KR20120068526A - System and method for transmitting data based on udp - Google Patents

Abstract

PURPOSE: A user datagram protocol(UDP)-based data transmitting system and a method for the same are provided to transmit and receive controlling messages by verifying whether the message is omitted based on given serial numbers. CONSTITUTION: A transmitting part(200) divides one message into a plurality of packets. The transmitting part applies destination IDs to the packets and transmits the packets through networks based on an IP multi-casting or broadcasting method. If the packets are received through the networks, a receiving part(250) verifies whether the destination IDs of the packets are matched to the ID of the receiving part. The received packets are assembled to generate an original message, and the original message is transmitted to a higher level.

Description

WDP-based data transmission system and method {SYSTEM AND METHOD FOR TRANSMITTING DATA BASED ON UDP}

The present invention relates to a reliable message system based on including user datagram protocol (UDP) IP multicasting or broadcasting to support multiple receivers. More specifically, the present invention relates to a system based on multiple servers, such as a system based on multiple servers. Data transmission system and method for providing UDP-based message segmentation and re-assembly (SAR) and retransmission to provide reliability and efficiency based on UDP multicasting between devices in a system will be.

In general, the UDP protocol is an unreliable transmission service, in which a data transmission side transmits data regardless of whether or not the reception side receives the data. Therefore, the transmission efficiency of the data is good because the generated data can be continuously transmitted, but there is a problem that the reliability of the data cannot be provided because the sender does not check the data reception status and thereby retransmit. It is a communication service capable of multicasting and broadcasting because there is no need to maintain a reception state.

Recently, the need for reliable data transmission such as TCP has been raised along with the efficiency of data transmission provided by UDP while using UDP-based communication services.

However, UDP-based retransmission systems have problems in networks that include broadcasting or IP multicasting. In other words, because multiple receivers receive messages, complex retransmission mechanisms are needed to ensure the reliability of all receivers, and in order to provide reliable retransmission mechanisms to only one receiver, specific recipients and Need processing.

However, specifying a specific receiver introduces another problem in multiserver systems. In other words, since the transition between the master and the slave often occurs, the sender needs to always check who is the master and transmit. Therefore, an effective communication mechanism should be provided for efficient and reliable data transmission in a UDP broadcast based communication system having a plurality of receivers.

Accordingly, the present invention is a message transmission system for providing UDP-based reliable communication in a communication system including multiple servers, that is, IP multicasting or broadcasting with a plurality of recipients, and before applying data using UDP. The service divides the message according to one packet size, and transmits the divided packet to the local network through multicasting by assigning a serial number and a destination ID, and determines whether the destination ID is the same as its own ID at the receiving end. The present invention provides a UDP-based data transmission system and method for determining whether a message is missing based on a serial number, and performing a reliable and efficient communication by transmitting and receiving a control message if necessary.

The present invention described above is a UDP-based data transmission system, comprising: a transmitter for dividing a message into a plurality of packets, assigning a destination ID, and transmitting the packet through an IP multicasting or broadcasting method through a network; In case of receiving the packet, it checks whether the destination ID of the packet matches its ID, and if it matches, receives the packet, assembles the received packet into an original message, and transmits the received packet to a higher layer.

According to the present invention, in a message transmission system for providing reliable communication based on UDP, a message is divided into one packet size in an application service before transmitting data using UDP, and the divided packet is serial number and destination ID. And transmit it to the local network through multicasting, and the receiver determines whether the destination ID is the same as its ID, and judges whether the message is missing by using the assigned serial number, and sends a control message to the transmitter if necessary. Receiving has the advantage of performing reliable and efficient communication.

1 is a network diagram of a UDP communication system according to an embodiment of the present invention;
2 is a block diagram of a transmitter / receiver of a slave server according to an embodiment of the present invention;
3 is a flowchart illustrating an operation control in a transmitter according to an embodiment of the present invention;
4 is a flowchart illustrating an operation control in a receiver according to an exemplary embodiment of the present invention.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

In describing the embodiments of the present disclosure, when it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present disclosure, the detailed description thereof will be omitted, and the following terms are used in the embodiments of the present disclosure. Terms are defined in consideration of the function of the may vary depending on the user or operator's intention or custom. Therefore, the definition should be based on the contents throughout this specification.

Combinations of each block of the block diagrams and respective steps of the flowcharts may be performed by computer program instructions (executable engines), which may be executed on a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment. As such, instructions executed through a processor of a computer or other programmable data processing equipment create means for performing the functions described in each block of the block diagram or in each step of the flowchart. These computer program instructions may be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular manner, and thus the computer usable or computer readable memory. The instructions stored therein may also produce an article of manufacture containing instruction means for performing the functions described in each block of the block diagram or in each step of the flowchart.

In addition, computer program instructions may be mounted on a computer or other programmable data processing equipment, such that a series of operating steps may be performed on the computer or other programmable data processing equipment to create a computer-implemented process to generate a computer or other program. Instructions for performing possible data processing equipment may also provide steps for performing the functions described in each block of the block diagram and in each step of the flowchart.

In addition, each block or step may represent a portion of a module, segment or code that includes one or more executable instructions for executing specific logical functions, and in some alternative embodiments referred to in blocks or steps It should be noted that the functions may occur out of order. For example, the two blocks or steps shown in succession may, in fact, be performed substantially concurrently, or the blocks or steps may be performed in the reverse order of the corresponding function, as required.

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

1 is a block diagram of a reliable UDP communication system for a multi-server according to an embodiment of the present invention.

Referring to FIG. 1, the multi-server system of the present invention is composed of one master server 101 and one or more slave servers 102 and 103, wherein the servers are one or more computers. Are connected to devices 105, 106, and 107.

The devices 105, 106, 107 communicate with the servers 101, 102, 103 using IP multicasting or broadcasting, and the devices 105, 106, 107 communicate with each other. Communication with the master server 101 is always performed. The master server 101 is responsible for the communication with the devices 105, 106, and 107, and provides reliable communication with the data transmitted from the system device. Slave servers 102 and 103 do not require reliable communication as the master server 101, but devices 105, 106 because the data transmitted by devices 105, 106, 107 are transmitted by broadcasting. It is possible to receive the data transmitted by 107).

2 illustrates a detailed block configuration of a transmitter and a receiver of a slave server 102 in a UDP multicasting-based multi-server communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the slave server 102 according to the present invention includes a transmitter 200 and a receiver 250 for transmitting and receiving data with devices.

First, the transmitter 200 includes a message generator 202, a packet divider 204, a packet transmitter 206, a retransmitter 208, and the like. The message generator 202 generates a message to be broadcast to the devices 105, 106, and 107 and gives a unique message identifier (ID).

The packet divider 204 divides the message generated by the message generator 202 into one or more packets, and assigns a unique packet identifier to each divided packet. The packet transmitter 206 broadcasts the packet divided by the packet divider 204 through a network and transmits the packet.

The retransmitter 208 retransmits the message when a message reception failure is received from the receiver for the message divided into packets and transmitted to the network. In this case, the retransmitter 208 may temporarily store the message transmitted for retransmission of the message.

That is, the transmitter 200 assigns a unique message identifier to the message to be transmitted and divides the message into one or more packets. The divided packet is assigned a unique packet identifier. The divided packets are broadcasted to the network through IP multicasting or broadcasting.

At this time, if the message that the received all packets within a predetermined time after the broadcast of the last packet of the message, the transmitter 200 performs data transmission for the next message. However, if there is no response for a certain period of time, a message for confirming the data reception status is transmitted to the receiving side, and the receiving side performs retransmission of data for packets not received. At this time, if a message for requesting confirmation of reception status is transmitted for a certain number of times but there is no response, transmission of the message is stopped and transmission for the next message is started. Therefore, the transmitter 200 uses a timer and a retransmission buffer to retransmit the data.

In addition, the transmitter 200 uses a destination address so that only a desired destination device transmits a control message. The destination address may use an identifier unique to the device and may use one or more logical IDs. If one or more nodes have the same ID as the destination ID of the message, the one or more devices transmit the control message. In this case, the transmitter 200 recognizes that one or more destination devices exist, and performs exception processing such as an event generation.

Next, the receiver 250 includes a packet receiver 252, a packet checker 254, a packet assembly unit 256, a retransmission unit 258, and the like. The packet receiver 252 receives a packet transmitted by IP multicasting through a network.

The packet checking unit 254 checks the destination ID and the like for the packet received from the packet receiving unit 252 and checks whether the packet is received by the packet. The packet assembly unit 256 reassembles the received packets identified from the packet confirming unit 254 into one message. The retransmission unit 258 transmits a retransmission request for the corresponding packet to the network when there is a missing packet when the message is reassembled using the received packet.

That is, the receiver 250 receives the message transmitted by using broadcasting or IP multicasting, and checks whether the destination ID address of the received message matches its own address. At this time, if the destination ID address is matched with its own address, the control message for the received data is transmitted. Therefore, if data loss occurs, retransmission can be requested to the transmitting side. However, if the destination ID address does not match its own address, no control message for retransmission is sent.

In addition, the receiver 250 identifies the message through the message identifier and the packet identifier of the received packet, and assembles the packets to complete the message. At this time, if its ID matches the destination ID, after completing the retransmission process, the completed message is delivered to the upper layer. Otherwise, only the received message is delivered or deleted to the upper layer.

3 illustrates an operation control flow in the transmitter 200 in the slave server 102 according to an embodiment of the present invention. Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1, 2, and 3.

First, when a message is to be transmitted by broadcasting or IP multicasting through a network, the transmitter 200 generates a message (S300) and assigns a unique message identifier to the message to be transmitted (S302).

Subsequently, the transmitter 200 divides a message generated by inserting a unique message identifier into packet units (S304), assigns a unique packet identifier to the divided packets (S306), and then performs IP multicasting or broadcasting. Transfer to the network via (S308).

Thereafter, the transmitter 200 checks whether a message indicating that all the packets of the message have been received is received from the receiving side receiving the transmitted message as described above (S310), and receives all the packets within a predetermined time. When the notification receives the acknowledgment message, it performs the transmission process for the next message.

However, when the transmitting unit 200 does not receive an acknowledgment message indicating that all packets have been received within a predetermined time period from the receiving side which received the message, the transmitting unit 200 transmits a message requesting confirmation of the reception status of the message to the receiving side. (S312).

Accordingly, when the receiving side receives the message requesting confirmation of the reception status of the message, the receiving side transmits a response message confirming the reception status of the message. In this case, the above acknowledgment message may include information in the packet that failed to receive at the receiving side.

Then, the transmitter 200 checks whether a reception acknowledgment message transmitted in response to the reception status is received from the receiver (S314). If there is no response for a predetermined time, the transmitter 200 stops transmitting the message and then Start transmission (S316).

However, in contrast, when an acknowledgment message transmitted in response to the reception state is received from the receiver, the transmitter 200 checks the acknowledgment response message, and if the packet fails to be received at the receiver, the corresponding packet. It retransmits (S318).

4 illustrates an operation control flow in the receiver 250 in the slave server 102 according to an embodiment of the present invention. Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1, 2, and 3.

First, when receiving a fragmented packet of a message transmitted by broadcasting or IP multicasting through a network (S400), the receiver 250 checks the destination ID address of the packet (S402) and checks whether it matches its ID. (S404).

In this case, when the destination ID of the packet and its ID match, the receiver 250 receives the packets for the message (S406), and when the packet is completed, transmits a response message indicating that the message has been received to the sender. (S408).

Subsequently, the receiver 250 checks whether a loss of data has occurred, such as when a specific packet is missing for the received message (S410), and, if a loss of data occurs, for example, transmits a message about a missing packet. A message for requesting retransmission of the missing packet is transmitted to one transmitter (S412).

Accordingly, the receiving side retransmits the missing packet that failed to be transmitted in response to the retransmission request message of the receiving unit 250.

Then, the receiver 250 checks whether data such as a packet requested for retransmission from the receiver is retransmitted (S414), and if a missing packet or the like is received through retransmission, a message is transmitted through a message identifier and a packet identifier of the received packet. By identifying and assembling the packets to complete the message (S416).

Subsequently, the receiver 250 transmits the completed message to the upper layer through the retransmission process (S418).

As described above, the present invention is a message transmission system for providing UDP-based reliable communication in a communication system including multiple servers, that is, IP multicasting or broadcasting with a plurality of recipients, and transmits data using UDP. Before the application service divides the message according to one packet size, the packet is transmitted to the local network through multicasting by assigning the serial number and the destination ID, and the receiver determines whether the destination ID is the same as its ID. Then, it is determined whether the message is missing through the assigned serial number, and if necessary, it is possible to perform a reliable and efficient communication by sending and receiving a control message with the sender.

Meanwhile, in the above description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Accordingly, the scope of the invention should not be limited by the described embodiments but should be defined by the appended claims.

200: transmitter 202: message generator
204: packet division unit 206: packet transmission unit
208: retransmitter 250: receiver
252: packet receiving unit 254: packet checking unit
256: packet assembly unit 258: retransmission unit

Claims (1)

UDP-based data transmission system,
A transmitter for dividing a message into a plurality of packets, assigning a destination ID, and then transmitting the IP message through IP network through IP multicasting or broadcasting;
In case of receiving a packet through the network, it checks whether the destination ID of the packet and its ID match. If the packet is matched, the packet is assembled, the received packet is assembled into an original message, and delivered to a higher layer. Receiver
UDP-based data transmission system comprising a.

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