KR19980020689A - Cell relay and ed / drop device and method in active unidirectional dual bus - Google Patents

Abstract

The present invention relates to a cell relay and an ed / drop device and a method in a unidirectional duplex bus, using a simple multiplexing and a router structure rather than a switch structure to provide a requested service at a low price and to transfer service data between terminals. In order to provide a cell relay function and a cell add / drop function by providing a cell relay function and a cell add / drop function to each other, the terminal node, an intermediate node, and a head node are connected to a microprocessor for routing. Processor connection for receiving information and transmitting / receiving control and status information in the device and routing field among 56 bytes of data requested to be transmitted from the network is analyzed and dropped to the AAL layer or forwarded to the subscriber. 3 bytes of tag are attached to the cell that requested delivery from AAL layer. To the ability to pass nostalgia cell relay and the AAL connection portion and the nostalgia cell relay and the AAL connection with the hardware configuration, but the same, characterized by consisting of a subscriber effort cell relay and the AAL connection portion for connecting the data for the subscriber effort.

Description

Cell relay and add / drop device and method for unidirection dual-bus

1 is a schematic diagram of a bus type subscriber network.

2 is a block diagram of a cell relay and an add / drop device of the present invention.

3 is a cell relay and add / drop processing flow chart of the present invention.

4 is a detailed configuration diagram of FIG.

Explanation of symbols on the main parts of the drawings

21: processor connection

22: network cell relay and AAL connection

23: subscriber cell relay and AAL connection

The present invention relates to a method and apparatus for cell relay and ed / drop in a unidirectional dual bus, and particularly, when a broadband service network is built in a home or small business in the form of a bus in a broadband integrated telecommunication network, it is delivered in an ATM (Asynchronous Transfer Mode) layer. The present invention relates to an ATM cell relay and an add / drop method and apparatus for relaying a cell to another ATM layer or transmitting / receiving a cell to an ATM adaptation layer (AAL) layer.

Recently, with the development of communication technology, users are demanding a variety of high-quality services, as well as continuous services such as voice and video services, as well as burrs such as high-speed data services such as file transfer and real-time video services with variable bit rates. In order to provide the services of the service of the province, the Broadband Integrated Services Digital Network (B-ISDN) has emerged.

Conventional devices for constructing a broadband integrated telecommunication network are more than a scale for developing a large-scale switch to be applied to a national backbone network and providing broadband services to a private network or a large number of regions, rather than developing a device for providing a home or direct subscriber service. The focus has been on device development.

Most of these devices have been developed in a switch structure, which is suitable for use in the transmission and reception of traffic between regions requiring a large amount of input and output.However, the ring or bus structure can be used in homes or small-sized businesses that use direct services. The following disadvantages exist when compared to the multi-access configuration.

1. When the switch structure device is connected to each service terminal by transmission line, all the lines must be connected one-to-one to each terminal in the switch, so that the transmission line takes more than the ring or bus type, causing a price increase.

2. Difficult to maintain or operate by adopting complicated switch structure than simple multiplexer or bus type,

3. If additional input port is needed, multi-access can be done by simple extension between the previous terminal or between terminal and terminal, but in case of switch type, unnecessary port is wasted because it needs to be installed by switch unit for expansion of port. Results in.

1 is a block diagram of a bus type subscriber network to which the present invention is applied. In order to configure a service delivered from the network in the form of a bus, a head node 11, an intermediate node 12, and an end node 13 are configured.

The head node terminates the protocol on the network side and performs a function of connecting the functions of terminals corresponding to the intermediate node and the end node to the network.

The cell relay function is required to transfer cells from each intermediate node 12 to other intermediate nodes 12 and end nodes 13, and each node requests a service to the ATM adaptation layer to provide a requested service. The ability to deliver the cell (cell add and drop function) is required.

Accordingly, the present invention provides a cell relay and an ED / drop apparatus and method for providing a requested service at a low price and transferring service data between terminals using a simple multiplexing and router structure rather than a switch structure. There is a purpose.

In order to achieve the above object, the present invention provides a cell relay function that is located between an ATM tier and an AAL layer and connected to a microprocessor to transfer a cell from each intermediate node to another intermediate node and an end node constituting an active unidirectional bus structure. A cell relay and drop / drop device for providing a cell add and drop function for transferring a cell between the AAL layer and an ATM layer to request a service from each node and to provide a requested service, wherein the cell relay and the drop / drop device connect to and route the microprocessor. A processor connection unit for receiving information and transmitting and receiving control and status information in the device to a network cell relay and an AAL connection unit and a subscriber cell relay and AAL connection unit, and 56 bytes of data requesting transmission from the network through the processor connection unit. To compare and drop only the routing field in the AAL layer A network-oriented cell relay and an AAL connection unit which decides whether to transfer or copy, and transmits a tag (ta) of 3 bytes to a cell requesting delivery from the AAL layer to the ATM layer, and the processor connection unit. By comparing and analyzing only the routing field among 56 bytes of data requested by the subscriber, the system decides whether to drop, forward, or copy to the AAL layer. It is characterized by consisting of a subscriber-oriented cell relay and an AAL connection function to transfer a tag to the ATM layer.

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

Prior to the description, the cell relay and the add / drop devices are located between the ATM layer and the AAL layer to deliver 56 bytes of data transferred from the ATM layer to the AAL layer (REOP) or relay to another ATM layer. It is a kind of medium access control (MAC) device for routing (ADD) cells from the layer to the ATM layer in units of 56 bytes.

The cell relay and the ed / drop device are located above the Molly layer and the ATM layer having the same structure to form a unidirectional dual bus.

1) relay data in the form of an ATM cell that requests transmission from the network (or subscriber) to the subscriber (network); or

2) In addition to delivering data from each direction to the AAL layer

3) cell copy function to provide one-to-multiple services;

4) A cell requesting delivery from the AAL layer is delivered to the ATM layer with a 3-byte routing tag.

5) It has a function of discarding unregistered cell data.

2 is a block diagram illustrating the upper block of the cell relay and the add / drop apparatus according to the present invention.

The cell relay and the add / drop device 100 may be connected to the microprocessor 25 to receive routing information and to transmit and receive control and status information within the device. Only the routing field of 56 bytes of data is compared and analyzed to determine whether to drop to the AAL layer 27 or forwarded to the subscriber, and a 3-byte tag is sent to the cell for which the AAL layer 27 requests delivery. The routing field of the network cell relay and AAL connection unit 22 to be transmitted to the ATM layer 24 and the 56-byte data requested to be delivered from the subscriber is analyzed and dropped to the AAL layer 28, or to the network. It is composed of a subscriber-oriented cell relay and an AAL connection unit 23 which decides whether or not to deliver, and attaches a tag of 3 bytes to the cell requesting delivery from the AAL layer 28 and delivers it to the ATM layer 26.

The network relay and AAL connection unit 22 and subscriber-oriented cell relay and AAL connection unit 23 have the same hardware structure, and only adjust the routing path according to the connected position to transfer data to the network and subscriber.

3 is a flowchart illustrating processing of ATM cell relay and ED / drop according to the present invention, in which a mask byte, an AAL routing selector, a one-to-multiple routing selector, and a multiplexing sequence are inputted from a processor while allowing data input from each layer during initialization. 301, data entry from the ATM layer and the AAL layer is started.

After extracting the routing identifier of 3 bytes from the data input from the ATM layer (302) (303), and comparing the routing identifier with the same value as the AAL routing selector (304), if it is the same value, the cell is dropped into the AAL layer. If the routing identifier is not the same value as the AAL routing selector (305), the routing identifier is compared with the one-to-multiple routing selector (306). If the routing identifier is the same value, the cell is copied to the AAL layer (305) and the cell is transferred to another node. The cell is stored in the relay buffer for transmission (307).

If the routing identifier has a different value from the one-to-multiple routing selector, when the device is used at the end node, the input cell is discarded (309), and in the case of the intermediate node or the head node, the relay is transmitted to another node. The cell is stored in the buffer (307).

When data is input from the AAL layer (310), the signal is multiplexed with the relay cell in accordance with the order of multiplexing set by the processor (311), and after inserting a routing tag, the data is output to the ATM layer and transmitted to other nodes. (312).

The configuration and operation thereof will be described with reference to the detailed block configuration of FIG. 4, which is one embodiment of the present invention.

The detailed block structure of the present invention includes first and second ATM receiving controllers 401 and 406 which extract three bytes corresponding to routing information from 56 bytes of data transmitted from an ATM layer and store only cells in a FIFO buffer. First and second routers 402 and 407 for determining a transfer path, such as whether an AAL layer, a relay, or discard the cell stored in the packet buffer from the extracted 3 bytes of routing information; First and second cell transmitters 403 and 408 for extracting transmission paths and storing cells in the corresponding PIP buffers; first and second cell multiplexers 404 and 409 for multiplexing drop cells and relay cells; Including first and second ATM transmission controllers 405 and 410 for transmitting cells and relay cells transmitted from the layer to the ATM layer, the network cell relay and the AAL connection unit 22 and the subscriber cell relay and AAL connection unit 23 are configured. The processor connection 21 And a plurality of buffers 411, 412, 413, 414, 415, and 416 for storing only cells.

Referring to the operation of the present invention by such a configuration as follows.

First, the processor connection unit 21 reports the status of the network / subscriber-oriented cell relay and AAL connection units 22 and 23 to the microprocessor 25, and registers to receive appropriate control and alarm control logic for processing them when an alarm occurs. It consists of.

Each register has a register for controlling network direction and a register for controlling subscriber direction, and extracts and compares 1 byte of data corresponding to routing field among 56 bytes of data transferred from ATM layer It consists of a register for routing to each bit, a register for determining comparability for each bit, a register for controlling each envelope, and a register for reporting an alarm state of the envelope.

The first and second ATM receiving controllers 401 and 406 extract the routing field in synchronization with the data input control signal and transmit the 56-byte input data transferred from the ATM layer to the first and second routers 402 and 407. Only pure cells excluding fields are stored in the packets 411 and 414.

Only three bytes of the routing field of the 56 bytes are extracted from the data requested to be transferred by the ATM layer, and the buffer write data of 53 bytes is stored in the buffers 411 and 414 by the write write control signal.

The extracted routing field is transmitted to the router and the internal operation of the ATM receiver controller is sequentially controlled by the counter.

The routing identifiers transmitted from the first and second ATM reception controllers 401 and 406 to the first and second routers 204 and 207 are converted into routing direction determiners after the following process.

When the bits to be compared are selected by the mask byte transferred from the processor connection unit 21, the AAL routing selector and the one-to-multiple routing selector delivered from the microprocessor connection 21 and the first and second ATM reception controllers 401 and 406 are transmitted. The routing identifiers are compared bit by bit to determine whether to forward, broadcast or relay the AAL layer.

If the routing identifier has the same value as the AAL routing selector, the cell is routed to the AAL layer. If the routing identifier has the same value as the one-to-multiple routing selector, the cell is routed to the relay and the AAL layer.

When the cell relay and the ed / drop device of the present invention are used for the head node and the intermediate node,

end. If the routing identifier has a different value from the AAL routing selector but the same value as the one-to-multiple routing selector,

I. If it is different from each routing selector, it is filled. If it is used for an end node, the cell is discarded if the conditions A and B are satisfied.

The first and second cell transmitters 403 and 408 receive routing direction determiners and buffer pools of the buffers 413, 412, 415 and 416 inputted from the first and second routers 402 and 407, and start the cells in the buffers 413, 412, 415 and 416. The notifier stores the buffer start data of the cell start and the buffers 411 and 414 in the buffers 412, 413, 415 and 416, reads the data of the buffers 411 and 414 as the buffer output control signal, and transmits the state of the buffer to the processor connection unit 21.

The routing direction determiner consists of a 2-bit buffer selector and a 1-bit buffer selector valid period indicator.

The first and second cell transmitters 403 and 408 receive the relay / discard determinator from the processor connection unit 21 during the initialization process, and the buffer selector valid period indicator of the routing direction determiner is enabled, thereby disabling all the buffer selectors of 2 bits. If enabled, it determines whether to relay or discard the cell.

In addition, each of the buffers 412, 413, 415, and 416 detects when the buffer becomes full, thereby preventing further data from being used in the buffers 412, 413, 415, and 416, and notifies the processor 25 of the full state.

The first and second cell multiplexers 404 and 409 have a function of selecting one of a cell and a relay cell for which transfer is requested from the AAL layer and a function of reading a buffer in which the selected cell is stored.

When the cell forwarder 403 or 408 of the AAL layer and the other side requests cell delivery, the cell multiplexer 404, 409 is configured to select one of the packet buffers and the relay packet buffers 413 and 416 existing in the AAL layer according to a preset priority. At the same time as selecting the buffered buffer, whether the first and second ATM transmission controllers 405 and 410 can receive the cell is read by the cell validity interval indicator.

If the cell transfer is possible to the ATM transmission controllers 405 and 410 by this reading, the corresponding buffer is read and transmitted to the ATM transmission controllers 405 and 410.

The first and second ATM transmission controllers 405 and 410 use the selector of the cell multiplexer described above to create an ATM signal for connecting to the ATM layer. A tag insertion function for inserting a routing tag, and a function for transmitting whether a cell can be delivered to the first and second cell multiplexers 404 and 409.

In the first and second cell multiplexers 404 and 409, when a cell start and a cell validity indicator are asserted, the first and second ATM transmission controllers 405 and 410 attach a 3 byte tag to a 53 byte cell data front end. And insert it into the ATM layer along with the data output start signal and the data valid interval indication signal.

The routing tag inserted during data transfer to the ATM layer is filled with a preset value by the microprocessor connector 21.

As described above, the present invention can provide a requested service at a low price by using a simple multiplexing and router structure, and can provide service data between terminals.

Claims (9)

A cell relay function located between the ATM layer and the AAL layer and connected to a microprocessor to transfer a cell from each intermediate node to another intermediate node and an end node constituting an active unidirectional bus structure, and to request and request a service from each node. In the cell relay and the drop / drop device for providing a cell add and drop function for delivering a cell between the AAL layer and ATM layer to provide a, Processor connection means for receiving routing information in connection with the microprocessor and transmitting and receiving control and status information in the device to network-oriented cell relay and AAL connection means and subscriber-oriented cell relay and AAL connection means; The processor access means compares and analyzes only the routing field of 56 bytes of data requested to be forwarded from the network, and decides whether to drop, forward, or copy the packet to the AAL layer, and request delivery from the AAL layer. A network-oriented cell relay and an AAL connection means for attaching a tag of 3 bytes to a cell and delivering the same to the ATM layer; The processor access means compares and analyzes only the routing field of 56 bytes of data requested to be delivered from the subscriber, and decides whether to drop, forward, or copy the packet to the AAL layer, and requests the delivery from the AAL layer. Cell relay and ed / drop device in a unidirectional dual bus comprising a subscriber-oriented cell relay and an AAL connection means for attaching a tag of 3 bytes to the cell and delivering it to the ATM layer. The method of claim 1, Cell relay and ed / drop device in a unidirectional dual bus, characterized in that a plurality of FIFO buffers for storing only cells. The method according to claim 1 or 2, The network cell relay and the AAL connection means An ATM reception controller for extracting 3 bytes of routing information from 53 bytes of data transmitted from an ATM layer and storing only cells in the buffer; A router for determining a transfer path of a cell stored in the buffer from the extracted 3 bytes of routing information; A cell forwarder for extracting a forwarding path of a cell input from the router and storing the cell in a corresponding buffer; A cell multiplexer for multiplexing the drop cell and the relay cell delivered from the cell transmitter, and Cell relay and ed / drop device in a unidirectional dual bus comprising a ATM transmission controller for delivering the cell and relay cells transferred from the AAL layer to the ATM layer. The method according to claim 1 or 2, The subscriber cell relay and the AAL connection means ATM reception controller which extracts 3 bytes corresponding to routing information from 53 bytes of data transferred from ATM layer and stores only cells in the buffer, and transfer path of cells stored in the buffer from the extracted 3 bytes of routing information. With a router to determine, A cell forwarder for extracting a forwarding path of a cell input from the router and storing the cell in a corresponding buffer; A cell multiplexer for multiplexing the drop cell and the relay cell delivered from the cell transmitter, and Cell relay and ed / drop device in a unidirectional dual bus comprising a ATM transmission controller for delivering the cell and relay cells transferred from the AAL layer to the ATM layer. The method of claim 1, wherein the processor connecting means A cell relay and an ed / drop device in a unidirectional dual bus comprising a register for reporting the state of the cell relay and the AAL connection means to the microprocessor, a register for receiving proper control, and an alarm control logic for handling an alarm when an alarm occurs. . The method according to any one of claims 1, 2, and 5, The processor connection means A register for controlling network-directed cell relay and AAL access means, a register for controlling subscriber-oriented cell relay and AAL access means, and one byte of data corresponding to a routing field from 56 bytes of data transmitted from ATM layer are extracted. And a register for routing to the corresponding buffer after comparison, a register for determining comparability for each bit, a register for controlling each buffer, and a register for reporting an alarm state of the buffer. Cell relays and ed / drop devices on unidirectional dual buses. 5. The cell relay and ed / drop device of claim 4, wherein the cell transmitter determines to relay or discard the cell. The method of claim 4, wherein the ATM transmission controller ATM interface control function for making a connection signal with the ATM layer, tag insertion function for inserting 3 bytes of routing tag in front of a 53-byte cell, and cell relay in a unidirectional dual bus characterized by transferring whether or not a cell can be delivered And an ed / drop device. Interposed between the ATM layer and the AAL layer and connected to a microprocessor, multiple buffers, A cell relay function for delivering a cell from each intermediate node 12 constituting an active unidirectional bus structure to other intermediate nodes 12 and end nodes 13 and to request a service from each node and to provide the requested service. In the method using a cell relay and an add / drop device that provides a cell add and drop function for transferring the cell between the AAL layer and the ATM layer, A first step of extracting a 3-byte routing identifier from data input from the ATM layer; A second step of comparing whether the extracted routing identifier has the same value as the AAL routing selector; A third step of dropping the cell into the AAL layer if the same value is obtained by the comparison of the second step; If the routing identifier is not the same value as the AAL routing selector by the comparison of the second step, if the same value is compared with the one-to-multiple routing selector, the cell is copied to the AAL layer and not only to transfer the cell to another node, but also to deliver the cell to another node. Storing the cell in the relay buffer; If the routing recognizer has a different value from the one-to-multiple routing selector according to the comparison of the fourth step, when the cell relay and the add / drop device are used at the end node, the input cell is discarded and the intermediate node or the head node is discarded. A fifth step of storing the cell in a relay buffer when used to deliver the cell to another node; When data is input from the AAL layer, a sixth step of multiplexing with a relay cell in accordance with a predetermined sequence of multiplexing by the processor, inserting a routing tag, then outputting data to the ATM layer and transferring the data to another node is performed. Cell relay and ed / drop method in unidirectional dual bus.