CN102843667B - Method for deploying subnet mobile in separation mechanism mobility management system - Google Patents

Abstract

The invention relates to a method for deploying subnet mobile in a separation mechanism mobility management system. The method comprises the following steps of expanding a separation mechanism mobility management system, expanding the functions of AGW (access gateway), CGW (control gateway) and DGW (data gateway) in the system, and modifying the signaling interacted between entities to support the subnet mobile. In order to support preamble proxy, a DHCP (dynamic host configuration protocol) relay proxy is deployed on the AGW, a DHCP server is deployed on the CGW, and a mobile router (MR) is used as a DHCP client, so that the preamble can be allocated for an MNN (mobile network node) through correct interaction by the AGW and the DHCP relay proxy. According to the method provided by the invention, the mobility management network based on the separation mechanism is combined with the subnet mobile, so that the communication under the condition that the MR carriers an LFN (local fixed node) is realized; the DHCPv6 preamble proxy is supported, the preamble is allocated for the LFN by using dynamic address allocation, thus, the utilization of the address is increased, and the configuration of client TCP/IP (transmission control protocol/Internet protocol) is greatly simplified.

Description

A kind of method of disposing subnet movement in separation mechanism mobility management systems

Technical field

The present invention relates to a kind of method of disposing subnet movement in separation mechanism mobility management systems.

Background technology

Along with the quick growth of Wi-Fi handheld terminal and the growth to internet access demand, the NEMO technology that can manage a group node receives much concern.In order to support NEMO, the basic NEMO supported protocol (NEMO-BSP) of RFC3963 specification, but this agreement is the support to NEMO in MIPv6.Along with the appearance of the PMIPv6 of management Network Based, IETF MEXT and IETF NETEXT working group also proposed some drafts, carried out NEMO support in PMIPv6.

Patent application (application number: 201110152731) propose a kind of new mobility management protocol, be called separation mechanism mobility management systems, this system has good function, performance and extensibility, but do not support that subnet moves.

1.2 prior aries one related to the present invention

Patent application (application number: the network model of the separation mechanism mobile management 201110152731) proposed as shown in Figure 1.The program proposes three kinds of separation mechanisms: namely identity is separated with position, datum plane is separated with control plane, Access Network is separated with core net.The program defines three new functional entitys: IAD (Access GateWay, AGW), control gateway (Control GateWay, CGW) and data gateway (Data GateWay, DGW).

Changed according to the difference of the AGW of access with access address PCoA(by the home address (constant in an Access Network, to be HoA) mobile node MN being respectively used to identity information) be separated and realize identity with position and be separated;

By by the home address being used for identifying MN identity information be used for core network by core address be separated and realize being separated of Access Network and core net;

By the mobility signaling management function of LMA in PMIPv6 and data route forwarding function refinement are decomposed: be separated into control gateway, realize mobility signaling management function; Data gateway, realizes data route forwarding function.Thus realize control plane and be separated with datum plane.

1.2.1 the shortcoming of prior art one

Technical scheme one is only a kind of management method of mobile, does not relate to subnet and moves.Because the mobility in separation mechanism mobility management systems is based on PMIPv6 agreement, and the movement of single node in PMIPv6 support region, do not support the movement of a group node, therefore separation mechanism mobility management systems does not support the movement of a group node yet, and it can only ensure that a node moves freely and keeps node IP address constant in separation mechanism mobile management territory.

1.3 prior aries two related to the present invention

PMIPv6 provides the network connectivty of PMIPv6 territory interior nodes, because current PMIPv6 specification only supports the mobility of main frame, thus IETF proposes draft and solves the problem supporting subnet movement in PMIPv6, and ensure the network connectivty of mobile network node in mobile subnetwork (Mobile Network Node, MNN).

The agreement of network support subnet movement is called PNEMO agreement by this draft, and this agreement is an expansion of PMIPv6 agreement.In this agreement, MR does not participate in Signalling exchange, and signaling message is mutual between MAG and LMA.MR is VMN(Visited Mobile Node) and LFN(LocalFixed Node) transceiving data bag.MR also notifies the state of subnet to LMA and MAG simultaneously.

The MR of the description that draft is detailed is with access and the handoff scenario of the nested and VMN of LFN, subnet.Also illustrate the operation of MAG and LMA simultaneously.

1.4.1 the shortcoming of prior art two

PMIPv6 can only realize limited identity and be separated with position in territory, LMA, should processing controls signaling in the process of management mobile subnetwork, forward again from the packet mailing to mobile subnetwork, easily cause LMA to become single fault node in PMIPv6 network configuration, cannot reliability be ensured.This subnet moves scheme is simultaneously based on PMIPv6 agreement, have have IP address ambiguity to bring defect.

1.4.1 prior art three related to the present invention

As RFC 3315(R.Droms, Ed., J.Bound, B.Volz, T.Lemon, C.Perkins, M.Carney. " Dynamic Host Configuration Protocol for IPv6 (DHCPv6) " .RFC 3315, July 2003.) middle description, Dynamic Host Configuration Protocol server uses DHCPv6 agreement to provide the configuration informations such as the such as IPv6 network address to IPv6 node.It can distribute automatically can the reusable network address and other configuration informations.

In mobile subnetwork, MNN receives mobile network's prefix (Mobile NetworkPrefix by MR, MNP), DHCPv6 prefix proxy just can distribute one or more prefix for the mobile router on link, but proxy mobile IPv 6 does not but support DHCPv6 prefix proxy.Draft (A.Petrescu, M.Boc, C.Janneteau, " Network Mobility with Proxy MobileIPv6 ", draft-petrescu-netext-pmip-nemo-00.txt, March 5,2012.) describe one in proxy mobile IPv 6, use DHCPv6 prefix proxy to be the method that mobile subnetwork distributes prefix.When using DHCPv6 prefix proxy to distribute prefix, these prefixes need to bind in PMIPv6.

Here the simple Signalling exchange introduced between the Dynamic Host Configuration Protocol server of description in lower RFC 3315 and dhcp client.Interacting message between both is divided into four signalings to hand over (four-messagehandshake) and two signalings to hand over (two-message handshake) two kinds of situations.Two kinds of interacting messages as shown in Figure 2.

When a dhcp client needs server to its distributing IP address time, in order to obtain IP address, need to carry out four-message handshake.

When a dhcp client does not need Dynamic Host Configuration Protocol server to his distributing IP address time, dhcp client can by obtaining some configuration informations as available dns server and ntp server with response message, namely two-messagehandshake with the single alternately request of Dynamic Host Configuration Protocol server.

In order to allow dhcp client to send message to not Dynamic Host Configuration Protocol server on the same link, dhcp relay agent (DHCP relay agent) can be used to transmit message between Dynamic Host Configuration Protocol server and dhcp client.The operation of dhcp relay agent is transparent for dhcp client.Dhcp relay agent can allow not Dynamic Host Configuration Protocol server on the same link to communicate with dhcp client.

1.3.1 the shortcoming of prior art three

When described by this draft, LMA not only needs processing controls signaling also to want forwarding data bag, when LMA breaks down, network can be caused to occur paralysis, namely poor reliability.Equally, this prefix Proxy Signature Scheme is also based on PMIPv6 agreement, has the defect that IP address ambiguity is intrinsic.

Summary of the invention

For solving above the deficiencies in the prior art, the present invention proposes a kind of management method of the subnet movement in separation mechanism mobility management systems, separation mechanism mobile management is moved with subnet and combines, utilize the feature of separation mechanism mobile management, devise a kind of method of disposing subnet movement in separation mechanism mobility management network.The method can carry out mobile management to the group node in separation mechanism network, supports DHCP prefix proxy simultaneously.

Object of the present invention is achieved through the following technical solutions:

In separation mechanism mobility management systems, dispose a method for subnet movement, the method comprises the steps:

Step 1:MR is linked into AGW1, WAP (wireless access point) (Access Point on AGW1, AP) so detect that entering of MR sends log information to AGW1, after AGW1 receives log information, the access style of decision node, be mobile router or mobile node, and obtain the ID of corresponding access node, the mobile management process after completing these work on AGW1 is in wait state;

Step 2:MR then sends DHCPv6 CONFIRM message to dhcp relay agent;

After step 3:DHCP relay agent receives DHCP CONFIRM message, send DHCPv6 RELAY FORWARD message to Dynamic Host Configuration Protocol server;

After step 4:DHCP server receives this message, judge whether the address of carrying in message can be used, if available, then return to dhcp relay agent the DHCP RELAY REPLY message that a status code is 0;

After step 5:DHCP relay agent receives message, judge that the status code in message is 0, then inform that the mobile management process on AGW1 can send agent binding update PBU message;

Step 6:AGW1 sends PBU message to CGW1, and newly-increased MNP option and R flag bit in PBU message, AGW1 sets up the BUL relevant to MR simultaneously;

Step 7:CGW1 resolves after receiving PBU message, if legal, then send tunnel to DGW1 and sets up request message TxReq, also increase MNP option and R flag bit newly in this message, CGW1 sets up the BCE relevant to MR simultaneously;

After step 8:DGW1 resolves after receiving TxReq message, set up one is pointed to AGW1 tunnel by DGW1, and return a tunnel acknowledge message TxAck to CGW1, and set up the TCE relevant to MR on DGW1, add the route relevant to HNP and MNP;

Step 9:DGW1 inquires about the address pool on it, for HNP and MNP distributes corresponding core address, and the corresponding relation of the corresponding relation of HNP and core address, MNP and core address is injected in the kernel of DGW1 goes, also these two pairs of mapping relations are included in map updating message simultaneously and issue GMS, carry out up-to-date record;

After step 10:CGW1 receives TxAck message, just send the proxy binding acknowledgment messages PBA comprising HNP and R flag bit to AGW1;

After step 11:AGW1 receives PBA message, all over informing that DHCP process now can send DHCP REPLY message to MR;

Step 12:AGW1 parses the HNP information in PBA message, MR is advertised to by advertising of route RA, set up the other end in the tunnel being pointed to DGW1 by AGW1 simultaneously, and add the route about HNP and MNP, after MR receives HNP, generate the home address of oneself according to EUI-64;

After step 13:DHCP relay agent receives the notice that AGW1 sends, just send DHCP REPLY message to MR;

The MNP that DHCP distributes is advertised to LFN by RA message after receiving DHCP REPLY message by step 14:MR;

Step 15: after MR obtains home address HoA1, LFN acquisition subnet address MNP, packet can be sent to the CN being positioned at Access Network 2, here suppose that CN also completes corresponding steps, the home address obtained at Access Network 2 is HoAn, make LFN to CN initiating communication, packet forwards through MR and is first sent to AGW1, and data packet format is { HoAn, MNP, data };

Packet encapsulation is { DGW1_addr, PCoA, { HoAn by step 16:AGW1, MNP, data } } form, and packet is sent to DGW1 by bidirectional tunnel, wherein PCoA1 is also the Agent care-of address of the AGW1 of the current access of MR, and DGW1_addr is the address of DGW1 in Access Network side;

After step 17:DGW1 receives packet, first decapsulation is carried out to it, packet is reduced to { HoAn, MNP, data } form, then DGW1 carries out the inquiry of mapping relations, now on DGW1 store two core address only having the MNP of HNP1 and LFN of MR corresponding, first inquire about the source address MNP of local mapping table to packet to inquire about, obtain corresponding core address 1; But DGW1 now the information of the core address n relevant to HoAn, therefore DGW1 needs to inquire about with GMS interactive map to obtain core address corresponding to HoAn with response message;

Step 18:DGW1 and GMS interactive map are inquired about and response message, obtain the core address n that HoAn is corresponding;

Step 19:DGW1 after obtaining the core address map information required for packet, then carries out mapping to the source address of packet and destination address and replaces, and has replaced rear data packet format for { core address n, core address 1, data }, and has been sent to DGW2;

After step 20:DGW2 receives packet, and do not know the information of the home address of core address 1 correspondence, therefore the inquiry of DGW2 and GMS interactive map obtains MNP corresponding to core address 1 with response message; DGW2 is after the corresponding mapping relations of acquisition, and just carry out demapping replacement to the source address of packet, destination address, the data packet format after demapping is { HoAn, MNP, data };

Step 21:DGW2 owing to setting up the bidirectional tunnel between AGWn, then directly carries out tunnel encapsulation to packet, and data packet format is { PCoAn, DGW2_addr, { HoAn, MNP, data } }, and packet is sent to AGWn via tunnel;

Step 22:AGWn carries out tunnel decapsulation to packet after receiving packet, the data packet format { HoAn, MNP, data } after decapsulation, and by Packet Generation to MN.

The invention has the advantages that:

1. the mobility management network based on separation mechanism moves with subnet and combines by the present invention, separation mechanism mobility management systems is expanded, carry out Function Extension to AGW, CGW, DGW respectively, the signaling message mutual to inter-entity is expanded, and supports that subnet moves.

2. the present invention supports DHCPv6 prefix proxy, provides the deployment of DHCP related entities and the method with separation mechanism system interaction.And subnet moved combine with separate mapping network, achieve MR carry LFN scene under communication.

3. the present invention supports DHCPv6 prefix proxy, uses dynamic address allocation to distribute prefix for LFN, adds the utilance of address and greatly can simplify the configuration of client TCP/IP.

4. the present invention can support a group node to move freely in separation mechanism network domains and keep the continuity that communicates, and user can move between the diverse access point in a large region.

Accompanying drawing explanation

Fig. 1: existing separation mechanism mobile network figure;

Fig. 2: four signalings and two Signalling exchange flow charts;

Fig. 3: the subnet mobile management network topological diagram that the present invention is based on separation mechanism;

Fig. 4: based on the mobile management figure of separation mechanism subnet;

Fig. 5: the system flow chart disposing subnet movement in separation mechanism mobility management systems.

Embodiment

Subnet mobile management network topology based on separation mechanism of the present invention as shown in Figure 3.The present invention is main it is considered that dispose the scene of MR with attached LFN in separation mechanism mobility management systems, supports DHCPv6 prefix proxy simultaneously.Dynamic Host Configuration Protocol server is deployed on CGW by the present invention, and dhcp relay agent is deployed on AGW, and dhcp client is deployed on MR.

To describe from subnet below, functional entity and division and mobile messaging formal definition three aspects will introduce ins and outs of the present invention.

Subnet describes

The present invention disposes subnet when moving in separation mechanism mobility management systems, it is considered that the mobile management of whole subnet, comprises MR and LFN, as shown in the figure:

Wherein, MR is the mobile router of definition in [RFC 3963], LFN(Local Fixed Node) be the mobile node being under the jurisdiction of MR, it can only be followed MR and move together.For MR, need distribution specific home network prefix (Home Network Prefix, HNP), and HNP is constant when MR moves in separation mechanism territory.The LFN MNP configuration address belonging to specific NEMO.In this case, DGW is not only the packet that MR is redirected MR, also will be redirected the packet of the LFN belonging to MNP.

Functional entity divides and expansion

In separation mechanism mobility management systems, dispose subnet move and need the functional entity in separation mechanism mobility management systems to expand, be introduced in detail below:

（1）AGW

AGW is positioned at Access Network edge, functionally the MAG of similar PMIPv6.AGW detects the access of MR and leaves, and replace MR and CGW to carry out the mutual of mobile signaling protocol, newly-increased MNP option and R flag bit is needed with the PBU message that CGW is mutual, MNP option is used for carrying mobile subnetwork prefix, when R flag bit is 1, what represent access is mobile subnetwork, and what represent access when being 0 is single mobile node, needs newly-increased R flag bit in PBA message.AGW needs to distinguish access node is simultaneously MR or MN to carry out different disposal.AGW needs to set up tunnel with DGW, also will have next address of LFN in mobile subnetwork, also want the packet that can forward from subnet, be responsible for the data transmit-receive of MR and LFN above it.

AGW needs maintenance Binding Update list (Binding Update List, BUL), and need to increase mobile subnetwork prefix option in BUL and store the content relevant to MNP, concrete data structure is as follows, and wherein DGW1 is the address of DGW in Access Network side:

Table 1

Care-of Address	Home address	Mobile subnetwork prefix	Data gateway address
				PCoA1	HNP1	MNP	DGW1

（2）CGW

CGW has needed the function of the control plane of LMA in PMIPv6, is responsible for carrying out Signalling exchange between AGW, has assisted the mobile management of MR.CGW and DGW sets up in request message (TxReq) in mutual tunnel and needs newly-increased MNP option and R flag bit, and tunnel is set up in response message (TxAck) needs newly-increased R flag bit.CGW needs maintenance banding cache entry (Binding CacheEntries, BCE), and the data structure needing increase mobile subnetwork prefix option to store the content relevant to MNP concrete in BCE is as follows:

Table 2

（3）DGW

DGW completes the data plane functions of the LMA in PMIPv6, is responsible for setting up communication tunnel with AGW, and the packet mailing to MR and LFN is finally all addressed to DGW, and DGW forwards the packet mailing to mobile subnetwork.Therefore DGW needs maintenance tunnel cache entries list (Tunnel Cache Entries, TCE), and the data structure needing increase mobile subnetwork prefix option to store the content relevant to MNP concrete in TCE is as follows:

Table 3

MN identity descriptor	Home address	Care-of Address	Data gateway address	Mobile subnetwork prefix
					mn1@example	HoA1	PCoA1	DGW1	MNP1
mn2@example	HoA2	PCoA2	DGW1	MNP2

（4）LMS

On the other hand, DGW is also local mapping server simultaneously, record the core address that HoA and MNP of local all MR is corresponding, from the packet of MR and MNN when Access Network mails to core net via DGW, all to inquire about local map listing (the Local Mapping List on local mapping server, LML), source address HoA/MNP is replaced to corresponding core address.DGW is also responsible for upgrading and query messages with GMS interactive map.If local mapping table does not have corresponding list item, inquire about to GMS.When mobile subnetwork access or when leaving, DGW also will send information updating map listing to GMS while upgrading the map listing on LMS.The concrete data structure of local map listing is as follows:

Table 4

Core address	Access address
		Core address 1	HNP1
Core address 2	HNP2

Core address 3

MNP

（5）GMS

Global map server disposition is at core network, mainly complete the core address map locating function of the overall situation, when packet mails to core net via DGW, packets need inquires about a GMS, GMS needs maintenance one to comprise global map list (the Global Mapping List of mapping relations between overall all HoA and MNP and core address, GML), concrete data structure is as follows:

Table 5

Core address	Access address
		Core address 1	HNP1
Core address 2	HNP2
		Core address 3	HNP3
Core address 4	MNP

2.2.3 mobile messaging formal definition

In subnet moving process, need to comprise the MNP(Mobile Node Prefix of mobile subnetwork in the agent binding update messages that AGW sends to CGW) information, need to expand agent binding update messages, increase MNP option, the agent binding update messages form of expansion is as shown in table 6.

Table 6

The MNP mobile option increased in agent binding update messages is for carrying the prefix information of LFN, and MNP mobile option is with reference to the definition about HNP in RFC 5213.

Equally, what send to DGW CGW sets up request message and also will expand, and comprise MNP option, the tunnel of expansion is set up shown in request message table 7.

Table 7

The MNP mobile option that the tunnel request of setting up increases is for carrying the prefix information of LFN, and MNP mobile option is with reference to the definition about HNP in RFC 5213.

Below to using the signaling process of DHCP prefix proxy and data interaction flow process to be introduced within the system, flow process as shown in Figure 5.Composition graphs 3-4, sends packet for the MR being positioned at Access Network 1 to the CN being positioned at Access Network 2, from MR enters Access Network 1, starts to introduce the mutual basic procedure of mobile signaling protocol described in the invention.For DHCPv6, as described in RFC 3315, DHCPv6 process comprises the mutual and mutual two kinds of situations of four-message of two-message, and the present invention all supports both of these case, only introduces the mutual situation of two-message here.

For the situation that four-message is mutual, only need a step 2 as described below replace to the mutual flow process of four-message in Fig. 2 to step 4, then add use dhcp relay agent situation.For in step 5 as described below, when for four-message mutual time, need to judge in the DHCP RELAY REPLY received, whether to comprise IA-NA option (carrying Dynamic Host Configuration Protocol server in this option to the prefix of peer distribution), if comprise, then inform that the mobile management process on AGW1 sends PBU message.Here no longer the situation of the situation using four-message mutual in separation mechanism mobility management systems for the peer distribution prefix in mobile subnetwork is repeated.

Step 1:MR is linked into AGW1, so the AP on AGW1 detects that entering of MR sends log information to AGW1.After AGW1 receives log information, the access style of decision node is mobile router or mobile node, and obtains the ID of corresponding access node, and the mobile management process after completing these work on AGW1 is just in wait state.

Step 2:MR then sends DHCPv6 CONFIRM message to dhcp relay agent.

After step 3:DHCP relay agent receives DHCP CONFIRM message, send DHCPv6 RELAY FORWARD message to Dynamic Host Configuration Protocol server.

After step 4:DHCP server receives this message, judge whether the address of carrying in message can be used, if available, then return to dhcp relay agent the DHCP RELAY REPLY message that a status code is 0.

After step 5:DHCP relay agent receives message, judge that the status code in message is 0, then inform that the mobile management process on AGW1 can send agent binding update (PBU) message.

Step 6:AGW1 sends PBU message to CGW1, and newly-increased MNP option and R flag bit in PBU message, AGW1 sets up the BUL relevant to MR simultaneously.

Step 7:CGW1 resolves after receiving PBU message, if legal, then send tunnel to DGW1 and sets up request message (TxReq), also increase MNP option and R flag bit newly in this message.CGW1 sets up the BCE relevant to MR simultaneously.

After step 8:DGW1 resolves after receiving TxReq message, set up one is pointed to AGW1 tunnel by DGW1, and return a tunnel acknowledge message (TxAck) to CGW1, and set up the TCE relevant to MR on DGW1, add the route relevant to HNP and MNP.

Step 9:DGW1 inquires about the address pool on it, for HNP and MNP distributes corresponding core address, and the corresponding relation of the corresponding relation of HNP and core address, MNP and core address is injected in the kernel of DGW1 goes, also these two pairs of mapping relations are included in map updating message simultaneously and issue GMS, carry out up-to-date record.

After step 10:CGW1 receives TxAck message, just send the proxy binding acknowledgment messages (PBA) comprising HNP and R flag bit to AGW1.

After step 11:AGW1 receives PBA message, all over informing that DHCP process now can send DHCP REPLY message to MR.

Step 12:AGW1 parses the HNP information in PBA message, MR is advertised to by advertising of route (RA), set up the other end in the tunnel being pointed to DGW1 by AGW1 simultaneously, and add the route about HNP and MNP, after MR receives HNP, generate the home address of oneself according to EUI-64.

After step 13:DHCP relay agent receives the notice that AGW1 sends, just send DHCP REPLY message to MR.

The MNP that DHCP distributes is advertised to LFN by RA message after receiving DHCP REPLY message by step 14:MR.

Step 15: after MR obtains home address HoA1, LFN acquisition subnet address MNP, can send packet to the CN being positioned at Access Network 2.Here suppose that CN also completes corresponding steps, the home address obtained at Access Network 2 is HoAn.Make LFN to CN initiating communication, packet forwards through MR and is first sent to AGW1, and data packet format is { HoAn, MNP, data }.

Packet encapsulation is { DGW1_addr, PCoA, { HoAn by step 16:AGW1, MNP, data } } form, and packet is sent to DGW1 by bidirectional tunnel, wherein PCoA1 is also the Agent care-of address of the AGW1 of the current access of MR, and DGW1_addr is the address of DGW1 in Access Network side

First step 17:DGW1 carries out decapsulation to it, packet is reduced to the form of { HoAn, MNP, data } after receiving packet.Then DGW1 carries out the inquiry of mapping relations, two core address only having the MNP of HNP1 and LFN of MR corresponding now DGW1 stored, and first inquires about the source address MNP of local mapping table to packet and inquires about, obtain corresponding core address 1; But DGW1 now the information of the core address n relevant to HoAn, therefore DGW1 needs to inquire about with GMS interactive map to obtain core address corresponding to HoAn with response message.

Step 18:DGW1 and GMS interactive map are inquired about and response message, obtain the core address n that HoAn is corresponding.

Step 19:DGW1 after obtaining the core address map information required for packet, then carries out mapping to the source address of packet and destination address and replaces, and has replaced rear data packet format for { core address n, core address 1, data }, and has been sent to DGW2.

After step 20:DGW2 receives packet, and do not know the information of the home address of core address 1 correspondence, therefore the inquiry of DGW2 and GMS interactive map obtains MNP corresponding to core address 1 with response message.DGW2 is after the corresponding mapping relations of acquisition, and just carry out demapping replacement to the source address of packet, destination address, the data packet format after demapping is { HoAn, MNP, data }.

Step 21:DGW2 owing to setting up the bidirectional tunnel between AGWn, then directly carries out tunnel encapsulation to packet, and data packet format is { PCoAn, DGW2_addr, { HoAn, MNP, data } }, and packet is sent to AGWn via tunnel.

Step 22:AGWn carries out tunnel decapsulation to packet after receiving packet, the data packet format { HoAn, MNP, data } after decapsulation, and by Packet Generation to MN.

So far the communication process of LFN to CN is completed.

Should be appreciated that above is illustrative and not restrictive by preferred embodiment to the detailed description that technical scheme of the present invention is carried out.Those of ordinary skill in the art can modify to the technical scheme described in each embodiment on the basis of reading specification of the present invention, or carries out equivalent replacement to wherein portion of techniques feature; And these amendments or replacement, do not make the essence of appropriate technical solution depart from the spirit and scope of various embodiments of the present invention technical scheme.

Claims (1)

1. in separation mechanism mobility management systems, dispose a method for subnet movement, it is characterized in that, the method comprises the steps:

Step 1: mobile router MR is linked into access gateway AG W1, WAP (wireless access point) (Access Point on AGW1, AP) so detect that entering of MR sends log information to AGW1, after AGW1 receives log information, the access style of decision node, be mobile router or mobile node, and obtain the ID of corresponding access node, the mobile management process after completing these work on AGW1 is in wait state;

Step 2:MR then sends DHCPv6CONFIRM message to dynamic host configuration protocol DHCP relay agent;

After step 3:DHCP relay agent receives DHCP CONFIRM message, send DHCPv6RELAY FORWARD message to Dynamic Host Configuration Protocol server;

After step 4:DHCP server receives this message, judge whether the address of carrying in message can be used, if available, then return to dhcp relay agent the DHCP RELAY REPLY message that a status code is 0;

After step 5:DHCP relay agent receives message, judge that the status code in message is 0, then inform that the mobile management process on AGW1 can send agent binding update PBU message;

Step 6:AGW1 sends agent binding update PBU message to control gateway CGW1, and newly-increased subnet address MNP option and R flag bit in PBU message, AGW1 sets up the BUL relevant to MR simultaneously;

Step 7:CGW1 resolves after receiving PBU message, if legal, then send tunnel to DGW1 and sets up request message requests message TxReq, also increase MNP option and R flag bit newly in this message, CGW1 sets up the BCE relevant to MR simultaneously;

After step 8:DGW1 resolves after receiving TxReq message, set up one is pointed to AGW1 tunnel by DGW1, and return a tunnel acknowledge message TxAck to CGW1, and set up the TCE relevant to MR on DGW1, add the route relevant to HNP and MNP;

Step 9:DGW1 inquires about the address pool on it, for HNP and MNP distributes corresponding core address, and the corresponding relation of the corresponding relation of HNP and core address, MNP and core address is injected in the kernel of DGW1 goes, also these two pairs of mapping relations are included in map updating message simultaneously and issue global map server GMS, carry out up-to-date record;

After step 10:CGW1 receives TxAck message, just send the proxy binding acknowledgment messages PBA comprising HNP and R flag bit to AGW1;

After step 11:AGW1 receives PBA message, inform that DHCP process now can send DHCPREPLY message to MR;

Step 12:AGW1 parses the HNP information in agent binding confirmation PBA message, Mobile routing MR is advertised to by advertising of route advertising of route RA, set up the other end in the tunnel being pointed to DGW1 by AGW1 simultaneously, and the route of adding about HNP and MNP, the home address of oneself is generated after MR receives HNP according to EUI-64;

After step 13:DHCP relay agent receives the notice that AGW1 sends, just send DHCP REPLY message to MR;

After step 14:MR receives DHCP REPLY message, by RA message, the MNP that DHCP distributes is advertised to transceiving data bag LFN;

Step 15: after MR obtains home address HoA1, LFN acquisition subnet address MNP, packet can be sent to the CN being positioned at Access Network 2, CN needs to complete corresponding step 1 to 14 in Access Network 2, the home address obtained at Access Network 2 is HoAn, make LFN to CN initiating communication, packet forwards through MR and is first sent to AGW1, and data packet format is { HoAn, MNP, data };

Packet encapsulation is { DGW1_addr by step 16:AGW1, PCoA, { HoAn, MNP, data } } form, and packet is sent to DGW1 by bidirectional tunnel, wherein Agent care-of address PCoA1 is also the Agent care-of address of the AGW1 of the current access of MR, and DGW1_addr is the address of DGW1 in Access Network side;

After step 17:DGW1 receives packet, first decapsulation is carried out to it, packet is reduced to { HoAn, MNP, data } form, then DGW1 carries out the inquiry of mapping relations, now on DGW1 store two core address only having the MNP of HNP1 and LFN of MR corresponding, first inquire about the source address MNP of local mapping table to packet to inquire about, obtain corresponding core address 1; But DGW1 now the information of the core address n relevant to HoAn, therefore DGW1 needs to inquire about with GMS interactive map to obtain core address corresponding to HoAn with response message;

Step 18:DGW1 and GMS interactive map are inquired about and response message, obtain the core address n that HoAn is corresponding;

Step 19:DGW1 after obtaining the core address map information required for packet, then carries out mapping to the source address of packet and destination address and replaces, and has replaced rear data packet format for { core address n, core address 1, data }, and has been sent to DGW2;

After step 20:DGW2 receives packet, and do not know the information of the home address of core address 1 correspondence, therefore the inquiry of DGW2 and GMS interactive map obtains MNP corresponding to core address 1 with response message; DGW2 is after the corresponding mapping relations of acquisition, and just carry out demapping replacement to the source address of packet, destination address, the data packet format after demapping is { HoAn, MNP, data };

Step 21:DGW2 owing to setting up the bidirectional tunnel between AGWn, then directly carries out tunnel encapsulation to packet, and data packet format is { PCoAn, DGW2_addr, { HoAn, MNP, data } }, and packet is sent to AGWn via tunnel;

Step 22:AGWn carries out tunnel decapsulation to packet after receiving packet, the data packet format { HoAn, MNP, data } after decapsulation, and by Packet Generation to MN.