WO2012075778A1

WO2012075778A1 - Method and system for managing data messages during handover of mobile nodes

Info

Publication number: WO2012075778A1
Application number: PCT/CN2011/074350
Authority: WO
Inventors: 孙默; 吴强
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-12-10
Filing date: 2011-05-19
Publication date: 2012-06-14
Also published as: CN102547845A; CN102547845B

Abstract

The present invention discloses a method for managing data messages during handover of mobile nodes, which is used in a network where the identity is separated from the location. Said method includes the following steps: when a mobile node performs the handover, a first access gateway equipment where a correspondent node (CN) of the mobile node (MN) is located transmits, according to a corresponding mapping entry of said MN stored in a mapping table of the first access gateway equipment, a received data message which is transmitted to said MN to a second access gateway equipment where said MN is located; said second access gateway equipment forwards said data message and the corresponding correspondent entry of said CN stored in a correspondent information table of the second access gateway equipment to a third access gateway equipment, wherein, the aging period of the mapping entries stored in said mapping table is T1, the aging period of the correspondent entries stored in said correspondent information table is T2, and T2>T1. The present invention ensures the normal communication between the MN and the CN during the mobility handover process of the MN and after the handover is finished.

Description

Method and system for managing data message when mobile node switches

The present invention relates to the field of communications technologies, and in particular, to a method and system for managing data packets when a mobile node switches.

BACKGROUND OF THE INVENTION IP addresses in the Transmission Control Protocol/Internet Protocol (TCP/IP), which is widely used in the Internet, have dual functions, and serve as a communication layer host network interface of the network layer in the network topology. The location identifier, which is also the identity of the transport layer host network interface. TCP/IP did not consider host mobility at the beginning of the design. However, as host mobility becomes more prevalent, the semantic overload defects of such IP addresses are becoming increasingly apparent. When the IP address of the host changes, not only the route changes, but also the identity of the host of the communication terminal changes. This will cause the load on the router to become heavier, and the change of the host identity will also cause the application and connection to be interrupted. The purpose of identification and location separation is to solve the problem of semantic overload and severe routing load of IP addresses, and to separate the dual functions of IP addresses, thereby realizing dynamic redistribution and mitigation of mobility, multiple townships, and IP addresses. Support for issues such as routing load and mutual visits between different network areas in the next generation Internet. In the prior art, the network router based implementation method is one of the solutions for identity identification and location separation. The basic idea of this scheme is: The network is divided into an access layer and a core layer. The mobile node in the network has two types of identification: an Access Identifier (AID) and a Routing-Location Identifier (Routing-Location Identifier). Referred to as RID). Each user terminal in the network is configured with a unique AID, and the AID remains unchanged during the mobile process; in the data forwarding process, the AID can only be used at the access layer, and the RID can only be used at the core layer; The topology of the identity and location separation framework is shown in Figure 1. Correspondingly, the network is divided into an access network and a backbone network. As shown in FIG. 1 , in the network-based identity and location separation framework, the method mainly includes: a radio access network (Radio Access Network, RAN for short), access Gateway Gateway (AGR), General Switch Router (GSR), Identifier Mapping Server (IDMS), and authentication center. The following are introduced separately:

AGR, which is responsible for providing access services for various mobile nodes, and assigning RIDs to the accessed user terminals.

When receiving the data packet sent by the user terminal, the AGR queries the AID-RID mapping table in the local cache (CACHE) according to the destination address in the data packet (ie, the AID of the communication peer): If the corresponding AID-RID is found. Mapping the entry, the RID of the communication peer that is found is encapsulated in the packet header and sent to the backbone network for forwarding processing; if the corresponding AID-RID mapping entry is not found, the data packet is forwarded to the backbone network, and The IDMS initiates the process of querying (communicating the peer) AID-RID mapping information, and saves the IDMS return corresponding AID-RID mapping locally, so as to prepare for subsequent forwarding. Alternatively, when the AGR does not find the corresponding AID-RID mapping entry, the AGR may choose not to forward the data packet to the backbone network, but initiate the process of querying the AID-RID mapping information (communicating the peer end) to the IDMS, and wait for the IDMS. After the corresponding AID-RID mapping is returned, the RID of the communication peer that is found is encapsulated in the packet header and sent to the backbone network for forwarding processing.

When receiving the data packet sent to the user terminal, the AGR decapsulates the data packet, and strips the newly added RID packet header in the data packet to the terminal.

The main function of the GSR is to select and forward data packets based on the routing location identifier RID in the data packet. IDMS is mainly responsible for maintaining the mapping relationship between user identity and location identifier in the network, and providing query services to access gateway routers and other mapping servers. The authentication center is responsible for recording information such as the user terminal category and the user terminal service level, and performs legality authentication and authorization on the user terminal when the user terminal accesses. The certificate authority supports two-way authentication between the network and the user terminal. The radio access network is responsible for providing and maintaining a Layer 2 link between the user terminal and the access gateway router AGR; and is responsible for radio resource management in the cellular mobile network application scenario. From the above, under the framework shown in Figure 1, the network can be divided into an access network and a backbone network. The access network is located at the edge of the backbone network and is responsible for access of all terminals. In the RAN part of the access network, all The user terminals are all addressed using the AID. The backbone network is responsible for accessing the router of the user terminal through different access networks. There is no overlap between the access network and the backbone network in the topology relationship. The application layer between the communication hosts uses the AID to identify the peer. The communication between the user terminals only needs to use the AID of the peer. The access gateway router is located at the demarcation point between the backbone network and the access network, and serves as an interface between the access network and the backbone network, and is responsible for providing access services for the user terminals, maintaining user terminal connections, and forwarding user terminal data. All communication of the user terminal is forwarded and managed by the access gateway router of the access network. The process of forwarding the data packet between the user terminal and the communication peer is as follows: When the user terminal sends the data packet, the corresponding access gateway router sends a request for querying the routing mode of the user terminal to the mapping server. The mapping server stores the routing manners of all user terminals in the network, and the mapping server selects the corresponding routing mode and returns the information to the access gateway router AGR. The AGR forwards the data packet sent by the MN according to the routing manner of the mobile node (Mobile Node, MN for short) returned from the mapping server. If the user terminal and the communication peer belong to the same access gateway router service range, the AGR forwards the data packet directly to the communication peer. If the user terminal and its corresponding communication peer belong to different AGRs, the AGR forwards the data packet to the backbone network. When forwarding a data packet belonging to a different AGR, the AGR also carries the RID information in the forwarded data packet (the RID corresponds to the AID); correspondingly, when the user terminal receives the data packet, the access gateway router performs the opposite. The operation, that is, stripping the RID information and forwarding the data message to the user terminal. Of course, the AGR also stores the routing mode of the user terminal from the mapping server in its own cache. When the user terminal (mobile node) has subsequent packets, the AGR queries the routing mode of the MN from its own cache. The data packet is forwarded according to the routing mode. The related interface of the network architecture based on the network identity identification and location separation framework is shown in FIG. 2, S1/D1 is an interface between the user terminal and the access gateway router AGR, and S1 is used for signaling of user access management, and D1 is Data forwarding interface; S2 is used for switching management signaling when switching between AGRs, D2 is used for data forwarding between AGRs; D3 is a data forwarding interface between AGR and GSR, and S4/S5/S6 is used for querying and maintaining AIDs. - The signaling interface of the RID mapping relationship, D4m is the data forwarding interface between the AGR and the IDMS. Wherein, when the visited IDMS (visted IDMS) has no direct connection relationship with the home IDMS (Home IDMS), the relay IDMS (Broke IDMS) forwards the signaling between the visted IDMS and the Home IDMS. The method for implementing mobile node handover management under the above network architecture is described in detail below. The communication peer (Correspondent Node, CN for short) and the mobile node (Mobile Node, ΜΝ for short) establish communication, and send and receive data packets between each other. In the process of establishing a communication relationship with the ΜΝ, the AGR of the CN can query the mapping server IDMS to query the mapping relationship between the AID and the RID of the MN according to the AID carried in the ΜΝ message, thereby obtaining the routing location identifier RID of the MN; The AGR maintains the AID and RID mapping table of the MN locally, as shown in Table 1 below: Table 1 Communication peer identity location location mapping table of the mobile node

When the radio access network detects the mobility of the MN (ie, the location of the MN changes from one AGR coverage to another AGR coverage), the handover procedure is initiated and the handover procedure is triggered. During the handover process, the gateway AGR and the ingress gateway AGR establish a forwarding relationship. During the handover process or after the handover is completed, the gateway AGR forwards the received data packet addressed to the MN (user terminal) to the hand-in gateway. AGR is forwarded to the MN by the hand-in gateway AGR. In order to avoid the problem of route bypass after the handover, after the handover is completed, the new mapping relationship of the MN is notified by the handover gateway AGR to the access gateway router where all the CNs of the MN are located. In this way, all the access gateway routers where the CN is located can send subsequent packets directly to the MN's hand-cut gateway AGR, thereby avoiding route bypass. In order to avoid the problem of route bypass, it is necessary to save the information of all the CNs corresponding to each locally accessed MN at the access gateway router, and the gateway AGR can notify the CN of the new MN mapping relationship according to the saved information. The access gateway router where it is located. Therefore, in use, the access gateway router of the mobile node is first required to save the information of the communication peers of all locally accessed MNs, and secondly all the access gateway routers where the MN is located can be individually or with the help of the mapping server. The access gateway router that informs the communication peer to access. If the mapping server cannot provide the help of forwarding notification, the AGR where the MN is located must save the information of the access gateway router where the communication peer is located. Table 2 and Table 3 show that the access gateway router where the MN is located is protected if the mapping server cannot provide assistance. An organization form of the stored local access mapping table and the communication peer mapping table. Table 2 Local access user terminal identifier mapping table of the access gateway router

Communication peer mapping mapping table of access gateway router

In Table 2 and Table 3, the communication peer information also needs to set a timer to decide that if the mobile node does not communicate with the communication peer for a long time, the information of the communication peer should be deleted to save the AGR where the mobile node is located. Memory space. However, the above solutions also have the following problems:

When the AGR that the CN is located processes the first packet sent to the MN, it queries the mapping server for the mapping between the AID and the RID of the MN, and caches the entry of the mapping relationship locally, as in the format of Table 1 above. The processing of subsequent messages can be found directly in the local cache. However, the local cache cannot cache the mapping relationship of the MN for a long time. If the aging is deleted, the MN after the handover, that is, the gateway AGR, does not send a message to update the mapping relationship to the AGR where the CN is located. At this time, after the MN handover is completed, there is no data packet handover tunnel between the MN's cut-out AGR and the cut-in AGR, and the AGR of the CN does not receive the mapping relationship update message, and continues to cut out to the MN. The AGR sends a packet, causing the packet to be lost and the communication to be interrupted. Therefore, the mapping relationship between the MN and the MN is required to be periodically requested to be updated by the mapping server. However, if the time interval for requesting the update from the mapping server is too large, the communication terminal still exists. The problem, if the interval for requesting updates is too small, the performance requirements of AGR are very high, so that the load of AGR will be heavy.

SUMMARY OF THE INVENTION The technical problem to be solved by the present invention is to provide a mobile node into the deficiencies of the prior art. When the mobility switch is performed, the load of the access gateway device can be effectively alleviated, and the method and system for managing the data packet loss of the message are reduced as much as possible. In order to solve the above technical problem, the present invention uses the following technical solutions: A method for managing data packets when a mobile node switches, the method is applied to an identity and location separation network, and the method includes: when a mobile node performs handover And the first access gateway device where the mobile node communication peer is located sends the received data packet addressed to the mobile node to the mobile according to the mapping entry corresponding to the mobile node stored in the mapping table. a second access gateway device where the node is located; the second access gateway device forwards the data packet and the peer entry corresponding to the communication peer end stored in the peer information table to the third access a gateway device, the third access gateway device forwarding the data packet to the mobile node; and after the mobile node handover is completed, the first access gateway device is configured according to the third access gateway Sending, by the device, a mapping entry corresponding to the mobile node, sending the received data packet sent to the mobile node to the third access gateway device, and then The third access gateway device forwards the data packet to the mobile node, where the aging period of the mapping entry stored in the mapping table is T1, and the peer entry stored in the peer information table The aging period is T2 and T2 > T1. In the above method, a first timer is set in the first access gateway device, and the first timer periodically updates the mapping entry in the mapping table every aging period T1; in the second access gateway device A second timer is set, and the second timer periodically updates the peer entry in the peer information table every aging period Τ2. In the above method, the mapping entry stored in the mapping table is a routing mapping relationship corresponding to the mobile node. The method further includes: presetting a data packet to identify whether the mobile node has a data packet in the aging period T1. Passing the identifier bit and initializing the value of the identifier bit; the first access gateway device determines whether the mobile node has a data packet passing during the aging period T1, and if so, the mobile node identifier bit The value is set to 1, if not, the value of the mobile node identifier bit is set to 0; when the first timer traverses the mapping table, if the value of the mobile node identifier bit is 1, The value of the mobile node identifier bit is set to 0, and if the value of the mobile node identifier bit is 0, the deletion is performed. A mapping entry corresponding to the mobile node. In the above method, the peer entry stored in the peer information table is related information corresponding to the communication peer end; the method further includes: presetting a flag for identifying whether the communication peer end is in the aging period T2 The identifier of the data packet is initialized and the value of the identifier bit is initialized; the second access gateway device determines whether the data packet is passed by the communication peer in the aging period T2, and if yes, the The value of the communication peer identifier bit is set to 1, if not, the value of the communication peer identifier bit is set to 0; when the second timer traverses the peer information table, if the communication pair If the value of the terminal identifier is 1, the value of the communication peer identifier bit is set to 0; if the value of the identifier of the communication peer is 0, the peer entry corresponding to the communication peer is deleted. The method further includes: storing the value information of the T1 in a data message sent by the communication peer to the mobile node; when the mobile node communication peer communicates with the mobile node, The second access gateway device extracts the value information of T1 in the data packet sent by the first access gateway device, and sets the value of the aging period T2 accordingly. In the above method, the value information of the T1 is saved in an option field or a reuse service type TOS field in an IP header of the data message. In the above method, the peer entry stored in the peer information table is related information corresponding to the communication peer end; the method further includes: presetting a flag for identifying whether the communication peer end has an aging period T2 And determining, by the identifier bit of the data packet, a value of the identifier bit; and determining, by the second access gateway device, a basic polling time T, if the second access gateway device determines the polling time T If the communication peer has data "^", the value of the identifier of the communication peer is set to an initial value, and if no data packet is passed, the value of the identifier of the communication peer is decremented by one. When the value of the identifier of the communication peer is reduced to 0, the peer entry corresponding to the communication peer is deleted, where T2>T. In the above method, the step of initializing the value of the identifier includes : The value of the aging period T2 is set according to the value information of the aging period T1, and the value of the aging period T2 of the second timer is used as the value of the flag bit of the communication peer. In the above method, the T2 is 2Τ1. A system for managing data packets during handover of a mobile node, the system being applied to an identity and location separation network, the system comprising: a mobile node, a mobile node communication peer, and a first access gateway where the mobile node communication peer is located a device, a second access gateway device where the mobile node is located, and a third access gateway device; the first access gateway device is configured to: when the mobile node performs handover, the first access gateway device is configured according to a mapping entry corresponding to the mobile node stored in the self mapping table, sending the received data packet addressed to the mobile node to the second access gateway device; and when the mobile node is switched Sending, by the first access gateway device, the received data packet sent to the mobile node to the third according to the mapping entry corresponding to the mobile node sent by the third access gateway device Access gateway device;

The second access gateway device is configured to: when the mobile node performs handover, the data packet sent by the first access gateway device and the communication pair stored in a peer information table thereof The peer entry corresponding to the terminal is forwarded to the third access gateway device; the third access gateway device is configured to: when the mobile node performs handover,

The aging period of the mapping entry stored in the mapping table is T1, and the aging period of the peer entry stored in the peer information table is Τ2, and Τ2> Τ1. In the foregoing system, a first timer is set in the first access gateway device, and the first timer periodically updates the mapping entry in the mapping table every aging period T1; in the second access gateway device A second timer is set, and the second timer periodically updates the peer entry in the peer information table every aging period Τ2. In the above system, the mapping entry stored in the mapping table is a route mapping relationship corresponding to the mobile node; The first access gateway device is further configured to: preset a flag for identifying whether the mobile node passes the data packet in the aging period T1 and initialize the value of the identifier bit; determining the aging period T1 Whether the mobile node has a data packet to pass, if any, the value of the mobile node identifier bit is set to 1, if not, the value of the mobile node identifier bit is set to 0; When a timer traverses the mapping table, if the value of the mobile node identifier bit is 1, the value of the mobile node identifier bit is set to 0, and if the value of the mobile node identifier bit is 0, the deletion is performed. A mapping entry corresponding to the mobile node. In the above system, the peer entry stored in the peer information table is related information corresponding to the communication peer; the second access gateway device is further configured to: preset one for identifying the communication peer Whether there is an identifier of the data packet passing through the aging period T2 and initializing the value of the identifier bit; determining whether the communication peer has a data packet in the aging period T2, and if so, the communication pair The value of the end identifier bit is set to 1, if not, the value of the communication peer end identification bit is set to 0; when the second timer traverses the peer information table, if the communication peer end identifier If the value of the bit is 1, the value of the communication peer identifier bit is set to 0; if the value of the flag bit of the communication peer is 0, the peer entry corresponding to the communication peer is deleted. In the foregoing system, the first access gateway device is further configured to: save the value information of the T1 in a data packet sent by the communication peer end to the mobile node; The setting is: when the mobile node communication peer communicates with the mobile node, extracts the value information of the T1 in the data packet sent by the first access gateway device, and sets the value of the aging period T2 accordingly. . In the above system, the peer entry stored in the peer information table is related information corresponding to the communication peer; the second access gateway device is further configured to: preset one for identifying the communication peer Whether there is an identifier bit for the data packet passing through the aging period T2 and initializing the value of the identifier bit; and presetting a basic polling time T, if it is determined that the data packet is passed by the communication peer end during the polling time T , the value of the identification bit of the communication peer is set to an initial value, and if no data packet is passed, The value of the identifier of the communication peer is decremented by 1. When the value of the identifier of the communication peer is reduced to 0, the peer entry corresponding to the communication peer is deleted, where T2>T. An access gateway device, where the access gateway device is applied to an identity and location separation network, and the access gateway device is configured to: when the access gateway device is an access gateway accessed by a mobile node communication peer end The device, when the mobile node performs handover, the access gateway device accessed by the mobile node communication peer end receives the received destination according to the mapping entry corresponding to the mobile node stored in the self mapping table. The data message of the mobile node is sent to the access gateway device accessed by the mobile node before the handover; and after the handover of the mobile node is completed, the access gateway device accessed by the mobile node communication peer is a mapping entry corresponding to the mobile node sent by the access gateway device accessed by the mobile node after the handover of the mobile node, and sending the received data packet addressed to the mobile node to the mobile node after the handover Accessing the gateway device; when the access gateway device is an access gateway device accessed before the mobile node switches, when the mobile node performs handover, the mobile device The data packet sent by the access gateway device accessed by the peer end of the point communication and the peer end entry corresponding to the communication peer end stored in the peer information table are forwarded to the mobile node for switching. a gateway device; when the access gateway device is an access gateway device accessed by the mobile node after handover, when the mobile node performs handover, the access gateway accessed before the mobile node switches And forwarding, by the mobile node, the data packet sent by the access gateway device that is accessed by the mobile node communication peer to the mobile node The aging period of the mapping entry stored in the mapping table is T1, and the aging period of the peer entry stored in the peer information table is Τ2, and Τ2> Τ1. In the foregoing access gateway device, a first timer is set in the access gateway device that is accessed by the mobile node communication peer end, and the first timer periodically updates the mapping entry in the mapping table every aging period T1; A second timer is set in the access gateway device that is accessed before the mobile node is switched, and the second timer periodically updates the peer entry in the peer information table every aging period Τ2. In the access gateway device, the mapping entry stored in the mapping table is the mobile node pair. The access routing device is configured to: when the access gateway device is an access gateway device that is accessed by the mobile node communication peer, the access gateway device is further configured to: preset one for identifying that the mobile node is aging Whether there is an identifier bit passing through the data packet and initializing the value of the identifier bit in the period T1; determining whether the mobile node has a data packet passing in the aging period T1, and if so, the mobile node identifier bit The value is set to 1, if not, the value of the mobile node identifier bit is set to 0; when the first timer traverses the mapping table, if the value of the mobile node identifier bit is 1, The value of the mobile node identifier bit is set to 0. If the value of the mobile node identifier bit is 0, the mapping entry corresponding to the mobile node is deleted. In the access gateway device, the peer entry stored in the peer information table is related information corresponding to the communication peer; and the access gateway device is the access accessed before the mobile node switches. The gateway device, the access gateway device is further configured to: preset a flag for identifying whether the communication peer has a data packet passing through the aging period T2 and initialize the value of the identifier bit; Whether the data communication message is passed by the communication peer end in the period T2, if yes, the value of the communication peer end identification bit is set to 1, if not, the value of the communication peer end identification bit is set to 0 And when the second timer traverses the peer information table, if the value of the communication peer identifier bit is 1, the value of the communication peer identifier bit is set to 0; If the value of the identifier of the terminal is 0, the peer entry corresponding to the communication peer is deleted. In the foregoing access gateway device, when the access gateway device is an access gateway device that is accessed by the mobile node communication peer, the access gateway device is further configured to: save the value information of the T1 in the The communication gateway sends the data packet to the mobile node; when the access gateway device is the access gateway device that is accessed before the mobile node switches, the access gateway device is further configured to: When the mobile node communication peer communicates with the mobile node, extracts the value information of T1 in the data packet sent by the access gateway device accessed by the mobile node communication peer end, and sets the aging period T2 accordingly. The value. In the foregoing access gateway device, the peer entry stored in the peer information table is related information corresponding to the communication peer end; When the access gateway device is an access gateway device that is accessed before the mobile node is switched, the access gateway device is further configured to: preset a flag for identifying whether the communication peer end is in the aging period T2 Having a flag for passing the data packet and initializing the value of the flag bit; and presetting a basic polling time T, if it is determined that the data packet is passed by the communication peer within the polling time T, the The value of the identifier bit of the communication peer is set to an initial value. If no data packet is passed, the value of the identifier bit of the communication peer is decremented by 1. When the value of the identifier of the communication peer is reduced to 0, the value is deleted. The peer entry corresponding to the communication peer, where T2>T. In the foregoing access gateway device, when the access gateway device is an access gateway device that is accessed before the mobile node switches, the access gateway device is configured to initialize the value of the identifier bit as follows: The value of the aging period Τ2 is set according to the value information of the aging period T1, and the value of the aging period Τ2 of the second timer is used as the value of the flag bit of the communication peer. In the above access gateway device, the Τ2 2Τ1.

Because the above technical solution is adopted, the present invention sets the second access gateway device (cut-out gateway device) where the mobile node is located to be able to connect the communication peer when the mobile node performs mobility switching. The data packet sent by the first access gateway device to the mobile node is forwarded to the third access gateway device (cut-in gateway device), and the mobile node corresponding to the mobile node stored in the gateway peer information table can also be cut out. All peer entries corresponding to the CN peer are forwarded to the hand-in gateway. After the handover of the mobile node is completed, the first access gateway device where the communication peer is located can directly forward the data packet sent by the communication peer to the mobile node to the hand-cut gateway according to the mapping entry of the gateway sent by the gateway device. device. It can be seen that during the handover process of the mobile node or after the handover is completed, the data packets of the mobile node and the communication peer are basically not interrupted. This is mainly because Τ2>Τ1, so that the ΜΝ corresponding to the mapping table stored in the access gateway router where the CN is located before the peer entry corresponding to the CN stored in the peer information table of the access gateway device where the ΜΝ is located is aged The mapping entries are hardly aged, thus ensuring normal communication between the UI and the CN during the mobility handover and after the handover is completed. At the same time, through the setting of Τ2>Τ1, the access gateway device does not need to periodically map to the mapping server. The update mapping table mapping entry and the request to update the peer information entry of the peer information table are sent, thereby effectively reducing the load on the access gateway device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a network topology of a prior art network-based identity and location separation architecture;

2 is a schematic diagram of a related interface of a network architecture of a network-based identity identification and a location separation framework according to the prior art; FIG. 3 is a schematic diagram of a processing flow of a data packet in a case where a mobile node is dynamically set with a timer duration in the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be further described in detail by way of specific embodiments with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other. In an existing identity and location separation network, a mobile node MN may appear when it moves from a range covered by one access gateway device (for example, access gateway router AGR) to another access gateway device (such as AGR). Communication interruption and loss of data packets. Aiming at the technical problems of communication interruption, low forwarding efficiency and high system performance requirements in the current identity and location separation network, the present invention proposes that when the mobile node performs handover in the identification network, the mobile can be effectively guaranteed. The normal communication between the node and the mobile node communication peer, thereby minimizing the packet loss scheme. The main idea of the present invention is: when the mobile node MN performs handover, the first access gateway device (for example, the access gateway router AGR1) where the mobile node communicates with the opposite CN is mapped according to the MN stored in its own mapping table. The data packet sent to the MN is sent to the second access gateway device where the mobile node MN is located (for example, the access gateway router AGR2, also called the gateway AGR), and the data packet is forwarded by the AGR2. Give the third access gateway device (for example: The gateway router AGR3, also referred to as the gateway gateway AGR, is forwarded to the MN by the AGR3. In the process of forwarding the data packet to the AGR3 by the AGR2, the AGR2 is also stored in the communication peer CN corresponding to the peer information table. The peer mapping entry is forwarded to AGR3. After the MN handover is completed, the AGR1 can directly send the received data packet addressed to the MN to the AGR3 according to the mapping entry corresponding to the MN sent by the AGR3, and then forward the data packet to the MN by the AGR3. The aging period of the mapping entry stored in the mapping table of the AGR1 is T1, and the aging period of the peer entry stored in the peer information table of the AGR2 is T2, and T2>T1. That is to say, AGR1 periodically updates the information of the stored mapping entries in the mapping table every time T1, and AGR2 periodically updates the information of the stored peer entries in the peer information table every time Τ2. In order to make the period update time T1 of the AGR1 mapping entry longer, and to ensure that the lack of peer information does not occur during the handover, the periodic update time Τ2 of the peer entry of the peer information table in AGR2 needs to be greater than T1. In this way, when the CN initiates a service flow, when the information of the corresponding mapping entry in the mapping table of the AGR1 is not aged, the CN corresponding to the corresponding information in the peer information table of the AGR2 The information of the peer entry also exists. Since the mapping entry corresponding to the data packet exchange between the UI and the CN changes, the mapping entry after the handover is referred to as a new mapping entry corresponding to the UI. After the handover is completed, the hacked gateway AGR3 can notify the CN of the corresponding new mapping entry, thereby ensuring that the AGR3 and the AGR1 where the CN is located can communicate normally, thereby reducing the loss of data packets as much as possible. It should be noted that the access gateway device may select an access gateway router, but is not limited to an access gateway router, for example, a switch having a routing function may be selected. In the following embodiments, the access gateway device is described by taking an access gateway router as an example. If the value of the aging period Τ2 is set to be less than or equal to the value of the aging period T1, when the CN initiates a service flow during the handover process, the information of the corresponding mapping entry in the mapping table of the AGR1 is not yet available. When aging, the information of the peer entry corresponding to the CN in the peer information table of AGR2 may have been deleted due to aging, so that the communication between ΜΝ and CN is interrupted after the completion of the ΜΝ. For the values of the first timer T1 and the second timer Τ2, you can use the global static configuration. For example, the AGR timer is configured during network deployment by the NMS. In the configuration, Τ2 is greater than T1. In practical use, the aging periods T1 and T2 are controlled by setting a timer. For example, in an embodiment, a first timer D1 is set in AGR1, D1 is used to time the aging period T1, and AGR1 periodically updates the mapping entries in the mapping table every aging period T1; in AGR2, set one The second timers D2 and D2 are used to time the aging period T2, and the AGR2 periodically updates the peer entry in the peer information table every aging period T2. Through the setting of D1 and D2, the peer entry in the table is updated at a predetermined time timing. Furthermore, the accuracy and timeliness of updating the mapping entries and the peer entries are guaranteed. In an embodiment, the mapping entry stored in the mapping table of the AGR1 is specifically a routing mapping relationship corresponding to the MN, where the routing mapping relationship is specifically a mapping relationship between a user identity (AID) and a routing location identifier (RID), that is, an AID. -RID mapping relationship, as shown in Table 1. As can be seen from Table 1, the route mapping relationship of multiple mobile nodes is cached in the mapping table. That is to say, a plurality of mapping entries corresponding to the MN are cached in the mapping table. If a timer is set for each mapping entry, the system requires a large number of timers, which makes the system expensive. Therefore, in an embodiment, a uniform timer (the first timer D1 in the above) is set for all mapping entries in the mapping table, and an identifier bit is set for each MN, and the identifier is used to identify Whether the MN passes data packets in an aging period T1. The value of the identifier of the MN is initialized at the same time. The initialization mode is as follows: The initial value of the identifier bits of all MNs is set to 1, that is, all mobile nodes have data packets passing by default in an aging period T1. During the aging period T1, the AGR1 task forwards the data packet and sets the identifier value of the MN's identification bit with the data packet to 1. For a MN that has no data packets passing through the aging period T1, the value of its flag is set to zero. The first timer D1 traverses the mapping table once every aging time T1. When the first timer is traversing the mapping table, if the value of the identifier of the mobile node is 1, the value of the identifier bit is set to 0, if the mobile node If the value of the flag bit is 0, the corresponding mapping entry of the mobile node is deleted in the mapping table. With this scheme, AGR1 only needs to set a common timer for all mobile nodes, and can also implement mapping entries corresponding to the stored MNs in the mapping table without sending a query request to the mapping server. Timing update processing. In an embodiment, the peer entry stored in the peer information table is specifically corresponding to the MN. Corresponding information corresponding to the CN of the communication peer; specifically, the peer entry stored in the peer information table is the CN corresponding to the MN and the information of the AGR to which the CN belongs. Similarly, as can be seen from Table 2 and Table 3, a plurality of peer entries corresponding to CNs are also stored in the peer information table. Then, accordingly, there are many CNs. If a timer is set for each CN, the system requires a large number of timers, which also increases the overhead of the system. Therefore, as with the mapping table, a timer (the second timer D2 in the above) is also uniformly set for all the CNs stored in the peer information table. And setting an identifier bit for each CN, the identifier bit is used to identify whether the CN has data in an aging period T2. The value of the identifier bit is initialized at the same time. The initialization method is as follows: Set the value of the flag corresponding to all CNs in the peer information table to 1. AGR2 determines whether the CN has a data packet in the aging period T2, that is, whether the CN has a data packet processing in the period T2; if yes, the value of the flag corresponding to the CN is set to 1, if not, The value of the flag corresponding to the CN is set to 0; the second timer D2 traverses the mapping table once every time T2, and when D2 traverses the mapping table, if the value of the flag of the CN is 1, the value of the flag is If it is set to 0, if the value of the CN flag is 0, the information of the peer entry corresponding to the CN is deleted in the peer information table. With this scheme, AGR2 only needs to set a common timer for all communication peers. It can also implement the peer entry corresponding to the CN of the peer information table without sending a query request to the mapping server. Update processing. It can be seen that the mapping entry of the MN stored in the mapping table is updated by the AGR1 timing T1 and the peer entry of the CN stored in the peer information table is updated periodically by the AGR2, and the scheme of setting T2>T1 is set. In the process of mobility switching, the data packets sent by AGR1 can be sent to AGR3 through AGR2 and forwarded to AGR3 through AGR3. After the mobility switching is completed, the AGF3 gateway can be switched. The new route mapping mode is sent to the AGR1 where the CN is located in time to ensure that the AGR1 can exchange the normal data packets between the new ones. Embodiment 1 : In the following, a specific embodiment is used to compare 情况1>Τ2, and how to ensure normal communication between ΜΝ and CN in the case of Τ2>Τ1 is described in detail. For example, the period T1 of H without D1 is 10, and the value of period T2 of D2 is 8. The CN initiates a certain service flow at time 1. At this time, the mapping entry corresponding to the MN in the mapping table of the AGR1 and the peer entry corresponding to the CN in the peer information table are created at time 1, and the mapping table of the AGR1 is in the MN. The value of the flag bit and the value of the flag bit of the CN in the peer information table are set to 1 at time 1. D1 traverses the mapping table at time 10, and since the value of the MN's flag bit is 1, the value of its flag bit is set to zero. Similarly, D2 traverses the peer information table at time 8 when the value of the flag of the CN is 1, and the value of its flag is set to zero. Assume that there is a data message interaction between the CN and the MN at time 18. For D2, in the period from time 8 to time 16, since the CN has no data packet processing, at time 16, the information of the peer entry corresponding to the CN in the peer information table will be deleted. If the MN has a mobility switch at time 17, then, since the peer information table corresponding to the CN corresponding to the service flow does not exist in the peer information table of the AGR2, the gateway AGR3 cannot be obtained. The information about the peer entry corresponding to the corresponding CN of the MN, so AGR3 will not notify AGR1 of the new route mapping relationship corresponding to the MN. At this time, the AGR1 where the CN is located does not receive the request for updating the route mapping relationship sent by the AGR3, and the AGR1 does not update the new route mapping relationship corresponding to the MN of the service flow initiated by the MN stored in the mapping table. Then, for the data packet sent by the CN to the MN, AGR1 sends according to the route mapping relationship of the MN stored in the current mapping table. In fact, at this time, the AGR1 data packet is sent to the AGR2, and the MN has already switched to the AGR3. The AGR2 and the AGR3 have no communication tunnel at this time. Therefore, the AGR2 can only discard the data packet. Because the MN always has data packets in the AGR1, the mapping entries corresponding to the MN in the mapping table of the AGR1 cache will not be aged, so the data packets sent by the CN to the MN will continue to be lost. Assume that the value of T2 is 10 and the value of T1 is 8. Similarly, CN initiates a certain service flow at time 1. In this case, the mapping entry corresponding to the MN in the mapping table and the peer entry corresponding to the CN in the peer information table. Created at time 1. Similarly, the identification value of the identification bit of the MN in the mapping table of AGR1 and the identification value of the identification bit of the CN in the peer information table are all set to 1 at time 1. D1 traverses the mapping table at time 8 . Since the value of the MN's flag bit is 1, the value of its flag bit is set to zero. Similarly, D2 traverses the peer information table at time 10, and at this time, since the value of the flag of the CN is 1, the value of its flag is set to zero. It is assumed that there is a data message interaction between the CN and the MN at time 14, and the MN performs a mobile handover at time 15. For D1, since the MN has data packet processing in the 8-16 time period, the mapping bar corresponding to the MN in the mapping table is not deleted at time 16. Head. For D2, in the time period of 10-20, the CN has data packet processing, so at time 20, the peer entry of the CN is still stored in the peer information table. In the MN process at time 15, the peer entry corresponding to the CN corresponding to the MN in the peer information table in the self-cache is also forwarded to the AGR3. Therefore, the MN's hand-in gateway AGR3 can obtain the information of the peer entry corresponding to the CN at time 15. When there is a data packet exchange between the MN and the CN, the AGR3 sends an update request for the route mapping relationship to the AGR1, and notifies the AGR1 of the new route mapping relationship corresponding to the MN, so that the data packet is not lost. In order to ensure the effect of the seamless handover, the MN can also update the processing of the peer entry information of the CN in the peer information table of the AGR3 in the AGR2 to AGR3 handover process. Delete it when you are done. In actual applications, if T2 is greater than T1, in fact, the aging period of AGR at both ends may not be synchronized, and there are still some problems. For example, the value of the period T1 of D1 is 8, and the value of the period T2 of D2 is 10. The data packet of a certain service flow is exchanged between CN and MN at time 10, if the period of D1 is 9/17/25. . . . , and the period of D2 is 1/11/21. If no message passes AGR1 and AGR2 from time 10 to time 21, the peer entry corresponding to CN in the peer information table of AGR2 will Because the aging is deleted, the mapping entry of the MN in the AGR1 mapping table has not been aged. Therefore, if the MN switches between the times 22-26, the AGR1 will still send a data message to the AGR2, and the CN will also appear. The problem of communication interruption between MNs. Therefore, in an embodiment, in order to completely avoid the problem of communication interruption between the CN and the MN, the seamless handover between the CN and the MN is ensured, and the value of the aging period T2 of the second timer is set to T1. Twice or more than twice. When T2 2T1, the peer entry corresponding to the CN in the peer information table must be aged after the mapping entry corresponding to the corresponding mapping table, so that normal communication between the CN and the UI can be guaranteed. At this time, the value of Τ 1 can also be appropriately relaxed to reduce the load on the device. It should be noted that, in the actual mobile switching process, the value of the aging period Τ2 can be dynamically set according to the value of the aging period T1 of D1, as long as Τ2 > T1 is guaranteed. In an embodiment, the value of the period Τ2 of the D2 is dynamically set in the following manner, and the value information of the period T1 is saved in the data packet sent by the communication peer CN to the mobile node. Therefore, when the MN communicates with the CN, the AGR2 where the MN is located extracts the value information of the T1 in the data packet sent by the CN, and the value of the aging period T2 of the D2 can be set accordingly. Of course, in order to ensure seamless switching, the value of T2 is set to be twice or more than T1. Generally, a part of the field is selected from the IP header of the packet to carry the value information of the first timer T1. In an embodiment, specifically, the value information of T1 is stored in an option field sent to the IP header of the MN message or a reuse service type TOS field. If you use the option field in the IP header to carry the value information of T1, the specific format of the option field can be as shown in Table 4 below: Table 4 IP option field carrying T1 value information Option type Option length timer value Example 2:

The following is a detailed description of a method for managing data packets when a mobile node performs handover in the case of dynamically setting a timer duration. As shown in FIG. 3, the specific process is as follows:

301. The CN initiates a service flow to the MN;

302. The CN sends the message to the AGR1. 303. After receiving the data packet of the service flow, the AGR1 queries the mapping server for the mapping entry of the corresponding AID-RID in the mapping table, and caches the mapping entry locally after the query. And the outer layer encapsulation of the data packet according to the route mapping relationship, and the option of the timer in the IP header of the packet is set according to the duration of the first timer T1 configured locally by AGR1 during encapsulation. The value of T1 is selected according to the actual requirement; 304, AGR1 sends the data packet to AGR2;

Set the local T2 timer duration according to the value of the first timer T1 in the timer option in the IP header;

306. AGR2 forwards the data packet to the MN. It can be seen from the above process that the value of the aging period T1 of the D1 of the AGR can be used. Local configuration. Therefore, AGR2 receives different values of the aging period T1 of D1 sent by multiple AGRs. In this case, the second timer D2 can also use the method of setting the value of the identifier bit to achieve A method of setting different timers for different peer entries in the peer mapping table. In an embodiment, a basic polling time T is also preset for the AGR2. If the AGR2 determines that the CN has a data message in the polling time T, the value of the CN flag is set to an initial value. When the data packet is passed, the value of the flag bit of the CN is decremented by 1. When the value of the flag bit of the CN is reduced to 0, the peer entry corresponding to the communication peer is deleted. The method for initializing the value of the identifier bit may be: setting the value of the aging period T2 according to the value of the aging period T1, and setting the value of the aging period T2 of the second timer as the value of the identifier of the communication peer. . Embodiment 3: It is assumed that the D Γ aging period Τ 来自 from AGR1 received by AGR2 is 5, and the received D1 "aging period T1" from AGR1 "is 8, then the basic timer of AGR2 The polling time T can be set to 1, where the selection of T needs to satisfy T2>T. Thus, the aging period of the timer of the corresponding peer entry in the peer information table corresponding to AGR1' is 10, and the corresponding AGR1' The initial value of the value of the communication peer identifier bit is also set to 10; the timer aging period of the corresponding peer entry in the peer information table corresponding to AGR1" is 16, and the value of the identifier bit of the communication peer corresponding to the AGR1" It is also set to 16. Then, every time AGR2 polls, if there is no data packet passing by the communication peer, the value of the identification bit of the communication peer is decremented by one, and if there is a message, the value is reset to the initial value. It is possible to achieve different effects of different communication peer aging times. It is assumed that, in the AGR2 polling, if the communication peer corresponding to AGR1' does not have "^ text passing, the value of the corresponding flag bit of the communication peer is decremented by one. Then, after AGR2 polling, the value of the corresponding identification bit of the corresponding communication peer of AGR1' is 9. When the value of the flag of the CN is reduced to 0, the peer entry corresponding to the communication peer is deleted. In addition, the present invention also provides a management system for identifying data packets when a mobile node switches in a network, including a mobile node, a mobile node communication peer, a first access gateway device where the mobile node communication peer is located, and a mobile node where the mobile node is located. a second access gateway device, and a third access network router; when the mobile node performs handover, the first access gateway device according to the mapping entry corresponding to the mobile node stored in the self mapping table, Receiving, the data packet sent to the mobile node is sent to the second access gateway device, and the second access gateway device sends the data packet And the peer entry corresponding to the communication peer end stored in the peer information table is forwarded to the third access gateway device, where the third access gateway device forwards the data packet to the Mobile node

After the handover of the mobile node is completed, the first access gateway device sends the received data to the mobile node according to the mapping entry corresponding to the mobile node sent by the third access gateway device. Sending the packet to the third access gateway device, and then forwarding, by the third access gateway device, the data packet to the mobile node; wherein, an aging period of the mapping entry stored in the mapping table For T1, the aging period of the peer entry stored in the peer information table is T2, and T2>T1. among them,

The first access gateway device is configured to: when the mobile node performs handover, the first access gateway device receives the received message according to a mapping entry corresponding to the mobile node stored in the self mapping table. Sending, to the second access gateway device, the data packet sent to the mobile node; and, after the handover of the mobile node is complete, the first access gateway device sends the data according to the third access gateway device. The mapping entry corresponding to the mobile node sends the received data packet addressed to the mobile node to the third access gateway device; the second access gateway device is configured to: when the mobile node Forwarding, by the first access gateway device, the data packet sent by the first access gateway device and the peer entry corresponding to the communication peer end stored in the peer information table to the third access gateway device The third access gateway device is configured to: when the mobile node performs handover, the first

Node

The aging period of the mapping entry stored in the mapping table is T1, and the aging period of the peer entry stored in the peer information table is Τ2, and Τ2> Τ1. The first timer is set in the first access gateway device, and the first timer periodically updates the mapping entry in the mapping table every aging period T1; and the second access gateway device is configured to be configured. The second timer updates the peer entry in the peer information table periodically every aging period Τ2. The mapping entry stored in the mapping table is a route mapping relationship corresponding to the mobile node; the first access gateway device is further configured to: preset a flag for identifying whether the mobile node is in the aging period T1 Having the identifier of the data packet and initializing the value of the identifier bit; determining whether the mobile node has a data packet passing in the aging period T1, and if so, setting the value of the mobile node identifier bit to 1 If not, the value of the mobile node identifier bit is set to 0; when the first timer traverses the mapping table, if the value of the mobile node identifier bit is 1, the mobile node is The value of the identifier bit is set to 0. If the value of the mobile node identifier bit is 0, the mapping entry corresponding to the mobile node is deleted. The peer entry stored in the peer information table is related information corresponding to the communication peer end;

The second access gateway device is further configured to: preset a flag for identifying whether the communication peer passes the data packet in the aging period T2 and initialize the value of the identifier bit; Whether the data communication message is passed by the communication peer end in T2, if yes, the value of the communication peer end identification bit is set to 1, if not, the value of the communication peer end identification bit is set to 0; And when the second timer traverses the peer information table, if the value of the communication peer identifier bit is 1, the value of the communication peer identifier bit is set to 0; If the value of the flag bit is 0, the peer entry corresponding to the communication peer is deleted. The first access gateway device is further configured to: save the value information of the T1 in a data packet sent by the communication peer end to the mobile node; the second access gateway device is further configured to And: when the mobile node communication peer communicates with the mobile node, extracts the value information of T1 in the data packet sent by the first access gateway device, and sets the value of the aging period T2 accordingly. The peer entry stored in the peer information table is the related information corresponding to the communication peer; the second access gateway device is further configured to: preset one to identify the communication peer in the aging period Whether there is a flag for passing the data packet in T2 and initializing the value of the identifier bit; and presetting a basic polling time T, if it is determined that the communication peer has a data packet in the polling time T If yes, the value of the identifier of the communication peer is set to an initial value. If no data packet is passed, the value of the identifier of the communication peer is decremented by one, and the value of the identifier of the communication peer is decreased. When it is 0, the peer entry corresponding to the communication peer is deleted, where T2>T.

The embodiment also discloses an access gateway device, where the access gateway device is applied to an identity and location separation network, and the access gateway device is configured to: when the access gateway device is a mobile node communication peer Accessing the access gateway device, when the mobile node performs handover, the access gateway device accessed by the mobile node communication peer end according to the mapping entry corresponding to the mobile node stored in the self mapping table, Receiving, the data packet sent to the mobile node is sent to the access gateway device accessed by the mobile node before the handover; and when the mobile node is switched, the mobile node is connected to the communication peer The access gateway device sends the received data packet addressed to the mobile node to the mobile node according to the mapping entry corresponding to the mobile node sent by the access gateway device accessed by the mobile node after the handover. An access gateway device that is accessed after the handover; when the access gateway device is an access gateway device accessed before the mobile node switches, when the mobile node is The data packet sent by the access gateway device accessed by the mobile node communication peer end and the peer entry corresponding to the communication peer end stored in the peer information table are forwarded to the mobile terminal. The access gateway device accessed after the node is switched;

When the access gateway device is an access gateway device that is accessed after the mobile node is switched, when the mobile node performs handover, the mobile gateway node transmits the access gateway device that is accessed before the handover. Transmitting, to the mobile node, the data packet, and transmitting, by the mobile node, the data packet sent by the access gateway device accessed by the mobile node to the mobile node; The aging period of the mapping entry stored in the mapping table is T1, and the aging period of the peer entry stored in the peer information table is Τ2, and Τ2> Τ1. The first timer is set in the access gateway device that is connected to the mobile node communication peer end, and the first timer periodically updates the mapping entry in the mapping table every aging period T1; Setting a second timer in the access gateway device that is connected before the handover, the second timing The peer entry in the peer information table is updated periodically every aging period T2. The mapping entry stored in the mapping table is a routing mapping relationship corresponding to the mobile node; when the access gateway device is an access gateway device accessed by a mobile node communication peer, the access gateway device The method is further configured to: determine a flag for identifying whether the mobile node passes the data packet in the aging period T1 and initialize the value of the identifier bit; and determine whether the mobile node has data in the aging period T1. Passing, if yes, setting the value of the mobile node identifier bit to 1, if not, setting the value of the mobile node identifier bit to 0; when the first timer traverses the mapping table If the value of the mobile node identifier bit is 1, the value of the mobile node identifier bit is set to 0, and if the value of the mobile node identifier bit is 0, the mapping entry corresponding to the mobile node is deleted. . The peer entry stored in the peer information table is related information corresponding to the communication peer end;

When the access gateway device is an access gateway device that is accessed before the mobile node is switched, the access gateway device is further configured to: preset a flag for identifying whether the communication peer end is in the aging period T2 Having the identifier of the data packet and initializing the value of the identifier bit; determining whether the data packet is passed by the communication peer in the aging period T2, and if yes, setting the value of the communication peer identifier bit If not, the value of the communication peer identifier bit is set to 0; when the second timer traverses the peer information table, if the value of the communication peer identifier bit is 1, Then, the value of the communication peer identifier bit is set to 0; if the value of the identifier bit of the communication peer is 0, the peer entry corresponding to the communication peer is deleted. Wherein: the access gateway device is an access gateway device that is accessed by the mobile node communication peer end, and the access gateway device is further configured to: save the value information of the T1 in the communication peer end In the data packet of the mobile node; when the access gateway device is an access gateway device that is accessed before the mobile node switches, the access gateway device is further configured to: when the mobile node communicates When the peer communicates with the mobile node, extracting T1 in the data packet sent by the access gateway device accessed by the mobile node communication peer end The value information is set, and the value of the aging period T2 is set accordingly. The peer entry stored in the peer information table is related information corresponding to the communication peer end; when the access gateway device is an access gateway device accessed before the mobile node switches, the connection The gateway device is further configured to: preset a flag for identifying whether the communication peer passes the data packet in the aging period T2 and initialize the value of the identifier bit; and preset a basic polling time T If it is determined that the data packet is passed by the communication peer in the polling time T, the value of the identifier of the communication peer is set to an initial value, and if no data packet is passed, the communication peer is The value of the identifier bit is decremented by 1. When the value of the identifier bit of the communication peer is reduced to 0, the peer entry corresponding to the communication peer is deleted, where T2>T. The access gateway device is configured to initialize the value of the identifier bit as follows: when the access gateway device is an access gateway device that is accessed before the mobile node switches: according to the aging period The value information of T1 is set to the value of the aging period Τ2, and the value of the aging period Τ2 of the second timer is used as the value of the flag bit of the communication peer. Wherein, the Τ2 2Τ1.

By applying the present invention, the aging period of the timer in the access gateway device of the mobile node, the gateway device, and the access gateway device where the CN is located is reasonably set, so that the mobile node can effectively mitigate the context switching. The load on the access gateway device does not cause the interruption of communication between the CN and the UI, thus ensuring that the data packets are not lost when the mobile node switches.

One of ordinary skill in the art will appreciate that all or a portion of the above steps may be performed by a program to instruct the associated hardware, such as a read only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module unit in the foregoing embodiment may be implemented in the form of hardware, or may be implemented in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software. The above content is a further detailed description of the present invention in combination with specific embodiments, and cannot It is to be understood that the specific embodiments of the invention are limited only by the description. A person skilled in the art can make a plurality of simple deductions or substitutions without departing from the spirit and scope of the invention.

Industrial Applicability The present invention ensures normal communication between the MN and the CN during the MN mobility switching process and after the handover is completed. At the same time, through the setting of T2>T1, the access gateway device does not need to periodically send the update mapping table mapping entry to the mapping server and update the request of the peer information entry, thereby effectively reducing the load on the access gateway device. .

Claims

Claim

A method for managing a data packet when a mobile node is switched, wherein the method is applied to an identity and location separation network, and the method includes: when a mobile node performs handover, where the mobile node communicates with the peer end Sending, by the access gateway device, the received data packet addressed to the mobile node to the second access gateway device where the mobile node is located, according to the mapping entry corresponding to the mobile node stored in the mapping table. Transmitting, by the second access gateway device, the data packet and the peer entry corresponding to the communication peer end stored in the peer information table to the third access gateway device, where the third access The gateway device forwards the data packet to the mobile node; and when the mobile node completes the handover, the first access gateway device corresponds to the mobile node sent by the third access gateway device a mapping entry, the received data packet sent to the mobile node is sent to the third access gateway device, and then the third access gateway device The data packet is forwarded to the mobile node; wherein, the aging period of the mapping entry stored in the mapping table is T1, and the aging period of the peer entry stored in the peer information table is T2, and T2>T1 .

The method of claim 1, wherein the first timer is set in the first access gateway device, and the first timer periodically updates the mapping entries in the mapping table every aging period T1; A second timer is set in the second access gateway device, and the second timer periodically updates the peer entry in the peer information table every aging period Τ2.

The method of claim 2, wherein the mapping entry stored in the mapping table is a routing mapping relationship corresponding to the mobile node; the method further includes: presetting a Whether there is an identifier of the data packet passing through the aging period T1 and initializing the value of the identifier bit; the first access gateway device determines whether the mobile node passes the data packet during the aging period T1, if any, The value of the mobile node identifier bit is set to 1, if not, the value of the mobile node identifier bit is set to 0; when the first timer traverses the mapping table, if the mobile node If the value of the identifier bit is 1, the value of the mobile node identifier bit is set to 0, and if the value of the mobile node identifier bit is 0, the deletion is performed. A mapping entry corresponding to the mobile node.

The method of claim 2, wherein the peer entry stored in the peer information table is related information corresponding to the communication peer; the method further includes: presetting one for identifying the Whether the communication peer has an identifier for the data packet passing through the aging period T2 and initializes the value of the identifier bit; the second access gateway device determines whether the communication peer has a data packet in the aging period T2. Passing, if yes, setting the value of the communication peer identifier bit to 1, if not, setting the value of the communication peer identifier bit to 0; when the second timer traverses the peer In the information table, if the value of the communication peer identifier bit is 1, the value of the communication peer end identification bit is set to 0; if the value of the identification bit of the communication peer end is 0, the communication is deleted. The peer entry corresponding to the peer.

5. The method of claim 2, the method further comprising: storing the value information of the T1 in a data message sent by the communication peer to the mobile node; when the mobile node communicates When the peer end communicates with the mobile node, the second access gateway device extracts the value information of T1 in the data packet sent by the first access gateway device, and sets the value of the aging period T2 accordingly.

6. The method according to claim 5, wherein the value information of the T1 is saved in an option field or a reuse service type TOS field in an IP header of the data message.

The method of claim 6, wherein the peer entry stored in the peer information table is related information corresponding to the communication peer; the method further includes: presetting a message for identifying the communication Whether the peer end has an identifier for the data packet passing in the aging period T2 and initializes the value of the identifier bit; and further presets a basic polling time T for the second access gateway device, if the second connection The gateway device determines that the data of the communication peer end passes the data in the polling time T, and sets the value of the identifier bit of the communication peer to an initial value. If no data packet passes, the communication is performed. The value of the identifier of the peer is decremented by 1. When the value of the identifier of the peer is reduced to 0, the peer entry corresponding to the peer is deleted, where T2>T.

The method of claim 7, wherein the step of initializing the value of the identifier bit comprises: setting a value of the aging period T2 according to the value information of the aging period T1, and The value of the aging period T2 of the second timer is used as the value of the flag bit of the communication peer.

The method according to any one of claims 1 to 8, wherein the T2 2Τ1.

A system for managing data packets during handover of a mobile node, wherein the system is applied to an identity and location separation network, the system comprising: a mobile node, a mobile node communication peer, and a mobile node communication peer a first access gateway device, a second access gateway device where the mobile node is located, and a third access gateway device; the first access gateway device is configured to: when the mobile node performs handover, the An access gateway device sends the received data packet addressed to the mobile node to the second access gateway device according to the mapping entry corresponding to the mobile node stored in the mapping table; After the mobile node handover is completed, the first access gateway device sends the received data packet to the mobile node according to the mapping entry corresponding to the mobile node sent by the third access gateway device. Sending to the third access gateway device; the second access gateway device is configured to: when the mobile node performs handover, the first connection The data packet sent by the gateway device and the peer entry corresponding to the communication peer end stored in the peer information table are forwarded to the third access gateway device; the third access gateway device is set to : when the mobile node performs handover, the first

Node

The aging period of the mapping entry stored in the mapping table is T1, and the aging period of the peer entry stored in the peer information table is Τ2, and Τ2> Τ1.

The system of claim 10, wherein a first timer is set in the first access gateway device, and the first timer periodically updates a mapping entry in the mapping table every aging period T1; Setting a second timer in the second access gateway device, where the second timer is aging cycle

T2 periodically updates the peer entry in the peer information table.

The system of claim 11, wherein the mapping entry stored in the mapping table is a routing mapping relationship corresponding to the mobile node; the first access gateway device is further configured to: preset one for Determining whether the mobile node has an identifier for passing the data packet in the aging period T1 and initializing the value of the identifier bit; determining whether the mobile node has a data packet passing through the aging period T1, if any, The value of the mobile node identifier bit is set to 1, if not, the value of the mobile node identifier bit is set to 0; when the first timer traverses the mapping table, if the mobile node identifier bit If the value of the mobile node is 0, the value of the mobile node identifier is set to 0. If the value of the mobile node identifier is 0, the mapping entry corresponding to the mobile node is deleted.

The system of claim 11, wherein the peer entry stored in the peer information table is related information corresponding to the communication peer; the second access gateway device is further configured as: An identifier for identifying whether the communication peer has a data packet passing through the aging period T2 and initializing the value of the identifier bit; determining whether the communication peer has a data packet in the aging period T2, If yes, the value of the communication peer identifier bit is set to 1, if not, the value of the communication peer identifier bit is set to 0; when the second timer traverses the peer information table If the value of the communication peer identifier bit is 1, the value of the communication peer identifier bit is set to 0; if the value of the identifier of the communication peer is 0, the communication peer is deleted. Corresponding peer entry.

The system of claim 11, wherein: the first access gateway device is further configured to: save the value information of the T1 in a data packet sent by the communication peer end to the mobile node; The second access gateway device is further configured to: when the mobile node communication peer communicates with the mobile node, extract the value information of T1 in the data packet sent by the first access gateway device, and Set the value of the aging period T2 accordingly.

The system of claim 14, wherein the peer entry stored in the peer information table is related information corresponding to the communication peer; the second access gateway device is further configured to: preset one And determining, by the communication peer, whether an identifier of the data packet passes in the aging period T2 and initializing the value of the identifier bit; and preset a basic polling time T, if it is determined that the polling time T is If the data packet is passed by the communication peer, the value of the identifier of the communication peer is set to an initial value, and if no data packet is passed, the value of the identifier of the communication peer is decremented by 1. When the value of the identifier of the communication peer is reduced to 0, the peer entry corresponding to the communication peer is deleted, where T2>T.

An access gateway device, wherein the access gateway device is applied to an identity and location separation network, and the access gateway device is configured to: when the access gateway device is a mobile node communication peer Accessing the access gateway device, when the mobile node performs handover, the access gateway device accessed by the mobile node communication peer end according to the mapping entry corresponding to the mobile node stored in the self mapping table, Receiving, the data packet sent to the mobile node is sent to the access gateway device accessed by the mobile node before the handover; and when the mobile node is switched, the mobile node is connected to the communication peer The access gateway device sends the received data packet addressed to the mobile node to the mobile node according to the mapping entry corresponding to the mobile node sent by the access gateway device accessed by the mobile node after the handover. An access gateway device that is accessed after the handover; when the access gateway device is an access gateway device that is accessed before the mobile node switches, when the mobile node performs cutting Transmitting, by the mobile node, the data packet sent by the access gateway device accessed by the mobile node communication peer end, and the peer end entry corresponding to the communication peer end stored in the peer information table to the mobile node for switching The access gateway device that is accessed later; when the access gateway device is an access gateway device that is accessed after the mobile node switches, when the mobile node performs handover, the mobile node is switched before the mobile node Transmitting, by the access gateway device, the data packet sent by the access gateway device to the mobile node; when the mobile node handover is completed, sending the mobile node to the access gateway device accessed by the access peer device The data packet is forwarded to the mobile node, where the aging period of the mapping entry stored in the mapping table is T1, and the peer information table The aging period of the peer entry stored in it is T2, and Τ2> Τ1.

The access gateway device according to claim 16, wherein a first timer is set in an access gateway device that is connected to the mobile node communication peer end, and the first timer is aging cycle T1 And periodically updating the mapping entry in the mapping table; setting a second timer in the access gateway device that is accessed before the mobile node is switched, and the second timer periodically updates the peer information table in the aging period Τ2 The opposite entry.

The access gateway device according to claim 17, wherein the mapping entry stored in the mapping table is a route mapping relationship corresponding to the mobile node; when the access gateway device is a mobile node communication peer end Accessing the access gateway device, the access gateway device is further configured to: preset a flag for identifying whether the mobile node passes the data packet in the aging period T1 and initialize the value of the identifier bit Determining whether the mobile node has a data packet passing in the aging period T1, if yes, setting the value of the mobile node identifier bit to 1, if not, setting the value of the mobile node identifier bit to 0: when the first timer traverses the mapping table, if the value of the mobile node identifier bit is 1, the value of the mobile node identifier bit is set to 0, if the mobile node identifier bit A value of 0 deletes the mapping entry corresponding to the mobile node.

The access gateway device according to claim 17, wherein the peer entry stored in the peer information table is related information corresponding to the communication peer; when the access gateway device is the mobile The access gateway device that is connected before the node is switched, the access gateway device is further configured to: preset a flag for identifying whether the communication peer passes the data packet in the aging period Τ2 and initialize the location Determining the value of the identifier bit; determining whether the communication peer has a data message in the aging period Τ2, if yes, setting the value of the communication peer identifier bit to 1, if not, then the communication The value of the peer identifier bit is set to 0. When the second timer traverses the peer information table, if the value of the communication peer identifier bit is 1, the value of the communication peer identifier bit is set. Set to 0; if the value of the identifier of the communication peer is 0, delete the peer entry corresponding to the communication peer.

The access gateway device according to claim 17, wherein: when the access gateway device is an access gateway device accessed by a mobile node communication peer, the access gateway device is further configured to: The value information of the T1 is stored in the data packet sent by the communication peer to the mobile node; when the access gateway device is the access gateway device accessed before the mobile node switches, The access gateway device is further configured to: when the mobile node communication peer communicates with the mobile node, extract the value of T1 in the data packet sent by the access gateway device accessed by the mobile node communication peer end Information, and set the value of the aging period T2 accordingly.

The access gateway device according to claim 20, wherein the peer entry stored in the peer information table is related information corresponding to the communication peer; when the access gateway device is the mobile node The access gateway device that is connected before the handover, the access gateway device is further configured to: preset a flag for identifying whether the communication peer passes the data packet in the aging period T2 and initialize the The value of the flag bit is set; and a basic polling time T is preset. If it is determined that the data packet is passed by the communication peer end within the polling time T, the value of the flag bit of the communication peer is set to an initial value. If no data packet is passed, the value of the identifier of the communication peer is decremented by 1. When the value of the identifier of the communication peer is reduced to 0, the peer entry corresponding to the communication peer is deleted, where , T2>T.

The access gateway device according to claim 21, wherein, when the access gateway device is an access gateway device that is accessed before the mobile node switches, the access gateway device is set as follows The method initializes the value of the identifier bit: according to the value information of the aging period T1, setting the value of the aging period Τ2, and using the value of the aging period Τ2 of the second timer as the communication peer end The value of the flag bit.

The access gateway device according to any one of claims 16-22, wherein

2Τ1.