CN1949931B - Method for updating roaming user address and access controller - Google Patents

Abstract

The invention discloses a roaming user address updating method and access controller, comprising the steps of: when the current foreign access controller of a roaming user terminal detects that the state of the roaming tunnel for the roaming user terminal to roam from home netowrk to roaming foreign netowrk is worsened, the foreign access controller uses the roaming user terminal as local user terminal, connected in parallel; and broadcasts and sends out an address updating message whose source address is the user terminal's MAC address. And the invention can implement normal communication when the roaming user terminal's HA (home agent) fails or the tunnel between HA and FA (foreign agent) fails and before the user terminal does not actively send the message.

Description

A roaming user address update method and access controller

technical field

The invention relates to wireless local area network technology, in particular to a roaming user address updating method and an access controller.

Background technique

WLAN (Wireless Local Area Network, Wireless Local Area Network) provides a wireless connection service of a local area network. Because it can provide high-speed wireless data access, WLAN is one of the more popular technologies in the IT industry at present, and it is also a popular wireless access method. WLAN usually adopts centralized AC-AP (Access Controller-Access Point, access controller-access point) architecture. Among them, the AC provides centralized management of the WLAN network, and the AP establishes a link with the AC and joins the WLAN network to provide wireless access services.

Wireless roaming is the key to solving user mobility. In the HA (Home Agent, Home Agent)-FA (Foreign Agent, Roaming Agent) roaming architecture, all data to the roaming user terminal must first be sent to the HA, that is, the AC in the HA, and then pass through the HA-FA , that is, the roaming tunnel between the user terminal's home AC and the roaming AC reaches the roaming user.

As shown in FIG. 1, in an existing wireless network, a user terminal 1 (STA1) roams from its home network 1 to a roaming network 3, and accesses the roaming network through a roaming AP (not shown in the figure). Access controller AC3, STA1 in its home network is responsible for access control by AC1; wireless user 2 (STA2) accesses home access controller AC2 through its home AP (not shown in the figure), AC2 is responsible for access control of STA2 in its home network.

At this time, when there is a packet destined for STA1, for example, a packet sent from PC or STA2 to STA1 first arrives at AC1, then is sent to AC3 through the roaming tunnel between AC1 and AC3, and finally reaches STA1.

However, once AC1 or the roaming tunnel between AC1 and AC3 fails, STA1 has re-associated with AC3 as a common user terminal, that is, STA1 has associated with AC3 as a local user terminal. Then, when STA1 does not actively send a message to the network, other network devices other than AC3, such as STA2, do not know that STA1 has re-associated with AC3 as a local user terminal. In other words, if STA1 does not actively send packets, other network devices will continue to send packets destined for STA1 to AC1. Since AC1 or the roaming tunnel between AC1 and AC3 has failed at this time, it can be seen that the message cannot reach AC3, and thus STA1 will not receive the data.

It can be seen that when the HA of a roaming user terminal fails or the roaming tunnel between HA and FA fails, before the user terminal actively sends a message, that is, if the user terminal only receives data and does not send data, Since the network device does not know that the HA of the roaming user terminal fails or cannot handle the failure, even if the roaming user associates (Association/Re-Association, association-re-association) with the FA as a normal user; the data sent to the user will still be sent to HA, leading to business interruption, communication interruption.

Therefore, how to provide a roaming user address update method and an access controller to solve the problem when the HA of the roaming user terminal fails or the roaming tunnel between the HA and FA fails, and the user terminal does not actively send messages Under the same conditions, the normal progress of communication can also be guaranteed.

Contents of the invention

The technical problem to be solved by the present invention is to provide a roaming user address update method and an access controller to realize that when the HA of the roaming user terminal fails or the roaming tunnel between HA and FA fails, and the user terminal does not actively send Before the message, the normal progress of communication can still be guaranteed.

In order to solve the problems of the technologies described above, the present invention provides the following solutions:

A method for updating a roaming user address, comprising the steps of:

When the roaming access controller where the roaming user terminal is currently located detects that the state of the roaming tunnel where the roaming user terminal roams from its home network to the roaming network has deteriorated, the roaming access controller sends the roaming user terminal Associated as a local user terminal;

Broadcasting and sending an address update message whose source address is the MAC address of the user terminal to the outside of the roaming access controller.

In the method of the present invention, the state of the roaming tunnel where the roaming user terminal roams from its home network to the roaming network deteriorates is that the home access controller of the roaming user terminal periodically reports to the roaming site The access controller sends a message, if the roaming access controller does not periodically receive the message, it is judged that the state of the roaming tunnel is deteriorating; or the roaming access controller of the roaming user terminal periodically sends a report to the home If the local access controller sends a message, if the roaming access controller does not periodically receive the response message sent by the home access controller, it determines that the state of the roaming tunnel is degraded.

In the method of the present invention, the roaming access controller associates the roaming user terminal as a local user terminal by directly setting the state of the roaming user terminal from a roaming user terminal state to a local user terminal state.

In the method according to the present invention, the roaming access controller associates the roaming user terminal as a local user terminal, and the roaming access controller sends a de-association message or a de-authentication message to force The user terminal goes offline and reassociates as a local user terminal.

An access controller, comprising: a roaming tunnel detection module, an association trigger module, and an address update broadcast sending module;

The roaming tunnel detection module is used to detect the roaming tunnel of the roaming user terminal, and when it is detected that the state of the roaming tunnel is deteriorating, trigger the association trigger module;

The association triggering module is used to associate the roaming user terminal roaming through the roaming tunnel in deteriorating state as a local user terminal according to the triggering of the roaming tunnel detection module, and trigger the address update broadcast sending module;

The address update broadcast sending module is used to broadcast and send an address update message, and the source address of the address update message is the MAC address of a roaming user terminal roaming from a roaming tunnel in a deteriorating state.

In the access controller of the present invention, the roaming tunnel detection module is further configured to trigger the association trigger module when the tunnel detection message sent by the home access controller of the roaming user terminal cannot be received periodically .

In the access controller of the present invention, the roaming tunnel detection module is further configured to periodically send a tunnel detection message to the access controller at which the roaming user terminal belongs. When the terminal home accesses the response message sent by the controller, the association triggering module is triggered.

In the access controller of the present invention, the association triggering module is further configured to, according to the triggering of the roaming tunnel detection module, directly change the state of the roaming user terminal roaming from the roaming tunnel in the deteriorating state to the roaming user The terminal status is set to the local user terminal status.

In the access controller according to the present invention, the association triggering module is further configured to send a deassociation message or de-authentication message, and receive the re-association of the user terminal as a local user terminal.

The method and the access controller of the present invention associate the roaming user terminal as a local user terminal by responding to the fault event of the home access controller of the roaming user terminal or the roaming tunnel, and at the same time broadcast the transmission source address as the The address update message of the MAC address of the user terminal triggers the network device to update the forwarding table of the user terminal, so that the data that needs to reach the user terminal is directly directed to the roaming access controller; therefore, the current When the HA of a roaming user terminal fails or the roaming tunnel between HA and FA fails, and before the user terminal actively sends a message, the normal communication can still be guaranteed.

The technical problems to be solved, the key points of the technical solutions and the beneficial effects of the present invention will be further described in conjunction with the embodiments and with reference to the accompanying drawings.

Description of drawings

FIG. 1 is a schematic structural diagram of a wireless network in the prior art;

Fig. 2 is the flowchart of the method described in the embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a wireless network according to an embodiment of the present invention.

Detailed ways

Referring to Figure 2, when the user terminal roams from its home network to the roaming network, the method described in the embodiment of the present invention includes the following steps:

Step 101: The roaming access controller AC where the user terminal is currently located detects whether the state of the roaming tunnel where the roaming user terminal roams from its home network to the roaming network deteriorates, and if it is found that the state of the roaming tunnel deteriorates, execute Step 102; otherwise, no action and end.

Here, the state of the roaming tunnel deteriorates, for example, the home access controller of the user terminal is down, or the roaming tunnel is in a fault state of communication interruption, or in a fault state such as congestion. The roaming access controller AC of the user terminal detects whether the roaming tunnel is deteriorated, which can be implemented in various ways. For example, the roaming access controller AC of the user terminal periodically sends a message, such as a Keep Alive message, to its home access controller, and then detects whether the corresponding response message can be periodically received If the response message can be received, it means that the roaming tunnel and the home AC are normal. If no response message is received, it means that the roaming tunnel or the home AC is faulty. For another example, both the roaming AC and the home AC of the user terminal may periodically send a tunnel detection message to each other, such as a Keep Alive message, or the home AC may periodically send a Keep Alive message to the roaming AC. message; if the roaming AC periodically receives the Keep Alive message from the home AC, it indicates that both the roaming tunnel and the home AC are normal. If no Keep Alive message is periodically received from the home AC, It indicates that the roaming tunnel or the home AC is faulty.

Step 102: The roaming access controller AC of the user terminal associates the user terminal as a local user terminal;

Here, the roaming access of the user terminal to the controller AC may be associated with the user terminal as a local user terminal in a manner of direct association or indirect association. The direct association means that the roaming AC directly sets the state of the user terminal from the roaming user terminal state to the local user terminal state. As for the indirect association mode, it may be implemented by roaming the access controller AC and performing common message exchange with the user terminal. For example, the roaming access controller AC sends a DEASSOCIATION (disassociation) message or a DEAUTHENTICATION (deauthentication) message to force the user terminal to go offline and make it re-associate with the roaming access controller AC as a local user terminal. .

Step 103: The roaming access controller AC broadcasts an address update message whose source address is the MAC address of the user terminal to the external network to trigger the network device to update the forwarding table of the user terminal, so that The data of the user terminal is directly directed to the roaming access controller.

Here, the roaming access controller AC broadcasts an address update message whose source address is the MAC address of the user terminal to the external network. message, as long as the source address of the sent message is the MAC address of the user terminal. For example, the logical link layer XID (Exchange Identifier, exchange identifier) of 802.2 type 1 can be used to update the response message, and the source MAC of the message is set to the MAC address of the user equipment, so that the network device receives the message Afterwards, the forwarding table of the user equipment will be updated to guide the data to the roaming access controller; the destination address of the address update message is set to a broadcast address, and the DSAP field and the SSAP field are set to NULL, For the control word of the message, reference may be made to the definition in the 802.2 protocol, which will not be repeated here.

Referring to FIG. 3 , the wireless local area network according to the embodiment of the present invention includes: a PC, a local switch LSW, a first user terminal STA1, a second user terminal STA2, a first access controller AC1, and a second access controller AC2, the third access controller AC3.

Among them, the PC accesses the WLAN through the LSW; STA1 roams from its home location (the network where AC1 is located) to the roaming location (the network where AC3 is located), and establishes a roaming tunnel AC1-AC3; STA2 is responsible for its local access through AC2. into control.

The third access controller AC3 includes: a roaming tunnel detection module 10 , an association trigger module 20 , and an address update broadcast sending module 30 .

The roaming tunnel detection module 10 is configured to detect the roaming tunnel of the roaming user terminal, and trigger the association triggering module 20 when the state of the roaming tunnel is detected to deteriorate.

The association triggering module 20 is configured to associate the roaming user terminal roaming through the faulty roaming tunnel as a local user terminal according to the triggering of the roaming tunnel detection module 10 , and trigger the address update broadcast sending module 30 .

The address update broadcast sending module 30 is configured to broadcast and send an address update message, the source address of the address update message is the MAC address of the roaming user terminal roaming from the faulty roaming tunnel.

First, when STA1 roams from its home location (the network where AC1 is located) to the roaming location (the network where AC3 is located) and establishes roaming tunnels AC1-AC3, the roaming tunnel detection module 10 in AC3 detects the status of the roaming tunnels AC1-AC3 Is it getting worse. For example, the roaming tunnel detection module 10 in AC3 periodically sends a Keep Alive message to AC1, and then detects whether the corresponding response message can be received periodically, if it can be received, it means that the roaming tunnels AC1-AC3 and AC1 is normal, if no response message is received, it indicates that the roaming tunnel AC1-AC3 or AC1 is faulty, and the roaming tunnel detection module 10 sends a trigger signal to the association trigger module 20 . For another example, the roaming tunnel detection module 10 and AC1 in AC3 can also periodically send a tunnel detection message to the other party, such as a Keep Alive message, or the roaming tunnel detection module 10 in AC3 can be sent periodically by AC1 Send the Keep Alive message; then, if the roaming tunnel detection module 10 in AC3 periodically receives the Keep Alive message from the home AC, it shows that the roaming tunnels AC1-AC3 and AC1 are all normal. If the Keep Alive message from AC1 is received, it indicates that the roaming tunnels AC1-AC3 or AC1 are faulty, so the roaming tunnel detection module 10 sends a trigger signal to the association trigger module 20.

When the association trigger module 20 in AC3 is triggered by the trigger signal sent by the roaming tunnel detection module 10, the association trigger module 20 can directly set the state of the roaming user terminal from the roaming user terminal state to the local user terminal state. Or, the association triggering module 20 sends a DEASSOCIATION (disassociation) message or a DEAUTHENTICATION (deauthentication) message to force the user terminal to go offline and make it re-associate with the roaming access controller AC as a local user terminal.

After AC3 associates the user terminal roaming from the faulty roaming tunnel as a local user terminal through the association trigger module 20, the address update broadcast sending module 30 in AC3 broadcasts to the external network the address whose source address is the MAC address of the user terminal The message is updated to trigger other network devices (such as LSW and AC2) in the network to update the forwarding table of STA1, that is, to establish a mapping relationship between the MAC address of STA1 and AC3. Here, it can be realized by broadcasting private special messages, or by broadcasting existing communication messages, as long as the source address of the sent messages is the MAC address of the user terminal.

At this time, if there is another message sent from PC or STA2 to STA1, because other network devices (such as LSW and AC2) in the network have updated the broadcast message according to the received address, the forwarding address of STA1 has been updated. Published, therefore, the data that needs to reach said STA1 is directed to AC3.

It can be seen that when AC1 of STA1 fails or the roaming tunnel between AC1-AC3 fails, and before STA1 actively sends a message, if there is a message in the network that needs to reach STA1, according to the method described in the embodiment of the present invention And the system can reach STA1 directly through AC3 instead of through the faulty roaming tunnels AC1-AC3 or AC1, thereby ensuring the normal progress of communication.

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus a necessary general-purpose hardware platform, and of course also by hardware, but obviously the former is a better implementation. Based on such an understanding, the technical solution of the present invention or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product includes several instructions to make a computer device (which can be a personal computer, server, or network equipment, etc.) to execute the method described in the embodiment of the present invention.

Likewise, it can also be implemented by a computer device, which includes software for executing the method of the present invention and hardware necessary for running the software.

A method for updating a roaming user address and an access controller described in the present invention are not limited to the applications listed in the instructions and implementation methods, and it can be fully applied to various fields suitable for the present invention. For those familiar with the field Additional advantages and modifications can readily be realized by one, so the invention is not limited to the specific details, representative devices and A pictorial example is shown and described here.

Claims (9)

1. a method for updating roaming user address is characterized in that comprising the steps:

When the roaming place at the current place of roaming user terminal access controller detects roaming tunnel state that described roaming user terminal roams into the roaming place network from its belonging area network and worsens, described roaming place access controller with this roaming user terminal as the LUT association;

The broadcast transmission source address is the address renewal message of described user terminal MAC Address outside the access controller of described roaming place.

2. method according to claim 1, it is characterized in that: described roaming user terminal worsens from the roaming tunnel state that its belonging area network roams into the roaming place network, be that ownership place access controller by described roaming user terminal periodically sends message to the roaming place access controller, if the roaming place access controller is not periodically received described message, judge that the roaming tunnel state worsens; Perhaps the roaming place access controller of described roaming user terminal periodically sends message to the ownership place access controller, if the roaming place access controller is not periodically received the response message that the ownership place access controller sends, judge that the roaming tunnel state worsens.

3. method according to claim 1, it is characterized in that: described roaming place access controller as the LUT association, is that the state of directly described roaming user terminal is set to the LUT state by the roaming user terminal state with this roaming user terminal.

4. method according to claim 1, it is characterized in that: described roaming place access controller with this roaming user terminal as the LUT association, be that described roaming place access controller removes related message or removes message identifying by transmission, the force users terminal rolls off the production line and makes it related again as LUT.

5. an access controller is characterized in that comprising: roaming tunnel detection module (10), related trigger module (20), address renewal broadcast transmission module (30);

Described roaming tunnel detection module (10) is used for the roaming tunnel of roaming user terminal is detected, and when detecting the roaming tunnel when being in state deteriorating, triggers related trigger module (20);

Described related trigger module (20) is used for the triggering according to roaming tunnel detection module (10), and the roaming user terminal that will come by the roaming tunnel roaming that is in state deteriorating is associated as LUT, and triggers the address and upgrade broadcast transmission module (30);

Broadcast transmission module (30) is upgraded in described address, is used for the broadcast transmission address and upgrades message, and the source address that message is upgraded in described address is the MAC Address that is in the roaming user terminal that the roaming tunnel roaming of state deteriorating comes.

6. access controller according to claim 5, it is characterized in that: described roaming tunnel detection module (10), be further used for when the tunnel detection messages that can not receive periodically that roaming user terminal ownership place access controller sends, triggering related trigger module (20).

7. access controller according to claim 5, it is characterized in that: described roaming tunnel detection module (10), be further used for periodically sending the tunnel detection messages to roaming user terminal ownership place access controller, in the time can not periodically receiving the response message that roaming user terminal ownership place access controller sends, trigger related trigger module (20).

8. access controller according to claim 5, it is characterized in that: described related trigger module (20), be further used for the triggering according to roaming tunnel detection module (10), the state of the roaming user terminal that the directly described roaming tunnel roaming that is in state deteriorating is set to the LUT state by the roaming user terminal state.

9. access controller according to claim 5, it is characterized in that: described related trigger module (20), be further used for triggering according to roaming tunnel detection module (10), remove related message or remove message identifying to the roaming user terminal transmission that the described roaming tunnel roaming that is in state deteriorating comes, and receive of the again association of described user terminal as LUT.

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