KR100439238B1 - Method for operating reliable protocol of transmit data between transmission unit - Google Patents

Abstract

According to another aspect of the present invention, there is provided a method of operating a release protocol for transmitting / receiving data between transmission units, the method comprising: registering a port and a device driver for performing a release service to a release service module operating between transmission units; When the port and the device driver are registered, fragmenting the target data in a lower layer to a size that can be transmitted by the corresponding device and transmitting the fragment data unit to the upper layer in segment data unit units; In the transmission of the segment data unit signal, the lower layer performs retransmission when the occurrence of the sequence error is confirmed, and the upper layer receives the received segment data unit signal to reassemble the received data and transmit a response message to the sender. Including the steps, it is possible to ensure the reliability and stability of the transmission and reception data during communication between each self and the device in the transmission unit.

Description

{Method for operating reliable protocol of transmit data between transmission unit}

The present invention relates to a method of operating a release protocol for transmitting / receiving data between transmission units. In particular, the transmission / reception data is error in managing resources of various databases for any device existing on the network when a plurality of transmission units are configured. The present invention relates to a method of operating a release protocol of transmit / receive data between transmission units to improve stability and reliability by allowing transmission to be performed without transmission.

In general, IPC (Interprocess Communication) is a function provided by the operating system to allow two processes to communicate with each other, so that processes of other systems can be used within the same system or over a network.

So IPC communicates with the system kernel even on the same or different systems. When multiple processes try to use a shared resource, they need a format that can make that resource available to only one process at a time. So each process performs the steps of reading the serial number file, using the read serial number, and incrementing the serial number.

In the case where the transmission service by the transmission unit is performed, the protocol may provide a separate additional service for use by the entity.

In other words, priority is applied to ensure that frames are delivered without delay on the network, retransmitted data is given a higher priority than previous transmissions, and certain messages, such as control messages, need to reach their destination within a minimum delay. Make sure At this time, the priority is assigned based on the message, or the priority is assigned based on the connection.

In addition, by setting the class of the service, it is adapted to the case where a certain kind of data requests the minimum throughput or the maximum delay time, and secures the security.

In addition, in the OSI reference model, data transmission between layers is performed in data units. This data unit is a unit for exchanging information between entities of adjacent layers through the same entity or service access point. There are two types of data units: a service data unit (SDU) and a protocol data unit (PDU). .

(N) Layer SDUs look at data transmitted between (N + 1) entities from (N) service perspectives, and (N) Layer PDUs look at (N) protocol views of data transmitted between (N + 1) entities. As seen from (N) layer protocol control information (PCI) and (N) layer service data unit (SDU).

Therefore, the sender encapsulates the data unit added from the lower layer to the data layer from the highest layer to the lowest layer, and the receiver extracts only the necessary data from its own layer from the data unit received from the lowest layer to the highest layer. Decapsulization is performed to deliver to the higher layers.

However, in the related art, there is a technical limitation that the reliability and stability of the transmission / reception data are not sufficiently secured during the communication between the units and the devices by configuring the transmission unit network.

The present invention was created to solve the above-mentioned conventional problems, and an object of the present invention is to transmit / receive data in managing resources of various databases for an arbitrary device existing on a network when configuring a network with a plurality of transmission units. The present invention provides a method of operating a protocol for transmitting / receiving data between transmission units to improve stability and reliability by ensuring that the data is transmitted without error.

In order to achieve the above object, a method of operating a protocol for transmitting / receiving data between transmission units according to an embodiment of the present invention includes registering a port and a device driver for performing a release service to a release service module operating between transmission units. Steps; When the port and the device driver are registered, fragmenting the target data in a lower layer to a size that can be transmitted by the corresponding device and transmitting the fragment data unit to the upper layer in segment data unit units; In the transmission of the segment data unit signal, the lower layer performs retransmission when the occurrence of the sequence error is confirmed, and the upper layer receives the received segment data unit signal to reassemble the received data and transmit a response message to the sender. It is characterized by including the step.

1 is a block diagram of a relatable service module according to the present invention;

2 is a master slave block diagram to which the present invention is applied;

3 is an exemplary diagram of data transmission / reception side data loss of a transmission unit;

4 is a master slave block diagram during module testing;

5 is a flowchart of a method of operating a release protocol of transmission / reception data between transmission units according to an embodiment of the present invention.

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

1 is a block diagram of a relatable service module according to the present invention, FIG. 2 is a master slave block diagram to which the present invention is applied, FIG. 3 is an exemplary diagram of data transmission / reception side data loss of a transmission unit, and FIG. 4 is a module. Fig. 5 is a block diagram of a master slave block at the time of testing, and Fig. 5 is a flowchart of a method of operating a release protocol of transmission / reception data between transmission units according to an embodiment of the present invention.

The Reliable Protocol of the present invention is a protocol that guarantees that the transmitted data is received at the receiving side without loss even if the transmitted data is transmitted through a channel with high reliability.

Therefore, it implements a module that provides two levels of relatable services of OSI layer, and applies window flow control and Go-back-N error control.

Accordingly, the relatable service module may include: rpl2_send calling a function for sending a PDU at a higher layer, a confirm notifying that the relatable service has been normally performed at a higher layer, a timeout indicating that the PDU failed to be sent, Receives data that is normally received and recombines the received data to the upper layer through the reply function.

IPC device drivers applied for communication between processors include MDIPC driver, MTIPC driver, and MPC860 HDLC driver.

The MDIPC driver directionally divides the DPRAM into two, one for writing in A and reading in B, and the other for writing in B and reading from A. It is used in point-to-point structure. The feature of MDIPC is that bit-level error control is not supported, and the size of frame that can be transmitted / received at one time depends on the size of DPRAM.

MTIPC is a device driver that supports multi-point using HDLC devices such as MT8952 and supports bit-level error control.The size of the frame that can be transmitted / received is 256 bytes but there is no problem in speed and it is a multiple of 8 Can be used at higher speeds.

In addition, the MPC860 HDLC driver supports the HDLC protocol and can be used as a replacement for the MT8953.

The interfaces of these IPC drivers are provided with send and receive functions.

Therefore, in the implementation of the relatable service module of the present embodiment, the transmit function in the module is transmitted by using the send function of each device, and the receive function is obtained by using the receive function provided by each device to process the data. The size is defined at the device installation stage. If the device driver sends the received data to the Reliable Protocol Layer 2 (RPL2) as a reply function, the data driver defines a data reception reply function in the RPL2 to receive data from the device driver.

Then, as shown in Fig. 5, registration of the port and the device is performed (ST21).

2 shows a registration relationship between a port and a device.

The port is registered by the user and provides data transmission and reception services through the port. Port properties include port ID, device ID to use, logical link number of device, window size, maximum frame size of upper layer, and reply function defined in higher layer.

Device registration registers a device ID, a lower layer maximum frame size, and a pointer of a device's transmission / reception function. It also registers and informs the user whether the device driver should provide a reception function in the device driver to deliver data reception to RPL2, or whether it should be provided by RPL2 through a reply function.

For example, the registration of the above-described ports and device drivers is shown in Tables 1 and 2 below.

Port id Device id Device logical link Send buffer Receive buffer Buff, Win Management Callback Upper tier MFL Win size One A One S_buff1 R_buff1 Buff, Win Management Callback 1500 64 2 B One S_buff2 R_buff2 Buff, Win Management Callback 1024 128 3 B 2 S_buff3 R_buff3 Buff, Win Management Callback 2048 128

Device ID Lower layer send function Upper layer receive function Lower layer MFL A send1 recv1 256 B send2 recv2 512

Thus, when the port and the device driver are registered, the receiving target data is fragmented by the lower layer to the size that the corresponding device can transmit and transmitted to the upper layer in the segment data unit (ST22).

In operation ST22, the lower layer device performs segmentation when generating the SDU signal, and receives the SDU signal transmitted from the upper layer and reassembles the SDU signal.

Segmentation is to cut the data to send to the upper layer as large as the device of the lower layer can be sent, one SDU is assigned the same serial number, the number of PDU (Protocol Data Unit), the header information together with the size of the data The PDU creates a PDU with the coefficient corresponding to the SDU and stores it in the prepared send buffer so that the device driver can send it. At this time, serial number can be managed by application and up to 65535. When 65536 is reached, it recursively returns to 0.

In the case of reassembly, the received data is stored in the prepared receiving buffer until the reception is completed as much as the number indicated by the number of PDUs in the header information after removing the header of the received data if the same number is checked. Subsequently, the pointer and size of the receiving buffer are sent to the upper layer, and a new receiving buffer is prepared in the corresponding port for receiving the next PDU, and the next PDU is received.

In addition, when transmitting, the buffer management sequentially assigns the remaining value obtained by dividing the segmented PDU by the window size as a sequence number, and sequentially stores the prepared PDU in the corresponding port, and manages the location of the transmitting PDU as a current_input_ptr value. The transmit buffer is fixed at a fixed size. When the end is reached, the current buffer is moved and managed for the first time.

In case of receiving buffer management, the receiving buffer is allocated for each port by the maximum buffer size of the upper layer, and the received PDU is stored in the serial number unit.When one SDU is created, it is delivered to the upper layer and a new receiving buffer is allocated. The next SDU will be saved. The buffer sent to the upper layer is free at the upper layer.

The window size is defined by the user at the port installation stage according to the performance of the device. As the window size, the PDU can be sent without a response message. Windows are managed through the window start and end points. Thus, when a response message arrives from the receiving side, the window moves by the number of acknowledged PDUs.

In step ST22, when transmitting data in units of segment data, the lower layer determines whether a sequence error has occurred and if the sequence error is confirmed, Go-Back-N error control for retransmitting the corresponding SDU is performed (ST24 and ST25).

That is, as shown in FIG. 3, if the transmitting frame is lost while the transmitting side transmits frame i and continues to transmit the next frame, the receiving side creates a REJ i frame and transmits it to the transmitting side because the sequence numbers are not in order. Receiving the REJ frame, the transmitting side retransmits from frame i. If retransmission occurs more than a predetermined number of times for the same frame, a retransmission error message is transmitted to a higher layer.

The transmitting side transmits the frame as much as the window size and waits for a response message from the receiving side. At this time, the transmitting side starts the set timer and waits for the predetermined time. If there is no message during this waiting time, the sender sends a timeout signal to the receiver and restarts the timer.

The receiving end receiving the timeout sends the frame number being received in the receive Expect frame. The receiver receiving the receiver-to-signal signal retransmits the received frame number. If the timeout timer also expires, it sends a timeout signal up to three times, and if it is longer, it notifies that the link with the receiver has been disconnected.

Information about timers and retransmission counters is maintained for each port.

Then, the higher layer receives the received segment data unit signal, reassembles the data, and transmits a response message (ACK) to the transmitter (ST26 and ST27).

The test for the relatable service module thus operating may be applied to the master slave block as shown in FIG.

The module for testing is implemented in a Point To Multipoint (PTM) environment using a Null LinkDevice Driver Emulator. The interface provided by the test module can be confirmed by the help command.

To create a test environment, environment variables are set for each terminal. The nlk_ptm.ncf file in the test directory is the script for the ptm configuration. Running this file produces node.nlk0, node2.nlk1, and node3.nlk2.

Running source node1.nlk0 on the terminal establishes an environment where the logical link number of the device is zero. Performing the same way in other terminals, an environment as shown in Fig. 4 is set.

So, by assigning unique ID to port and device for each terminal, registering and initializing, it becomes possible to send and receive

E.g,

master: port-ins 0 1 1 1500 128

Port-ins 1 1 2 1500 128

dev-ins 1 512

init

slave 1: port-ins 0 1 0 1500 128

dev-ins 1 512

init

slave 2: port-ins 0 1 0 1500 128

dev-ins 1 512

init

send 1 0 1200

// Send SDU of size 1200 byte once through port 0

send-on 0 1200

// Send SDU of size 1200 bytes through port 0 in set time unit

send-off 0

// stops sending to port 0

time 100

// Set time to perform transmission time in 100 clock ticks

discard 0 10

// Discard 10% of data from device with logical link number of device 0

('//' is a comment)

Accordingly, it is possible to increase the reliability of the data transmission of the transmission unit by determining whether the data is error or correct.

According to the method of operating a release protocol of transmission / reception data between transmission units according to the present invention, the transmission unit and system control to a user are assured by ensuring the reliability and stability of the transmission / reception data during communication between each Self and devices within the transmission unit. It has the effect of ensuring the convenience of management and improving the reliability of the system.

Although the preferred embodiment of the present invention has been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments. Therefore, the above description does not limit the scope of the following claims.

Claims (4)

(a) registering a port and a device driver for performing a relatable service to a relatable service module operating between transmission units; (b) when the port and the device driver are registered, fragmenting the target data in a lower layer to a size that a corresponding device can transmit, and transmitting the segment data unit to a higher layer in segment data unit units; (c) When the occurrence of a sequence error is confirmed in the lower layer when the segment data unit signal is transmitted, retransmission is performed, and the upper layer receives the received segment data unit signal to reassemble the received data and sends a response message to the transmitting side. Reliable protocol operation method of the transmission and reception data between transmission units comprising the step of transmitting a. The method of claim 1, wherein in step (a), The port is registered by the user with a port ID, the ID of the device to be used, the logical link number of the device, the window size, the maximum frame size of the upper layer, the reply function defined in the upper layer, And the device registers a device ID, a lower layer maximum frame size, and a pointer of a transmission / reception function of the device. 6. The method of claim 1, wherein in step (b), When transmitting in the segment data unit unit, the segment data unit to which the lower layer is to be sent to the upper layer is given the same serial number and inputted in the header information together with the number of PDUs (Protocol Data Units) and the data size to correspond to the SDU. PDUs are created in the prepared send buffer as many times as possible so that the device driver can send them. In the case of reassembly in the higher layer receiving the transmitted segment data unit, if the received data is the same number after checking the serial number, the received data is removed by the number indicated by the number of PDUs in the header information after removing the header of the received data. Store the received buffer to the upper layer, send the pointer and size of the receive buffer to the upper layer, and prepare a new receive buffer for receiving the next PDU in the corresponding port to receive the next PDU. How to use the Reliable Protocol. The method of claim 1, wherein in step (c), If the sending side transmits the frame as much as the window size and there is no response message for the set waiting time, it sends the timeout signal to the receiving side and restarts the timer. Receiving side receiving the timeout puts the frame number waiting to be received in the receiver-to-frame, and the transmitting side receiving the receiver-to-signal retransmits from the sent frame number, and if the timeout timer expires, it sends the timeout signal up to the set number And a communication method for transmitting / receiving data between transmission units, characterized in that the link to the receiver is disconnected when the link is over.