JP2829057B2 - Address management method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention provides a method for connecting a plurality of networks to a MAC (Media Access
l) A method of updating an address table effective for address management of a network in which nodes interconnected in a layer are interconnected in a mesh or a star by a transmission line.

[Prior art]

Conventionally, IEICE, Technical Research Report, SSE88-108
In "Study of LAN inter-connectors", a LAN inter-connect device (hereinafter referred to as a bridge node) that interconnects a bus-type LAN with a LAN using a loop-type backbone LAN is called a bridge node to perform address filtering. Registered the MAC addresses of all terminals connected to the bus type LAN
It has an AFT (address filtering table) and a NAT (node address table) in which destination bridge node addresses for each MAC address are registered. A method of constructing the AFT and NAT by learning is discussed.

[Problems to be solved by the invention]

According to the above-mentioned conventional technology, when data is transmitted, the MFT of the terminal is transmitted to the AFT of the bridge node to which the data transmission terminal is connected.
Write AC address. The NAT writes the MAC address of the source terminal and the address of the source bridge node only when data is sent to a terminal registered in the AFT of the own bridge node. When transmitting data to a terminal that is not registered in the NAT, it broadcasts because the destination bridge node address is unknown. In this conventional example, the NAT is not updated unless a terminal registered in the AFT is communicated, so that there is a problem that the number of broadcasts increases for NAT construction and the throughput at the bridge decreases. An object of the present invention is to reduce the number of broadcasts and suppress a decrease in throughput.

[Means for Solving the Problems]

In order to achieve the above object, according to the present invention, in a network in which each node connects a plurality of nodes accommodating a plurality of terminals via a transmission line in a star or mesh shape, each of the nodes has its own node. A table for storing network configuration information including terminal addresses of all terminals accommodated by the other nodes and network route information to the terminal; a network address management method for connecting terminals to each other and transmitting / receiving information based on the table; Means for searching a table for each node, transmitting means for adding the terminal address and the route information to the information and transmitting the information to the destination node, and information obtained by adding the terminal address of the destination terminal when the search means cannot find the destination terminal. Broadcasting means for broadcasting to other nodes, and terminal address of own node or source terminal received by searching means And updating means for updating a table with the terminal address of the own node or the received source terminal address and the route information when the address and the route information are not found. The information transmission by the means and the updating of the table by the updating means when the terminal of the own node is not registered, and the receiving node updates the table configuration by the updating means when the source terminal is not registered, thereby updating the network configuration information of the table of each node. The address management method is used to execute communication between terminals.

[Operation]

With the above-described configuration, the transmitting node performs information transmission by the broadcast unit when the destination terminal is not registered and updates the table by the updating unit when the terminal of the own node is not registered. The receiving node updates the table when the source terminal is not registered. , The network configuration information in the table of each node is updated and matched, so that the number of times of broadcasts that occur due to unknown addresses due to unregistered address tables is reduced, and a decrease in network throughput is prevented. .

【Example】

FIG. 1 shows a switching network composed of nodes 101, 102 and 103, LANs 104 and 105 connected to the node 101, and a node 102.
This is a network configured by a LAN 106 connected to the LAN 103 and a LAN 110 connected to the node 103. Data transfer is performed within each LAN and between the LAN and the node using a LAN frame, and data transfer between the nodes is performed using fixed-length packets (hereinafter, referred to as cells). A cell is provided with a call number (hereinafter, referred to as VCI) indicating destination and route information and an identification number of LAN frame data (hereinafter, referred to as MID). In addition, each node has a function of receiving LAN frame data received from the LAN and making it a cell,
It has the function of exchanging cells by VCI in the cell and the function of receiving cells and assembling them into LAN frame data according to the contents of MID, and transparently connects LANs and LANs at the MAC layer. In this embodiment, a non-hierarchical MAC is
Allocate layer addresses and assign the same number of VCI and MI to each LAN.
Assign D. FIG. 2 is a block diagram of each node (101, 102, 103 in FIG. 1). The node 201 includes a control unit 202, an exchange unit 203, a LAN interface unit 204, and a transmission unit 205. When the LAN interface unit 204 receives the LAN frame data 206 (details will be described later), the LAN interface unit 204 divides the cell into cells, and registers the destination terminal address and the VCI of the LAN connecting the destination terminal address and the destination terminal address according to the destination terminal address. VCI is searched from the address table (details will be described later)
The VCI is attached to the cell and transmitted to the switching unit 203. Exchange unit 20
Reference numeral 3 has outgoing line information indicating an outgoing line corresponding to the VCI, determines a transmission line to be transmitted according to the outgoing line information, and outputs a cell to the transmission line. That is, if the VCI is a number assigned to the LAN connected to its own node, it is output to the LAN interface unit 204 connected to the LAN, and the VCI is assigned to the LAN connected to the other node. If applicable, the LAN
Output to the outgoing line connected to the connected node
The electric signal is converted into an optical signal by 205 and output to a transmission line. Next, the operation at the time of reception will be described. Upon receiving the cell from another node, the transmission unit 205 converts the optical signal into an electric signal and sends the electric signal to the switching unit 203. The switching unit 203 analyzes the VCI of the cell received from the transmission unit 205 and outputs the cell according to the outgoing line information corresponding to the VCI. Then, the LAN interface unit 204
Then, the cells sent from the transmission line are transferred to LAN frame data 2
Assemble at 06 and send to LAN. The control unit 202 has an interface with an input / output device (not shown), and controls the registration and rewriting of the outgoing line information and the address table from the outside.
Also, initialization is performed in the node, and failure processing is performed when a failure occurs. FIG. 3 is a diagram showing an address table provided in the LAN interface unit of each node. The address table 300 includes a terminal address 301 and a VCI 302 assigned to each LAN to which the terminal is connected.
Is registered. The address table 300 is provided in the LAN interface unit 204 provided corresponding to each LAN, and the VCI 302
If it is a LAN terminal not connected to the LAN interface unit, register the VCI allocated to the LAN connected to the terminal, and if it is a LAN terminal connected to the LAN interface unit Register '0'. The address table is composed of a RAM, is connected to the processor by a control bus, and has a configuration in which data can be written and read by access from the processor. FIG. 4 is a diagram showing a configuration of LAN frame data. The LAN frame data has a destination terminal address 401 and a source terminal address 402 each having 6 octets, and a frame check sequence 403 for error detection of the LAN frame data.
Area is provided. If the first and second bits of the destination terminal address are 1, a broadcast is indicated (details will be described later). Note that oct. Represents an 8-bit quantity. FIG. 5 is a diagram showing a cell configuration. The cell header 501 has a VCI 502 area allocated to the destination LAN, and the adaptation header 503 has a MID 504 area allocated to the source LAN. Also LAN
If the frame data 206 is less than 62 oct., It is put into the information part 505 of one cell, and if the LAN frame data exceeds 62 oct., It is divided and put into the information part 505 of a plurality of cells. A cell in which the LAN frame data fits into one cell is called a single cell, the first cell when divided into multiple cells is the first cell, the last cell is the last cell, and the cells between the others. Is called an intermediate cell. Cell is cell type 506
If the last two bits of the cell type 506 are '11' and the first two bits are 11, the address table updating cell, '0
If it is 0, it indicates a response cell. The last two bits of the cell type 506 are '00'. If the first two bits are '10', it is the first cell. If it is '00', it is an intermediate cell. Represents a single cell. Furthermore, the VCI 502 uses all '1's as broadcast VCIs, carries the address of the terminal to be updated to 6 oct. From the beginning of the information section 505, and accommodates the terminal to be updated to the next 12 bits.
A cell carrying the LAN VCI is used as an address table updating cell (details will be described later). FIG. 6 is a diagram showing a configuration of the LAN interface unit 204. The LAN interface unit receives the LAN frame data 206 transmitted from the LAN via the LAN interface 602, performs a frame sequence check, and if normal, sends the destination terminal address to the routing control 603, and sends the data to the buffer 604. Send out. The routing control 603 stores the address table 300 with the destination terminal address.
And if the terminal address is not registered, sends a VCI indicating that it is for broadcast to the cell header generation unit 606, and the terminal address is registered, and the VCI corresponding to the terminal address is not registered In this case, judge that the data is in the local LAN and discard the data.
If I is registered, it is judged to be data to another LAN and the VCI allocated to the destination LAN is
Send to 606. The cell header generation unit 606 converts the cell header 501 (FIG. 5) necessary for exchange and the LAN frame data from the cell.
Adaptation header 503 needed to play 206
(FIG. 5). Further, the cell assembling / disassembling unit 60
The cell is assembled in step 7, and the cell is transmitted to another node. In addition, the cell received from another node performs a cell sequence check in the cell assembling / disassembling unit 607, and if the result is normal, sends the cell header and the adaptation header to the reassembly control 609 and sends the data to the buffer 608. The header reassembly control 609 analyzes the adaptation, collects the data of the information part of the cell with the same MID in the buffer 608, assembles a LAN frame, converts the speed by the LAN interface 602, and sends out the LAN frame data 206. . Processor 610
Performs processing of an instruction from the control unit 202 (FIG. 2) and communication with the terminal, management of the address table 300, and troubleshooting of the LAN interface unit 204 (FIG. 2). Next, a method of updating the address table in the above network will be described. First, the first address management method will be described with reference to the sequence diagrams of FIGS. 7, 8, and 9 as an example of a case where data is transferred from the terminal 108 to the terminal 107. The node 102 receives the LAN frame data transmitted by the terminal 108 from the LAN 106 (701 in FIG. 7) and determines whether the LAN frame data is data to be stored in the LAN accommodated in the own node based on the destination terminal address 401. Then, the address table 300 of the LAN interface unit 204 is searched (702 in FIG. 7) to determine whether the data is for the LAN accommodated by another node. Since the terminal 107 is accommodated by the LAN 105, the node 102 inserts the VCI 502 allocated to the LAN 105 into the cell header 501 of the cell and the MID 504 allocated to the LAN 106 into the adaptation header 503. Next, if the received LAN frame data 206 is equal to or less than 62 oct., It is regarded as a single cell.
If it exceeds 2 oct., It is divided into a plurality of cells and the data is transmitted to the node 101 which accommodates the LAN connecting the destination terminal (FIG. 7, 703). On the other hand, node 101
Is analyzed, and if it is determined that the cell is addressed to the own node,
The cell is fetched and sent to the LAN interface unit 204 connecting the LAN 105. The LAN interface unit 204 has a source terminal address 402 and a MID 50
4 is retrieved, and the address table 300 is searched by the source terminal address 402. If the source terminal address 402 is registered in the terminal address 301, the VCI 30
The MID 504 is written in 2 and if not registered, the source terminal address 402 is written in the area (blank) of the terminal address 301 of the address table 300, and the MID 504 is written in the VCI 302 (FIG. 7, 704). The node 101 transmits the received data to the terminal 107 regardless of whether the table 300 is registered or not registered (FIG. 7, 705). Next, the operation when the accommodation position of the destination terminal is unknown due to the movement or new installation of the terminal will be described by taking as an example that the terminal 109 has been moved or newly installed. First, upon receiving the LAN frame data (801 in FIG. 8), the node 102 uses the destination terminal address 401 of the LAN frame data sent from the terminal 106 from the LAN 106 accommodated in the own node to transmit the LAN frame contained in the own node. The address table 300 of the LAN interface unit 204 is searched (802 in FIG. 8) to determine whether the data is the data into the LAN or the data to the LAN accommodated by another node. Since the terminal address of the terminal 109 has not been registered, the node 102 broadcasts the cell (803 in FIG. 8). The LAN interface unit 204 of each node (the node 101 in this embodiment) that has received the broadcast cell transmits the source terminal address 402 and the MID from the head cell or a single cell.
504 is retrieved, and the address table 300 is searched by the source terminal address 402. If the source terminal address 402 is registered in the terminal address 301, the address table 300
The MID 504 of the received cell is registered in the VCI 302, and if not registered, the source terminal address 402 is written in the area (blank) of the terminal address 301 of the address table 300, and the VCI 302
The MID 504 is written in (step 804 in FIG. 8). Node 101
Transmits the received data to the terminal 109 irrespective of registration or non-registration in the table 300 (FIG. 8, 80
Five). Next, registration of the nodes 101 and 102 in the address table 300 when a call is transmitted from the terminal 109 that has been moved or newly installed will be described. In the node 101, the LAN frame data 206
Is received by the LAN interface unit 204 of the LAN 105 (the ninth
901), the address table 300 is searched by the source terminal address 402 of the LAN frame data 206. Terminal 109
Is moved or newly installed, the address table 300 is in an unregistered state, so the source terminal address 402 is written to the terminal address 301 and '0' is written to the VCI 302 (FIG. 9, 902). Thus, the address table of the LAN interface unit 204 connecting the LAN 105 is registered. In addition, another node (the node 102 in this embodiment) has an interface unit (a LAN to which the LAN 105 is not connected).
The registration of the interface unit 204 into the address table 300 is performed when a cell including the LAN frame data 206 from the terminal 109 is received. That is, the node 101 that has received the LAN frame data transmitted by the terminal 109 converts the data into cells and transmits the cells to the transmission path (FIG. 9, 90
3). On the other hand, the LAN interface unit 204 of the node 102 that has received the cell from the node 101 extracts the source terminal address 402 and the MID 504 from the head cell or a single cell. Next, the address table 300 is searched by the source terminal address 402. At this time, since the source terminal address is not registered in the terminal address 301, the LAN interface unit 204 recognizes that it has not been registered, and enters the source terminal address 402 in the area (blank) of the terminal address 301 of the address table 300. And the MID 504 is written to the VCI 302 (904 in FIG. 9), and the address table is registered.
The node 102 transmits the received data to the terminal 108 regardless of whether the table 300 is registered or not registered (FIG. 9, 905). Next, a description will be given of a second address management method for rewriting an address table by access from an input / output device (not shown) of the node 101. First, the control unit 202 is accessed from the input / output device of the node 101, and the processor 610 (the sixth
4), an address table rewrite instruction for rewriting the address table is transmitted. When recognizing the address table rewrite instruction, the processor rewrites the address table 300. The LAN interface unit 204, which has rewritten the address table 300, places the terminal address to be updated to 6 oct. From the beginning of the information unit 505, the VCI of the LAN connected to the terminal to be updated to the next 12 bits, and sets the cell type 506 to Address table update cells all set to '1' to node 10
Broadcast to 2,103. On the other hand, the reassembly control 609 of each LAN interface unit 204 of each node that has received the broadcast cell puts the data in the buffer 608, judges that the cell is the address table update cell from the cell type, and converts the data in the buffer 608. Send to processor 610. Then, the processor 610 receiving the data sends the LAN frame data.
The address of the terminal to be updated and the VCI of the LAN connected to the terminal to be updated are extracted from 206, the address table 300 is searched by the extracted terminal address, and the terminal address 301 is retrieved.
If the extracted terminal address is registered, the VCI of the LAN to which the terminal is connected is written to the VCI 302. If the terminal address is not registered, the terminal address of the terminal to be updated is stored in the area of the terminal address 301 (blank) in the address table. Write the VCI of the LAN connected to the terminal to the VCI 302. The LAN interface unit 204 having rewritten the address table transmits a response cell indicating the completion of the update to the LAN interface unit 204 of the node that transmitted the address table update cell. The processor 610 of each LAN interface unit 204 of the node that has transmitted the address table update cell has a table in which one bit is allocated to each LAN interface unit 204 in the network. 'Is written, and when the response cell comes, LA
The response cell is monitored by writing "0" to the bit corresponding to the N interface unit 204, and the address table updating cell is sent again to the LAN interface unit 204 which does not return the response cell within a predetermined time. Next, a third address management method in which the address table 300 is rewritten by a terminal connected to the LAN will be described. First, an address is allocated to the LAN interface unit 204 of each node. Then, communication is performed between the processor 610 of the LAN interface unit 204 and the LAN terminal. When LAN frame data is sent from the LAN terminal to the LAN interface unit 204, the routing control 603 of the LAN interface unit 204 puts the data in the buffer 604, and transmits the data from the destination terminal address 401 to the own LAN interface unit 204. It is determined that there is, and the data in the buffer 604 is sent to the processor 610. The processor 610 receiving the data extracts the terminal address of the terminal that updates the contents of the table from the data and the VCI of the LAN accommodating the terminal, searches the terminal address 301 of the address table 300 by the extracted terminal address, If the extracted terminal address is registered in the terminal address 301, VCI30 in the address table 300
Register the VCI of the LAN that houses the terminal in 2, and
If not registered, the terminal address of the terminal to be updated is written in the area (blank) of the terminal address 301 in the address table, and the VCI of the LAN accommodating the terminal is written in the VCI 302. Next, a fourth address management method will be described with reference to FIG. The node 103 has an address database 111 in which addresses of all terminals in the network and VCIs of LANs accommodating the terminals are registered. The address database 111 is managed by a maintenance person and always stores the latest information.
Disable communication to unregistered terminals. For example, when newly registering the terminal 109, the maintenance person needs to input the address database 111 from the input / output device (not shown) of the node 103.
Update. Thereafter, when communication is performed from the terminal 108 to the terminal 109, it is identified that the terminal address of the terminal 109 is not registered in the address table 300 of the LAN interface unit 204 of the LAN 106, and the address database 111 of the node 103 is identified.
, The address table 605 of the LAN interface unit 204 of the LAN 106 is updated. An address is assigned to each node in advance, and an address table updating cell is used to read information from the address database 111. First, the LAN interface unit 204 connecting the LAN 106 sends an address table update cell in which the address of the unregistered terminal is added to the first 6 oct. Of the information part to the node 103. When receiving the address table update cell, the node 103 searches the address database 111 for a VCI corresponding to the address of the unregistered terminal according to the address of the unregistered terminal, and puts the address of the unregistered terminal on the first 6 oct. With the VCI retrieved in 12 bits, and transmits the address table updating cell to the LAN interface unit 204 connecting the LAN 106. The reassembly control 609 of the LAN interface unit 204 of the node 102 that has received the address table update cell puts data in the buffer 608,
The cell type is determined to be an address table update cell, and the data in the buffer 608 is sent to the processor 610.
The processor 610 that receives the data sends the address of the terminal to be updated from the data and the LAN containing the terminal to be updated.
Fetches the VCI of the terminal address in the address table 300
The terminal address of the terminal to be updated is written in the area 301 (blank), and the VCI of the LAN to which the terminal is connected is written in the VCI 302. Next, a description will be given of a fifth address management method for broadcasting immediately after a moved or newly installed terminal is incorporated into a LAN. First, a LAN interface unit that connects a moved or newly installed terminal or a LAN accommodating the terminal, when the moved or newly installed terminal is incorporated into the LAN,
Immediately broadcast. On the other hand, the LAN interface unit 204 of each node receiving the broadcast cell extracts the source terminal address 402 and the MID 504 from the head cell or single cell, searches the address table 300 by the source terminal address 402, and Recognizing that the terminal address 402 is not registered, the source terminal address 402 is written in the area (blank) of the terminal address 301 of the address table 300, and the VCI
The address table is updated by writing the MID 504 to 302. FIG. 11 is a network configuration diagram in a case where nodes are connected in a star configuration. It is apparent that the present invention can manage (update) the address table even in a network in which the nodes are connected in a star configuration, similarly to the above-described operation.

【The invention's effect】

As is clear from the above description, according to the present invention, all address tables in the network can be updated by one broadcast,
Also, by updating one address table from all terminals in the network, all address tables in the network can be updated.
It is possible to reduce the number of times of broadcasting and suppress a decrease in throughput.

[Brief description of the drawings]

FIG. 1 is a diagram showing a network configuration according to an embodiment of the present invention.
FIG. 3 is a block diagram of a node in FIG. 1, FIG. 3 is a diagram showing an address table showing correspondence between destination terminal addresses and VCIs, FIG. 4 is a diagram showing a LAN frame data format for data transfer between a terminal and a node, FIG. 5 is a diagram showing a cell format for data transfer between nodes, FIG. 6 is a block diagram of a LAN interface unit for converting between a LAN frame data format and a cell format in a node, FIG. 7, FIG. FIG. 9 is a sequence diagram for explaining the operation of the present invention, and FIGS. 10 and 11 are network configuration diagrams for explaining another embodiment of the present invention. 101,102,103 …… Node, 104,105,106,110 …… LAN, 10
7,108,109… Terminal, 204… LAN interface section, 300
…… Address table, 301… Terminal address, 302 ……
VCI, 401: destination terminal address, 402: source terminal address, 502: VCI, 504: MID, 506: cell type.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yoshihiro Takiyasu 1-280 Higashi Koikekubo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. (72) Inventor Takashi Morita Takashi Morita 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Totsuka Plant of Hitachi, Ltd. (56) References JP-A-64-23646 (JP, A) JP-A-63-245039 (JP, A) JP-A-1-129550 (JP, A) JP-A-1-166643 (JP, A) JP-A-63-65734 (JP, A) JP-A-61-238141 (JP, A)

Claims (1)

(57) [Claims] 1. A network in which a plurality of nodes each accommodating a plurality of terminals are connected in a star-like or mesh-like manner by a transmission line, wherein each of the nodes includes all nodes accommodated by its own node and other nodes. An address management method for a network, comprising: a table for storing network configuration information including a terminal address of a terminal and the network route information to the terminal; and Means for searching the table, transmitting means for adding the terminal address and the route information to the information and transmitting the information to a destination node, and adding the terminal address of the destination terminal when the search means cannot find the destination terminal Broadcast means for broadcasting the received information to another node, and the terminal address or reception of the own node by the search means. Updating means for updating the table with the terminal address of the own node or the received source terminal address and the received route information when the transmitted source terminal address and the route information are not found; The information transmission by the broadcasting means at the time of non-registration and the updating of the table by the updating means when the terminal of the own node is not registered, and the receiving node updates the table by the updating means at the time of unregistering the source terminal. An address management method for executing communication between terminals by matching the network configuration information in the table of each node.