CN1783833A

CN1783833A - Mobile IPv6 Smooth switching system and method

Info

Publication number: CN1783833A
Application number: CNA2004100973746A
Authority: CN
Inventors: 杨武学
Original assignee: Beijing Samsung Telecommunications Technology Research Co Ltd; Samsung Electronics Co Ltd
Current assignee: Beijing Samsung Telecommunications Technology Research Co Ltd; Samsung Electronics Co Ltd
Priority date: 2004-11-29
Filing date: 2004-11-29
Publication date: 2006-06-07

Abstract

This invention relates to a mobile Ipv6 smooth switching, which contains plurality f mobile nodes for sending switching instruction, plurality of routers for converting data package sent to mobile node, buffer memory management equipment between internet and router for managing the switched data package. Said invented BME manages buffer resource with high availability and convenient management. Each AR does not execute complexing buffer management, reduces AR load and has lower package loss rate.

Description

Mobile IPv 6 Smooth switching system and method

Technical field

The present invention relates to the internet mobile communication field, particularly mobile IPv 6 Smooth switching system and method.

Background technology

It is mobile IP v 6 (IPv 6) agreement that IETF (internet engineering task tissue) has formally issued RFC 3775 " Mobility Support in IPv6 " in June, 2004.Mobile IP v 6 is to make the mobile node MN of roaming can visit the agreement of IPv6 network pellucidly.

Fig. 1 has described the principle of standard mobile IP v 6:

The subnet at mobile node (MN) 103 original places is a home network 106, and the address with home network prefix that obtains in home network is a home address.Home agent (HA) 104 is arranged in home network, and special disposal communication node (CN) 101 is for the visit of MN (mobile node) 103.When MN 103 was in home network 106, CN 101 was 108 and 109 path access MN 103 by label.When MN 103 moves to field network 105, acquisition belongs to the temporary address of field network---also claim Care-of Address (CoA), and register (Binding Update) to HA (home agent) 104, make HA 104 know the network at MN 103 current places and the CoA that is using.Like this, when the home address of CN 101 visit MN 103 (number in the figure is 110 path), HA 104 these messages of interception, and be forwarded to the current CoA of MN (number in the figure is 111 path) by the tunnel.Know the CoA of MN 103 as CN 101 after, can also be directly and the CoA of MN 103 communicate (number in the figure is 112 path).When MN 103 when a field network moves to another field network, couple in router 102 changes thereupon, its CoA in field network also should change, and to the new CoA of HA 104 registrations.

This process is called standard and switches.When mobile node when a network moves to the another one network, message dropping is more serious in the standard handoff procedure, causes service quality to descend even the interruption of service.

In order to address the above problem, a kind of framework that takes over seamlessly of mobile IP v 6 has been proposed at present.Fig. 2 has described the method for this switching.This framework has defined two kinds of situations:

(1) MCNA (mobile Control Network is assisted/(no) assistance): require the packet of the PAR202 buffer memory MN 201 of current sub network, succeed in registration at new subnet up to MN 201.In case registration is finished, MN 201 is just having legal CoA in new subnet, and cached data packet 204 is transmitted to MN 201 from PAR (previous couple in router) 202 through the tunnel, like this, has reduced the possibility of data-bag lost in the moving process.

(2) NCMA (network control is mobile-assisted) method: PAR 202 can predict MN201 and will switch to which NAR (new couple in router) 203.PAR 202 will need cached data packet directly to send to preservation among the NAR 203 by tunnel 204.After MN 201 moves to new subnet, cached data packet before can directly obtaining from NAR 203.

Along with development of Internet, the MN quantity in the network can get more and more.Each AR (couple in router) safeguards that separately buffer memory may cause the serious waste of cache resources, also is unfavorable for centralized management.Each AR safeguards that separately buffer memory can increase the weight of the burden of AR, and then influences the communication quality of MN.

Summary of the invention

The purpose of this invention is to provide the system and method that takes over seamlessly (packet loss is low) between the subnet that is used for mobile IP v 6 that a kind of logic is simple, function is healthy and strong, under wireless mobile environment, improve the mobile IP v 6 success rate for switching, reduce IP packet loss rate.

According to an aspect of of the present present invention, the system that a kind of mobile Ipv6 takes over seamlessly comprises:

A plurality of mobile nodes are used to send switching command;

A plurality of routers are used to transmit the packet that is sent to mobile node;

Also comprise cache management equipment, the packet when being used to manage the mobile node switching.

According to another aspect of the present invention, the method that a kind of mobile Ipv6 takes over seamlessly comprises step:

A plurality of mobile nodes send switching command;

A plurality of routers are transmitted the packet that is sent to mobile node;

Packet when cache management equipment control mobile node switches.

BME unified management cache resources of the present invention, the utilance of buffer memory is higher, manages more convenient.Each AR needn't carry out complicated cache management, has reduced the burden of AR, and still can reach lower packet loss requirement.

Description of drawings

Fig. 1 is that the mobile IP v 6 standard is switched schematic diagram;

Fig. 2 is the existing schematic diagram that takes over seamlessly;

Fig. 3 is a mobile IP v 6 BMEASH network diagram;

Fig. 4 is a mobile IP v 6 BMEASH sequential chart;

Fig. 5 is the flow chart that PAR carries out BMEASH;

Fig. 6 is the flow chart that NAR carries out BMEASH;

Fig. 7 is the flow chart that MN carries out BMEASH.

Embodiment

Fig. 3 has described the network diagram of mobile IP v 6 BMEASH (BME is auxiliary to be taken over seamlessly).

When MN 301 will be when a subnet moves to the another one subnet, PAR 302 will mail to the data pack buffer of this MN 301 in BME (cache management equipment) 304.After MN 301 moves to new NAR 303 coverages, BME will be just now cached data packet be forwarded to the up-to-date CoA of MN 301.Buffer memory among the BME is unified management, can adopt certain algorithm dynamic assignment.BME can be a functional module of independent equipment or router.

Fig. 4 has described mobile IP v 6 BMEASH sequential chart.

[406] in router advertisement message, increase an option, the address that is used to preserve BME.PAR402 informs MN 401 by router advertisement with the address of BME 403.The up-to-date address that MN 401 preserves BME304.When MN401 detects oneself will shift out PAR402 the time, MN401 sends " cache request " information to PAR402.

[407] after PAR 402 receives " cache request " information, send " buffer memory initialization request " to BME 403.

[408] BME 403 for after this MN distributes buffer memory, returns " buffer memory initialization affirmation " to PAR 402 according to certain algorithm.

[409] PAR 402 returns " buffer memory affirmation " information to MN 401.

[410] PAR402 is the packet of MN 401 when being transmitted to MN 401 with the destination, also is forwarded to BME 403 by the tunnel and preserves.

[411] a certain moment after this, MN 401 disconnects with the old link of PAR 402.

[412] the new link establishment between MN 401 and the NAR 404 is got up.

[413] MN 401 obtains a new CoA address by the address assignment and the collision detection process of standard.

[414] MN 401 sends to NAR 404 and takes over seamlessly request, includes the address of BME 403 in this request.

[415] the take over seamlessly home address that request extract MN 401 of NAR 404 from receiving.And to BME 403 transmissions " buffer memory is transmitted request ".

[416] BME 403 searches buffering area as index value with home address.After searching successfully, BME 403 returns " buffer memory is transmitted and confirmed " information to NAR404.By tunneling technique the IPv6 of nearest buffer memory bag is transmitted to MN 401 simultaneously.The outer field destination address in tunnel is the Care-of Address that MN 401 obtains recently.

[417] NAR 404 returns " taking over seamlessly affirmation " information to MN.

[418] MN 401 receptions are from the packet of BME 403.

[419] MN 401 sends up-to-date " Binding Update " to HA/CN 405.

[420] MN 401 receives " binding acknowledgement " that HA/CN 405 sends.

[421] MN 401 receptions are from the packet of HA/CN 405.In order to keep the order of IP bag, the IP bag that MN 401 transmits priority treatment BME 403 as far as possible.

Fig. 5 has described the flow chart of PAR execution BMEASH

[501] PAR receives " cache request " information of MN.

[502] PAR sends the buffer memory initialization request to BME, and requiring BME is the buffer memory that MN distributes some.

[503] PAR will receive replying of BME.Comprise the information whether BME allows this MN IP bag of buffer memory in replying.

[504] if BME does not allow buffer memory, then PAR does not carry out the BMEASH operation, and the standard of promptly getting back to is switched.

[505] PAR sends out message to MN, notifies its request failure.

[506] if BME allows the IP bag of this MN of buffer memory, then PAR sends out message to MN, notifies it to ask successfully.

[507] PAR is transmitted to BME by the IPv6 bag that tunneling technique will send to MN, is that the IPv6 bag preserved in keyword by BME with the MN home address.Simultaneously, PAR still will transmit packet by current chain road direction MN.

Fig. 6 has described the flow chart of NAR execution BMEASH

[601] NAR receives the request that takes over seamlessly that MN sends.Illustrate that MN has been connected to the network at NAR place and has obtained a new Care-of Address CoA.Take over seamlessly the address that includes BME in the request.

[602] NAR extracts the home address of MN, sends " buffer memory forwarding request information to BME then.

[603] NAR will receive the affirmation information of BME, show whether BME allows buffer memory to transmit.

[604] if BME does not allow the IP bag in this MN forwarding cache, NAR sends out message to MN, notifies it to take over seamlessly failure.So just got back to the standard switching.

[605] if BME allows the IP bag in this MN forwarding cache, NAR sends out message to MN, notifies it to take over seamlessly success.

Fig. 7 has described the flow chart of MN execution BMEASH

[701] when MN will shift out the scope of PAR, it sends " cache request " to PAR.

[702] MN will receive the affirmation information of PAR, show whether BME can provide the buffer memory service to it.

[703] judge whether BME can provide the buffer memory service.

[704] if BME can not provide the buffer memory service, the standard of then getting back to is switched.

[707] if BME can provide the buffer memory service, then when the old link disconnection, after new link establishment 705 and address configuration and collision detection 706 were finished, MN sent the request that takes over seamlessly to NAR.The address (address of BME obtains by the PAR router advertisement) that comprises BME in the request.

[708] MN will receive the confirmation that takes over seamlessly of NAR transmission, show that the request that takes over seamlessly is success or failure.

[709] if what receive is the affirmation information that takes over seamlessly failure, the standard of then getting back to is switched.

[710] MN receives by the BME cached data packet by the tunnel.

[711] MN sends normal binding update messages to HA and CN.Afterwards, MN can receive the new packet from HA/CN.

Claims

1. system that mobile Ipv6 takes over seamlessly comprises:

A plurality of mobile nodes are used to send switching command;

2. by the described system of claim 1, it is characterized in that described cache management equipment is a functional module of an autonomous device or router.

3. by the described system of claim 1, it is characterized in that described router comprises previous couple in router and new couple in router.

4. by the described system of claim 3, it is characterized in that:

The packet that described previous couple in router will mail to mobile node is forwarded to cache management equipment buffer memory;

When mobile node successfully inserted new subnet, cache management equipment was transmitted to the mobile node present care-of address with institute's cached data packet again.

In the network of mobile IP v 6, introduce a new logical device " cache management equipment " (BME, Buffer Management Equipment), be responsible for the unified management of buffer memory by it.A BME can provide service for several AR.When certain MN when a subnet switches to the another one subnet, the packet that PAR will mail to this MN is forwarded to the BME buffer memory.When MN successfully inserts new subnet by the time, BME again will be just now cached data packet be transmitted to the current CoA of MN.

5. method that mobile Ipv6 takes over seamlessly comprises step:

A plurality of mobile nodes send switching command;

A plurality of routers are transmitted the packet that mobile node sends;

Packet when cache management equipment control mobile node switches.

6. by the described method of claim 5, it is characterized in that any one couple in router can send " buffer memory is transmitted request " to cache management equipment.

7. by the described method of claim 5, it is characterized in that the packet when described cache management equipment control mobile node switches comprises step:

(1) the buffer memory initialization request of the previous couple in router of reception, echo reply information;

(2) the IPv6 bag buffer memory regular hour of mailing to certain moving nodes local address that previous couple in router is forwarded;

(3) buffer memory that receives new couple in router is transmitted request, echo reply information;

(4) the IPv6 bag that will belong to certain moving nodes local address sends to this mobile node present care-of address by the tunnel.

8. by the described method of claim 6, it is characterized in that described any one couple in router can send " buffer memory is transmitted request " and comprise step to cache management equipment:

After mobile node is connected to new subnet, take over seamlessly request to the couple in router transmission, wherein include the address of cache management equipment;

New couple in router sends " buffer memory is transmitted request " according to the cache management device address that mobile node provides to cache management equipment.

9. by the described method of claim 8, it is characterized in that the address of described cache management equipment is obtained by following method:

Be that router advertisement message increases an option, the address packet of cache management equipment is contained in the router advertisement message;

Couple in router is given mobile node by router advertisement message with the address notification of cache management equipment;

Mobile node is preserved the up-to-date address of cache management equipment.