KR100836170B1 - Work-group ethernet lan switching device using cam and method thereof - Google Patents

Abstract

A workgroup Ethernet LAN(Local Area Network) switching device and method using a CAM(Content Addressable Memory) are provided to register the address of each computer and switch board numbers in the address tables of all switch boards as entry in parallel, thereby reducing bottle neck caused by traffic for making the address tables between the switch boards and increasing access and a throughput time. A workgroup Ethernet LAN switching device using a CAM(60) comprises a switch port(10(1)~10(N)), a switch module(20), an internal address management unit(50), the CAM, a CPU(30), and an extension port(40). The switch port inputs and outputs frames for transceiving data from each computer(A11~A1N) connected in a workgroup Ethernet LAN. The switch module transfers a frame according to a receiving address in the frame, destination where the data is to be transmitted. The internal address management unit outputs a source address in the frame, destination for transmitting the data, and the number of a switch board including each component as entry. The CAM stores and updates the source address and the entry of the switch board number. The CPU inquires the data of the source address, and receives and outputs a corresponding switch board number. The extension port is connected to switch boards(100(1)~100(N)) to transfer the frame to the switch board of a corresponding number.

Description

Work-Group Ethernet LAN Switching Device Using CAM and Method

1 is a schematic configuration diagram of a workgroup Ethernet LAN including a workgroup Ethernet LAN switching device using a CAM according to the present invention.

Figure 2 is a block diagram schematically showing a switch board of a workgroup Ethernet LAN switching device using a CAM according to the present invention.

3 is a conceptual diagram schematically showing a switch board of a workgroup Ethernet LAN switching device using a CAM according to the present invention.

4 is a diagram conceptually illustrating a process of forming an address table of a workgroup Ethernet LAN switching device using a CAM according to the present invention;

5 is a diagram conceptually illustrating a frame transmission process within a switch board of a workgroup Ethernet LAN switching device using a CAM according to the present invention;

6 is a conceptual diagram illustrating a frame transmission process between switch boards of a workgroup Ethernet LAN switching device using CAM according to the present invention.

7 is a flowchart schematically illustrating a workgroup Ethernet LAN switching method using a CAM according to the present invention.

 <Brief description of reference numerals for the main parts of the drawings>

1: workgroup Ethernet LAN switch device 10: switch port

20: switch module 30: central processing unit

40: expansion port 50: internal address management unit

51: source address extractor 53: switchboard number combiner

55: CAM Register 60: CAM

100: switch board

The present invention relates to a workgroup Ethernet LAN switching device and method using a CAM, and more specifically, to the switch board of the workgroup Ethernet LAN switching device using the CAM, the content addressing memory to the address and switch board number of each computer By registering in the address table in parallel as an entry on all switch boards, the bottlenecks caused by traffic for the address table creation between the switch boards are reduced, and the contents can be searched to increase accessibility and processing speed, and use the CAM address table. The present invention relates to a workgroup Ethernet LAN switching device and a method for efficiently using a switching device by transmitting a frame only to a corresponding switch board.

In general, a work-group local area network (LAN) is a work-unit local area network, in which each computer forming a small network such as a school or a company is a work-group Ethernet LAN switching device. It is connected to a plurality of switch ports in the switch board of the made of data transmission between the computer connected to the switching device is made possible.

In addition, the switching device may include a plurality of switch boards. When the number of users increases in a workgroup LAN, the network should be expanded, and accordingly, the switch board further includes the number of switch ports connected to the computer. Let's do it.

In addition, switching is used for communication between computers connected in the switch board and communication between computers connected to other switch boards. In the case of communication between computers connected in the switch board, switching is possible by simple switching in a switch module, but other switches In the case of communication between board computers, data is transmitted and received by connecting between switch boards through expansion ports.

However, in the case of communication between computers connected to different switch boards, an entry in the address table such as the address of the data to be transmitted through the expansion port and the number of the switch board is exchanged, and thus, a bottleneck of the expansion port in transmitting and receiving data. May occur, and thus data processing and transmission are delayed, and in searching for an address to which data is transmitted, by using general memory (SRAM, DRAM) that requires sequential searching using numbers as addresses, There was a problem such as a delay in time.

The present invention has been made to solve the above problems, using the CAM, the content addressing memory on the switch board of the workgroup Ethernet LAN switching device, the address table and the switch board number of each computer as an entry table to all switch boards. By registering in parallel, the bottleneck caused by traffic for address table creation between switch boards is reduced, accessibility and processing speed can be increased by searching by contents, and frames are transmitted only to the corresponding switch board using CAM address table. Accordingly, an object of the present invention is to provide a workgroup Ethernet LAN switching device and method using a CAM capable of efficiently using a switching device.

In order to achieve the above object, the present invention provides a switch port for inputting and outputting a frame for data transmission and reception from each computer connected in a workgroup Ethernet LAN; A switch module for transferring a frame according to a reception address in a frame that is a destination to which data is to be transmitted; An internal address manager for outputting, as an entry, a source address in a frame which is a sender for transmitting data and a number of a switch board including each component; CAM for storing and updating entries of source address and switch board number; A central processing unit for querying a source address and receiving and outputting a corresponding switch board number; Expansion ports interconnected to forward frames to the corresponding switch board number; It includes.

The internal address manager may include: a source address extractor for extracting a source address in a NM frame; A switch board number combiner for combining the switch board number and the source address and outputting them as an entry; A CAM register for outputting to the CAM to store entries of the source address and the switch board number; Characterized in that comprises a.

The CAM may include an address table storing entries of the source address and the switch board number; It includes, characterized in that the storage and updating is performed in parallel between each switch board.

In addition, a first step of storing an entry of the physical address and the switch board number of each computer in the workgroup Ethernet LAN in an address table in the CAM; A second step of determining, by the switch module, if the frame according to the data transmission request is transmission in the corresponding switch board; A third step of transmitting a frame through the corresponding switch port in the switch module if the transmission is to the same switch board, and receiving a corresponding switch board number at the receiving address in the frame from the central processing unit if the transmission is to the other switch board; Transmitting a frame to the switch board; It includes.

Herein, in the second step, the switch module transmits a network management (NM) frame to an internal address manager to form an entry of a source address and a corresponding switch board number in a frame; Comparing the entry with the corresponding entry in the CAM and updating the corresponding entry in the CAM of each switchboard if different; It characterized in that it further comprises.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic configuration diagram of a workgroup Ethernet LAN including a workgroup Ethernet LAN switching device using a CAM according to the present invention. As shown in the figure, the workgroup Ethernet LAN switching device 1 using the CAM according to the present invention is a switch board (Switch Board, 100) and the switch port (Switch Port, 10 included in the switch board 100) ) And a computer connected to the switch port 10 in a one-to-one correspondence.

In addition, each switch board 100 includes a predetermined number of switch ports 10, which may be changed according to the specifications of each switch board 100, and one switch board 100 may be connected to a plurality of users. It includes a plurality of switch ports 10 provided to be connected.

For example, if the number of switch ports 10 included in one switch board 100 is 12, it supports 12 ports, so that 12 network users can be connected to the switch board 100. will be.

That is, 12 network users connected to switch board 1 (100 (1)) are connected to the network users' computers from switch port 1 (10 (1)) to switch port 12 (10 (12)), respectively. Data can be transmitted and received by switching between 12 persons connected to Switchboard 1 (100 (1)).

In other words, when transmitting the frame from the first computer of the switch board 1 (100 (1)) whose physical address is A11 to the Nth computer of the switch board 1 (100 (N)) whose physical address is A1N, Since it is connected to the first switch port 1 (10 (1)) and A1N is connected to the Nth switch port N (10 (N)), the frame is transmitted and received within the same switch board 1 (100 (1)). The switch module (not shown), which is the upper node of each switch port 10, may transfer the frame of A11 to A1N.

In addition, when the number of users increases, the switch board 100 includes a plurality of switch boards 100 in accordance with the expansion of the network to switch the data transmission and reception between the plurality of switch boards 100. The stack type switch board 100 capable of data communication between the plurality of switch boards 100 is used.

Here, like the switch board 100, each switch board 100 includes a predetermined number of switch ports 10, which can be changed according to the specifications of each switch board 100, one switch board ( 100 includes a plurality of switch ports 10 provided to be connected to a plurality of users.

For example, if the number of switch ports 10 included in one switch board 100 is 12 and the number of switch boards 100 included in workgroup Ethernet LAN switch equipment 1 is 12, a total of 144 It can contain up to 144 network users, which can accommodate 144 computers.

That is, 12 network users connected to Switch Board 1 (100 (1)), as well as 12 users in Switch Board 1 (100 (1)), Switch Board 2 (100 (2)), Switch Board 3 (100 ( 3), ..., data can be transmitted and received to each user's computer of the switch board 12 (100 (12)).

In other words, when transmitting a frame from the first computer of the switch board 1 (100 (1)) whose physical address is A11 to the Nth computer of the switch board N (100 (N)) whose physical address is ANN, The ANN is connected to the first switch port 1 (10 (1)) and the Nth switch port N (10 (N)) of different switch boards, and each switch board 100 is connected to an expansion port, so that the switch Frames can be sent and received between boards.

Here, the first # of A ## defines the switch board, the second # is defined by the switch port, and A ## is defined as the physical address of the computer.

2 is a block diagram schematically illustrating a switch board of a workgroup Ethernet LAN switching device using a CAM according to the present invention. As shown in the figure, the switch board 100 according to the present invention includes a plurality of switch ports 10, a switch module 20, a central processing unit 30, an expansion port 40, and an internal address management unit 50. ) And the CAM 60.

Herein, the number of switch ports 10 is defined as N. The number N of switch ports 10 supported according to the specification of the switch board 100 (1) may be changed, and the switch port 10 and Computers of network users are connected to correspond one-to-one, and the number of computers is equal to the number of switch ports 10.

In addition, the switch module 20 transmits and receives the switch port 10 in the form of an Ethernet frame, and transmits and receives the switch port 10 in the form of a general data frame, and transmits the same to the internal address manager 50. Parallel to the switching operation of the switch module 20 is transmitted in the form of NM frame for network management (NM: Network Management).

In addition, the switch module 20 receives an Ethernet frame through a switch port 10 to which an Ethernet frame including transmission data is input from each computer, and receives a destination address and a source address included in the Ethernet frame. If (Source Address) is a computer address connected to the switch port 10 of the same switch module 20, it is a data transmission between computers located in the same switch board 100 (1). The frame is transmitted to the connected switch port 10 so that the frame is transmitted to the computer having the corresponding address.

Here, the frame represents a package of information transmitted in a unit of information transmitted in data communication, such as a preamble, a synchronization signal, a reception address, which is an address of a destination computer receiving the frame, and a frame. It consists of a packet type that distinguishes the type of source address, TCP / UDP, etc. of the computer that transmits and transmits the data, data that is pure data to be transmitted, and CRC, which is a checksum for error detection.

In addition, when the reception address and the source address included in the Ethernet frame are not a computer address connected to the switch port 10 of the same switch module 20, the communication is data communication between the switch boards 100 and the switch module 20. Since the frame cannot be transmitted, the frame is transferred to the CPU 30.

In addition, the CPU 30 queries a CAM (Content Address Memory) 60, which is a content addressing memory, about a frame that cannot be transmitted by the switch module 20 with a destination address in the frame. In response to outputting a switch board number (#) connected to a computer having a reception address in an address table in which a reception address and a switch board number are listed as entries in the CAM 60 as a response, the switch board number (#) Is input from the central processing unit 30 and outputs the frame to the expansion port 40 to transmit the frame to the switch board.

In addition, the expansion port 40 receives the corresponding switch board number (#) according to the destination address (Destination Address), and outputs the frame to transmit the frame only to the corresponding switch board (100).

When the computer connected to the plurality of switch ports 10 is booted, the internal address manager 50 propagates its address through a broadcast packet to the network to inform its existence for network access. Receives the physical address of the computer connected to the switch port 10, combines the entry with the number (1) of the switch board 100 (1) to which the computer is connected, and outputs it to be registered in the CAM 60.

Here, the entries are connected in parallel so as to be stored not only in the CAM 60 but also in each CAM 60 of each switch board 100 (1), ..., 100 (N) and outputted from the internal address manager 50. The contents are stored simultaneously in the CAM 60 of each switch board 100 (1), ..., 100 (N).

For example, assuming that the entry output from the internal address management unit 50 of the switch board 1 (100 (1)) is (A, B), the CAM 60 of the switch board 1 (100 (1)) is described above. Since the entries A and B are stored, as well as the CAMs 60 are connected in parallel, they are also stored in the CAMs 60 of the respective switch boards 100 (2), ..., 100 (N), and the switch board 3 ( Assuming that the entry output from the internal address management unit 50 of 100 (3) is (C, D), the entry (C, D) is stored in the CAM 60 of the switch board 3 (100 (3)). Of course, since the CAM 60 is connected in parallel, it is also stored in the CAM 60 of each switch board 100 (1), 100 (2), 100 (4) ..., 100 (N) and all switch boards ( (A, B) (C, D) are tabled and stored in 100 (1), ..., 100 (N)).

Therefore, if each computer connected to each switch board (100 (1), ..., 100 (N)) is stored in all CAM 60 at the address of the corresponding computer, switch board 1 (100 (1)) The entries of (A11, 1), ..., (A1N, 1), which are the physical addresses of the computers and the number of the switch boards, are output from the internal address management unit 50, and the respective switch boards 100 (2), ... The entry of each switch board 100 (2), 100 (N) is also stored in the CAM 60 of 100 (N), and each switch board 100 (1), 100 (3) is also stored. , (A1,1), (A1N, 1), (A21,2) ... (A2N, 2), (A31,3) ... (A3N) All entries of (AN1, N) (ANN, N) are stored in all switch boards 100 (1), 100 (N).

Also, when an Ethernet frame from each computer is input to the switch module, the computer of the receiving address included in the frame is in the switch board 100, such as the computer of the source address, or of the receiving address contained within the frame. In both cases in which the switch board 100 is different from the computer of the source address, the switch module 20, which is the upper node of the computer of the source address, transmits an NM frame to the internal address manager 50.

Due to the above operation, all computers in the network store the computer address and the number of the switch board to which the computer is connected as an entry in the CAM 60 when booting, but changes such as replacing the main body while the network is running may occur. Therefore, when the NM frame is input to the internal address manager 50 to update it to the CAM 60, the internal address manager 50 uses the source address and the switch board number (#) of the frame as entries. Combine, output the entry to the CAM 60, and if the entry is the same as the entry of the CAM 60 (if no changes such as replacing the body have occurred), the entry is not updated. If is not the same as the entry of the CAM 60 (when a change such as replacing the body occurs), the entry is updated with the entry.

The CAM (Content Addressable Memory) 60 is a content addressable memory device that addresses and accesses actual data contents when storing or reading data in the storage device. The processing speed and accessibility are higher than those of general storage devices (SRAM and DRAM) that perform phosphorus retrieval.

Here, since the addresses of the computers connected to all the switch ports 10 and the corresponding switch board number (#) are stored in the CAM 60 as an entry, they are transmitted from the central processing unit 30 to another switch board 100. If you enter a destination address in a frame to be queried, you can search for the corresponding switch board number (#) entered by entering the destination address instead of comparing it sequentially. It has high processing speed and easy access.

As described above, when a change of the computer body or the like occurs, even in the entry update process in the address table, the search for comparison with the previous data is not a general storage device (SRAM, DRAM) but a CAM. By performing through, it has a high processing speed and accessibility.

3 is a conceptual diagram schematically showing a switch board of a workgroup Ethernet LAN switching device using a CAM according to the present invention. As shown in the figure, in the workgroup Ethernet LAN switching device 1 according to the present invention, a plurality of switch boards 100 (1),. It is made to send and receive.

The switch board 100 includes a plurality of switch ports 10, a switch module 20, a central processing unit 30, an expansion port 40, an internal address manager 50, and a CAM 60. .

Here, a computer of a network user is connected to the switch port 10, and the number of computers is equal to the number of the switch ports 10.

In addition, the switch module 20 processes the frame within the switch module 20 or transfers the frame to the central processing unit 30 according to a reception address in the frame that is the destination to which data is transmitted. The NM frame for supporting NM (Network Management), which is output separately in parallel with the switching process, is transmitted to the internal address manager 50.

In this case, if the receiving address is a computer address in the same switch board 100 (1), the switch module 20 transmits the frame to the corresponding computer, and if the receiving address is a computer address in another switch board 100 (#). Since the frame cannot be transmitted from the switch module 20, the frame is transmitted to the CPU 30.

The CPU 30 queries the CAM 60 for a frame that cannot be transmitted by the switch module 20 with a destination address in the frame, and in the address table in the CAM 60. When the switch board number (#) is output as a response, the frame is output to the expansion port 40 to receive the switch board number (#) from the central processing unit 30 and transmit the frame to the corresponding switch board. .

In addition, the expansion port 40 receives the corresponding switch board number (#) according to the destination address (Destination Address), and outputs the frame to transmit the frame only to the corresponding switch board (100).

When the computer connected to the plurality of switch ports 10 is booted, the internal address manager 50 propagates its own address through a broadcast packet to the network to inform its presence for network access. Receives the physical address of the computer connected to the switch port 10, combines the entry with the number (1) of the switch board 100 (1) to which the computer is connected, and outputs it to be registered in the CAM 60.

To this end, the internal address manager 50 includes a source address extractor 51, a switch board number combiner 53, and a CAM register 55.

Here, the source address extractor 51 extracts a source address from the NM frames transmitted from the switch module 20, combines the source address and the switch board number in the switch board number combiner 53 as an entry, and the CAM The register 55 outputs an entry to the CAM 60 and to all CAMs 60 connected in parallel.

In addition, when the switch module 20 processes all the Ethernet frames input from its switch port 10 inside the switch module 20 or when the transfer to the central processing unit 30 to process, The NM frame for NM (Network Management) support, which is output separately from the switch module 20 in parallel with the switching process, is transmitted to the internal address manager 50, in which case the internal address manager 50 has a change in the frame. And outputs it to be updated to the CAM 60.

In addition, since the address of the computer connected to the switch port 10 and the corresponding switch board number (#) are combined and stored as an entry, the CAM 60 inputs the receiving address in the frame as a query, and the corresponding switch board Search for the number (#) and print it out.

In addition, when a change such as a replacement of the main body of the computer occurs, as described above, the internal address manager 50 receives an NM frame for NM (Network Management) from the switch module 20, and uses the CAM 60 to use it. By comparing with an existing entry value of), an entry in the address table is updated.

4 is a diagram conceptually illustrating a process of forming an address table of a workgroup Ethernet LAN switching apparatus using a CAM according to the present invention. As shown in the figure, the process of forming an address table of the workgroup Ethernet LAN switching apparatus according to the present invention starts when all the computers in the workgroup Ethernet LAN network are booted.

In the booting process, each computer transmits a broadcast packet to a switch port 10 connected to each computer in order to notify its existence (①).

When the broadcast packet is received by the switch module 20 (2), the broadcast packet is a broadcast packet that is received by all the computers of the network, so that the switch module 20 has all of its own switch ports 10 and the center. Delivering a broad packet to the processing device 30, and in parallel with the switching process, delivers the NM frame for NM (Network Management) to the source address extractor 51 of the internal address management unit 50 (③), The source address extractor 51 extracts each computer address A11,..., A1N and outputs it to the switch board number combining unit 53 (④). In the switch board number combining unit 53, the computer address ( A11, ..., A1N) and the switch board number (#) are combined into entries [(A11, #), ..., (A1N, #)] and output to the CAM register 55 (5).

The CAM register 55 also outputs the series of entries to be stored in the address table tabled in the CAM 60 of all the switch boards 100 (1), ..., 100 (N) (6).

Here, as in the case of the switch board 1 (100 (1)), the same process as above occurs in the remaining switch boards 100 (2), ..., 100 (N), and thus all switch boards 100 (1), ..., 100 (N)) completes storing of all computer addresses and the numbers of the switch boards to which the computer is connected (⑦).

5 is a diagram conceptually illustrating a frame transmission process within a switch board of a workgroup Ethernet LAN switching apparatus using a CAM according to the present invention. As shown in the figure, the frame transmission in the same switch board according to the present invention is as follows.

Here, it is assumed that the address of the transmitting computer transmitting the frame including the data to be transmitted is A11, and the address of the receiving computer receiving the frame is A1N-1.

Then, the first computer connected to the switch board 1 (100 (1)), that is, the computer with the address of A11, enters A11 as its source address in the source address, and A1N-1 as the computer address to receive the frame in the destination address. Inputs and outputs a frame in which data to be transmitted and packet type are input to switch port 1 (10 (1)) (①).

In addition, switch port 1 (10 (1)) transmits to the switching module 20 provided for transmitting the frame by switching (②), and switch board 1 (100 (1)) to the receiving address A1N-1. It is determined that the computer in the ()), and transmits the frame to the switch port N-1 (10 (N-1)) (③).

Here, since the switch port N-1 (10 (N-1)) receiving the frame is connected to a computer having an address A1N-1, data transmission is completed by transferring the frame to the computer.

At this time, the switch module 20 outputs an NM frame for NM (Network Management), which is output separately in parallel with the above switching process, to the source address extracting unit 51 of the internal address management unit 50, thereby providing a source address ( A11) to extract (④), and transfer it to the switch board number combining unit 53 and combine it into an entry of (A11,1) (⑤) and deliver it to the CAM register 55, in the CAM register 55 Outputs to the CAM 60 of all switch boards 100 (1, ‥‥, 100 (N)) as well as the CAM 60 of the switch board 1 (100 (1)), and compares the entries with existing entries. (⑥) If there is a change, update it, and if it is the same, the process ends without change.

6 is a diagram conceptually illustrating a frame transmission process between switch boards of a workgroup Ethernet LAN switching apparatus using a CAM according to the present invention. As shown in the figure, a method of transmitting a frame to another switch board according to the present invention is as follows.

Here, it is assumed that the address of the transmitting computer transmitting the frame including the data to be transmitted is A11, and the address of the receiving computer receiving the frame is A4N.

In the first computer connected to the switch board 1 (100 (1)), that is, the computer with the address of A11, A11, which is its address, is input to the source address, and A4N, which is the computer address to receive the frame, is input into the receiving address. And outputs a frame in which data to be transmitted and packet type are input to switch port 1 (10 (1)) (①).

In addition, at switch port 1 (10 (1)), a switch for determining whether the frame is to be delivered in the same switch board 1 (100 (1)) or to another switch board (100 (#)). The frame is transmitted to the module 20 (②).

Since the switch module 20 is not a computer in the switch board 1 (100 (1)) by the reception address A4N, the switch module 20 is not a frame that can be transmitted from the switch module 20, so that the expansion port 40 is used. Transfer to the central processing unit 30 so that it can be transmitted to the other switch board (100 (#)) through (③).

Here, the central processing unit 30 requests a response to the CAM 60 in response to the receiving address A4N (④), and in the CAM 60 a computer having the receiving address A4N is connected to a switch board 100. It outputs switch board number (#) in response so that it is connected to (#)).

Thus, the switch board number (#) is output as 4, and it is transmitted to the expansion port 40 together with the frame (6), and each switch board 100 (1) connected to the expansion port 40 is ... Instead of delivering the frame to (N), the frame is transferred only to the switch board 4 (100 (4)) (⑦).

In addition, the switch board 4 (100 (4)) receiving the frame transmits the frame to the central processing unit 30 through the expansion port 40 (⑧), and the central processing unit 30 switches the module. (9), find a switch port to which a computer having a receiving address (A4N) is connected in the switch module 20 responsible for switching between computers connected within the switch board 4 (100 (4)) by switching. By transmitting the frame (i), data reception is completed.

At this time, the switch module 20 outputs an NM frame for NM (Network Management) which is separately output in parallel with the above switching process to the source address extracting unit 51 of the internal address management unit 50, and thus the source address ( A11) to extract, transfer it to the switch board number combining unit 53, combine it into an entry of (A11, 1), and transfer it to the CAM register 55, and the corresponding switch board 1 (100) in the CAM register 55. When not only the CAM 60 of (1), but also the CAM 60 of all switch boards 100 (1), ..., 100 (N) are output, the entries are compared with existing entries, and there are changes. If it is the same, the process is terminated without change.

7 is a flowchart schematically illustrating a workgroup Ethernet LAN switching method using a CAM according to the present invention. As shown in the figure, the workgroup Ethernet LAN switching method using the CAM according to the present invention starts by booting a computer in the workgroup LAN (S11).

Here, the entry of the physical address and the switch board number of each computer in the booted network is stored in the address table in the CAM (S13), and it is checked whether there is a data transmission request (S20).

If there is a data transmission request in step S20, the switch module determines the received address and source address of the input Ethernet frame through an address table made of computer addresses connected to its switch port inside the switch module ( S21), this is a step of confirming whether the computer of the receiving address and the computer of the source address are connected to the same switch board, and if the computer of the receiving address and the computer of the source address are connected to different switch boards, The frame is transmitted to the central processing unit (S22).

Further, the frame transmitted in the step S22 is queried by the central processing unit to the CAM with a receiving address to obtain a switch board number to which the computer of the receiving address is connected as a response (S23).

Then, the frame is transmitted through the expansion port to the switch board number to complete the transmission (S24).

Here, in step S21, if the computer of the receiving address and the computer of the source address are connected to the same switch board, the frame is transmitted to the computer corresponding to the receiving address (S25).

In parallel with the switching process such as step S22 and step S25, the switch module 20 outputs an NM frame for network management (NM) for an Ethernet frame entered through the switch port 10. The internal address manager extracts a source address from the NM frame and combines the source address with the switch board number (S31).

Then, a comparison is made with the entries of the source address and the switch board number of the address table in the CAM (S33), and it is checked whether the corresponding entry in the address table and the entry generated in the step S31 are the same (S35).

At this time, if it is not the same, the existing entry is updated with the generated entry (Update, S37), and if it is the same, the existing entry is maintained.

In addition, it is checked whether there is no more data transmission request in the workgroup Ethernet LAN (S40). If there is no data transmission request, the switching method according to the present invention is terminated, and if the transmission request occurs, the step ( Return to S20).

In the above description of the preferred embodiments of the present invention by way of example, the scope of the present invention is not limited only to these specific embodiments and those skilled in the art are appropriate within the scope described in the claims of the present invention. It will be possible to change.

As described above, the present invention having the configuration as described above uses the CAM, which is a content addressing memory, on the switch board of a workgroup Ethernet LAN switching device, and the address table of each computer as an entry table to all switch boards. By registering in parallel, the bottleneck caused by traffic for address table creation between switch boards is reduced, accessibility and processing speed can be increased by searching by contents, and frames are transmitted only to the corresponding switch board using CAM address table. Thereby, the effect, such as the efficient use of a switching device, can be achieved.

Claims (5)

A switch port for inputting and outputting frames for data transmission and reception from each computer connected in a workgroup Ethernet LAN; A switch module for transferring a frame according to a reception address in a frame that is a destination to which data is to be transmitted; An internal address manager for outputting, as an entry, a source address in a frame, which is a source for transmitting data, and a number of a switch board including each component; A content addressing memory (CAM) for storing and updating entries of source addresses and switch board numbers; A central processing unit for querying a source address and receiving and outputting a corresponding switch board number; Expansion ports interconnected to forward frames to the corresponding switch board number; Workgroup Ethernet LAN switching device using a CAM comprising a. The method of claim 1, The internal address management unit A source address extractor for extracting a source address in an NM frame; A switch board number combiner for combining the switch board number and the source address and outputting them as an entry; A CAM register for outputting to the CAM to store entries of the source address and the switch board number; Workgroup Ethernet LAN switching device using a CAM, characterized in that comprises a. The method of claim 1, The CAM is An address table storing entries of the source address and the switch board number; It includes, Workgroup Ethernet LAN switching device using a CAM, characterized in that the storage and update is connected in parallel between each switch board. A first step of storing an entry of a physical address and a switch board number of each computer in the workgroup Ethernet LAN in an address table in the CAM; A second step of determining, by the switch module, if the frame according to the data transmission request is transmission in the corresponding switch board; A third step of transmitting a frame through a corresponding switch port in the switch module if the transmission is to the same switch board, and receiving a corresponding switch board number from the central processing unit to a receiving address in the frame at the transmission to the other switch board; Transmitting a frame to the switch board; Workgroup Ethernet LAN switching method using a CAM comprising a. The method of claim 4, wherein In the second step, The switch module transferring a network management (NM) frame to an internal address manager to form an entry of a source address in the frame and a corresponding switch board number; Comparing the entry with the corresponding entry in the CAM and updating the corresponding entry in the CAM of each switchboard if different; Workgroup Ethernet LAN switching method using a CAM characterized in that it further comprises.

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