agent 130.

  As will be appreciated by those skilled in the art, the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. Similarly, specific naming and partitioning of modules, features, attributes, procedures, nodes, servers, connection agents, and other aspects are not essential or important, and the invention or its features The mechanism that implements may take different names, splits, and / or forms. Furthermore, as will be apparent to those skilled in the relevant art, the modules, features, attributes, procedures, nodes, servers, connection agents, and other aspects of the present invention may be software, hardware, firmware, or these three Can be implemented as a combination. Needless to say, wherever the components of the present invention are implemented as software, this component can be statically or dynamically as a standalone program, as part of a larger program, as multiple separate programs. Can be implemented as a linked library, as a kernel loadable module, as a device driver, and / or any or any other known to those skilled in the field of computer programming now or in the future This method can also be implemented. In addition, the present invention is in no way limited to implementation in any particular programming language, nor is it limited to any particular operating system or environment. Accordingly, the disclosure of the present invention is illustrative and is not intended to limit the scope of the invention.

FIG. 2 is a block diagram illustrating a high-level overview of a mobile dual stack node in an IPv6 section of an IPv4 and IPv6 mixed network connected to IPv6 communication over an IPv6 network according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating a high-level overview of a mobile dual stack node in an IPv4 section of an IPv4 and IPv6 mixed network connecting to IPv6 communication over an IPv6 network according to an embodiment of the present invention. FIG. 4 is a block diagram of an expanded stack of mobile dual stack nodes according to one embodiment of the present invention. 6 is a flowchart illustrating steps for connecting to IPv6 communication after a mobile dual stack node moves to an IPv4-only network according to an embodiment of the present invention. FIG. 5 is a flowchart illustrating steps for a mobile dual stack node and IPv6 connection agent to optimize handoff when a node moves in an IPv4 only network according to an embodiment of the present invention.

Explanation of symbols

100 IPv4 and IPv6 mixed network 105 IPv4 dedicated section 110 IPv6 compatible section 115 IPv4 dedicated node 120 IPv6 compatible node 125 Mobile dual stack node 130 IPv6 connection agent 150 Communication network 190 IPv6 device 205 IPv4 stack 210 IPv6 stack 215 IPv4 movement detection module 220 IPv4 Dynamic address configuration module 225 ISATAP client module 230 MIPv6 client module 240 IP layer type detection module 245 IPv6 connection agent discovery module 250 ISATAP establishment module 310, 320, 330, 340, 350, 360 steps 410, 420, 430, 44 , 450 step

Claims (32)

A method for a mobile dual stack node to connect to IPv6 communication over a network with IPv4 components, comprising:
Determining that the node has moved;
Obtaining a new IPv4 address;
Determining that the visited network does not have any IPv6-capable components;
Determining an IPv4 address of an IPv6 connection agent;
Obtaining a MIPv6 care-of address;
Configuring the IPv6 connection agent with the MIPv6 care-of address. Determining that the node has moved comprises:
Detecting that the node is disconnected from one of a first network and a first sub-network;
2. The method of claim 1, comprising detecting that the node is connected to one of a second network and a second sub-network.   The method of claim 1, wherein the step of obtaining a new IPv4 address comprises using one of DHCP (Dynamic Host Control Protocol) and PPP (Point-to-Point Protocol).   The method of claim 1, wherein determining that the visited network does not have any IPv6-enabled components comprises determining not to receive an IPv6 router advertisement within a specified time.   The method according to claim 1, wherein the step of determining an IPv4 address of the IPv6 connection agent comprises one of a step of sending an IPv4 anycast message and a step of querying a DNS (Domain Name System) server.   In response to determining that the determined IPv4 address of the IPv6 connection agent is the same as the IPv4 address of the IPv6 connection agent previously used by a node, a binding update is sent to the IPv6 connection agent The method of claim 1, further comprising:   The method of claim 6, wherein sending the binding update to the IPv6 connection agent comprises sending a previous MIPv6 care-of address used by the node and the obtained MIPv6 care-of address. An IPv6 connection agent is a method for optimizing handoff when a client moves in an IPv4-only network,
Receiving a binding update having a first MIPv6 care-of address and a second MIPv6 care-of address;
Transmitting the packet to the second MIPv6 care-of address in response to receiving the packet sent to the first MIP care-of address. A mobile dual stack node for connecting to IPv6 communication via a network with IPv4 components,
A software portion configured to determine that the node has moved;
A software part configured to obtain a new IPv4 address;
A software portion configured to determine that the visited network does not include any IPv6-capable components;
A software portion configured to determine an IPv4 address of an IPv6 connection agent;
A software part configured to obtain a MIPv6 care-of address;
And a software unit configured to construct the IPv6 connection agent using the MIPv6 care-of address. Detecting that the node has moved is
Detecting that the node is disconnected from one of the first network and the first sub-network;
10. The system of claim 9, comprising detecting that the node is connected to one of a second network and a second subnetwork.   The system of claim 9, wherein obtaining the new IPv4 address includes using one of DHCP (Dynamic Host Control Protocol) and PPP (Point-to-Point Protocol).   The system of claim 9, wherein determining that the visited network does not include any IPv6-enabled component includes not receiving an IPv6 router advertisement within a specified time.   The system according to claim 9, wherein the IPv6 connection agent determines an IPv4 address including one of sending an IPv4 anycast message or inquiring a DNS (Domain Name System) server.   In response to the determined IPv4 address of the IPv6 connection agent being the same as the IPv4 address of the IPv6 connection agent previously used by the node, a binding update is sent to the IPv6 connection agent. The system according to claim 9, further comprising a software unit configured as described above.   15. The system of claim 14, wherein sending the binding update to the IPv6 connection agent comprises sending a previous MIPv6 care-of address used by the node and the obtained MIPv6 care-of address. An IPv6 connection agent is a system for optimizing handoff when a client node moves in an IPv4-only network,
A software portion configured to receive a binding update having a first MIPv6 care-of address and a second MIPv6 care-of address;
And a software unit configured to transmit the packet to the second MIPv6 care-of address in response to receiving the packet sent to the first MIPv6 care-of address. A mobile dual stack node is a computer readable recording medium comprising a computer program product for connecting to IPv6 communication via a network with IPv4 components,
The computer program product is:
Program code for determining that the node has moved;
Program code for obtaining a new IPv4 address;
Program code for determining that the visited network does not have any IPv6 compatible components;
A program code for determining an IPv4 address of an IPv6 connection agent;
Program code for obtaining a MIPv6 care-of address;
A computer-readable recording medium comprising program code for configuring the IPv6 connection agent using the MIPv6 care-of address. Determining that the node has moved is
Detecting that the node is disconnected from one of the first network and the first sub-network;
The computer-readable recording medium according to claim 17, comprising detecting that the node is connected to one of a second network and a second subnetwork.   18. The computer-readable recording medium according to claim 17, wherein obtaining the new IPv4 address includes using one of DHCP (Dynamic Host Control Protocol) or PPP (Point-to-Point Protocol). .   The computer-readable recording medium according to claim 17, further comprising: determining that the visited network does not include any IPv6-compatible component from not receiving an IPv6 router advertisement within a specific period of time.   18. The computer-readable recording medium according to claim 17, wherein determining the IPv4 address of the IPv6 connection agent includes one of sending an IPv4 anycast message or inquiring a DNS (Dynamic Name System) server. . The computer program product is:
To send a binding update to the IPv6 connection agent in response to the determined IPv4 address of the IPv6 connection agent being the same as the IPv4 address of the IPv6 connection agent previously used by the node. The computer-readable recording medium according to claim 17, further comprising: Sending the binding update to the IPv6 connection agent comprises:
23. The computer readable recording medium of claim 22, comprising transmitting a previous MIPv6 care-of address used by the node and the obtained MIPv6 care-of address. An IPv6 connection agent is a computer readable recording medium comprising a computer program product for optimizing handoff when a client node moves in an IPv4 dedicated network,
The computer program product is:
Program code for receiving a binding update having a first MIPv6 care-of address and a second MIPv6 care-of address;
A recording medium comprising: a program code for transmitting the packet to the second MIPv6 care-of address in response to reception of the packet sent to the first MIPv6 care-of address. A mobile dual stack node for connecting to IPv6 communication via a network with IPv4 components,
Means for detecting that the node has moved;
Means for obtaining a new IPv4 address;
Means for determining that the visited network does not have any IPv6-capable components;
Means for determining an IPv4 address of an IPv6 connection agent;
Means for obtaining a MIPv6 care-of address;
And means for configuring the IPv6 connection agent using the MIPv6 care-of address. Determining that the node has moved is
Detecting that the node is disconnected from one of the first network and the first sub-network;
26. The system of claim 25, comprising detecting that the node is connected to one of a second network and a second subnetwork.   26. The system of claim 25, wherein obtaining the new IPv4 address includes using one of DHCP (Dynamic Host Control Protocol) or PPP (Point-to-Point Protocol). 26. The system of claim 25, comprising determining that the visited network does not have any IPv6-enabled components from not receiving an IPv6 router advertisement within a specified time.   26. The system of claim 25, wherein determining the IPv4 address of the IPv6 connection agent includes one of sending an IPv4 anycast message or querying a DNS (Domain Name System) server.   To send a binding update to the IPv6 connection agent in response to the determined IPv4 address of the IPv6 connection agent being the same as the IPv4 address of the IPv6 connection agent previously used by the node. 26. The system of claim 25, further comprising:   31. The system of claim 30, wherein sending the binding update to the IPv6 connection agent comprises sending a previous MIPv6 care-of address used by the node and the obtained MIPv6 care-of address. An IPv6 connection agent is a system for optimizing handoff when a client node moves in an IPv4-only network,
Means for receiving a binding update having a first MIPv6 care-of address and a second MIPv6 care-of address;
Means for transmitting the packet to the second MIPv6 care-of address in response to receiving the packet sent to the first MIPv6 care-of address.

Images