CN1705304A - AAA authentication method during fast switch-over process - Google Patents
AAA authentication method during fast switch-over process Download PDFInfo
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- CN1705304A CN1705304A CN 200410009156 CN200410009156A CN1705304A CN 1705304 A CN1705304 A CN 1705304A CN 200410009156 CN200410009156 CN 200410009156 CN 200410009156 A CN200410009156 A CN 200410009156A CN 1705304 A CN1705304 A CN 1705304A
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Abstract
This invention discloses a AAA attestation method in quick switching, which contains the new router generating temporary user list containing existing period for mobile node in quick switching, the mobile node making formal AAA attestation, said invention uses the temporary user list to provide access service and keeping communication without interruption and reducing switching delay.
Description
Technical field
The present invention relates to computer network field, more particularly, relate to a kind of method of in fast handover procedures, carrying out the aaa authentication process in the mobile IP v 6.
Background technology
Along with wireless communication technology and rapid development of network technology, people only have been not content with and have entered the Internet in the fixed location, but expect a kind of ubiquitous access way.Mobile IP v 6 is the mobility solution that IETF proposes, and terminal transport layer in moving process is connected be not interrupted.
Be the technical term of being correlated with below:
1, mobile node (MN): can keep the not interrupted mobile host of current connection from a link switchover to another link.Mobile node is supported mobile IPv 6 protocol in this article.
2, correspondent node (CN): be the fixing/mobile host of communicating by letter, can be called for short Correspondent Node with mobile node.
3, home address: distribute to the permanent global address of mobile node, be used for indicating uniquely mobile node.
4, Care-of Address (CoA): when mobile node moves to field network, distribute to the temporary address of mobile node.
5, home agent (HA): the router or the server that are positioned at the moving nodes local network.When mobile node moved to the other places, home agent was intercepted and captured the message that is sent to mobile node, then this message is carried out tunnel encapsulation, and is forwarded to the current location of mobile node.
6, binding: the home address of mobile node and the association between the Care-of Address.
7, registration: mobile node sends the Binding Update message to home agent or communication node, to register the process of a binding.
8, WAP (wireless access point) (AP): for mobile node provides wireless connections to insert the two-layer equipment of the Internet.
9, couple in router (AR): the default router of mobile node.
In mobile IP v 6, mobile problem is regarded as addressing and routing issue.When mobile node (MN) when roaming to field network, MN uses two addresses: home address and Care-of Address.Home address each layer more than network layer uses, and is used for indicating uniquely MN; Care-of Address uses in network layer, makes message can route to the current location of MN.
Mobile node will produce switching when mobile between two different subnets.Mobile node obtains new Care-of Address on new subnet, this need re-register to home agent, and binds again to Correspondent Node.Owing to reasons such as protocol processes and signal strength signal intensities, switch to produce and postpone, cause mobile node can not transmit and receive data within a certain period of time, make communicating by letter between Correspondent Node and the mobile node temporarily interrupt.The excessive requirement that just can not satisfy as real time communication such as video, audio frequency of switching delay when transport layer protocol is TCP, can reduce the throughput of TCP greatly.
To switch the delay cause and connect break period in other words in order to reduce, some fast switch over method have been proposed in mobile IP v 6, mainly comprise two kinds of handover mechanisms: switch in advance and based on the switching in tunnel (referring to document: " mobile IP technology ", Sun Limin etc. write, the Electronic Industry Press, 2003.8, P125～P130).Wherein, the mobile Ipv6 that the most representative IETF of being proposes switches draft (draft-ietf-mipshop-fast-mipv6-00) fast, and this draft has proposed a kind of pre-switch (PredictiveFast Handoff) method.The method needs link layer that two layers of (link layer) pre-switch triggering signal (Pre-trigger) are provided, and is about to take place two layers of switching so that MN can know in advance, thereby begins three layers of (network layer) handoff procedure in advance.In fact, for present most of wireless technologys, still lack and predict that effectively, accurately two layers switch the link-layer technologies that takes place.Therefore, how to realize veritably that still there is query in this quick handover scheme.
In existing switching based on the tunnel, after mobile node has moved to new network and set up the connection of the second layer, set up bidirectional tunnel between the new and old couple in router under mobile node moves front and back, transmit data message by the tunnel.Mobile node uses the Care-of Address that the identical network prefix is arranged with old router.In this method, owing to need between new and old couple in router, carry out Signalling exchange between the two, setting up bidirectional tunnel, so handover delay has been introduced in the processing of these signaling messages.
In the prior art, another influences the business-like factor of mobile IP v 6 technology is exactly the aaa authentication problem, and aaa authentication is meant authentication (Authentication), authorizes (Authorization) and charge (Accounting).The most representative is the mobile IP v 6 expansion draft (draft-le-aaa-diameter-mobileipv6-03) of Diameter.In existing aaa authentication process, access device generally adopts Access Control List (ACL) (Access Control List, ACL) forwarding of control user data.The user of unauthenticated does not have corresponding list item in ACL, its data can not be forwarded; There is the list item of a correspondence in the user of authentication success at ACL, and its data can be forwarded.If in the quick handover scheme of mobile IP v 6, consider access authentication, when MN switches to the another one network, just should initiate at first again to authenticate, normal transceive data just then, but this can increase handover delay undoubtedly.The method of present more employing is context transfer (ContextTransfer), promptly the network transitions at the AAA information of MN place before it to the network that may switch to or switch to.Like this, after MN finishes link layer and switches, transceive data immediately just.But this method also has certain limitation, such as, this method need exchange message between two networks, to transmit the AAA information of MN.This mode will be introduced extra handover delay because of transmit AAA message between two couple in routers in some cases.
In sum, in the changing method in the prior art, switching itself and aaa authentication process all can increase handover delay.
Summary of the invention
The purpose of this invention is to provide a kind of fast switch over method, will switch fast and combine, to reduce handover delay with access authentication in conjunction with the aaa authentication process.
To achieve these goals, a kind of method of in fast handover procedures, carrying out the aaa authentication process provided by the invention, be used for the fast handover procedures of mobile node when old couple in router moves to new couple in router, described new couple in router has access control function; Wherein:
In fast handover procedures, described new couple in router for mobile node generates casual user's list item, E-Packets so that this new couple in router can be described mobile node in its Access Control List (ACL); This casual user's list item has a life cycle;
After described casual user's list item generated, mobile node carried out formal aaa authentication process; If formal aaa authentication process is finished before casual user's list item expires, then new couple in router is replaced described casual user's list item with formal user's list item; If formal aaa authentication process remains unfulfilled when interim list item expires, then delete described casual user's list item, this new couple in router stops to provide access service for mobile node.
The current IP address that comprises described mobile node in described casual user's list item.The current IP address of described mobile node is the old Care-of Address of mobile node in the configuration of old couple in router place.
Perhaps, the current IP address of described mobile node is the new Care-of Address of mobile node in the configuration of new couple in router place.The aaa authentication process of mobile node and the Binding Update process of mobile node are carried out basically simultaneously, and described mobile node passes through the Binding Update process to its new Care-of Address of home agent/Correspondent Node Binding Update.
The present invention is provided with the casual user's list item with life cycle on new couple in router, make mobile node after switching to new couple in router, new couple in router can be at casual user's list item in life cycle, temporarily provide access service for mobile node, keep the unlikely interruption of communication, reduced switching delay.
Description of drawings
Fig. 1 is a mobile IP v 6 handoff scenario schematic diagram;
Fig. 2 is a fast switch over method flow chart of the present invention;
Fig. 3 is the ICMP stem in the RS+ message;
Fig. 4 delivers address option in the FRA+ message.
Embodiment
Below in conjunction with the drawings and specific embodiments the present invention is described in further detail.
The present invention carries out the method for aaa authentication process in fast handover procedures, be to carry out its aaa authentication process in the quick process of quick switching of mobile node.But, the present invention does not limit concrete fast handover procedures, the inventive method is carried out in the fast handover procedures that is described below, can also carry out in more existing other fast handover procedures, for example the present invention is equally applicable to set up between the new and old couple in router under mobile node moves front and back mentioned in " background technology " fast handover procedures of bidirectional tunnel.In the following description, will describe the present invention in detail as preferred implementation with the aaa authentication process of in a preferred fast handover procedures, carrying out.
Handoff scenario as shown in Figure 1, MN is connected under the couple in router oAR by WAP (wireless access point) oAP at first, and has finished process to the HA/CN Binding Update at this.MN switches to new couple in router nAR by WAP (wireless access point) nAP subsequently.OAR and network that nAR has jurisdiction over all belong to field network.MN is oCoA at the Care-of Address of oAR place configuration, and the Care-of Address that disposes at the nAR place is nCoA.
The present invention carries out in fast handover procedures as shown in Figure 2, and step is as follows:
1) after mobile node MN switched to new couple in router nAR and set up the connection of the second layer (link layer), the link layer of mobile node can produce link startup (Link-up) triggering signal.The generation of Link-up signal is different because of the difference of wireless technology, is example at this with the wireless lan (wlan) based on 802.11 agreements, the generation condition of this signal of brief description.In IEEE 802.11b agreement, link layer handover procedure comes down to mutual a series of management frames (Frame) between the wireless network card of MN and AP (Access Point, WAP (wireless access point)).When MN sends or receive certain type management frames, indicate the generation of certain part link layer event.Wireless adapter card provides the Link-up signal demand to exist in the Firmware of wireless adapter card the DLL (dynamic link library) of this signal is provided, and needs the support of driver.
2) after MN receives Link-up signal from link layer, send router solicitation RS+ message to router nAR immediately, move detection.The ICMPv6 stem form of RS+ message as shown in Figure 3, the difference of RS+ and common RS message are to have added a flag bit in its ICMPv6 stem, and this flag bit is ' C ' in one embodiment.In the RS+ message, this flag bit---for example ' C ' shows that transmit leg MN request couple in router nAR is its co-located care-of address and generates casual user's list item.In addition, also comprise an IP address option in the RS+ message, its content is the IPv6 address of current couple in router, and the effect of this option will be seen clearlyer hereinafter.
Preferably, consider safety factor, couple in router nAR should monitor the transmission rate of RS+ message, to prevent Denial of Service attack (DoS).If the RS+ transmission rate is too fast, couple in router nAR stops to provide service for this user, and charges to security log.
3) after router nAR receives the RS+ message of MN transmission, detect this message and whether comprise flag bit ' C '.If no, just handle according to general RS message; Otherwise, illustrate that this RS message is that mobile node is at the router solicitation RS+ message that sends between transfer period fast.At this moment, router nAR needs also to judge whether mobile node MN three layers (network layer) has taken place switched.Deterministic process is as follows: address that IP address option in the RS+ message is comprised and the IPv6 address of router nAR oneself compare, if the two is identical, illustrate that three layers of switching do not take place MN, at this moment the router nAR router of replying a routine to MN is replied (RA) message and is got final product; Otherwise, illustrating that three layers of switching have taken place MN, this moment, router nAR did following three work:
3a) co-located care-of address
According to the MAC Address of the MN that comprises in the network prefix of router receiving port and the RS+ message, router nAR is the new Care-of Address nCoA of MN structure, checks then whether this address is used by other users, to guarantee the uniqueness of this Care-of Address nCoA.If be used, then nAR need distribute another address for MN, and verifies the uniqueness of this address again.In the specific implementation of IPv6, access device generally adopts Access Control List (ACL), and (this is as well known to those skilled in the art for AccessControl List, the ACL) forwarding of control user data.Therefore, when the present invention specifically implements, can verify the uniqueness of this new Care-of Address nCoA according to the user list of access control lists (ACL) or similar this function.
3b) generate casual user's list item with certain life cycle for mobile node
For the couple in router with access control function, router can not provide access service for the user of any unauthenticated mandate.If MN finds to switch to new network, just begin fast handover procedures, MN needs to send quick Binding Update (FBU) message to oAR as early as possible, but nAR this moment does not obtain the Certificate Authority information of any relevant MN, so nAR can not transmit FBU.From security consideration, this moment, MN should first authenticated/authorized, and then switched fast, but may cause bigger handover delay like this, especially when needs hometown AAA server (AAAh) participates in verification process.
In the present embodiment, when router nAR is after mobile node MN has disposed the Care-of Address nCoA of " unique ", router nAR is that this user's current IP address generates casual user's list item with nCoA in its Access Control List (ACL), this user's list item has a life cycle, and this casual user's list item is routed device nAR deletion in its life cycle to after date.After setting up this casual user's list item, in the life cycle of this casual user's list item, if it is the message (being sent to the message of MN) of nCoA or when receiving source address during the message (from the message of MN) of nCoA that nAR receives destination address, just can normally transmit according to casual user's list item.Should be noted that, in fact this fashion of mobile node MN is not finished its aaa authentication, this casual user's list item that generates for mobile node is in order to allow mobile node MN can pass through router nAR transceive data message, to carry out its normal aaa authentication process and to accelerate handoff procedure.When this point will be seen clearlyer in the following description.
The length of this casual user's list item life cycle is relevant with the normal aaa authentication required time of mobile node MN, the designer can be provided with the life cycle of this user's list item according to concrete aaa authentication required time, so that normal aaa authentication process can be finished in this life cycle.In general, can be set to 5 seconds the life cycle of casual user's list item～10 seconds.
It should be noted that, though new in the present embodiment couple in router nAR generates casual user's list item with new Care-of Address nCoA, but be to be understood that, in other embodiment, when mobile node MN is not configured to new Care-of Address, also can use it to generate casual user's list item as user's current IP address at the old Care-of Address oCoA of old couple in router oAR configuration.One of ordinary skill in the art as can be known, this does not influence enforcement of the present invention.
3c) the structure router is replied (RA+) message
Replying the RA message with common router compares, the router response message here is except for example comprising option such as network prefix, MAC Address, also will add a new Care-of Address option in the router response message, its content is the Care-of Address of new couple in router nAR for this MN configuration.For being different from general RA message, this router response message can being become and be referred to as the RA+ message.The form of Care-of Address option as shown in Figure 4.
3d) send the RA+ message to MN
After having constructed the RA+ message, nAR sends to MN with this message.RFC2462 regulation, for fear of conflict, router receives that not sending router immediately behind router solicitation (RS) message replys (RA) message, but wants random delay 0s to 0.5s.As a kind of preferred version, adopted a kind of quick RA scheme to send the RA+ message among the present invention, promptly on a link, allow a router and do not carry out above-mentioned time-delay, but send RA immediately.For being different from other RA messages, the RA+ message that sends under this quick RA mechanism is called FRA+.
4) after MN receives FRA+, judge whether to have taken place three layers of switching according to the information such as network prefix that comprise among the FRA+.If three layers of switching do not take place, then do not carry out following operation; Otherwise:
4a) construct quick Binding Update (FBU) message.The source address of the Ipv6 stem of FBU is the nCoA that comprises in the FRA+ message, and destination address is the IPv6 address of oAR.Comprise oCoA in the home address option of FBU (Home Address Option).
4b) send the FBU message to old couple in router oAR.
5) after oAR receives FBU, carry out following operation according to message content:
5a) set up binding list item between nCoA and the oCoA.
5b) set up a tunnel, the entry address in this tunnel is the Ipv6 address of oAR, and exit address is for being the Care-of Address nCoA of mobile node.This tunnel has a life cycle, and after date is crossed in the tunnel will be deleted.Can be provided with the life cycle in this tunnel in the Lifetime territory in the FBU option, and the service time in the tunnel between life cycle and oAR and MN is relevant, and depends on that MN to the time that HA/CN carries out Binding Update, is traditionally arranged to be 5～10 seconds and gets final product the service time in tunnel.
5c) send binding fast and reply (FBACK) message to MN.
Like this, it is the message of oCoA that oAR intercepts and captures destination address, carries out the IPv6/IPv6 encapsulation then, makes to be forwarded to MN at last in the source of outer field IPv6 stem, the entrance and exit address that destination address is respectively the tunnel.These messages are in the decapsulation of MN place, and then are delivered to application program.
6) MN receives FBACK, has successfully carried out associative operation if this message shows oAR, then sets up reverse tunnel, and its entry address is nCoA, and exit address is the IPv6 address of oAR.After reverse tunnel is set up, so just between oAR and MN, set up a bidirectional tunnel (Bi-directional Tunnel), the life cycle of this bidirectional tunnel and step 5b) in the tunnel consistent life cycle.
Like this, MN is that the message of oCoA carries out the IPv6/IPv6 encapsulation to the source address that is about to send, and makes the source of outer field IPv6 stem, the entrance and exit address that destination address is respectively the tunnel.These messages through decapsulation, and then are forwarded to real destination after arriving oAR.
Notice that after reverse tunnel was set up, only source address was to send after the datagram of oCoA encapsulates through IPv6/IPv6.Because MN is nCoA to the aaa authentication message of HA/CN transmission and the source address of Binding Update message, therefore can not adopt tunnel style, but directly send.
7) mobile node MN sends aaa authentication message and Binding Update message with source address nCoA to HA/CN by router nAR, carries out aaa authentication in a usual manner basically simultaneously and to the Binding Update of HA/CN.
Mobile node MN is generally finished before bidirectional tunnel is expired the Binding Update of HA/CN, and after mobile node MN was finished the Binding Update of HA/CN, data flow brought into use new Care-of Address nCoA to transmit, and bidirectional tunnel expires and be deleted subsequently.If for some reason, MN does not finish in the life cycle in the tunnel to the Binding Update process of HA/CN, at this moment just must continue to use the tunnel to communicate.Generally speaking, be set to 5 seconds the life cycle in tunnel earlier～10 seconds, if also will continue to use the tunnel, MN can resend the life cycle that the FBU message upgrades the tunnel.
The formal aaa authentication process of mobile node MN is generally finished before casual user's entry expiration, after the aaa authentication of mobile node MN is finished, to on router nAR, generate formal user's list item for mobile node MN, new couple in router nAR replaces casual user's list item with formal user's list item, owing to generated formal user's list item before casual user's list item expires, therefore communication can not be interrupted.If the aaa authentication of mobile node MN is not passed through, then deleted behind casual user's entry expiration, nAR stops to provide access service for MN.
Claims (5)
1, a kind of method of carrying out the aaa authentication process in fast handover procedures is used for the fast handover procedures of mobile node when old couple in router moves to new couple in router, and described new couple in router has access control function; Wherein:
In fast handover procedures, described new couple in router for mobile node generates casual user's list item, E-Packets so that this new couple in router can be described mobile node in its Access Control List (ACL); This casual user's list item has a life cycle;
After described casual user's list item generated, mobile node carried out formal aaa authentication process; If formal aaa authentication process is finished before casual user's list item expires, then new couple in router is replaced described casual user's list item with formal user's list item; If formal aaa authentication process remains unfulfilled when interim list item expires, then delete described casual user's list item, this new couple in router stops to provide access service for mobile node.
2, method of carrying out the aaa authentication process in fast handover procedures according to claim 1 is characterized in that, comprises the current IP address of described mobile node in described casual user's list item.
3, method of carrying out the aaa authentication process in fast handover procedures according to claim 2 is characterized in that, the current IP address of described mobile node is the old Care-of Address of mobile node in the configuration of old couple in router place.
4, method of carrying out the aaa authentication process in fast handover procedures according to claim 2 is characterized in that, the current IP address of described mobile node is the new Care-of Address of mobile node in the configuration of new couple in router place.
5, method of in fast handover procedures, carrying out the aaa authentication process according to claim 4, it is characterized in that, the aaa authentication process of mobile node and the Binding Update process of mobile node are carried out basically simultaneously, and described mobile node passes through the Binding Update process to its new Care-of Address of home agent/Correspondent Node Binding Update.
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| CNB2004100091562A CN100486246C (en) | 2004-05-31 | 2004-05-31 | Method for AAA authentication in mobile IPv6 fast switch-over process |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102761928A (en) * | 2011-04-25 | 2012-10-31 | 上海无线通信研究中心 | Heterogeneous network switching method for group user based on business QoS |
| CN109067764A (en) * | 2018-08-29 | 2018-12-21 | 新华三技术有限公司 | A kind of method and device for establishing equipment list item |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2003046533A (en) * | 2001-08-02 | 2003-02-14 | Nec Commun Syst Ltd | Network system, authentication method therefor and program thereof |
| CN1479493A (en) * | 2002-08-31 | 2004-03-03 | 深圳市中兴通讯股份有限公司 | Interconnectioin system |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102761928A (en) * | 2011-04-25 | 2012-10-31 | 上海无线通信研究中心 | Heterogeneous network switching method for group user based on business QoS |
| CN109067764A (en) * | 2018-08-29 | 2018-12-21 | 新华三技术有限公司 | A kind of method and device for establishing equipment list item |
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