JP3124926B2 - Virtual LAN method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a virtual LAN for managing a logical configuration of a LAN, and more particularly, to a local area network (hereinafter referred to as L).
AN), which appropriately controls the traffic flow and improves the utilization rate of the entire network by efficiently using the transmission medium, along with the LAN segmentation (division method), as well as the movement, change, and addition of computers. The present invention relates to a logical configuration management method of a LAN for facilitating management.

In particular, based on a LAN switching technology based on a network, a structure which does not depend on the physical world so as to be able to change dynamically in response to a change in business structure such as a work group or a project of an organization such as a company is developed. A virtual LAN (hereinafter, referred to as a VLAN) system that logically segments into a shape is formed.

More specifically, the network automatically reconfigures with respect to the movement of a terminal, etc., and furthermore, uses processing and QOS which support transmission quality such as transmission bandwidth and delay time on demand according to demand. (Quality of Sevice) guarantee technology.

[0004]

2. Description of the Related Art In order to control traffic flow, IE is used.
OSI is used for bridges including the EE 802.1D standard.
Destination address (D
A) is filtered and divided into segments, but as is well known, unknown and multicast
Not filtered.

In a multi-port bridge having a plurality of bridge ports, each port is divided into different segments, packets input from the plurality of ports are temporarily stored in a buffer, and bridging is performed between the plurality of segments.
For bridges with LAN switches, 4 per port
About 000 addresses can be learned, and the LAN switch sends packets to all ports by multicast all at once for learning, and switches and intelligent HUs connected to each port by the source address of the reply packet
B, MAC addresses of terminals and the like can be learned.

[0006] IEEE802.10 (Security Local A)
rea Metropolitan Networks) is studying a method of distributing encryption keys and attaching security tags, and FDD
The packet to which the tag information is added is exchanged between the bridges connected to the I backbone. IEEE
In 802.11, SDE PDU (Secure Data Exchan
ge Protocol Data Unit), which is composed of a clear header located after the MAC header and a protected header to be encrypted. The clear header of this SDE is IEEE8
02.10 LSAP (Link layer Sevice Access Poin
t), an SAID (Security Association Identifier), and an optional MDF (Management-Defined Field). The protected header of the SDE PDU is composed of a station ID, a flag, a fragmentation identifier, and a security label.
Attempts have been made to apply this tagging to a virtual LAN (hereinafter referred to as VLAN). In this case, the above SA
Since the ID area is used as the VLAN ID and the SDE indicator of the LSAP code enables the identification of the VLAN frame, the LSAP 3 bytes and S
A tag area of a total of 7 bytes of 4 bytes of AID is transmitted.

Furthermore, at present, the bridge standard IEEE
E802. Extension of ID is being considered (IE
EE802. Ip). The main content is dynamic
Multicast filtering service, management of transmission delay by user priority, function of dividing frame queuing into up to eight user priorities, and dividing forwarding into two traffic classes (normal, priority) Function to perform.

[0008] For this additional function, the filtering database provides for static filtering:
User priority can be used when forwarding to any port, and the group
Address and broadcast address can be included, while for dynamic filtering, user priorities can be used when forwarding to learned ports and MAC addresses cannot include group and broadcast addresses . In order for a terminal to register a group with the bridge, a group address registration protocol (GAR
P) to exchange information about the membership of the dynamic multicast group. The port between the bridge and the bridge becomes a proxy terminal. Terminals can communicate directly with the bridge to join and leave the group.

That is, in the standardization of a bridge, a terminal registers a dynamic multicast group to the bridge, and indicates that this group is static. By prioritizing applications such as video conferencing, frame forwarding delays are preserved. IEEE 802.1p
The standardization work has just begun, and the contents may change at the draft stage before formal standardization.

Currently, LAN vendors have their own VLs.
Since an AN is constructed, it is difficult to connect a VLAN to a multi-vendor. In addition, IEEE 802.1 Interworki
ng Task Group is an IEEE 802.1p "Traffic
Class and Dynamic Multicast Filtering Seveice in B
Standardization of “ridgedLocal Area Networks (Supplement to 802.1D)” is under consideration (P802.1p / D1 November 8, 1995)
Was distributed to members of the standards group. Since those skilled in the art can know each other, they have been excerpted and summarized as publicly available materials at this time.

Meanwhile, the LAN switch stores the MAC address of the terminal connected to each port based on the source address (SA), checks the destination address (DA) of the input packet, and outputs it to the corresponding port. . That is, similarly to the multi-port bridge, segmentation is performed for each port. In a LAN switch, when a plurality of MAC addresses are stored in each port, it is possible to perform the same operation as a multi-port bridge in which each port is segmented.

The first characteristic of the LAN switch is that data can be transferred simultaneously and in parallel, for example, while data is being output from a certain input port to a certain output port, data is transferred from another input port to another output port. That is, the throughput is improved, and the bandwidth available to the terminal is increased. The second feature of the LAN switch is that a plurality of ports are bundled to form a VLAN group.

The LAN switch with the VLAN function allocates a VLAN group for each port to a terminal directly connected to the LAN switch without depending on the MAC address. The LAN switch determines which VLA each port
The VLAN address table of the LAN switch based on the source address (SA), based on the source address (SA), indicates whether the terminal belongs to the N group and what MAC address is connected to the port as a member of the VLAN group. Is stored by learning or setting.

In a LAN switch of the same vendor, a packet length is increased and a header carrying private VLAN group information is added to the data link layer, and the packet data is encapsulated by this header.
Layer 2 VLAN of SI protocol hierarchy model
Call. Such a second-level VLAN group is also called a switched domain.

This encapsulation allows the LAN switch to route packets only to switches in a particular VLAN group. The port of the LAN switch may be occupied by one specific terminal (one MAC address) or may be connected to a plurality of terminals. Also, LA
Basically, one VLAN group is assigned to the port of the N switch. However, it is possible to assign a plurality of VLAN groups by connecting a LAN switch to the port or by encapsulating a packet by a terminal. Become.

The unicast packet is transferred to a port to which a terminal having a destination address (DA) is connected.
Packets of the same VLAN group are multicast to segments of a plurality of switches of this VLAN group. When the terminal having the destination address (DA) is connected to the output port of the switch according to the VLAN address table, the packet is output from this port.
Generally, broadcasts are forwarded to all VLAN groups across the switched domain, but there is also a method of forwarding to a specific port based on the source address (SA).

The VLAN group can be allocated statically from a dedicated management console or dynamically by automatically tracking (tracking) when a terminal moves between different ports and dynamically allocating a VLAN group to a port. Multiple LAN switches F
When connected to a backbone such as DDI and assigning a VLAN group via the backbone, it is necessary for the VLAN packet encapsulated in the data link layer to pass through the backbone LAN.

As is well known, communication across the above switched domain is through an external router. VLA across routers, such as when going through a WAN
To configure N, the router also needs to know the VLAN definition to ensure that the encapsulated packet is forwarded by the router. Traditionally,
The Internet, which is a typical protocol of the network layer at the third level of the OSI protocol layer model,
In the protocol (IP: RFC791), a router is divided into subnets based on a network address, and DHCP (RFC1541: Dynamic Ho
It has also been standardized to automatically obtain an IP address from a server (st Configuration Protocol) using the DHCP protocol.

Since the performance and the IP address of the router are limited, a private virtual network group configuration based on the following switching is effective to increase the bandwidth and facilitate the management. It is. In order to form a logical virtual group at the third level of the protocol hierarchy model of the OSI, a switch at the third level, called a virtual network, has been developed. This encapsulates a header for defining a private virtual network group by adding it to the network layer.
Even if the MAC address of the terminal is the same, multiple VLAs
N groups can be assigned.

On the other hand, the asynchronous transfer mode (ATM: Asyncr
onous Transfer Mode) integrates various services such as voice, image, and data that have different traffic requirements from the beginning, and supports the transmission quality (QOS) required for each service. This is a switching method for exchanging cells.
End-to-end bus and virtual channels
Because it can correspond to the end logical virtual network group, the virtual
The configuration of the network group can be interconnected with the ATM.

The major LAN vendor's solution implements the VLAN function with a backbone ATM switch, and allows an existing LAN terminal to be connected to an ATM connection terminal.
LAN emulation supports intercommunication of LAN frames. The LAN emulation based on the LAN switch with the ATM interface also supports the second layer VLAN of the OSI protocol hierarchy model like the LAN switch. A plurality of LAN switches with an ATM interface are connected to the ATM backbone, and a router with an ATM interface of the ATM backbone is connected to the VLA.
It supports logical virtual groups at the third level of routing between N or the protocol hierarchy model of OSI.

Currently, the ATM Forum in the United States is studying the standardization of a multi-protocol system on ATM that integrates ATM and the conventional Internet. As a result, the logical virtual group at the third level of the OSI protocol hierarchy model is changed to the WAN by the ATM switch.
Supported with broadband.

[0023]

In the method of setting a VLAN group for each port as described above, a port dedicated to a virtual group is required, and all ports to which a plurality of terminals are connected are limited to the same VLAN group. Is done. When the terminal moves, there is a problem that the network administrator must connect to the designated port or statically set the VLAN group of the port to which the terminal is connected each time.

In the standardization of the IEEE 802.1p bridge for setting a VLAN group out of band, only the priority processing of a static VLAN group and a multicast group is supported. On the other hand, a plurality of VLs different for each terminal, not for each port
The current means for setting the AN group is to add an extra header or tag to the packet, so that if another vendor's device whose header or tag definition is unknown is interposed in the middle, the VLAN group is set to another It could not be extended by relaying vendor equipment.

The present invention has been made in view of the above points, and has as its object to comply with the conventional traditional standards, without adding an extra header or tag to a packet, and furthermore, by using a LAN. In order to provide a virtual LAN that can perform dynamic automatic band management for terminal movement by configuring a virtual group that supports unicast and multicast priority processing for each terminal independently of the switch port. is there.

[0026]

In order to achieve the above object, according to the first aspect of the present invention, an extra header or tag is not added to a packet and the packet is not dependent on a port of a LAN switch and is based on the characteristics of the packet. Configure a virtual group for each terminal, set the client address of the virtual group and the priority for each group in the virtual group registration table, and allocate the unicast and multicast traffic A LAN group switch is provided with a virtual group agent that performs dynamic automatic configuration management for terminal movement by a group learning unit.

According to the present invention, the name of the virtual group and its client address are registered in the virtual group registration table, and the name of each LAN switch distributed to the network is registered in the virtual group routing table. A LAN switch is cascaded to each port by registering an optimum connection port address to which virtual group is connected to the port, a plurality of virtual groups are assigned to each port, and members are assigned to each virtual group. The LAN switch is provided with a virtual group agent for registering a MAC address and selecting an optimal routing path between ports of each virtual group.

According to a third aspect of the present invention, in the first or second aspect, the LAN switch is distributed to a network.
And assign a virtual group to each LAN switch.
Equipped with connection port and prepared for each LAN switch
Virtual group agent
The virtual group registration table
For the virtual group registration table
Virtual group management message
By exchanging messages with each other, the virtual
It is characterized in that the group registration table is updated .

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. A LAN switch having an important role in the virtual LAN of the present invention will be described with reference to FIG. The virtual LAN according to the present invention does not add an extra header or tag to a packet having a frame format conforming to the standard as shown in FIG. -Configure a group.

Here, the client address represents a set of features such as a MAC address determined by a LAN medium access method, a network address determined by a network OS or a communication protocol, and an application address determined by application software or a user definition. I have. In the LAN switch S shown in FIG. 1, the virtual group identification unit 1 checks a pair of client address and the client address, which are the destination and the source of the packet, with the virtual group registration table 2 of the virtual group agent VGA. Then, a virtual group including both client addresses is identified, and as a result of the virtual group identification for the terminal movement, the client group is identified.
When the addresses match but the input ports 4 ₁ ... Are different, a port change message is output to the virtual group learning unit 3 of the virtual group agent VGA.

The virtual group learning section 3 is for performing dynamic automatic configuration management with respect to the movement of the terminal. Upon receiving the port change message, the virtual group learning section 3 has a virtual group registration table provided in the virtual group agent VGA. 2 and perform dynamic automatic configuration management. The virtual group registration table 2 is provided for each group. As shown in FIG. 3, a client address and a priority for each virtual group can be set, and the virtual group registration table 2 is provided in the virtual group agent VGA. The group control unit 6 allocates a band of each traffic type of unicast, multicast, and broadcast in group units according to the virtual group priority.

The virtual group control unit 6 causes the forwarding unit 5 to transfer the packet to the designated output port 7 ₁ ... By the scheduling control. Further, the virtual group routing table 8 provided in the virtual group agent VGA stores the LAs in which the virtual groups are distributed on the LAN.
An optimum connection port address is registered which port of the N switch is connected to. The virtual group routing table 8 is configured for each virtual group, and the structure of the virtual group routing table 8 in FIG. 1 is a virtual group for virtual group identification and virtual group learning.
It has the same structure as the group registration table 2. In the LAN switch S of FIG. 1, a pair of client address and the client address, which are the destination and the source of the packet, are compared with the virtual group registration table 2, and the client addresses of both the destination and the transmission source of the packet are compared. Are identified, the virtual group can be defined by the same structure as the virtual group registration table 2 as shown in FIG. 3, and can be combined into one on implementation.

In the virtual group routing table 8 having the structure shown in FIG. 3, an optimum connection port address is registered as a routing connection port. That is, in the configuration of the distributed LAN switch, since another LAN switch is cascaded to the port of each LAN switch, the connection port to which the LAN switch is connected reaches the home switch to which the terminal is connected. This is the port name corresponding to the optimal route.

As a result of the virtual group identification for the movement of the terminal, the client address matches but the port is different. When the virtual group identification unit 1 outputs a port change message, the virtual group learning unit 3 Virtual topology change messages
This is sent to the group distribution management unit 9. At this time, the virtual group distribution management unit 9 learns about the topology change and dynamically updates the virtual group routing table 8.

By the way, each LA distributed in the network
When the connection ports of each virtual group are distributed to the N switches and the virtual group registration table 2 and the virtual group routing table 8 are further distributed to each LAN switch, the virtual group identification unit 1 of each LAN switch Checks the input port 4 ₁ ... And the source address of the packet against the virtual group registration table 2, detects a topology change such as terminal movement, and automatically changes the virtual group registration table 2 and the virtual group routing table 8. There is a virtual group learning unit 2 that is updated dynamically.

The virtual group distribution management unit 9 cooperates with other LAN switches based on detection of a topology change such as the movement of a terminal or the movement of a LAN switch as a virtual group agent. By dynamically managing the virtual group registration table 2 and the virtual group routing table 8 distributed to the switches, a virtual group is shared between a plurality of LAN switches in the network.

Originally, a configuration is also possible in which the virtual group agent I distributed to each LAN switch is provided in a virtual group server acting as a proxy for a virtual group unit or a group of virtual groups. In this case, the virtual group
The server can manage the state of the virtual group agent I, mediate the communication between the agents I, cooperate with each other as an agent function of the VLAN switch, and register the virtual group registration table and the virtual group routing table. Manage tables dynamically. The virtual group registration table and the virtual group routing table that are updated and managed in the virtual group server are cached in each of the distributed LAN switches, and the virtual group server stores the change information in the table. Distribute to each LAN switch.

In FIG. 1, packets from the input ports 4 ₁ ... Are stored in the area of the buffer 11 designated by the buffer management unit 10, and at the same time,
Generates a packet pointer pointing to this location. The virtual group identification unit 1 checks a pair of the client address of the destination and the source of the packet against the virtual group registration table 2 and checks the virtual address.
When the group is identified, the packet pointer is stored in the virtual group-based queuing unit 12a of the buffer pointer queuing table 12, and the data in the buffer 11, which is a shared memory, is not moved, but is queued only by the pointer. . In the case of a broadcast packet, a packet pointer is stored in the broadcast queuing unit 12b. Further, if the address is a unicast address and does not correspond to a virtual group, the pointer indicating the storage address of the packet in the transmission buffer is unowned.
It is queued in the group queuing unit 12c.

The virtual group control unit 6, the output port 7 ₁ ... output port 7 by the port state detection of _one ...
When the is empty, it instructs the forwarding unit 5 to transmit a packet. The forwarding unit 5 reads the pointer of the designated packet from the buffer 11, and sends out the packet data in the buffer 11 from the output ports 7 ₁ .

With respect to the scheduling control of packet forwarding, the virtual group control unit 6 operates the priority processing timer (not shown) in the virtual group control unit 6 according to the priority of the virtual group.
, And the packets are forwarded in the order of the queue of the virtual group at short time intervals in descending order of priority.

In general, the priority of a virtual group that performs communication with a large amount of traffic such as video information is high. However, even if the traffic is small, if a message is not transmitted within a time allowed for a transaction or feedback control of an online system without fail. The priority of the virtual group that does not become high is also high. The timing of processing packets of a low priority virtual group in batch processing, file transfer, etc. is the longest, and the higher priority group checks the buffer 11 in a shorter cycle and processes higher priority packets first. I do.

A packet having a high priority is input after data input.
Forwarding is performed within the allowable setting time of the priority processing timer set from the virtual group distribution management unit 6. In addition, the following three types of virtual groups may be configured according to the client address, and a configuration in which virtual groups having different definition methods such as a protocol layer are operated independently and a configuration in which virtual groups are mixed are possible.

(1-1) A VLAN group at the second level of the OSI protocol hierarchy model in which the MAC address is defined as a client address. (1-2) A plurality of network addresses depending on a communication protocol or a network OS are transmitted to a client
A VLAN group at the third level of the OSI protocol hierarchy model defined as an address.

(1-3) A virtual custom group in which an application address defined by a user or by application software is used as a client address. Here, the configuration of (1-1) is the second-layer LAN switch, and the configuration of (1-2) is the third-layer LA switch.
The configuration of the N switch and (1-3) is called a custom LAN switch.

The order of the virtual group identification is as follows: first, a virtual custom group, then a virtual network group, and finally, a VLAN group, a custom LAN switch. It operates as a third-layer LAN switch or a second-layer LAN switch identified only by a MAC address in the order of the virtual network group depending on the mounting state and selection. For this reason, the client address of the virtual group registration table 2 and the virtual group routing table 8 is such that the network address and the user-defined address are blank in the second-layer LAN switch, and the user-defined address is blank in the third-layer LAN switch. The address is blank, and in the custom LAN switch, MA
The C address, network address, and user-defined address are all specified.

The virtual custom group, the virtual network group, and the VLAN group are assigned to the virtual custom group,
As a result of the group identification, when the client address matches but the port is different, a port change message is output. Therefore, the operation of the virtual group learning unit 3 differs depending on whether the home switch of the terminal has been changed. If there is no home switch change, the virtual group learning unit 3 performs dynamic automatic configuration management by updating the home switch port of the virtual group registration table 2. If there is a home switch change, the virtual group distribution management unit 9 of the new home switch to which the terminal has moved exchanges virtual group management messages to exchange the home switch name and the home switch name in the virtual group registration table of another LAN switch. Update the home switch port.

As shown in FIG. 1, the LAN switch S has a virtual group routing table 8 and a buffer pointer queuing table 12 for each virtual group. Then, since other LAN switches are cascaded to the port of each LAN switch,
A plurality of virtual groups and a plurality of terminals are assigned to each port, and a LAN switch to which each terminal is directly connected is a home switch, which is connected to the home switch port.

When the terminal is directly connected to the LAN switch, the home switch name in the virtual group routing table 8 of the LAN switch is its own switch name. If the terminal is not directly connected to the LAN switch, the home switch name will be different,
The connection port is a port name corresponding to an optimal route to a home switch to which the terminal is connected.

When the virtual group learning section 3 sends a topology change message to the virtual group distribution management section 9 in response to the movement of the terminal, the virtual group distribution management section 9 of the new home switch to which the terminal has moved. Exchanges a virtual group management message to update the home switch name and home switch port in the virtual group registration table 2 of another LAN switch, and the virtual group distribution management unit 9 of the LAN switch adjacent to the home switch changes the virtual ·group·
Update the routing connection port and the distance of the client in the routing table 8, and send the virtual group management message to another neighboring LAN switch to change the topology with the virtual group registration table 2 with the topology change.
And the update information of the virtual group routing table. Other LAN switches are adjacent LA
The virtual group registration table 2 and the virtual group routing table 1 are updated according to the update information of the virtual group registration table 2 and the virtual group routing table 8 accompanying the topology change by the virtual group management message from the N switch. 8 by updating the virtual group registration table 2 and the virtual group routing table 8 by sequentially transmitting the virtual group management message to the other LAN switches. virtual·
The group routing table 8 can be updated dynamically.

The virtual group distribution management section 9 exchanges management information of each LAN switch opening as a virtual group agent, and exchanges each L such as a MAC address of each LAN switch and a virtual group.
Cooperate while exchanging management information between AN switches,
In the connection port column of the virtual group routing table 8 of each LAN switch, a connection port to an optimum routing bus with a small number of relay stages of the LAN switch is indicated for each LAN switch, and further priority processing is performed. The priority processing timer setting of the scheduling according to the number of relay stages of the LAN switch is determined so that the delay time is guaranteed.

Thus, in the LAN switch S shown in FIG.
From the virtual group identification and the virtual group learning, it is possible to know which LAN switch is connected to which port. Further, since the virtual group distribution management unit 9 exchanges the change information of the virtual group routing table 8 with another LAN switch, even when the change information of the topology of the LAN switch is entered, each of the adjacent LAN switches is changed. Virtual
By transmitting the group management message, the virtual group routing table 8 can be dynamically updated by learning the movement of the terminal.

In this way, the virtual group
In the routing table 8, the client address of the member is generated for each virtual group, and the optimal routing path between the members of each virtual domain is registered. Therefore, the virtual group control unit 6 sets the priority processing timer. Each virtual
Since the optimum routing bus between the ports of the group is selected and forwarded, the delay time of the high-priority packet is maintained.

With regard to the movement / change of the LAN switch S itself, the virtual group distribution management unit 9 sequentially manages the routing connection port and the distance of the client in the virtual group routing table 8 between adjacent LAN switches. Update by communicating messages. Regarding the multicast and broadcast of the virtual group, the virtual group set by the virtual group
Forwarding processing is sequentially performed on ports based on the group routing table.

Further, the client looks up the destination client address and forwards the port to the port learned in advance. Packets with broadcast and destination addresses not in the table are multicast to all ports as they leave the switch domain. In response to the virtual group change request, the agent of the terminal home switch cooperates to update the virtual group registration table 2 and the virtual group routing table 8.

By the way, in a general LAN application, a plurality of clients share a server database in a client-server model, and in the online transaction processing of the accounting-related business, the database is accessed multiple times. And high priority, data extraction (data query) for information grasp, analysis, simulation, decision support
In data warehouses and data warehouses, we want to know the results quickly and interactively, so high-speed communication and small delay time are required. In a video conference of multicast communication, it is necessary to send much more data with small delay time. And the amount of data increases. In addition, Virtual Corporation via WAN requires communication between servers in remote locations, and Electric Commerce requires interactive communication with many Yasue in remote locations. In addition, supervisory control messages for maintaining the network must be processed with the highest priority.

FIG. 4 shows a system configuration diagram of a network using a virtual LAN according to the present invention made in view of this point. In this system, a LAN switch provided with a virtual group agent VGA shown in FIG. A plurality of S ₁ ... Are distributed and each LAN switch S ₁ .
Terminal A ₁ ... connected to, B ₁ ..., C ₁ ... belong to individually virtual group. Here, it should be noted that the VLAN group (layer 2 level) corresponds to the network interface card (NI
C) Only one can be defined for each MAC address, but the virtual network group (layer 3 level)
Can define multiple groups of different communication protocols, and virtual custom groups can further define multiple groups at the application level. In FIG. 4, for simplicity, each terminal A ₁ ..., B ₁ .
₁ ... Are shown as communicating as one virtual group.

This is shown in FIGS. 5 and 6 in an abstract manner. FIG. 5A shows that the client U belongs to a plurality of virtual groups VA, VB, and VC, and that the client U connects to different servers A, B, and C depending on the application or project.
FIG. 5B shows each virtual group VA, VB, VC.
It is shown that each belong client U ₁ ... is to connect each virtual group VA, VB, to a common server S which is provided to correspond to the VC to.

FIG. 6 shows a VLAN group (layer 2 level).
Are represented by the switched domains SA, SB, and SC, and the communication and broadcast barriers between the switched domains SA, SB, and SC are routed between the switched domains.
In addition to the service LS, the switch domains SA and S
4 shows the arrangement of a network service server N and a network management server M between B and SC. FIG. 7 shows the concept of the virtual group service, in which each LAN switch Sa ...
Has a virtual group agent VGA, which cooperates to dynamically support virtual groups. As a result, as shown in FIG. 8, the virtual group registration table 2 and the virtual group routing table 8 are stored in the shared table TB.
As a result, a dynamic virtual group configuration for optimal routing and terminal movement is realized.

FIG. 7 shows the virtual group agent VGB of the LAN switches Sa... As shown in FIG.
A virtual group learning unit 3, a virtual group registration table 2, a virtual group routing table 8, a virtual group distribution management unit 9, and a virtual group control unit 6 are provided as important parts, and a virtual group control The function of extracting the port change message in the section 6 is also an important part.

In the virtual group identification section 1, the client address and the client address are encoded together by one hash function, and are compared with the virtual group registration table 2 similarly encoded by the hash function. However, there is no problem of an increase in delay time as compared with a method of adding a header or a tag to a packet.

Then, the MAC address is
At the second layer level of the OSI protocol hierarchy model, defined as an address, the VLAN conforms to the traditional standard, and does not add extra headers or tags to the packet. Support groups. In this case, the virtual group identification unit 1 of the LAN switch S checks the pair of MAC address 1 and MAC address 2 that are the destination and the source of the packet against the virtual group registration table 2 and checks both Ms.
Identify the virtual group that contains the AC address.

At the third level of the OSI protocol hierarchy model in which a plurality of network addresses depending on the communication protocol are defined as client addresses, an extra header or tag is added to the packet in accordance with the conventional standard. To support VLAN groups on terminals that conform to traditional standards without adding In this case, the virtual group identification unit 1 of the LAN switch S checks a pair of network addresses, which are the destination and the source of the packet, and the network address against the virtual group registration table 2, and the virtual group including both network addresses is included.・ Identify the group.

Further, at the application level of the OSI protocol hierarchical model in which the client address is the application address defined by the user or by the application software, the packet conforms to the traditional standard, and an extra header or extra packet is added to the packet. It supports the setting of a virtual custom group in which different media access methods and communication protocols are mixed without adding a tag. In this case, the virtual group identification unit 1 checks a pair of application address and the application address, which are the destination and the transmission source of the packet, with the virtual group registration table 2 to identify a virtual group including both application addresses. I do.

In the virtual group registration table 2 having the structure shown in FIG. 3, a client name is usually registered for each client address. VLAN group,
It is also possible to register a different client name for each virtual network group and each virtual custom group.
When a LAN group, a virtual network group, and a virtual custom group are respectively defined, a row defining a VLAN group and a virtual network group are defined in the virtual group registration table 2. A row and a row defining a virtual custom group are included.

The virtual group identification unit 1 gives the highest priority to the collation of the virtual custom group, and then the virtual network. The group, finally the VLAN group, and finally the VLAN group are collated. Here, the client name is registered together with the type of the device, as is the identification code of the device such as a LAN switch or a terminal. When the type of device is a LAN switch, the virtual group distribution management unit 9 registers the MAC address directly connected to the port of the LAN switch or the switch connection map 9a indicating whether the device is indirectly connected. Thereby, the connection map information of the entire network can be obtained by combining the virtual group registration table 2 and the switch connection map 9a. Since the connection between the ports adjacent to each other can be known, the topology can be drawn in a connection relation diagram, and this connection open-circuit diagram is called a map (MAP). If the topology has a tree structure, route search is easy, but if the topology is a mesh, it is necessary to compare the transmission time distances of a plurality of routes. When LAN switches having the same transmission speed are connected in multiple stages, the number of stages is regarded as the distance. Terminal A _9, for example, from the terminal A ₁
Are reflected in the numbers of the distances of the clients of the respective terminals in the respective virtual group routing tables 8.

The configuration of the forwarding section 5 depends on the configuration of the switch. Many of the well-known systems are configured by a shared high-speed parallel bus, and the bandwidth of the bus is set to about twice the total transmission bandwidth of the ports, and is widely used for a chassis-type backplane. In a parallel configuration using crosspoint switches, input buffer type,
There are methods such as an output buffer type. In the configuration of the LAN switch S in FIG. 1, since the buffer 11 is a shared memory, the overall configuration is a shared buffer type (storage and handling type), but the forwarding unit 5 can be combined with the various switching methods described above. It is.

Further, it is possible to operate as a cut-through type by not performing the checksum of the frame format shown in FIG. The operation mode of the LAN switch S, that is, a storage and exchange type that performs a checksum,
Alternatively, the cut-through type setting that is not performed
The cut-through type, defined by the group type in the group registration table 2, increases the throughput of the LAN switch S but does not allow filtering of defective packets. For the priority of the forwarding, the setting of the priority of the virtual group registration table 2 has priority over the operation mode of the switch.

Since the LAN switches S are connected in multiple stages, the packet transmission delay time is
It depends on the availability of ports and the waiting time for queuing. For this reason, it is necessary to cooperatively guarantee the transmission time as a system. As a control packet between the LAN switches S, a virtual group management message is exchanged between the virtual group distribution management units 9.
Usually, an S (Management Information Base) is used to manage individual devices on a subnetwork based on an MIB.
NMP (RFC1157: Simple Network Management Protco
l) and RMON (RF
A network management protocol such as C1271: Remote Monitoring) is exchanged between the network management protocol agent 13 and an external network management manager to support industry standards such as fault management, security, and statistics collection. In FIG. 1, reference numeral 14 denotes a switch communication protocol control unit.

In a general virtual network, virtual group information is added to a packet itself,
Grouped by information such as the subnet address of the third layer protocol of the OSI protocol layer model, and LA
The N switch S checks this information, but changing the subnet setting in router segmentation is complicated, and
In a system in which terminal changes are almost 30% per year, the cost of network management and maintenance has become a problem that cannot be ignored.

The purpose of the VLAN group for registering a virtual group only with the M @ C address according to the present invention is to improve priority processing, learning load distribution, and routing efficiency. The priority processing is, for example, the highest in the management group, the second highest in the time critical group that guarantees the delay time, the second is the switch control group that dynamically updates the registration table, then the high-speed terminal, and finally A low-speed terminal that does not require priority processing is assigned the lowest rank. SNMP or RMON network management is set in the management group.

Normally, a management group and a time critical group that have a high priority are registered statically, and a switch, a high-speed terminal, a low-speed terminal that does not need priority processing,
It is learned and registered dynamically. When a plurality of virtual groups VA are concentrated on the client U as shown in FIG. 5 (a) and on the server S as shown in FIG. 5 (b), the client address is paired with the destination and source address. Define and identify virtual groups VA... So that a client can use a single MAC address to multiple servers A.
Although it is possible to belong to an AN group, in the case of a server, in order to ensure that a client belongs to a plurality of virtual groups VA with a single MAC address, a network interface card (NIC) of the server is simply used. If only one MAC address is supported, multiple NICs are connected to the LAN switch and a MAC address is assigned to each virtual group VA..., Or even a single MAC is at the third layer level or higher. Need to support multiple virtual groups in a virtual network group or a virtual custom group.

[0072] The network service server shown in Figure 6 N, or virtual network service server VN as shown in FIG. 7 each LAN switch S ₁ ...
(Sa...) And the mutual communication with other networks outside the virtual group. LAN switch S ₁ ... (Sa ...) terminal A ₁ Virtual Group agent VGA while cooperation with commutation of the virtual group management messages between virtual group agent VGA for each LAN switch S of ..., B ₁ .., C ₁ .

Network service server N or virtual network service server VN
And each LAN switch S ₁ ... (Sa.
Virtual agent between group agent VGA
By exchanging group management messages, a shared table TB is constructed as shown in FIG. 8 to form a cooperative virtual group, and communication with the outside of the virtual group is supported. The shared table TB is
It includes the virtual group registration table 2 and the virtual group routing table 8 of FIG.

In the configuration example shown in FIG. 6, the network service server N can manage the virtual group registration table 2 and the virtual group routing table 8, and in this case, the network service server N The lookup table cached and provided in the switch S is compared with the client address.

Also, in the configuration shown in FIG.
Can be sent to the entire virtual group in a connection between the servers. For example, as for the virtual service corresponding to the virtual group VA, only the terminals belonging to the virtual group VA can be received. The broadcast issued by the client is limited to the virtual group VA to which the client belongs, and the network service server N follows the broadcast of the unknown group from the client in cooperation with the virtual group server A. Regarding the broadcast of the Unknown Group, the Virtual Group
Server A ... sees the protocol type of the packet and throws it to a specific network service server N or virtual group server A ... The setting of a new virtual group is performed by the network service server N. In FIG. 6, M indicates a network management server, and SA... Indicate switched domains.

For example, a virtual group server A is assigned to each virtual group VA, and the multicast for each virtual group A is a multicast request sent from each client to this server A and a server A ... .. Perform multicast processing for each client, each server A.
According to the multicast setting registered in the virtual group agent VGA of the AN switches S ₁ .
N switch S ₁ ... memorizes the packet pointer of the multicast message to the multicast virtual group-specific queuing table, LAN switches S ₁ ... is by executing the multicast processing, each virtual group VA ... of Server A ... and L
The LAN switches S cooperate with the AN switches S ₁ .
₁ ... to support a virtual group VA ... multicast. In this case, the LAN switches S ₁ may have a server function.

A virtual group server A is assigned to each virtual group VA. Broadcasting is performed when a communication request handled by server A can respond to a broadcast request issued from each client. Server A ... responds,
If server A ... cannot respond, each server A will be forwarded to router LT.
... is advance by LAN switches S ₁ ... broadcast settings registered in the virtual group agent VGA of, LAN switches S ₁ ... are stored in the broadcast queuing table packet pointer of the broadcast message, the LAN switch S ₁ ... Forward the broadcast to the router LT, so that each virtual group VA.
, And LAN switches S ₁ ... Cooperate, while LAN switches S ₁ .
Supports broadcast of ... In the case of the LAN switch operating as the second layer VLAN group, the virtual groups VA are routed, but communication with other than the virtual groups VA depends on the external router LT.

In the example of the system configuration shown in FIG.
LAN switch SS with interface
Connection to the ATM interface
Layer 2 VLAN VLAN emulated on
Via the ATM interface
Expand virtual groups. ATM interface
Virtual group on LAN switch SS with base
Incorporating the agent VGA and ATM interface
Terminal A directly connected to the base_ThreeB _TwoOr B_FourVLA including
N groups are integrated.

When the LAN switch SS with the ATM interface supports LAN emulation,
An existing LAN can be directly connected to the port. Further AT
SS with M interface itself supports multi-protocol, virtual group agent VGA
By having L with ATM interface
A shared table TB is built in the AN switch SS,
Layer-level virtual network groups as well as virtual custom groups are also supported.
In FIG. 9, LEC denotes a LAN emulation client, each LAN switch S ₁ , S ₂ has a LAN emulation server function (LES, BUS), and server B has a LAN emulation server function (L
ES, BUS, BUS).

[0080]

According to the first aspect of the present invention, a virtual group is formed for each terminal based on the characteristics of the packet without adding an extra header or tag to the packet and without depending on the port of the LAN switch. While setting the client address of the virtual group and the priority for each group in the group registration table,
A virtual group agent that allocates unicast and multicast traffic bands in groups and performs dynamic automatic configuration management for terminal movements by a virtual group learning unit.
Since the switch is provided in the switch, the VLAN can be realized without changing the existing packets, and the existing terminals can be incorporated into the virtual group without any change.

According to a second aspect of the present invention, a virtual group name and its client address are registered in a virtual group
A LAN switch is cascade-connected to each port by registering an optimum connection port address to which port of each LAN switch distributed to the network is connected to which port in the group routing table, and Multiple virtual
Since the LAN switch is provided with a virtual group agent for allocating groups, registering member MAC addresses for each virtual group, and selecting an optimal routing path between ports of each virtual group, a medium access method is used. In addition, it is possible to set a virtual group in which communication protocols and applications are mixed, and it is possible to support a configuration of a virtual group centered on a server corresponding to a plurality of types of terminals and protocols.

According to a third aspect of the present invention, the LAN switch
Distributed in the network, each LAN switch has a bar
It has a connection port for the char group and each L
The virtual group agent provided for the AN switch
Virtual Group Registration
Virtual group for each LAN switch
Virtual when changes to the registration table are detected
・ By exchanging group management messages with each other,
To update the above virtual group registration table
Therefore, a virtual group can be automatically configured dynamically even when a terminal moves, and in an environment where many LAN switches are distributed, the virtual group agents of each LAN switch cooperate with each other to form a virtual group. The configuration and the optimal routing path can be automatically corrected, and QOS (Quality of Service) is guaranteed by priority processing in units of virtual groups such as applications and projects.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a VLAN switch using the present invention.

FIG. 2 is a diagram illustrating a MAC frame format of a general LAN.

FIG. 3 is a configuration diagram of a virtual group registration table and a virtual group routing table of the above.

FIG. 4 is a system configuration diagram of an embodiment of the present invention.

FIG. 5 is an image diagram of a virtual service group according to the embodiment.

FIG. 6 is an image diagram of a switched group according to the first embodiment;

FIG. 7 is a configuration diagram of a virtual group service according to the embodiment.

FIG. 8 is a configuration diagram of a closed system according to another embodiment.

FIG. 9 shows L with an ATM interface according to another embodiment.
FIG. 2 is a system configuration diagram including an AN switch.

[Explanation of symbols]

S LAN switch VGA Virtual group agent 1 Virtual group identification unit 2 Virtual group registration table 3 Virtual group learning unit 6 Virtual group control unit 8 Virtual group routing table 9 Virtual group distribution management unit

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-9-288627 (JP, A) JP-A-9-284328 (JP, A) JP-A-9-275418 (JP, A) JP-A 9-288 233110 (JP, A) JP-A-9-214540 (JP, A) JP-A-9-186715 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 12/28 H04L 12 / 56 JICST file (JOIS)

Claims (3)

(57) [Claims] 1. A virtual group is formed for each terminal based on characteristics of a packet without adding an extra header or tag to the packet and not depending on a port of a LAN switch, and a virtual group is registered in a virtual group registration table. Virtual address that sets the client address of each group and the priority of each group, allocates the bandwidth of unicast and multicast traffic on a group basis, and performs dynamic automatic configuration management for terminal movement by the virtual group learning unit.・
A virtual LAN system in which a group agent is provided in a LAN switch. 2. Registering the name of a virtual group and its client address in a virtual group registration table, and registering each LAN distributed on a network in a virtual group routing table.
By registering the optimal connection port address to which port of the switch and which virtual group is connected, a LAN switch is cascaded to each port, multiple virtual groups are assigned to each port, and each virtual group is assigned A virtual group agent for registering a member MAC address in a LAN switch and selecting an optimal routing path between ports of each virtual group in a LAN switch. 3. The LAN switch is distributed to a network.
And assign a virtual group to each LAN switch.
Equipped with connection port and prepared for each LAN switch
Virtual group agent
The virtual group registration table
For the virtual group registration table
Virtual group management message
By exchanging messages with each other,
3. The virtual LAN system according to claim 1, wherein the group registration table is updated .