WO2005083950A1

WO2005083950A1 - Layer 2 switch network

Info

Publication number: WO2005083950A1
Application number: PCT/JP2004/002361
Authority: WO
Inventors: Keiichi Shimizu; Akira Okubo; Masahiro Kuroda
Original assignee: Mitsubishi Electric Corporation; National Institute Of Information And Communications Technology, Incorporated Administrative Agency
Priority date: 2004-02-27
Filing date: 2004-02-27
Publication date: 2005-09-09
Also published as: JP4427653B2; JPWO2005083950A1

Abstract

A layer 2 switch network, having a layer 2 switch containing different kinds of radio access points and constituting a tree logically, is provided internally with a swap point for address swapping an MAC frame, transmitted to the MAC address of the old radio interface of a mobile terminal, to the MAC address of a new interface being switched when an interface being used for communication by a mobile terminal having a plurality of radio interfaces is switched so that high speed interface switching processing is realized while preventing loss of an MAC frame.

Description

Layer 2 switch network

Technical field .

The present invention relates to a layer 2 switch network comprising a layer 2 switch that accommodates heterogeneous wireless access points and logically forms a tree, and is particularly used by a bright mobile terminal having a plurality of wireless interfaces for communication. Interface

1

This is a thread related to the processing procedure when switching.

book

Background art

-In a heterogeneous wireless integrated IP network that accommodates mobile terminals with multiple types of wireless access interfaces, conventional interface switching was realized by a mobility management mechanism using the IP layer, commonly called Mobile IP ( For example, Non-patent: Reference 1, Non-patent 'reference 2).

In this method, a mobile terminal has a unique IP address for each interface (this is called a care-of address), a common IP address for the interface (this is called a home address), and a communication partner terminal has Show home dress. Then, the correspondence between the home address and the care-of address changed according to the interface switching is registered in the home agent in the network as needed. In this case, the communication partner terminal sends an IP bucket to the home address. This IP packet is captured by the home agent, and the IP packet is transmitted to the care-of address registered by the home agent. With such a transfer mechanism by the home agent, the mobile terminal can seamlessly continue the IP packet communication even after the interface switching.

With Mobile IP, the mobile terminal communicates the correspondence between the care-of address to use and its own home address instead of the home agent every time the interface is switched. Notification can also be made directly to the partner terminal.

Also, there is a case where the network interface is duplicated in order to increase the fault tolerance of the equipment installed in the LAN environment, although it is not the switching of the interface of the terminal in the heterogeneous wireless integrated IP network (for example, Non-Patent Document 3 Non-Patent Document 4). Also in this case, the two interfaces have a common IP address (in Non-Patent Document 4, the common IP address is called a relocatable IP address). However, this IP address belongs to the location where the device is installed, and when Mobile IP is supported, it corresponds to the care-of address instead of the home address. In this case, the care-of address common to the interface is used. Can be said to have In this case, if the interface is switched due to an interface failure, the correspondence between the real interface address (assuming an Ethernet interface, hereafter referred to as the MAC address) and the relocatable IP address changes. For this reason, when an interface fails, the terminal notifies the correspondent terminal of the correspondence between the MAC address and the relocatable IP address using the ARP protocol (in the case of IPv6, the neighbor discovery protocol). This is called unrequired ARP (gratui tous ARP).

Non-patent Document 1; "IP Mobility Support" by C. Perkins IETF RFC2002, 1996/10, P.8-11

Non-Patent Document 2; D. Johnson et al., "Mobility Support in IPv6" IETF Internet Draft draft-iet-mobile IP-IPv6-24.txt, 2003/6, P.15-19

Non-Patent Document 3; Hewlett-Packard Japan, Ltd., "White Paper: HP-UX High Availability" http: //wwwl.jpn.hp.cora/products/software/oe/hpux/document/pdf S / PDFHS03 -033- 02.pdf, 2003/10/31, P. 17

Non-Patent Document 4; Hewlett-Packard Japan, Inc., OPS Cluster Configuration with rservice Guard OP S Edition, 8th Edition, by Manufacturing, Manufacturing Part Number: B51 5

8-90045, 2002/3, P. 87-92

Mobile terminal interface switching in heterogeneous wireless integrated IP networks In the case of control using Mobile IP, the actual IP address (care-of address) of the interface changes due to movement, and the concept of a home address is needed to conceal this change. I have to manage the response. When this is performed by the home agent, the communication from the communication partner terminal to the mobile terminal basically always goes through the home agent, which is not desirable from the viewpoint of packet delay, band efficiency, and packet loss. If the correspondent terminal directly manages this association, the correspondent terminal needs to be directly aware of the complicated Mobile IP signaling procedure, which is not desirable.

Various enhancements have been proposed for Mobile IP to improve packet delay, bandwidth efficiency, and packet loss, but these will force terminals to perform more complex signaling control.

If the real IP address changes, the IP session with the communication partner terminal will be cut off, so a control mechanism such as Mobile IP will be required to maintain communication. If a network is configured in this way, the IP session with the communication partner terminal will not be disconnected, and complicated signaling procedures such as Mobile IP will not be required, and high-speed and low-delay handoff can be expected. For this reason, a system is conceivable in which the above-mentioned conventional technology related to failure switching of network interface duplication is applied to mobility control in a LAN that integrates heterogeneous radios and a wide area LAN. In this case, unlike a heterogeneous wireless integrated network based on Mobile IP, it can be configured such that the IP address seen from the communication partner terminal does not basically change, as in the conventional relocatable IP address. Therefore, complicated procedures such as Mobile IP are not required between terminals, and there is a possibility that high-speed movement can be supported more simply.

However, in the above system, transmitting gratuitous ARP to the communication partner terminal is not desirable for security. Immediately after switching the interface of the mobile terminal, as in the case of the high-speed handoff of Mobile IP, incorrect delivery to the I- Since the MAC frame cannot be transferred to the new interface, MAC frame loss may occur.

The present invention has been made in view of the above, and provides a high-speed interface switching mechanism with low MAC frame loss easily and safely on the premise of a network having a mobility management mechanism by a MAC layer. The purpose is to obtain a layer 2 switch network. Disclosure of the invention

In the present invention, in a layer 2 switch network having a layer 2 switch that accommodates heterogeneous wireless access points and logically forms a tree, when a mobile terminal having a plurality of wireless interfaces switches interfaces used for communication, A feature of the present invention is to provide a flip-flop inside the layer 2 switch network for address-switching the MA C frame transmitted to the MAC address of the old radio interface of the mobile terminal to the MAC address of the new interface to be switched to.

According to the present invention, a swap point for swapping the address of the MAC frame transmitted to the MAC address of the old radio interface of the mobile terminal to the MAC address of the new interface to be switched is provided in the layer ≥ switch network. As a result, high-speed interface switching processing is possible, and loss of a MAC frame can be prevented. Brief Description of Drawings

FIG. 1 is a conceptual diagram of a configuration diagram and behavior of a wide area LAN constituting the present invention. FIG. 2 is a conceptual diagram of a layer structure of a mobile terminal which is a premise of the present invention. FIG. 3 is a diagram showing a configuration of a layer 2 switch group arranged in an array and an operation concept of a MAC address swap according to the first embodiment. FIG. FIG. 5 is a diagram showing an interface switching sequence according to the second embodiment. FIG. 6 is a diagram showing an operation concept of a MAC address swap according to the third embodiment, and FIG. 7 is an interface switching sequence diagram according to the third embodiment. FIG. 8 is a diagram showing the concept of the operation of the MAC address swap according to the fourth embodiment. FIG. 9 is a diagram showing an interface switching sequence according to the fourth embodiment. FIG. 10 is a diagram showing the fifth embodiment of the present invention. FIG. 11 is a diagram illustrating an operation concept of a MAC address swap according to the first embodiment. FIG. 11 is an interface switching sequence diagram according to the fifth embodiment. FIG. 12 is an interface switching sequence diagram according to the sixth embodiment. FIG. 13 is an interface switching sequence diagram according to the seventh embodiment, and FIG. 14 is an interface switching sequence diagram according to the ninth embodiment. It is a switching sequence diagram.

• BEST MODE FOR CARRYING OUT THE INVENTION

In order to explain the present invention in more detail, this will be described with reference to the accompanying drawings. Embodiment 1

FIG. 1 shows a configuration diagram and a conceptual diagram of a behavior of a wide area LAN constituting the present invention. In FIG. 1, a wide area LAN 1 accommodates various types of wireless access points 3a to 3c such as a wireless LAN, a W-CDMA, and a 4G, and is composed of a plurality of layer 2 switches 2 power. I have. Edge switch 2 of the layer 2 switches constituting the wide area LAN accommodates wireless access points 3a to 3c and fixed terminals.

Reference numeral 4 denotes a mobile terminal having a plurality of types of wireless interfaces, and reference numeral 5 denotes a communication partner terminal that communicates with the mobile terminal. The communication partner terminal 5 is a target to be moved by the mobile terminal 4, and can be either a fixed terminal or a mobile terminal. If the communication partner terminal 5 is a mobile terminal, and it is regarded as a moving subject, it can be regarded as a mobile terminal 4. If it is considered as a moving target, it becomes the communication partner terminal 5.

The router 6 plays a role in configuring the network (wide area LAN) 1 shown in FIG. 1 as one IP subnetwork. Users connecting to network 1 recognize router 6 as the default router, and Communication with the router is performed via the router 6. When the mobile terminal 4 communicates via the router 6, the router 6 is recognized as a communication partner terminal.

The neighbor search server 7 has a function of preventing an address resolution request message such as a neighbor request from being broadcast in the wide area LAN 1, and is installed as necessary. Since the mobile terminal 4 obtains the MAC address from the IP address of the communication partner terminal, the address 力 the ability to multicast the rapid decision request message S, and the address resolution request message when the neighbor search server 7 is introduced. Is not broadcasted, and is directed to the neighbor search server 7, which performs a corner decision on the MAC address.

FIG. 2 shows a conceptual diagram of a layer structure of the mobile terminal 4 on which the present invention is based. In FIG. 2, the mobile terminal 4 has two wireless interfaces (IF. Wlan and IF. Wcdraa), for example, a wireless LAN and a W-CDMA. The mobile terminal 4 implements a separate physical layer / MAC layer / IP layer for each wireless interface, and an application is implemented above the IP layer (protocols of TCP or higher are also positioned here).

Here, in the present invention, it is assumed that the mobile terminal 4 has a common IP layer (actually, an IP address) for a plurality of radio interfaces. This common IP address is synonymous with the relocatable IP address described in Non-Patent Document 4.

Next, the basic behavior of the network according to the present invention will be described with reference to FIG. In FIG. 1, it is assumed that the mobile terminal 4 switches the interface to be used from the W-C DMA interface (IF. Wcdma) to the wireless LAN interface (IF. Wlan) for some reason. At this time, each device (element) and the mobile terminal in the network of the present invention perform high-speed interface switching with few MAC frame ports using the following two mechanisms.

'The first mechanism is that the layer 2 switches that compose the wide area LAN 1 are sent to the MAC address of the old interface after the interface switching. 2361

This is a MAC address swapping mechanism that recognizes a frame, converts this destination MAC address to a new interface MAC address, and transfers it.

'In addition, since the MAC address corresponding to the IP address common to the interface changes due to interface switching, as a second mechanism, the entry of the element that has the correspondence table between this IP address and the MAC address is updated. Implement the following mechanism. Elements having this correspondence table are the communication partner terminal 5 (or the norator 6) of the mobile terminal and the neighbor search server 7.

In the present invention, various control methods for realizing these two mechanisms are defined.

The group of layer 2 switches that make up the wide area LAN 1 are generally arranged in an array (or logically form a tree). The first embodiment is based on the premise that the layer 2 switch (referred to as a note switch) located at the top of the tree has a MAC addressless switch mechanism. FIG. 3 shows an example of this network. FIG. In FIG. 3, reference numerals 2a and 2b denote edge switches, 8 denotes a root switch located at the highest position of the grid, and 9 denotes a branch switch which connects the edge switch and the root switch to form a grid.

FIG. 4 is an interface switching sequence diagram in this network. In particular, in this sequence, the MA C cache that explicitly updates the correspondence table between the MAC address of the terminal that each switch has and the output port of the MA C frame addressed to the MAC address as the mobile terminal moves. It is assumed that the management protocol is supported by each switch.

The MAC cache management protocol mainly consists of an update entry (Update Entry) procedure and a cancel entry (Cancel Entry) procedure. The former is a procedure that creates and updates the MAC entry of a specified terminal. Yes, the latter is a procedure to delete the MAC entry of the specified terminal. In addition, this MAC cache management protocol operates on the premise of a tree-like network. In particular, switches that support this protocol are compatible with receiving MAC frames. If there is no MAC entry to operate, it operates to transmit this MAC frame toward the root switch without broadcasting.

The mobile terminal camping at the wireless access point 3 b 4 power The interface used is switched from the W-C DMA interface (IF. Wcdma) to nothing, and to the LAN interface (IF. Wlan). When camping on the access point 3a, the mobile terminal 4 first establishes a wireless-specific association with the wireless access point 3a, and executes an authentication procedure (Authentication Procedure;) as necessary.

If the authentication is successful, the wireless access point 3a transmits a control frame called an update entry request to the / rate switch 8. With this control frame, all the layer 2 switches that may be present on the path from the wireless access point 3a to the root switch 8 are used as the entry of the mobile terminal 4 (the MAC address of the mobile terminal 4 and the frame address of the frame addressed to the MA address). A correspondence table with the transmission port) is newly generated. Also, at this time, the mobile terminal 4 transmits a neighbor advertisement message (Neighbor Advertisement) corresponding to gratuitous ARP to the neighbor search server 7, as in Non-Patent Documents 3 and 4. Each switch of the network guides this to the neighbor search server 7, and the neighbor search server 7 stores the content.

In the first embodiment, thereafter, the mobile terminal 4 transmits a MAC address swap request to the wireless access point 3a. When the wireless access point 3a receives this, the wireless access point 3a transmits a swap entry request (Swap Entry Request), which is a layer 2 control frame, to the root switch 8. This control frame contains the MAC address of the old radio interface that has been used up to now, the MAC address of the radio interface after switching, and optionally, the swap time that indicates the set time of the switch. After receiving this control frame, the root switch 8 sets the MAC address of the old ill interface during the swap time. When a MAC frame addressed to the address is captured, the destination address is replaced (swapped) with the MAC address of the new wireless interface and transmitted.

Also, the root switch 8 receiving the Swap Entry Request sends a Cancel Entry Request in order to delete the MAC address of the old wireless interface stored in the Layer 2 switch under the hierarchy. Sent to the layer 2 switch under the hierarchy. The Cancel Entry Request is sent to the edge switch or to the line access point according to the output port corresponding to the MAC entry to be deleted, and each switch through which deletes the target MAC entry. As described above, each switch that supports the MAC cache management protocol operates to transmit the MAC frame to the root switch without broadcasting if there is no corresponding MAC entry when the MAC frame is received. Therefore, if there is no entry of the MAC address of the old radio interface in the Layer 2 switch due to the Cancel Entry Request, the MAC frame sent to the old MAC address is always transferred to the root switch 8. Will be.

If the correspondent terminal 5 has the MAC address of the mobile terminal 4 based on the neighbor discovery procedure and caches the MAC address inside itself, the correspondent terminal 5 sends the MAC address to the MAC address of the old wireless interface. Continue sending frames. At this time, for example, if the communication partner terminal 5 supports the neighbor reachability procedure required for the IPV 6, the mobile terminal 4 changes to the MAC address of the new wireless interface by this procedure. Can be detected by the communication partner terminal 5.

In the first embodiment, the mobile terminal 4 encrypts a neighbor advertisement message (Neighbor 'Advertisement) by using IP sec or the like. Then, only the neighbor search server Ί having the key receives this, so that the information stored in the neighbor search server 7 can be updated safely. The access to the neighborhood search server 7 is not limited to the time of interface switching, and may be always encrypted. The interface switching mechanism described in the first embodiment can be performed at high speed because the signaling at the terminal is almost unnecessary, and the MAC address swapping mechanism prevents loss of MAC frames. it can. Since the Swap Entry Request is issued on the responsibility of the wireless access point, if the association between the wireless access point and the mobile terminal is guarded for security, the swap of the MAC address can be controlled safely. Also, the point that the terminal does not directly rewrite the MAC cache of the communication partner terminal such as gratuitous' ARP improves the security performance against attacks that simulate movement. Embodiment 2

The second embodiment is based on the premise that the root switch 8 has a MAC address swap mechanism as in the first embodiment, but in the second embodiment, the mobile terminal 4 Is notified directly of the change in the MAC address. FIG. 5 shows an interface switching sequence diagram of the second embodiment.

The mobile terminal 4 camping on the wireless access point 3 b switches the interface being used from the WC DMA interface (IF. Wcdma) to the wireless LAN interface (IF. Wlan), and the wireless access point 3 a When camping, the mobile terminal 4 sets an association with the wireless access point 3a and executes an authentication procedure (Authentication Procedure) as in the first embodiment. If the authentication is successful, the wireless access point 3a transmits an update entry request (Update Entry Request) to the root switch 8 as in the first embodiment, so that the wireless access point 3a transmits the update switch request to the root switch 8. All the layer 2 switches that can exist on the route up to 8 generate a new entry for the mobile terminal 4.

Further, the mobile terminal 4 transmits a neighbor advertisement message (Neighbor Advertisement) corresponding to gratuitous ARP to the neighbor search server 7, as in the first embodiment. Ne Each switch of the network guides this to the neighbor search server 7, which stores the contents.

The mobile terminal 4 of the second embodiment always manages the communication partner terminal 5 and its MAC address, and when the transmission of the neighbor advertisement message to the neighbor search server 7 is completed, the MA of the communication partner terminal 5 Send a neighbor advertisement message with the C address as the destination address. The communication partner terminal 5 receiving this message immediately changes the destination of the MAC frame addressed to the mobile terminal 4 to that of the new interface after switching. The subsequent procedure is the same as in the first embodiment, and the mobile terminal 4 transmits a MAC address swap request to the wireless access point 3a. When this is received by the wireless access point 3a, the wireless access point 3a sends a swap entry request (Swap Entry Request) to the root switch 8. If the switch 8 receives a MAC frame addressed to the old wireless interface's MAC address during the swap time after receiving this control frame, the switch 8 replaces the destination address with the new wireless interface's MAC address. Root switch 8 that received the Swap Entry Request cancels the old wireless interface's MAC address stored in the layer 2 switch under the hierarchy. An entry request (Cancel Entry Request) is sent to the layer 2 switch under the hierarchy.

According to the embodiment 2, the neighbor advertisement message is not broadcast like the gratuitous ARP of Non-Patent Documents 3 and 4, and has advantages in terms of network bandwidth utilization efficiency and security (it is hard to snoop). Occurs. However, similar to gratuitous ARP, since the MAC cache of the communication partner terminal is rewritten directly, security becomes weak against attacks that simulate movement. 'Embodiment 3.

Embodiment 3 is based on the premise that the edge switch has a MAC address swapping mechanism. FIG. 6 shows an example of this network and a conceptual diagram of operation. FIG. 7 is an interface switching sequence diagram according to the third embodiment in this network.

The mobile terminal 4 camping at the wireless access point 3 b switches the interface being used from the W-C DMA interface (IF. Wcdma) to the wireless LAN interface (IF. Wlan), and When capping to 3a, the mobile terminal 4 executes the authentication procedure (Authentication Procedure) with the access point 3a in the same manner as in the first embodiment. If the authentication is successful, the wireless access point 3a transmits an update entry request (Update Entry .Request) to the root switch 8 in the same manner as in the first embodiment, so that the wireless access point 3a All the layer 2 switches that can exist on the route to the switch 8 generate a new entry for the mobile terminal 4.

Further, the mobile terminal 4 transmits a neighbor advertisement message (Neighbor Advertisement) corresponding to gratuitous ARP to the neighbor search server 7, as in the first embodiment. Each switch in the network guides this to the neighbor search server 7, which stores its contents.

Thereafter, the mobile terminal 4 transmits a MAC address drop request to the wireless access point 3a. The above procedure is the same as in the first embodiment.

When the wireless access point 3a receives the MA C address swap request, the wireless access point 3a receives the MAC address of the old wireless interface and the MAC address of the wireless interface after switching. And a MAC address swap request (Swap Entry Request) including an optional swap time is not sent to the root switch 8 but to the edge switch 2 b to which the wireless access point 3 b that has accessed using the old wireless interface is connected. Send to.

In each switch, the M. of the old radio interface included in the Swap Entry Request Since the AC address determines the key output port, this Swap Entry Request reaches the edge switch 2b to which the wireless access point 3b that has been accessing using the old wireless interface is connected. Note that the switching rules for the Swap Entry Request to reach the edge are the same as those of the Cancel Entry Request described in the first embodiment. After receiving the Swap Entry Request, the edge switch 2b changes the destination address to the MAC address of the new wireless interface if the edge switch 2b captures a MAC frame addressed to the MAC address of the old wireless interface during the swap time. Address (swap) and send. In the third embodiment, the root switch 8 that has received the Swap Entry Request performs the above-described cancellation for deleting the MAC address of the old wireless interface stored in the layer 2 switch under the hierarchy. It does not send an entry request (Cancel Entry Request) to the layer 2 switches under the hierarchy. As described above, in the third embodiment, since the switching route relating to the MAC address of the old wireless interface is not explicitly deleted, the MA C frame transmitted to the old MAC address must be swapped. The point reaches the edge switch. ',

In the third embodiment, the detection of the MAC address of the new radio interface and the encryption of the access to the neighbor search server in the communication partner terminal by the neighbor reachability procedure are the same as those in the first embodiment. As in the second embodiment, the mobile terminal can directly notify the communication partner terminal of the change in the MAC address.

In the third embodiment, the edge switch has a MAC address swap mechanism. However, the wireless access point may implement the swap mechanism at the edge of the network.

According to the third embodiment, as compared with the first embodiment, the step mechanism is distributed to the edges, so that it is possible to have scalability for mobility control traffic. However, it is the same as the mobile terminal in The transfer route from the communication partner terminal located under the switch is optimized, but in other cases, the transfer route becomes more and more redundant.

Embodiment 4

Embodiment 4 is based on the premise that the root switch and the edge switch have a MAC address switch mechanism. FIG. 8 shows an example of this network and an operation conceptual diagram. FIG. 9 is a sequence diagram of the interface switching in this network.

Embodiment 4 is a combination of Embodiments 1 and 3, in which the Swap Entry Request terminates at the root switch and also terminates at the edge switch. Therefore, if the mobile terminal moves across the root switch, the MAC address swap will be performed on the root switch, and if the mobile terminal does not cross the root switch, the MA address swap will be performed on the edge switch. .

In particular, there are cases where the number of entries that can be swapped by the root switch is limited due to resource issues. By swapping at the root switch only for a limited number of users based on the swap at the edge switch, an optimal solution can be obtained for balancing load distribution and route optimization.

Embodiment 5

Embodiment 5 is an example in which an entity (which is called a signaling server) that constantly grasps the position of a mobile terminal in a network and determines and controls handover between wireless access points of the same type or different types is provided. is there. In Embodiments 1 to 4, it has been assumed that a terminal determines a wireless access point to camp autonomously, but in Embodiment 5, a network signaling server determines a handover destination. This is called network-driven interface switching.

FIG. 10 shows an example of a network for realizing network-driven interface switching and an operation conceptual diagram of interface switching activation. In FIG. 10, reference numeral 10 denotes a signaling server connected to the root switch. Figure 11 shows this network. FIG. 6 is a sequence diagram of an interface switching in a network.

The signaling server 10 always keeps track of the position of the mobile terminal 4 (the wireless access point that is being capped) through procedures on TCP / IP, etc., and uses information from the mobile terminal 4 and the wireless access point 3. Mobile terminal 4 can determine the optimal wireless access point 3 to camp on.

If the signaling server 10 determines that the mobile terminal 4 should keep a different wireless access point, for example, the signaling server 10 sends a handover preparation request message to the mobile terminal 4 in order to prompt preparation for interface switching. Send to.

When the mobile terminal 4 receives the handover preparation request message, the mobile terminal 4 preliminarily performs a procedure necessary for switching the interface, such as performing an association setting (Association) with the designated wireless access point and executing an authentication procedure (Authentication Procedure). Execute.

If the authentication is successful, the wireless access point 3.a sends an update entry request (Update Entry Request) to the root switch 8 so that the route from the wireless access point 3a to the All the layer 2 switches that exist in the mobile terminal 4 newly generate an entry for the mobile terminal 4.

Thereafter, the mobile terminal 4 returns a handover preparation response message to the signaling server 10. Upon receiving this message, the signaling server 10 sends a handover start request message to the mobile terminal 4 to actually instruct the interface switching. Upon receiving this handover start request message, the mobile terminal 4 switches the interface and camps on the non-access point.

In the fifth embodiment, at the timing when the signaling server 10 detects the handover (for example, at the timing of transmitting a handover start request message), the signaling server 10 sends an IP address common to the interface and a Register the correspondence table of MAC address. At the same time, Instruct switch 8 to request MAC address swap. The behavior of the root switch 8 having received the MAC address swap request is the same as the operation at the time of receiving the Swap Entry Request specified in the first embodiment. That is, the root switch 8 that has received the Swap Entry Request deletes the cancel entry request (Cancel Entry Request) hierarchically in order to delete the MAC address of the old radio interface stored in the layer 2 switch under the hierarchy. Sent to subordinate Layer 2 switch. The Cancel Entry Request is sent to the edge switch or wireless access point according to the output port corresponding to the MAC entry to be deleted, and each switch that passes through deletes the target MAC entry.

When a network-driven interface switching mechanism is defined by the signaling server 10 as in the fifth embodiment, the signaling server 10 is responsible for registration with the neighbor discovery server 7 and registration with the MAC swap point. For this reason, if the signaling mechanism of the signaling server 10 can be safely defined, the security will be improved more than the mobile terminal 4 kicks them.

Embodiment 6

Embodiment 6 is the case of network-driven interface switching as in Embodiment 5, but the point of the MAC address swap is not the root switch 8 but the edge switch. FIG. 12 is an interface switching sequence diagram in this network.

In the sixth embodiment, at the timing when the signaling server 10 detects a handover, the correspondence table between the IP address and the MAC address is registered with the neighbor discovery server 7 and the old wireless interface is used via the route switch 8. A MAC address swap request is sent to the edge switch 2b to which the wireless access point 3b that has been accessing the device is connected. The root switch 8 that has received the MAC address swap request for the edge switch 2b transmits a Swap Entry Request to the edge switch 2b. Switching of Swap Entry Request, when this is received The behavior of the edge switch 2b is the same as that specified in the third embodiment. According to the sixth embodiment, since the registration with the neighbor discovery server 7 and the registration with the MAC swap point are the responsibility of the signaling server 10, if the signaling mechanism of the signaling server 10 can be safely defined, the mobile terminal 4 Is more secure than kicking them. Also, since the swap mechanism is distributed to the edge, it becomes possible to have scalability for mobility control traffic. ·

Embodiment 7

The seventh embodiment is the same as the fifth embodiment in the case of switching the network-driven interface, but the point of the MAC address swap is the -switch and the edge switch.

FIG. 13 is an interface switching sequence diagram in this network.

In the seventh embodiment, at the timing when the signaling server 10 detects the handover, the correspondence table of the IΡ address and the MAC address is registered with the neighbor discovery server 7 and the MAC address swap request is issued to the root switch 8. Instruct. The behavior of the root switch 8 that has received the MAC • address swap request is the same as the operation at the time of receiving the Swap Entry Request specified in the fourth embodiment.

According to the form of real danger 7, registration with the neighbor discovery server 7 and MA. Since the registration with the swap point becomes the responsibility of the signaling server 10, if the signaling mechanism of the signaling server 10 can be safely defined, the security will be improved more than the mobile terminal 4 kicks them. In addition, the Swap Entry Request is terminated at the root switch 8 and terminated at the edge switch. For this reason, if the mobile terminal moves across the root switch, the MA C address swap will be performed on the root switch, and if the mobile terminal does not cross the root switch, the MA C address swap will be performed on the edge switch. . Embodiment 8

Embodiment 8 assumes a network configuration similar to those of Embodiments 1 to 4, in which a mobile terminal transmits a Swap Entry Request to a switch that actually performs a MAC address swap.

When the wireless access point terminates the MAC address swap request and sends a Swap Entry Request to the switch that actually performs the MAC swap, a two-stage security association is formed. Therefore, security is improved. However, once the wireless access point terminates the MAC address swap request, it is necessary to add the function of receiving the MAC address swap request to the wireless access point. When the mobile terminal sends a Swap Entry Request to the switch that actually performs the MAC swap, the security capability is reduced, but the additional function to the wireless access point is not required.

Embodiment 9

In the ninth embodiment, the neighbor discovery server 7 transmits a MAC address swap request to the root switch 8, and the root switch 8 transmits a Swap Entry Request or a Cancel Entry Request to other switches as necessary. The feature is that a MAC address swap is set for the root switch, the edge switch, or both. FIG. 14 shows a sequence for setting a MAC address step on the root switch 8 in particular.

In FIG. 14, when the neighbor discovery server 7 receives a neighbor advertisement message issued by the mobile terminal 4, the neighbor discovery server 7 uses the IP address of the mobile terminal 4 to associate (previous) the mobile terminal that is being managed. Identify the MA address and update this entry with the notified new MA address.

At this time, since the neighbor discovery server 7 can identify both the old MA C address and the new MA C address, it can transmit the MA C address swap request to the root switch 8 simultaneously with the entry update. Root switch 8 receives MAC address swap request Then, the root switch 8 transmits a Cancel Entry Request to the wireless access point 3b that was held when the mobile terminal used the old wireless interface. The Cancel Entry Request is sent to the wireless access point 3b according to the output port corresponding to the MA C entry to be deleted, and each switch via which deletes the target MAC entry.

In the ninth embodiment, since the neighbor search server 7 executes a request for a MAC address swap, there is an effect of reducing signaling of the mobile terminal 4.

Industrial applicability

As described above, the interface switching method in the wide area LAN according to the present invention is useful for a network (2) having a mobile terminal mobility management mechanism by the MAC layer.

Claims

1. In a layer 2 switch network that accommodates heterogeneous wireless access points and has a layer 2 switch that logically constitutes a network,

When a mobile terminal having a plurality of wireless interfaces switches the interface used for communication, the MAC frame transmitted to the MAC address of the old wireless interface of the mobile terminal is replaced with the MAC interface of the new interface to be replaced. An address request for address swap to the MA address is stored inside the layer 2 switch network.

2

A switch network of Layer 2 switch, which is provided in

2. The wireless access point transmits a swap request message to the swap point after receiving the enclosure MAC address swap request from the mobile terminal, wherein the wireless access point transmits a swap request message to the swap point. Layer 2 switch network shown.

3. The layer 2 switch network according to claim 2, wherein the switch point is a clear root switch. '

4. The layer 2 switch network according to claim 2, wherein the swap point is a layer 2 switch or a wireless access point serving as an edge of the network.

5. The layer 2 switch network according to claim 2, wherein the swap points are a root switch of a tree and a layer 2 switch or a wireless access point serving as a network edge.

6. If the mobile terminal switches the interface used for communication, the mobile terminal The feature is that an update request for updating the correspondence table between the IP address of the wireless interface to be used after switching and the MAC address is sent to the neighbor discovery server existing inside the layer 2 switch network. The layer 2 switch network according to claim 1, wherein

7. The layer 2 switch network according to claim 6, wherein the update request is encrypted.

8. When the mobile terminal switches the interface used for communication, the mobile terminal requests that the correspondent terminal update the correspondence table between the IP address of the mobile terminal's interface and the MAC address. A layer 2 switch network according to claim 1, characterized by:

9. Always monitor the location of the mobile terminal and install a signaling server to determine the optimal wireless access point. This signaling server determines the interface switching of the mobile terminal, and the MA for the swap point. 2. The layer 2 switch network according to claim 1, wherein the layer 2 switch network requests a swap of a C address.

10. The layer 2 switch network according to claim 9, wherein said switch point is a clear root switch.

11. The layer 2 switch network according to claim 9, wherein the swap point is a layer 2 switch or a wireless access point serving as an edge of the network.

1 2. The swap point is the root switch of the tree and the network Layer 2 switch network according to claim 9

1 3. When the mobile terminal switches the interface used for communication, the neighbor discovery server sends a swap request message to the swap point of the MAC address. Layer 2 switch network as described.