KR100503423B1 - Memory mapping apparatus in multiple spanning tree protocol and method of the same - Google Patents

Abstract

A memory mapping apparatus and method in MSTP are disclosed. The memory stores information corresponding to the VALN identification information. The memory manager arranges the blocks in the memory such that the sum of the number of bits of each block is equal to or greater than the maximum number of VLAN identifications that the MST instance can accommodate. The calculating unit calculates the position of the bit corresponding to the VLAN identification information expressed as an integer one-to-one based on the number of bits. The mapping unit sets the bit corresponding to the calculated bit position to a predetermined logic state. By mapping each instance of MSTP and VLAN ID using a bitmap, the memory space required to store the VLAN ID is saved than the memory space required in the prior art.

Description

Memory mapping apparatus in multiple spanning tree protocol and method of the same}

The present invention relates to a memory mapping apparatus and method in MTP (Mutilple Spanning Tree Protocol), and more particularly, to a memory mapping apparatus and method relating to mapping relationship between an instance of MSTP and VLAN ID.

MSTP is a spanning tree protocol that provides a loopless path for a given VLAN based on a bridge network topology within a certain area. According to IEEE 802.1S, up to 64 instance IDs of MSTP can be supported, and up to 4096 VLAN IDs can be set for each instance.

In the conventional MSTP supporting system, at least 2 (VLAN ID) * 4096 (maximum number of VALN IDs) * 64 (maximum number of MSTP instances) = 524,208 bytes of memory space are required for VLAN ID mapping with each instance. In fact, MSTP has many data structures that need to be managed in addition to the instance and VLAN ID mapping tables. In fact, due to this memory usage problem, most of the conventional MSTP system equipment supports only 16 out of 64 instances.

An object of the present invention is to provide a memory mapping apparatus and method for efficiently saving memory for the mapping table of each instance and VLAN ID in MSTP.

Another technical problem to be achieved by the present invention is to provide a computer-readable recording medium having recorded thereon a program for executing a memory mapping method on a computer to efficiently save memory for each instance and VLAN ID mapping table in MSTP. There is.

In order to achieve the above technical problem, an embodiment of the memory mapping apparatus in the MSTP according to the present invention, a memory for storing information corresponding to the VALN identification information; A memory management unit for arranging the blocks in the memory such that the sum of the number of bits of each block is equal to or greater than the maximum number of VLAN identifications that the MST instance can accommodate; An operation unit calculating a position of bits corresponding to one-to-one correspondence with VLAN identification information expressed as an integer based on the number of bits; And a mapping unit which sets a bit corresponding to the calculated bit position to a predetermined logic state.

Another embodiment of the memory mapping apparatus in the MSTP according to the present invention for achieving the above technical problem is a memory in which a plurality of blocks including a predetermined number of bits are sequentially arranged; Bit search unit for sequentially searching the first block to the last block for the block of the memory, and sequentially searched from the first bit to the last bit for the bit of each block to read the position of the bit set to a predetermined logic state ; And an identification information calculation unit for calculating a VALN ID expressed as an integer based on the position of the block read by the bit search unit and the position of the bit.

In order to achieve the above technical problem, an embodiment of the memory mapping method in the MSTP according to the present invention determines the number of bits included in one block, and the sum of the number of bits in each block is the maximum that the MST instance can accommodate. Arranging blocks sequentially by determining the number of blocks to be equal to or greater than the number of VLAN identification information; Receiving VLAN identification information expressed as an integer value; Calculating a location of the bit corresponding to the received VLAN identification information based on the determined number of bits; And setting the calculated bit to a predetermined logic state.

Another embodiment of the memory mapping method in the MSTP according to the present invention for achieving the above technical problem, in the memory in which a plurality of blocks sequentially comprising a predetermined number of bits, from the first block to the block Searching sequentially to the last block, sequentially searching from the first bit to the last bit for each bit of the block, and reading the position of the bit set to a predetermined logic state; And calculating VALN identification information expressed as an integer based on the position of the read block and the position of the bit.

According to the present invention, by mapping each instance of MSTP and VLAN ID using a bitmap, the memory space required for storing the VLAN ID is saved than the memory space required in the prior art.

Hereinafter, a memory mapping apparatus and method in MSTP according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating an example of a bitmap memory structure according to the present invention.

Referring to FIG. 1, 64 MST instances 100 exist from ID 0 to ID 63, and each MST instance 100 includes 256 blocks 110, 120, and 130 from block 0 to block 255. Each block consists of 16 bits (112, 114). According to the present invention, the integer value of the input VLAN ID is mapped to a specific bit position corresponding to the integer value of the VLAN ID among the bits of the 256 blocks shown in FIG.

2 is a block diagram according to an embodiment of a memory mapping apparatus in MSTP according to the present invention for mapping integer values to bitmaps.

Referring to FIG. 2, the memory mapping apparatus according to the present invention includes a memory manager 200, an input unit 210, an operation unit 220, a mapping unit 230, and a memory 240.

The memory 240 stores a bitmap for VLAN identification information. The memory 240 may be configured as a storage space that stores only bitmaps. The memory may be a RAM, a ROM, or a memory device that uses magnetic, electrical or optical signals to store data. The memory 240 may be provided separately from the memory manager 200 or included as part of the memory manager 200.

The memory manager 200 determines the number of bits included in one block, and sequentially arranges the blocks by determining the number of blocks such that the sum of the number of bits of each block is equal to or greater than the maximum number of VLAN identification information that the MSTP instance can accommodate. As an example of the block arrangement, the memory manager 200 sequentially arranges 256 blocks including 16 bits in a memory or a memory device when supporting 4096 VLAN IDs. In addition, the memory management unit 200 may arrange 128 blocks including 32 bits to support 4096 VLAN IDs, and other combinations of bits and blocks may be possible. That is, the combination of bits and blocks may satisfy the condition that the sum of the number of bits in the array is equal to or greater than the maximum number of VALN IDs that each instance can accommodate.

The input unit 210 receives a VLAN ID corresponding to each instance 100 of the MSTP. According to IEEE 802.1S, up to 64 instance IDs of MSTP can be supported, and up to 4096 VLAN IDs can be set for each instance. Support for the maximum MSTP instance and VLAN ID may change as the standard changes. According to IEEE 802.1S, the VLAN ID is an integer value from 0 to 4095. The range of integer values may change in accordance with changes in the standard.

The calculator 220 calculates the quotient and the remainder by dividing the VLAN ID input by the input unit 210 by the number of bits determined by the memory manager 200.

The mapping unit 230 selects the position of the block based on the quotient calculated by the operation unit 220, determines the position of the bit in the block based on the remainder, and sets the bit in the determined block to 1. That is, if the position of the block starts from 1 and the position of the bit starts from 1, the position m of the block is 1 plus the quotient, and the position n of the bits in the block is 1 plus the rest. In this case, the mapping unit 230 sets the n-th bit of the m-th block to one.

For example, the VLAN ID is an arbitrary integer value between 0 and 4096, and when the memory manager 200 arranges 256 blocks including 16 bits in the memory, the input unit 210 serves as a VLAN ID. Suppose you have entered 20. The calculator 220 calculates the quotient 1 and the remainder 4 by dividing the input VALN ID 20 by the bit value. The mapping unit 230 selects the second block since the quotient is 1 plus 2, and the fifth block is selected because the remainder is 1 plus 5. The mapping unit 230 sets the fifth bit of the selected second block to one. If the position of the block starts at 0 and the position of the bit starts at 0, the position of the block is equal to the quotient and the position of the bit is equal to the remainder. In this way, the input integer value is mapped to the position of the bit.

The conventional memory space requires a minimum of 2 (VLAN ID) * 4096 (maximum number of VALN IDs) * 64 (maximum number of MSTP instances) = 524,208 bytes. Number) * 256 (number of blocks) * 64 (maximum number of MSTP instances) = 32,768 bytes of memory space are required. That is, it is possible to save about 1/15 of the conventional memory space.

3 is a block diagram according to an embodiment of a memory mapping method in MSTP according to the present invention for calculating a bitmap as an integer value.

Referring to FIG. 3, the memory mapping apparatus according to the present invention includes a memory 300, a bit searching unit 310, and an identification information calculating unit 320.

In the memory 300, a plurality of blocks including a predetermined number of bits are sequentially arranged, and each bit of each block is set to 0 or 1. The number of bits and the number of blocks are determined by the memory manager 200 of the memory mapping apparatus according to the present invention described with reference to FIG. 2. According to the IEEE 802.1S standard, MSTP supports 4096 VALN IDs, so that the number of bits can be 16 and the number of blocks can be 256. Other combinations of the number of bits and the number of blocks are possible.

The bit search unit 310 sequentially searches for the blocks arranged in the memory 300 from the first block to the last block, sequentially searches the first bit to the last bit of each block for the bit, and then positions the bits set to 1. Read out. That is, each bit is sequentially searched from the first bit of the first block to the last bit of the last block to read the position of the bit set to 1.

If the m-th bit of the n-th block selected by the bit search unit 310 is set to 1, the identification information calculating unit 320 subtracts 1 from n, multiplies the number of bits in one block, and adds m to the value calculated. Returns an integer value. That is, integer value = (n-1) * (number of bits in one block) + m. The integer value obtained is the VALN ID. The above process is performed from the first block to the last block to read the VLAN ID stored as a bitmap.

For example, the VLAN ID is an integer value between 0 and 4095, and the memory manager 200 arranges 256 blocks including 16 bits in the memory. In this case, it is assumed that the bit search unit 310 points to the fourth bit of the second block as the position of the bit set to one. The identification information calculating unit 320 calculates 1 (second block position-1) * 16 (number of bits in one block) + 4 (bit position) = 20. In this case, the VLAN ID is 20.

4 is a flowchart illustrating a memory mapping method in MSTP according to the present invention for mapping an integer value of a VLAN ID into a bitmap.

Referring to FIG. 4, the memory manager 200 includes 256 blocks for one MSTP instance and each block includes 16 bits (S400). The number of blocks and the number of bits may be determined such that the sum of the number of bits of each block is equal to or greater than the maximum number of VLAN identifications that the MSTP instance can accommodate. According to the IEEE 802.1S standard, when each MSTP instance supports 4096 VLAN IDs, the memory manager 200 arranges 16 bits and 256 blocks (S400). In addition, the memory management unit 200 may be arranged in 32 bits and 128 blocks, and other combinations of bits and blocks may be possible. That is, the combination of bits and blocks may satisfy the condition that the sum of the number of bits in the array is equal to or greater than the maximum number of VALN IDs that each instance can accommodate.

The input unit 210 receives a VLAN ID which is an integer value from 0 to 4095 (S410). According to IEEE 802.1S, up to 64 instance IDs of MSTP can be supported, and up to 4096 VLAN IDs can be set for each instance. The maximum MSTP instance and VLAN ID support size may change depending on changes in the standard. According to the IEEE 802.1S standard, the VLAN ID is an integer value from 0 to 4095. The range of integer values may change in accordance with changes in the standard.

The calculating unit 220 divides the received VLAN identification information by 16, which is the number of bits in one block, and calculates a quotient and remainder (S420). If the number of bits in one block is changed by the memory manager 200, the divisor 16 of the calculator 220 is changed.

The mapping unit 230 selects the position of the block based on the quotient calculated by the calculating unit 220, selects the position of the block as the bit position in the selected block based on the remainder, and sets the selected bit to 1 (S430).

For example, when the VLAN ID represented by an integer existing between 0 and 4095 is 20, the quotient and the remainder are 1 and 4, respectively, by the calculation unit 220. The mapping unit 230 selects the second block because the quotient is 1, and selects the fifth bit since the remainder is 4. Since the VLAN ID is an integer value from 0 to 4095, if the quotient is 0, the first block is indicated, and if the remainder is 0, the first bit is represented, the block and bit position are determined by adding 1 to the quotient and the remainder, respectively. .

Since the VALN ID is stored in a 1: 1 correspondence with each bit of the bitmap, the above-described calculation process of the block and the bit position may be calculated differently. In addition, when there is a memory including 257 blocks and 17 bits in each block, each quotient and remainder may be determined and used as the block position and the bit position as they are. have.

FIG. 5 illustrates another flow of the memory mapping method in the MSTP according to the present invention for calculating a bitmap as an integer value.

Referring to FIG. 5, 256 blocks including 16 bits are sequentially arranged in the memory 300, and each bit of each block is set to 0 or 1 (S500). The number of bits and the number of blocks are determined by the memory manager 200 of the memory mapping method according to the present invention described with reference to FIG. 4. According to the IEEE 802.1S standard, MSTP supports 4096 VALN IDs, so that the number of bits can be 16 and the number of blocks can be 256. Other combinations of the number of bits and the number of blocks are possible.

The bit search unit 310 sequentially increases the block positions from the first block to the last block of the memory 300. That is, the block positions are sequentially increased from the first block 0 to the last block 255 (S500). The bit search unit 310 sequentially increases the bit position from the first bit to the last bit of one block (S510). That is, the bit search unit 310 sequentially searches all bits from the first bit of the first block to the last block of the last block.

If the m-th bit of the n-th block retrieved by the bit search unit 310 is set to 1 (S520), the identification information calculation unit 320 calculates by multiplying the number of bits of one block after subtracting 1 from n. The integer value is obtained by adding m to the obtained value (S530). That is, integer value = (n-1) * 16 (number of bits in one block) + m (bit position). The integer value obtained is the VALN ID.

The invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, and may also be implemented in the form of a carrier wave (for example, transmission over the Internet). Include. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

The foregoing descriptions are merely illustrative of preferred embodiments, and the present invention is not limited to the above-described embodiments and can be variously changed within the scope of the appended claims. For example, the shape and structure of each component specifically shown in the embodiment of the present invention may be modified.

According to the present invention, by mapping each instance of MSTP and VLAN ID using a bitmap, the memory space required for storing the VLAN ID is saved than the memory space required in the prior art. In addition, since the size of the bitmap to which the VLAN ID is mapped can be easily extended, a large number of VLAN IDs can be easily supported. Since the bitmap is composed of blocks and bits, it is easy to manage and can be implemented with the number of blocks and the number of bits suitable for the performance of each system.

1 is a diagram illustrating an example of a bitmap memory structure according to the present invention;

2 is a block diagram of a memory mapping apparatus according to the present invention for mapping integer values to bitmaps;

3 is a block diagram of a memory mapping apparatus according to the present invention for calculating a bitmap as an integer value.

4 is a view showing a flow of a memory mapping method according to the present invention for mapping integer values to bitmaps, and

5 is a flowchart illustrating a memory mapping method according to the present invention for calculating a bitmap as an integer value.

Claims (11)

A memory for storing information corresponding to the VALN identification information; A memory management unit for arranging the blocks in the memory such that the sum of the number of bits of each block is equal to or greater than the maximum number of VLAN identifications that the MST instance can accommodate; An operation unit calculating a position of bits corresponding to one-to-one correspondence with VLAN identification information expressed as an integer based on the number of bits; And And a mapping unit configured to set a bit corresponding to the calculated bit position to a predetermined logic state. The method of claim 1, The calculating unit divides the VLAN identification information by the determined number of bits and calculates a quotient and remainder, The mapping unit selects a block position based on the quotient, and selects a bit position in the selected block based on the remainder to set the selected bit to a predetermined logic state. The method of claim 1, The identification information of the VLAN is an integer value between 0 and 4095, The number of bits is 16, the number of blocks is 256 The location of the selected block is the quotient plus one, and the location of the selected bit is the remainder plus one. A memory in which a plurality of blocks including a predetermined number of bits are sequentially arranged; Bit search unit for sequentially searching the first block to the last block for the block of the memory, and sequentially searched from the first bit to the last bit for each bit of the block to read the position of the bit set to a predetermined logic state ; And And an identification information calculation unit for calculating a VALN ID expressed as an integer based on the position of the block read by the bit searching unit and the position of the bit. The method of claim 4, wherein The identification information of the VLAN is an integer value between 0 and 4095, The number of bits is 16, the number of blocks is 256 The identification information calculating unit calculates an integer value by subtracting 1 from n and multiplying the number of bits by the m when the mth bit is read from the nth block by the bit searching unit. Memory mapping device in. Determining the number of bits included in one block, and arranging the blocks sequentially by determining the number of blocks such that the sum of the number of bits of each block is equal to or greater than the maximum number of VLAN identifications that the MST instance can accommodate; Receiving VLAN identification information expressed as an integer value; Calculating a location of the bit corresponding to the received VLAN identification information based on the determined number of bits; And And setting the calculated bit to a predetermined logic state. The method of claim 6, The calculating step includes calculating the quotient and the remainder by dividing the VLAN identification information by the determined number of bits. The setting step includes selecting a block position based on the quotient, and selecting a bit position in the selected block based on the remainder to set the selected bit to a predetermined logic state. Memory mapping method in. The method of claim 6, The identification information of the VLAN is an integer value between 0 and 4095, The number of bits is 16, the number of blocks is 256 The location of the selected block is the quotient plus one, and the location of the selected bit is the remainder plus one. In a memory in which a plurality of blocks including a predetermined number of bits are sequentially arranged, the blocks are sequentially searched from the first block to the last block, and the bits of each block are sequentially searched from the first bit to the last bit. Reading the position of a bit set to a predetermined logic state; And Calculating VALN identification information expressed as an integer based on the position of the read block and the position of the bit; and a memory mapping method of the MSTP. The method of claim 9, The identification information of the VLAN is an integer value between 0 and 4095, The number of bits is 16, the number of blocks is 256 The calculating may include obtaining an integer value by subtracting 1 from n and multiplying the number of bits by adding m to the m when the m th bit is read from the n th block by the reading step. Memory mapping method in MSTP. A computer-readable recording medium having recorded thereon a program for executing a memory mapping method in MSTP according to claim 6 or 9.