KR100238425B1 - Destination address processing apparatus for high-speed message routing - Google Patents

Abstract

The present invention relates to a destination address processing apparatus for fast message routing, wherein a prefix value of a destination address of the input message is received every time a message is input, and a prefix value of the same value is stored in comparison with the prefixes stored therein. A matching address outputting means for outputting the matching address which is an address value of the address, a matching address value outputted from the matching address outputting means and a subscriber identification area value of the destination address are received, and the size of the matching address is compared to the prefix of the destination address; Classifies whether the value is stored in the local prefix area or the remote prefix area, and if the value is stored in the local prefix area, determines the corresponding route information table area according to the matching address, and responds in the route information table area by the subscriber identifier. Table with stored route information A table address generating means for outputting a table and outputting a table address storing output path information corresponding to a matching address value in a designated route information table area if the prefix of the destination address is a value stored in a remote prefix area, and outputting the matching address. A plurality of areas storing route information directed to each of the terminals using one-to-one correspondence with the respective prefixes stored in the local prefix area of the means and the respective prefixes stored in the remote area of the matching address outputting means. By including a route information table consisting of one area for storing route information directed to an allocated connectionless server or packet switch, the processing is simple and easy, network operation and management is easy, and a large packet switch is configured. Can simplify the address processing unit, and It has an easy-effect mass topology during network operation and management in accordance with that to achieve the screen.

Description

Destination address handling device for high-speed message routing

The present invention relates to a destination address processing apparatus for fast message routing.

In general, a connectionless network that provides a connectionless data service is composed of a connectionless server connected to an ATM switch and virtual connections connecting a connectionless server with a terminal and a connectionless server as shown in FIG. 1.

The terminal divides a message in which an ATM address of a destination is added to a header of information to be delivered to a destination into segments of a predetermined length in the form of ATM Adaptation Layer type 3/4 (AAL 3/4). After that, the ATM header including the connectionless server and the set virtual connection number is added to make an ATM cell and transmitted to the connectionless server.

At this time, the connectionless server analyzes the destination address of the cellized message and delivers the same to the terminal or other connectionless server connected to the same server.

If the message is divided into a plurality of AAL 3/4 cells, the segment type value included in the AAL header of the first cell constituting the message is a Begin Of Message (BOM) and a segment of the last cell. The shape value is set as End Of Message (EOM), and the segment shape value of the cell (s) constituting the middle is set as Continuation Of Message (COM).

If the message is composed of one cell, the segment type value is set to a single segment message (SSM), and if multiple messages are divided into cells and multiplexed through a single virtual connection, they are multiplexed at the receiving side. In order to recover the original message from the cells, the AAL header of each cell has a multiplexing identifier (MID) region.

Multiple cells constituting one message are assigned the same MID value, and when cells constituting multiple messages are multiplexed, cells constituting different messages are assigned different MID values.

On the other hand, the destination address of the message is composed of 64 bits as shown in FIG. 2, and the destination address area includes a 4-bit address type area indicating whether the destination of the message is a single address message or a group address to be delivered to multiple destinations. It consists of an E.164 address field defined in the International Telecommunication Union (ITU) of up to 15 digits (binary coded in 4 bits).

If the E.164 address value is less than 15 digits, fill in at the front, and all unused areas at the back are filled with ones.

The E.164 address is composed of a country code designating a country, a region code designating a region, and a subscriber number as shown in FIG. 2, where the country code and region code can be omitted. It should be possible to deliver a message entered with a value to the appropriate destination.

The conventional technology of processing routing in the connectionless server stores the address values of all subscribers that are provided with connectionless service to all connectionless servers and virtual connection numbers destined for the destination in the routing table, and then the message is sent to the connectionless server. When entered, the destination address of the message is retrieved from the routing table and delivered to the destination based on the search results.

This prior art is effective when there are few connectionless service subscribers, but when there are very many subscribers, each connectionless server must have a very large table, so it is not easy to retrieve the destination address from the routing table at high speed each time a message arrives. In addition, since complex search algorithms must be applied for high-speed search, it is difficult to implement in hardware, and thus there is a limitation in speed.

In addition, when a new subscriber is added or deleted, it is difficult to operate and manage the network because the routing table of all connectionless servers must be changed.

In addition, there is a conventional technology that processes a message input from a terminal directly connected to a server and a message received from another server to a separate device. For the messages received from the terminals, a destination connectionless server is selected among the destination address values. The server determines a destination server by searching only a portion of the determined area, and determines a terminal connected to a connectionless server by searching only a subscriber address area of a destination address for messages arriving from another server.

However, there is a problem in that it is inefficient to process two kinds of messages in different ways because two hardwares having similar functions are required.

In addition, even if the message input from the terminal should be delivered to the other terminal connected to the same connectionless server, there is another problem that the efficiency is lowered because it is sent back to the connectionless server through the other connectionless server or ATM switch.

The present invention devised to solve the above problems greatly reduces the number of items to be searched compared to the number of terminals so that a simple connectionless server can be easily configured even when there are a plurality of terminals, and a large capacity connectionless network is constructed. In this case, the purpose is to facilitate the operation or management of the network.

According to the present invention for achieving the above object, every time a message is input, only the prefix of the destination address of the input message is received, and the matching value is the address value of the location where the prefix value of the same value is stored compared with internally stored prefixes. A matching address output means for outputting an address, a matching address value output from the matching means output means and a subscriber identification area value of the destination address are inputted, and the size of the matching address is compared so that the prefix of the destination address is a local prefix area; Whether the value is stored in the local prefix area or the value stored in the local prefix area, and if the value is stored in the local prefix area, the corresponding route information table area is determined by the matching address, and the corresponding route information in the route information table area is determined by the subscriber identifier. Outputs the stored table address, and the destination address If the prefix is a value stored in the remote prefix area, the table address generating means outputs a table address storing output path information corresponding to the matching address value in the designated route information table area, and each prefix stored in the local prefix area of the matching address outputting means. To a connectionless server or packet switch to which a plurality of areas for storing route information directed to each of the terminals using one-to-one correspondence with the corresponding prefix values and each prefix stored in the remote area of the matching address outputting means are allocated. It characterized in that it comprises a route information table consisting of one area for storing the route information.

According to the present invention, when a message is input to a connectionless server in a virtual connectionless network including a plurality of connectionless servers in an ATM network, only a prefix among ATM addresses in a message header is searched first, and the message is connected to a terminal connected to the connectionless server. Determining whether it should be delivered or transmitted to a non-connected server, and for a message to be transmitted to a non-connected server, finds the output virtual connection number only by the prefix search result, and sends the message to the terminal directly connected to the server. For, the output virtual connection is found by the prefix search result and the subscriber identifier.

In addition, when searching for a destination address, the number of entries to be searched should be limited to a certain number regardless of the number of terminals so as to enable a fast search by hardware. In order to avoid hardware redundancy in one connectionless server, You should be able to process messages entered from other servers and messages entered from other servers in the same way.

In the present invention, when a message is input to a connectionless server, only the prefix portion of the destination address of the message is first searched to determine whether the destination should be delivered to a terminal connected to its own server or to another server, and the message to be delivered to another server. If the output virtual connection number can be found using the search result, and if the message is to be delivered to the terminal directly connected to the server, the virtual connection number can be found by outputting the search result and the subscriber identifier area value of the destination address. have.

In addition, the present invention is applied to a connectionless server or packet switch that delivers a message or packet to a destination based on a destination address to form a large capacity network, and requires a high-speed search by dividing the destination address value into a prefix and a subscriber identifier. In this section, only prefixes are searched to determine whether the final destination of the destination address is a terminal connected directly to a connectionless server or a packet switch, a connectionless server or a packet switch, and the route information for outputting the corresponding message or packet according to the result. This is the destination address processor that searches for.

In order to route messages or packets at high speed, the route information corresponding to the destination address must be quickly retrieved.

1 is a configuration of a connectionless network using a connectionless server in the ATM network,

2 is a block diagram showing an address in the form of an E.164 address;

3 is a block diagram illustrating a structure of an address form processed by a connectionless server according to the present invention;

4 is a configuration diagram of a connectionless server processing in units of cells;

5 is a block diagram showing a correspondence relationship between a matching address output means for routing and output path information in the present invention;

6 is a block diagram of a destination address processing means for routing in the present invention;

7 is a block diagram of a table address generating means of the present invention.

In the present invention, for this purpose, E.164 addresses of the same length are allocated to all terminals used in the connectionless network, and a certain length of the front including an address type region and a part of the subscriber number is defined as a prefix as shown in FIG. The remaining area of is defined as subscriber identifier.

When a message is input to the server, the prefix portion of the destination address is first searched, and then the server to which the destination terminal is connected is determined. When the destination is a terminal directly connected to the server, the final destination is determined by the subscriber identifier region value.

In the present invention, a terminal connected to a connectionless server located in a different area or a plurality of connectionless servers located in the same area must be assigned a prefix value of a different value, and the terminals connected to one connectionless server may have a plurality of different connections. Prefixes can be assigned, but the number of available prefixes is limited within a certain value.

4 shows a configuration example of a connectionless server to which the present invention is applied.

This connectionless server handles AAL 3 / 4-celled messages on a cell-by-cell basis, ie multiple cellized messages are multiplexed so that the input cells pass through the header replication means while the BOM or SSM contains the destination address of the message. Duplicate the VPI, VCI, MID and destination address values of the cell and transfer the destination address values to the destination address processing means. The VPI, VCI and MID values are stored in the search area of the header translation table, and the destination output from the destination address processing means. The MIDo output from the VPIo, VCIo and MID generating means corresponding to the address is stored in the output area at the same position of the header conversion table.

The MID generating unit receives VPIo and VCIo and allocates and outputs MIDo values not used in the virtual connection.

Accordingly, all the cells pass through the header replication means without any change, and are transmitted to the delay means. In the delay means, the destination addresses of the messages constituting the cell passing through the delay means are processed by the destination address processing means, and the corresponding VPIo, VCIo and It temporarily stores cells until MIDo is stored in the header translation table.

That is, the cell is delayed until the information for header conversion is prepared in the header converting means, and then transferred to the header converting means.

In the header converting means, the VPI, VCI, and MID values of the input cell header are searched in the search area of the header conversion table, and the VPIo, VCIo, and MIDo values are read from the output area of the corresponding position, and the cell header is replaced with this value. After that, the cell is output.

In addition, if the processed cell is the EOM constituting the end of the message or SSM which is a single cell message, the header conversion table removes the information used for the cell header conversion from the header conversion table.

This operation reads the destination address from the cell containing the destination of the message and changes the cell header value to the MIDo value to distinguish the multiplexed message on the same virtual connection as the VPIo and VCIo, the virtual connection numbers destined for the destination. The cells to be configured can be delivered to the destination terminal.

Since the present invention is applied to the destination address processing means, the present invention can be applied not only to a cell unit processing method but also to a connectionless server processing a message unit.

5 is a structural example showing the operation of the destination address processing means of the present invention.

The matching address outputting means stores the prefixes of the address values used in the connectionless network.When the prefix of the destination address is input, the address of the area in which the prefix stored in the matching address outputting means is stored and the prefix having the same value as the inputted prefix is stored. Outputs a matching address as a value.

In addition, the route information table stores a VPIo value and a VCIo value, which are virtual connection numbers directed to a terminal or another server connected to a server. That is, the matching address outputting means and the route information table perform a function of a routing table for determining a virtual connection for outputting a message according to a destination address value of a message inputted to a connectionless server.

The matching address outputting means may be divided into a local prefix area for storing prefixes of addresses assigned to terminals directly connected to the server itself, and a remote prefix area for storing prefixes of addresses assigned to terminals connected to non-connected servers. It is.

In the example of FIG. 5, it is assumed that terminals directly connected to the server use four prefixes. In this case, the prefixes stored in the local prefix area of the matching address outputting means are each area from area 1 to area 4 of the route information table. 1 and 1 correspond to each other, and each prefix stored in the remote pyrifix area corresponds one to one with each entry in the route information table area 5. FIG.

Since the prefixes assigned to the terminals directly connected to the server are shared by a plurality of terminals, the virtual connection directed to the terminal must be found by the subscriber identifier of the destination address.

Therefore, if the prefix value inputted to the matching address outputting means is equal to any value stored in the local prefix area, the corresponding area of the route information table is determined by the matching address value, and the corresponding entry in the area is determined by the subscriber identifier of the destination address, That is, it reads and outputs the virtual connection numbers VIPo and VCIo to be output.

The size of each area (area 1 to area 4) of the route information table corresponding to the entry stored in the local prefix area is determined by the size of the subscriber identifier. In other words, if the size of the subscriber identifier is 3 digits, each area must have a size that can accommodate as many entries (2048) as the number of 12-bit combinations.

However, since each digit of the actual subscriber identifier uses only 0 to 9, a maximum of 1000 combinations used effectively by the 3-digit subscriber identifier are used.

Therefore, by changing the subscriber identifier coded by Binary Coded Decimal (BCD) to binary in the table address generating means, generating the path information table address, the size of the area corresponding to each prefix can be reduced to less than half. .

If the prefix value of the input destination address is the same as any value stored in the remote prefix area of the matching address outputting means, the message with the destination address must be delivered to the non-connected server to which the terminal using the prefix is connected. Regardless of this, the corresponding entry in area 5 of the route information table is read and output.

Accordingly, each prefix stored in the remote prefix area of the matching address outputting means has a one-to-one correspondence with each entry stored in the area 5.

The size of the local prefix area of the matching address output means is set to the maximum number that can be allocated to the terminals connected to one server. If the number of prefixes actually used is smaller than the size of the area, the unused area is invalid. ) Or enter a value greater than 9 for each digit that is not used in the prefix.

In the present invention, when a terminal is added to or deleted from a specific server, the virtual connection number needs to be added or deleted only in the path information table of the server where the addition or deletion is performed, and the operation and management of the network is easy because it does not affect other servers. .

6 shows a configuration of a destination address processing means to which the present invention is applied.

Only the prefix portion of the destination address inputted to the destination processing means is inputted to the matching address outputting means to search whether there is a value equal to the values stored in the matching address outputting means.

The matching address outputting means outputs the address value (matching address) of the matching address outputting position in which the prefix value equal to the input prefix value is stored, and the table address generating means is a subscriber of the matching address and the destination address which are outputs of the matching address outputting means. Inputs the identifier value and outputs the route information table address where the virtual connection number to which the message with the input destination address is displayed is stored. In the route information table, the VPIo and VCIo stored at the designated location are output.

7 is a configuration example of the table address generating means in the case of having a 3-digit subscriber identifier and a matching address which is an output of an 8-bit matching address output means.

A 15-bit address value made by outputting the selector for selecting the lower k bits (3 bits in the example of FIG. 7) of the matching address, which is the output of the matching address output means, as the upper bit and the input 12-bit subscriber identifier as the lower bit. In the input 1 of the selector, the base address indicating the start address of the area storing the virtual connection numbers set with the other server (area 5 of the route information table in the example of FIG. 5) and the matching address which is the output of the matching address outputting means. Inputs the 15-bit address created by adding the binary adder to input 2 of the selector.

In addition, the size determiner determines the size of the matching address that is the output of the matching address output means and determines whether the prefix of the destination address input to the matching address output means is a value stored in a local prefix area or a remote prefix area. Determine if it is.

The determination result thereof is input to the selector, and selects an appropriate input among the two inputs of the selector and outputs it as a table address value. That is, when the first four entries of the matching address output means are designated as the local prefix area as shown in FIG. 5, when the matching address value is 4 or less, the virtual connection number directed to the terminal directly connected to the server by combining the matching address and the subscriber identifier is shown. Select input 1, which is a stored address, and output it. If the matching address value is 5 or more, select input 2, which is an address value that stores a virtual connection number directed to another server, and output it as a table address value.

According to the present invention as described above, the number of prefixes processed by the matching address output means is much smaller than the number of terminals connected to the connectionless network, so that the processing is simple and speedy, and a large capacity network is possible even with a simple configuration. You can configure a connectionless server that can be applied to the configuration.If a terminal is added or deleted to a specific server, the virtual connection number must be added or deleted only in the route information table of the connectionless server where the addition is deleted. This has no effect on the network and has the effect of facilitating the operation or management of the network.

In addition, the present invention can be applied to the packet switch to determine the output path according to the destination address value as well as the connectionless server, it is possible to configure a large-capacity packet switch by searching the path information of the packet at high speed.

When routing is performed in this manner, the connectionless server needs to search only the prefixes used in the connectionless network instead of the addresses of all the terminals connected to the connectionless network, so the number of entries to be searched in a large network configuration is easy to implement.

Also, since the message input from the terminal and the message input from another server are processed by one device, the connectionless server can be simply configured as compared to the conventional method of dividing and processing into a separate device.

Accordingly, the present invention requires only changing the routing table of the connectionless server to which the changed terminal belongs even when adding / deleting a terminal, and does not require any modification to the routing table of another server. There is an easy advantage.

In the present invention, an address is allocated to have a different value of prefix for each connectionless server or packet switch, and the prefix is searched first in the connectionless server or packet switch so that the number of entries to be searched even in a large network configuration is determined by the number of terminals. By greatly reducing the number, the address processing apparatus can be simplified and speeded up, and network operation and management can be easily performed even when constructing a high speed large capacity network.

Claims (2)

Matching address output means for receiving only the prefix among the destination addresses of the input message and outputting the matching address which is the address value of the location where the prefix value of the same value is stored each time a message is input; The matching address value outputted from the matching address output means and the subscriber identification area value of the destination address are input to compare the size of the matching address to determine whether the prefix of the destination address is a value stored in a local prefix area or a remote prefix area. If the value is stored in the local prefix area, and determines the route information table area corresponding to the matching address, and outputs the table address in which the corresponding route information in the route information table area by the subscriber identifier, Table address generating means for outputting a table address storing output path information corresponding to a matching address value in a designated path information table area if the prefix is a value stored in a remote prefix area; A plurality of areas that store one-to-one correspondence with respective prefixes stored in the local prefix area of the matching address outputting means and to each of the terminals using the corresponding prefix value and stored in the remote area of the matching address outputting means. The destination address processing apparatus for high-speed message routing, characterized in that each prefix is composed of a route information table consisting of one area for storing route information directed to an allocated connectionless server or packet switch. According to claim 1, wherein the table address generating means, A lower bit selector for selecting a predetermined lower bit group determined by the size of the local prefix area among the input matching addresses; An address combiner which makes the lower bit selector output an upper bit and combines the input subscriber identifier into lower bits to produce an address value corresponding to the local prefix and the subscriber identifier; A binary adder for adding an address value corresponding to a remote prefix by adding a base address value and a matching address value, which are a start address of an area storing route information corresponding to the remote prefix area of the matching address outputting means; A size discriminator for comparing the size of the matching address value to determine whether the prefix of the destination address input to the matching address output means is a local prefix or a remote prefix and outputting a result; And A high speed selector configured to select and output an address value corresponding to a local prefix applied to a first input and a subscriber identifier or an address value corresponding to a remote prefix applied to a second input according to the output of the size discriminator Destination address processing unit for message routing.