CN100455117C

CN100455117C - Method for improving reliability of fast switch over business

Info

Publication number: CN100455117C
Application number: CNB2005100997410A
Authority: CN
Inventors: 陈洪飞; 张健
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2005-09-05
Filing date: 2005-09-05
Publication date: 2009-01-21
Anticipated expiration: 2025-09-05
Also published as: CN1929680A; WO2007028297A1

Abstract

This invention relates to one method to provide rapid switch business reliance, which comprises the following steps: in IPv6 network, when moving point MN to connect to front network PAR; MN moves the NAR transfer address of NCoA and binding the update to communication partner CN/ home agent HA; when MN transfers to network NAR to fulfill formal binding updating to interact said NCoA address and CN/HA.

Description

Improve the method for reliability of fast switch over business

Technical field

The present invention relates to the communications field, relate in particular to a kind of method that improves reliability of fast switch over business.

Background technology

Along with development of internet technology, and the appearance of a large amount of movable terminations, as notebook computer, PDA, mobile phone, mobile unit or the like, started the upsurge of mobile computing, increasing user can be connected to the Internet network by the common moving wireless network anywhere by various terminals.

For solving the demand of mobile service, on network level, introduced Mobile IP (mobile IP) technology.

The basic principle of Mobile IP technology is to make mobile node (MN) can carry out IP communication with initial IP address all the time in moving process, thus the upper layer application that guarantees the IP network layer carrying not interrupting and continuing property in keeping moving.

Along with the expansion of network size, the IPv6 technology will replace present IPv4 technology gradually with its huge advantage such as address space.Based on the Mobile IP of IPv6, i.e. Mobile IPv6 technology by the technical advantage of IPv6 self with to the improvement of Mobile IPv4 technology, becomes the upstart in Mobile IP field, more and more progressively should be used widely.

The basic principle of Mobile IPv6 technology is described below in conjunction with Fig. 1:

1. when mobile node is connected on its home network, take the mode the same to work with other stationary nodes.

2. whether mobile node oneself roams on the field network by the neighbor discovery mechanisms detection of IPv6.The nonlocal gateway of IPv6 can send router advertisement message periodically, the prefix that wherein comprises this field network, after mobile node is received the router advertisement message of nonlocal gateway, check that the prefix of field network wherein is different with the prefix of home network, then think to roam to field network.

3. when if mobile node finds oneself to have moved on the field network, it will on the basis of the router advertisement information of receiving by there being the automatic layoutprocedure in state or stateless address to obtain Care-of Address on the field network.This moment, mobile node had home address and Care-of Address simultaneously.

4. mobile node is registered to described Care-of Address on the home agent (HA) by " Binding Update " message.

5. mobile node also can be given described Care-of Address its communication parter by " Binding Update " message registration notification.Before the registration, need to carry out earlier the ReturnRoutability testing process between mobile node and the communication parter, be that mobile node sends Home Init Test message and Care-of InitTest message earlier to communication parter, after the latter handles, return Home Test message and Care-of Test message and give mobile node.

If 6. the communication parter of mobile node is not known its Care-of Address, just will data message be sent on the home network of mobile node according to the home address of mobile node, its home agent will be truncated to these data messages then, according to the mobile node present care-of address, utilize tunneling mechanism to give mobile node again with these data message forwarding.

And mobile node issues the message of communication parter and also can issue home agent by reverse tunnel earlier, hands to communication parter by home agent again.

Because under this mode, the data message between communication parter and the mobile node all will carry out transfer by home agent, so be called " triangle route " mode.

7. if knowing by " Binding Update ", communication parter the Care-of Address of mobile node then utilizes the route extension header of IPv6 directly to send data message to mobile node.Because first destination address of data message is a Care-of Address, second destination address is a home address, thus can described data message directly be sent to mobile node in the field network according to described Care-of Address, and do not need through the home agent transfer.

On the rightabout, the data message source address that mobile node is issued communication parter is a Care-of Address, and home address is kept in the destination extension header of data message.Like this, data message also can be issued home agent without reverse tunnel, but directly issues communication parter.

This mode, corresponding " triangle route " mode 6. is called " routing optimality " mode.

By foregoing description as can be seen, Mobile IPv6 technology has solved the mobile communication problem between mobile IPv 6 node and the IPv6 communication parter.

When mobile node was mobile on two foreign link, according to the regulation of RFC 3775 (MobilitySupport in IPv6), it was a moving process of realizing described mobile node by binding update messages, and detailed process is as follows:

Step 1, MN are according to ND (Neighbor Discovery; Neighbours find) the protocol discovery legacy network is unreachable, thus legacy network has been left in affirmation, roams into new network.

Step 2, MN are by the default router in the new network of RA (router advertisement) searching of ND agreement.

Step 3, MN utilize the prefix of the default router issue in the new network, generate new CoA (Care-of Address), and MN can have a plurality of Care-of Address, but can only have a main Care-of Address to come into force, and is used for the communication with CN/HA.

Step 4, after obtaining new main Care-of Address on the new default router, MN sends binding update messages to HA, to register new main Care-of Address.

After step 5, HA receive described binding update messages, create or the renewal banding cache.For new binding, HA must carry out DAD to the home address of binding and detect before returning binding acknowledgement message.

Wherein, the BU that stipulates in RFC3775 (Binding Update) message format is as follows:

Wherein:

Sequence#: the sequence number of binding update messages sequence number and BAK message will mate

A:Acknowledge determines by the A flag bit is set whether MN needs the affirmation of BU

H:Home Registration indicates by H is set whether this message is handled by HA

L：Link-Local?Address?Compatibility

K:Key Management Mobility Capability, effective when BU sends to HA,

Reserved: keep

Lifetime: the life span of Binding Update, 1 unit is 4 seconds

Mobility Options: mobile option

If step 6 is bound successfully, HA sends BA (Binding Acknowledgement; Binding acknowledgement) message is accepted this binding to MN.

Step 7, after MN guarantees that home address effectively, beginning is registered to each CN/HA.

Carry out a series of verification process between step 8, MN and the CN/HA.

After step 9, MN and CN/HA finished authentication, the flow between mobile node and the communication node was no longer delivered by home agent, and handoff procedure is finished.

In the said process, when MN switches at network, may need just can finish in several seconds or tens seconds, flow can be interrupted during this, thereby causes professional interruption.

In order to address the above problem, the technical scheme of the prior art relevant with the present invention one has been proposed, it is quick switching (faster handover) agreement that RFC4068 puts forward, its main thought is before the first step of RFC3775 regulation, obtain the information of adjacent networks in advance, generation will move to the IP address of adjacent networks.Then, MN will hand to oneself again according to the IP address of the adjacent networks that is generated after the flow that CN/HA sends over is handed to NAR by PAR.

Suppose that MN moves to another field network from a field network, as shown in Figure 2, PAR is the couple in router of network before MN moves, and NAR is the couple in router that MN moves the back network.The specific implementation process of prior art comprises as shown in Figure 3 at this moment:

Step 11, MN send in the PAR network in the ND message, send PtSolPr message to PAR, request AP (Access Point; Access point claims wireless lan transceiver again) and the network information.

Step 12, PAR loopback RtSolPr response message comprise the information of facing network mutually in the message, promptly comprise the information of facing network router NAR and AP mutually.

Step 13, MN receive described response message, do not support quick switching if the AP information of returning, illustrates network for empty, and then MN stops fast handover procedures; If be not empty, then MN generates NCoA (New Care-ofAddress; The Care-of Address of NAR network), prepare for moving to NAR.

Step 14, when MN confirm to move and will take place, then send FBU (Fast Binding Update; Quick Binding Update) message is given PAR, requires PAR to give NAR to the direct traffic of MN, comprises the NCoA that MN has generated in the described FBU message.

After step 15, PAR receive FBU message, bind previous Care-of Address PCoA (PreviousCare-of Address; The Care-of Address of PAR network) and NCoA, for being redirected, flow prepares; Finish after the binding, send out HI (Handover Initiate; Transfer initialization) message is to NAR, and whether NCoA is legal in inspection.

Step 16, described NAR reply HAck to PAR after receiving HI, confirm legitimacy.

Step 17, described PAR reply the FBAck message for MN and NAR, and PAR is redirected the MN flow to NAR afterwards.

Step 18, MN move out the PAR network and the PAR contact is interrupted.

Step 19, MN move to the NAR network, send FNA (Fast NeighborAdvertisement; Quick neighbor advertisement) message is announced to adhere to arrive the NAR network to NAR, and confirms the NCoA address with NAR.

The Binding Update of step 20, beginning RFC3775 regulation.

After the binding of carrying out the RFC3775 regulation, the mapping relations of record home address and Care-of Address in banding cache based on the information interaction between realization CN/HA of the information after the described binding and MN, specifically comprise then:

Step 21, MN send the CN/HA of data flow to far-end, and its source address is the PCoA address.

After step 22, described CN/HA receive described MN data flow, return corresponding information according to described PCoA address and give MN, destination address is the PCoA Care-of Address, and the home address of MN is included in the message ad-hoc location of RFC3775 regulation.

After step 23, described MN receive the message of described CN/HA transmission, mapping relations according to record home address and Care-of Address in the banding cache, described PCoA Care-of Address is converted to home address, and the data flow that receives is uploaded to application layer according to described home address, finish the reception of data message and handle.

Through after the above-mentioned steps, before the first step of RFC3775 regulation, the information of being faced network in advance mutually, generation will move to the IP address of facing network mutually, thereby before the Binding Update process of RFC3775 regulation is finished, just flow is redirected to NAR by PAR.

After moving to NAR Deng MN, though also do not finish the Binding Update process of RFC3775 regulation, but MN can receive that handing to NAR from PAR hands to the flow of oneself again, promptly as shown in Figure 4, CN/HA arrives described MN to the data flow of MN through CN/HA → PAR → NAR → MN, this moment, source address was the CN/HA address, and destination address is the PCoA address of MN, thereby can reduce the flow interrupt time.

After MN moved to NAR, as shown in Figure 5, MN was MN-＞NAR-＞CN/HA to the path of the data traffic of CN/HA, middle without PAR, since also do not finish the Binding Update process this moment, the PCoA address that source address is still distributed in the PAR network, and destination address is the CN/HA address.

In above-mentioned prior art, because therefore the PCoA address that the source address of the flow that MN sends is still distributed in the PAR network exists following defective:

When the NAR network carried out inspection of reversal path, the flow that causes MN to send to CN/HA was easily masked by the router in the NAR network, and then causes flow interrupt.

When being PCoA in order to solve above-mentioned source address, can be by the problem of the inspection of reversal path of NAR network filtration, the prior art relevant with the present invention two proposed, its basic thought is: set up a tunnel between MN-＞PAR, make MN transfer as shown in Figure 4 MN-＞NAR-＞PAR-＞CN/HA to the path of the data traffic of CN/HA.At this moment, MN is issued to the information of CN/HA, and two-layer IP heading is arranged, and ground floor is used for guarantee information from MN to PAR, can not be reversed route inspection filters out, source address is NCoA, and destination address is PAR, and second layer source address is the PCoA address of MN, destination address is the CN/HA address, after information utilized ground floor IP heading to arrive PAR from MN, PAR removed the ground floor heading, utilizes second layer heading to forward information to CN/HA.

By the technical scheme of prior art two as can be seen, MN sends to the source address of the data flow among the CN/HA when being PCoA though it can solve in the prior art one, the problem that can be filtered by the inspection of reversal path of NAR network,, there is following defective in it:

1, owing to increase one deck data message head, therefore can take the bandwidth of network more, make network become more congested.

2, MN and PAR need support the tunnel to handle, thereby can reduce the efficient of transmitting data message, and then reduce the processing speed of system.

Summary of the invention

In view of above-mentioned existing in prior technology problem, the purpose of this invention is to provide a kind of method that improves reliability of fast switch over business, by the present invention, avoided moving to the NAR network as MN, when using PCoA address transmitted traffic, because network uses inspection of reversal path, causes flow to be masked by the router in the NAR network, and then causes the problem of flow interrupt; And, by the present invention, the flow that sends at the NAR network as MN is during to CN/HA, source address can directly adopt NCoA, and need not to consider that flow can adopt other complicated technology because of the problem that source address is filtered by NAR, thereby avoided prior art two because one deck data message heads that increase need MN and PAR to support the tunnel to handle more, and a series of problems such as to cause that system handles speed is slow, network becomes more congested.

The objective of the invention is to be achieved through the following technical solutions:

A kind of method that improves reliability of fast switch over business provided by the invention comprises:

A, when mobile node MN be connected to be moved before during network PAR, described MN is before Binding Update, the Care-of Address NCoA when being about to of obtaining moved to new network N AR is pre-bound on communication parter CN or the home agent HA;

B, when described MN forwards described network N AR to, and finish before the formal Binding Update, use described NCoA address and CN or HA interactive information.

Wherein, before described steps A, comprise:

A0, MN are before moving in the network time, by carrying out information interaction generation NCoA with described PAR.

Wherein, described steps A 0 specifically comprises:

A01, MN send neighbours and find in the ND message in the PAR network, the router request message that sends agent advertisement is asked the access point AP information and the network information to PAR;

A02, PAR loopback agent router bulletin response message comprise the information of facing network router NAR and AP mutually in the message;

A03, MN receive described response message, if the AP information of returning is sky, then MN affirmation network does not support to switch fast and stop fast handover procedures; If be not empty, then MN generates NCoA.

Wherein, described steps A specifically comprises:

A1, after described MN obtains NCoA, send pre-binding Prep-BU message to CN or HA, what comprise in the message that described MN obtains delivers address NCoA in advance;

After A2, described CN or HA obtain the NCoA of described MN according to the message that receives, set up the described pre-binding relationship of delivering the home address of address and MN in advance, and it is recorded in the banding cache, the pre-binding acknowledgement Prep-BA of loopback message is given described MN then, and finishes pre-binding procedure.

Wherein, pre-binding Prep-BU message also comprises described in the steps A 1: life span is used to set and receives first data flow that MN sends from CN or HA and begin to calculate the described entry-into-force time of delivering address NCoA in advance.

Wherein, described step B specifically comprises:

B1, when described MN need move to NAR, by the information interaction between described MN and PAR, PAR is redirected flow that MN sends to NAR;

B2, when MN moves to the NAR network, send quick neighbor advertisement message to NAR, announce to be attached to NAR, confirm the NCoA address with NAR;

B3, MN adopt the NCoA address be pre-bound to CN or HA and CN or HA to carry out information interaction;

B4, MN set up the home address of MN and the binding relationship of described NCoA address at CN or HA, and by CN or HA it are recorded in the banding cache by the Binding Update process of RFC3775 regulation;

B5, realize information interaction between CN or HA and MN based on the binding relationship of the home address of described MN and described NCoA address.

Wherein, between described step B1 and step B2, comprise:

When MN shifts out the PAR network, interrupt getting in touch with PAR.

Wherein, described step B1 specifically comprises:

B11, when described MN need move to NAR, MN sends quick Binding Update FBU message to PAR, requires PAR to give NAR to the direct traffic of MN, comprises described NCoA information in the described FBU message;

After B12, PAR receive described FBU message,, and record in the buffer memory of PAR described NCoA and PCoA binding;

B13, when PAR receives the flow that MN sends, based on the relation of the NCoA and the PCoA of described binding, be redirected flow that MN sends to NAR.

Wherein, also comprise between described step B12 and described step B13:

B14, PAR verify the legitimacy of described NCoA by the information interaction between itself and NAR;

B15, after checking is passed through, described PAR replys binding fast for MN and NAR and replys the FBAck message.

Wherein, described step B14 specifically comprises:

B141, PAR send and transfer initialization HI message to NAR, and request NAR verifies whether described NCoA is legal;

B142, after described NAR receives described HI message, confirms that described NCoA is legal, reply to transfer confirm that Hack gives PAR.

Wherein, described step B3 specifically comprises:

B31, MN send data flow to CN or HA, and the source address of described data flow is Care-of Address NCoA;

B32, described CN or HA receive described data flow, and after verifying that according to the Care-of Address NCoA that writes down in its buffer memory described NCoA is legal, according to the home address of the MN that writes down in the described buffer memory and the binding relationship of described Care-of Address NCoA, replace described Care-of Address NCoA with the home address of MN;

B33, according to the home address after the described replacement described data flow is uploaded to application layer and handles.

Wherein, described step B32 specifically comprises:

B321, when described CN or HA receive first data flow that described MN sends, pick up counting, when the time arrives the life span of described setting, stop using described NCoA to receive the data flow that described MN sends; Otherwise, execution in step B322;

After B322, described CN or HA verify that according to the Care-of Address NCoA that writes down in its buffer memory the NCoA that carries in the described data flow is legal, according to the home address of the MN that writes down in the described buffer memory and the binding relationship of described Care-of Address NCoA, replace described Care-of Address NCoA with the home address of MN.

Wherein, described step B5 specifically comprises:

B51, MN send CN or the HA of data flow to far-end, and its source address is the NCoA address;

After B52, described CN or HA receive described MN data flow, return corresponding information according to described NCoA address and give MN, destination address is the NCoA address, and the home address of MN is included in the message ad-hoc location of RFC3775 regulation.

After B53, described MN receive the message of described CN or HA transmission, according to the described NCoA address of writing down in the banding cache and the binding relationship of home address, with described NCoA address transition is home address, and the data flow that receives is uploaded to application layer according to described home address, finish the reception of data flow and handle.

As seen from the above technical solution provided by the invention, among the present invention, in the IPv6 network, when mobile node MN be connected to be moved before during network PAR, the Care-of Address NCoA that MN will obtain when being about to move to new network N AR is pre-bound to communication parter CN/ home agent HA before Binding Update; When MN forwards described network N AR to, and finish before the formal Binding Update, use described NCoA address and CN/HA interactive information.By the present invention, when MN moves to the NAR network, use the NCoA address transmitted traffic that has generated to give CN/HA, thereby can avoid when network uses inspection of reversal path, the problem that the flow that MN adopts PCoA to send as source address is masked by the router in the NAR network, and then avoided the generation of flow interrupt; By the present invention, the flow that sends at the NAR network as MN is during to CN/HA, and source address can directly adopt NCoA, and need not to consider that flow can adopt other complicated technology because of the problem that source address is filtered by NAR, thereby avoided network congestion, accelerated the processing speed of system.

Description of drawings

Fig. 1 is the basic principle schematic of Mobile IPv6 technology;

Fig. 2 is the schematic network structure of MN when a field network moves to another field network;

Fig. 3 is a sequential chart of realizing MN binding procedure when mobile on field network in the prior art one;

Fig. 4 realizes MN on field network behind the binding procedure when mobile in the prior art one, CN/HA is to the data flow transmission path schematic diagram of MN;

Fig. 5 realizes MN on field network behind the binding procedure when mobile in the prior art one, MN is to the data flow transmission path schematic diagram of CN/HA;

Fig. 6 is the sequential chart of embodiment provided by the invention.

Embodiment

The invention provides a kind of method that improves reliability of fast switch over business, its core is: in the IPv6 network, when mobile node MN be connected to be moved before during network PAR, the Care-of Address NCoA that MN will obtain when being about to move to new network N AR is pre-bound to communication parter CN/ home agent HA before Binding Update; When MN forwards described network N AR to, and finish before the formal Binding Update, use described NCoA address and CN/HA interactive information.

Embodiment provided by the invention as shown in Figure 5, comprising:

Step 101, MN send neighbours and find in the ND message in the PAR network, send PtSolPr (router solicitation of agent advertisement) message and give PAR, the request AP (access point) and the network information.

Step 102, PAR loopback RtSolPr (agent router bulletin) response message comprise the information of facing network mutually in the message, promptly comprise the information of facing network router NAR and AP mutually.

Step 103, MN receive described response message, if the AP information of returning is sky, then MN affirmation network does not support to switch fast and stop fast handover procedures; If be not empty, then MN generates NCoA.

Step 104, after described MN obtains NCoA, send pre-binding Prep-BU message to CN/HA, what comprise in the message that described MN obtains delivers address NCoA in advance, and life cycle, be used to set and receive first data flow that MN sends from CN/HA and begin to calculate the described entry-into-force time of delivering address NCoA in advance.

The present invention is on the basis that RFC4068 switches fast, send to the pre-binding message of CN/HA by MN, being implemented in increases pre-binding function in the interaction message of mobile I Pv6, described pre-binding message is made amendment based on BU message format described in the prior, and its form is as follows:

Wherein,

Sequence#: the sequence number of binding update messages sequence number and BAK message will mate.

A:Acknowledge determines by the A flag bit is set whether MN needs the affirmation of BU.

H:Home Registration indicates by H is set whether this message is handled by HA.

L：Link-Local?Address?Compatibility。

K:Key Management Mobility Capability, expression message is effective when sending to HA.

P:Prep-Binging Update, after P was set up, expression was after MN moves to NAR, do not finish formal Binding Update before, MN uses NCoA to send data flow to CN/HA, is legal and can be received.

Reserved: keep.

After Lifetime:P was set up, Lifetime can not surpass the regular hour.

Mobility Options: mobile option.

By above-mentioned amended BU message format as can be seen, the present invention has increased the P field at reserved field, described P (Prep-Binging Update) field, after expression MN moves to NAR, before not finishing formal Binding Update, MN uses NCoA to send data flow to CN/HA, is legal and can be received.After P was set up, Lifetime (life span) can not surpass the regular hour.It is used for being provided with the entry-into-force time of delivering the address in advance, that is to say, delivers the address in advance and comes into force in Lifetime official hour section, surpasses the Lifetime official hour, and then CN/HA must stop to utilize the described address of delivering in advance to receive the data flow that MN sends.

Step 105, described CN/HA according to the message that receives obtain described MN deliver address NCoA in advance after, set up the described pre-binding relationship of delivering the home address of address and MN in advance, and it is recorded in its banding cache, loopback Prep-BA (pre-binding acknowledgement) message is given described MN, and is finished pre-binding procedure then.

When described MN need move to NAR, by the information interaction between described MN and PAR, the flow that is redirected M N transmission was to NAR.Specifically comprise:

Step 106, when described MN need move to NAR, MN sends FBU (Binding Update fast) message and gives PAR, requires direct traffic that PAR will give MN to NAR, comprises described NCoA information in the described FBU message;

After step 107, PAR receive described FBU message,, and record in the buffer memory of PAR described NCoA and PCoA binding;

Step 108, when PAR receives the flow that MN sends, based on the relation of the NCoA and the PCoA of described binding, be redirected flow that MN sends to NAR.

Through after the above-mentioned steps, also need PAR to pass through the legitimacy that information interaction between itself and NAR is verified described NCoA.Specifically comprise:

Step 108, PAR send HI (transfer initialization) message to NAR, and request NAR verifies whether described NCoA is legal;

Step 109, after described NAR receives described HI message, confirms that described NCoA is legal, reply HAck and give PAR.

Step 110, after checking is passed through, described PAR replys FBAck (binding is replied fast) message for MN and NAR.

Step 111, when MN moves out the PAR network, interrupt getting in touch with PAR.

Step 112, when MN moves to the NAR network, send FNA message to NAR, announce to be attached to NAR, confirm the NCoA address with NAR.

Step 113, MN adopt the NCoA address and the CN/HA that have been pre-bound to CN/HA to carry out information interaction.Specifically comprise:

Step 1, MN send data flow to CN/HA, and the source address of described data flow is for delivering address NCoA in advance;

Step 2, when described CN/HA receives first data flow that described MN sends, pick up counting, when the time arrives the life span of described setting, stop using described NCoA to receive the data flow that described MN sends; Otherwise, execution in step three.

Step 3, described CN/HA according to write down in its buffer memory deliver address NCoA in advance and verify that the NCoA that carries in the described data flow is legal after, according to home address and the described binding relationship of delivering address NCoA in advance of the MN that writes down in the described buffer memory, replace the described address NCoA that delivers in advance with the home address of MN.

Step 4, according to the home address after the described replacement described data flow is uploaded to application layer and handles.

Because in pre-binding message, be provided with Lifetime (life cycle), be used to set and receive first data flow that MN sends from CN/HA and begin to calculate the described entry-into-force time of delivering address NCoA in advance, so delivering address NCoA in advance can come into force in the Lifetime official hour is short, surpass the Lifetime official hour, then CN/HA must stop to receive.

Step 114, by the Binding Update process of RFC3775 regulation, set up the home address of MN and the formal binding relationship of main Care-of Address NCoA address, and it recorded in the banding cache.

When carrying out step 114, a plurality of Care-of Address of MN can be arranged, but when carrying out information interaction between CN/HA and MN in CN/HA, can only there be a main Care-of Address and one to deliver the address in advance and come into force.

Through after the above-mentioned steps, the present invention can be based on home address and the formal binding relationship realization CN/HA of described NCoA address and the information interaction between MN of described MN.Specific implementation process comprises:

Step 115, MN send the CN/HA of data flow to far-end, and its source address is the NCoA address;

After step 116, described CN/HA receive described MN data flow, return corresponding information according to described NCoA address and give MN, first destination address is the NCoA address, and second destination address is the home address of MN.

After step 117, described MN receive the message of described CN/HA transmission, according to the described NCoA address of writing down in the banding cache and the binding relationship of home address, with described NCoA address transition is home address, and the data flow that receives is uploaded to application layer according to described home address, finish the reception of data message and handle.

By the specific embodiments of the invention described above as can be seen, the present invention is at MN during also at the PAR network, give CN/HA with the pre-binding of the NCoA that has generated, MN can have a plurality of Care-of Address among the CN/HA, come into force but can only have a main Care-of Address and one to deliver the address in advance, in case MN moves to the NAR network, also do not finish Binding Update during, CN/HA allows MN to use NCoA to send data flow, with regard to what avoided that NAR starts inspection of reversal path the MN data flow is filtered problem like this.In order to guarantee safety, this pre-bound CoA address, can only use the very short time, be no more than 10 seconds at most, concrete number second is consulted to finish by pre-binding message and CN/HA by MN, surpass the second number of regulation when MN uses NCoA and CN/HA communication, and when also not finishing Binding Update, CN/HA will stop the data flow that the reception sources address is NCoA.

By the present invention, when MN moves to the NAR network, use the NCoA address transmitted traffic that has generated to give CN/HA, thereby can avoid when network uses inspection of reversal path, the problem that the flow that MN uses PCoA to send is masked by the router in the NAR network, and then avoided the generation of flow interrupt; By the present invention, the flow that sends at the NAR network as MN is during to CN/HA, and source address can directly adopt NCoA, and need not to consider that flow can adopt other complicated technology because of the problem that source address is filtered by NAR, thereby avoided network congestion, accelerated the processing speed of system.

The above; only for the preferable embodiment of the present invention, but protection scope of the present invention is not limited thereto, and anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claim.

Claims

1, a kind of method that improves reliability of fast switch over business is characterized in that, comprising:

2, method according to claim 1 is characterized in that, comprises before described steps A:

3, method according to claim 2 is characterized in that, described steps A 0 specifically comprises:

A02, PAR loopback agent router are announced response message, comprise the information of adjacent networks router and AP in the message;

4, according to claim 1,2 or 3 described methods, it is characterized in that described steps A specifically comprises:

A1, after described MN obtains NCoA, send pre-binding message to CN or HA, comprise the Care-of Address NCoA that described MN obtains in the message;

After A2, described CN or HA obtain the NCoA of described MN according to the message that receives, set up the pre-binding relationship of the home address of described Care-of Address and MN, and it is recorded in the banding cache, the pre-binding acknowledgement message of loopback is given described MN then, and finishes pre-binding procedure.

5, method according to claim 4 is characterized in that, pre-binding message also comprises described in the steps A 1: life span is used to set from CN or HA and receives the entry-into-force time that first data flow that MN sends begins to calculate described Care-of Address NCoA.

6, method according to claim 5 is characterized in that, described step B specifically comprises:

7, method according to claim 6 is characterized in that, comprises between described step B1 and step B2:

When MN shifts out the PAR network, interrupt getting in touch with PAR.

8, method according to claim 6 is characterized in that, described step B1 specifically comprises:

After B12, PAR receive described FBU message,, and record in the buffer memory of PAR described NCoA and previous Care-of Address PCoA binding;

9, method according to claim 8 is characterized in that, also comprises between described step B12 and described step B13:

10, method according to claim 9 is characterized in that, described step B14 specifically comprises:

11, method according to claim 6 is characterized in that, described step B3 specifically comprises:

12, method according to claim 6 is characterized in that, described step B32 specifically comprises:

13, method according to claim 6 is characterized in that, described step B5 specifically comprises: