WO2012075885A1

WO2012075885A1 - Data transmission method and device

Info

Publication number: WO2012075885A1
Application number: PCT/CN2011/082714
Authority: WO
Inventors: 曹家亮; 王德刚
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-12-10
Filing date: 2011-11-23
Publication date: 2012-06-14
Also published as: CN102571689B; CN102571689A

Abstract

The present invention provides a data transmission method and device used for communication between a serial port server and a host. The method comprises: when sending data to a peer end, buffering the data; encapsulating the data using the Reliable User Datagram Protocol (RUDP) and sending the encapsulated data; if no response corresponding to the sent data is received within a predetermined time range after the data is sent, sending the encapsulated data again; and, after receiving data sent from the peer end, sending a response corresponding to the sent data to the peer end. The present invention can realize reliable transmission by adding a reliability mechanism between a virtual serial port and a corresponding physical serial port.

Description

Data transmission method and device

Technical field

The invention relates to the field of communication and control, in particular to a method and a device for reliably communicating data between a virtual serial port on a host where the management software is located and a physical serial port on the serial port server.

Background technique

At present, virtual serial port technology has been widely used. The most critical indicator is reliability. Different virtual serial port software implementation schemes are different. Most existing solutions only solve reliability problems from the communication level, such as most network communication protocols. The Transmission Control Protocol (TCP) is used, but the reliability of the entire system is simply solved from the communication point of view.

From the software implementation point of view, the data transmission between the virtual serial port and the physical serial port directly uses TCP or User Datagram Protocol (UDP), which is simple and feasible. TCP is connection-oriented and can guarantee reliable transmission of data, but this is only reflected at the protocol level, and TCP itself consumes a lot of money, especially in some application environments (such as through a firewall) to limit TCP. UDP is connectionless, with less consumption and restrictions, but it is prone to packet loss, out-of-order, etc. in network transmission, and reliable transmission of data cannot be guaranteed.

Summary of the invention

It is an object of the present invention to provide a data transmission method and apparatus capable of realizing reliable transmission by adding a reliability mechanism between a virtual serial port and a corresponding physical serial port. In order to solve the above technical problem, the present invention provides a data transmission method for communication between a serial port server and a host, including:

When the data is sent to the peer end, the data is buffered; the data is encapsulated by the reliable user data packet protocol RUDP; and the data is not received within a preset time range after the data is sent. After the response corresponding to the sent data, the encapsulated data is retransmitted; and after receiving the data sent by the opposite end, the response corresponding to the received data is sent to the opposite end. The step of encapsulating the data by using RUDP includes: encapsulating the data into a user data packet protocol UDP packet, where the UDP packet includes a packet sequence number;

The step of sending a response to the peer end includes: after receiving the UDP packet sent by the peer end, acquiring a packet sequence number from the received UDP packet, and sending a response including the packet sequence number to the peer end; and the method further includes After receiving the response, the packet sequence number is obtained from the received response. If the obtained packet sequence number is the same as the packet sequence number of the transmitted data, it is considered that a response corresponding to the transmitted data is received.

The UDP packet further includes control information;

The method further includes: after receiving the UDP packet sent by the peer end, verifying the data in the UDP packet according to the control information in the UDP packet, and sending a response to the peer end if the verification succeeds.

The data refers to serial port data;

The method further includes: when transmitting the serial port data, using a virtual local area network VLAN identifier to identify the serial port data;

The step of sending a response corresponding to the received data to the peer end includes: after receiving the serial port data, if it is determined that the received serial port data includes the VLAN identifier, the response corresponding to the serial port data is sent to the opposite end. The method further includes: establishing, by using a network port, a correspondence between a physical serial port on the serial port server and a virtual serial port of the host;

And establishing, according to the correspondence, a transmission channel between the physical serial port on the serial server and the virtual serial port on the host.

The present invention also provides a data transmission device for communication between a serial port server and a host, the data transmission device comprising:

a data sending module, configured to: cache the data when transmitting data; and send the data after the data is encapsulated by a reliable user data packet protocol RUDP; and, a preset time range after the data is sent If there is no response corresponding to the sent data, then Send the encapsulated data; and

A data receiving response module is arranged to send a response corresponding to the received data after receiving the data.

The data sending module is configured to encapsulate the data into a user data packet protocol UDP packet when the data is encapsulated by RUDP, where the UDP packet includes a packet sequence number;

The data receiving response module is configured to send a response by: after receiving the UDP packet, obtaining a packet sequence number from the received UDP packet, and transmitting a response including the packet sequence number; and

The data sending module is further configured to: after receiving the response, obtain a packet sequence number from the received response, and if the obtained packet sequence number is the same as the packet sequence number of the sent data, the data is considered to be received and sent. Corresponding response.

The UDP packet further includes control information;

The data receiving response module is further configured to: after receiving the UDP packet sent by the peer end, verify the data in the UDP packet according to the control information in the UDP packet, and send the response if the verification succeeds .

The data refers to serial port data;

The data sending module is further configured to use the virtual local area network VLAN identifier to identify the serial port data when sending serial port data;

The data receiving response module is configured to send a response corresponding to the received data by: after receiving the serial port data, if it is determined that the received serial port data includes a VLAN identifier, sending, corresponding to the serial port data, Answer.

The data sending module is further configured to: establish a correspondence between a physical serial port on the serial port server and a virtual serial port of the host through a network port; and establish a physical serial port and a serial port on the serial port server according to the corresponding relationship The transmission channel between the virtual serial ports on the host.

The invention provides a data transmission method and device, which can realize reliable transmission by adding a reliability mechanism between a virtual serial port and a corresponding physical serial port.

BRIEF abstract 1 is a flowchart of a data transmission method according to an embodiment of the present invention;

2 is a schematic diagram of a data transmission process according to an embodiment of the present invention;

3 is a schematic diagram of a data retransmission mechanism in a data transmission process according to an embodiment of the present invention;

4 is a block diagram of a data transmission apparatus according to an embodiment of the present invention.

Preferred embodiment of the invention

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Referring to FIG. 1, the figure shows a data transmission method for communication between a serial port server and a host according to an embodiment of the present invention, including the steps of:

Step S101: When sending data to the peer end, buffering the data;

Step S102: Encapsulating the data by using a reliable user data packet protocol (RUDP) and sending it out;

Step S103: Resending the encapsulated data after receiving a response corresponding to the data within a preset time range after the sending of the data; and

Step S104: After receiving the data sent by the peer end, send a response corresponding to the received data to the opposite end.

In the embodiment of the present invention, reliable UDP transmission is used at the transmission link layer to monitor the order of UDP packets, effectively preventing packet loss and out-of-order, and adding a retransmission mechanism at the application level. When data transmission fails, Resend. Therefore, when communicating between the serial server and the host, the UDP consumption and the limited data transmission advantages are fully utilized, and the shortage of packet loss is improved, and hierarchical control is performed at the transmission link level and the application level. Ensure the reliability of data transmission.

Before performing step S101, the method further includes: establishing a data transmission channel between the serial port server and the host, where the network port is configured to establish a correspondence between the physical serial port on the serial port server and the virtual serial port of the host, and The corresponding relationship establishes a transmission channel between the physical serial port on the serial server and the virtual serial port on the host. In this way, the serial server is receiving When the data of a serial port is sent, it can be sent to the corresponding virtual serial port on the host through the corresponding transmission channel. Similarly, the host can also send the data on a virtual serial port to the corresponding serial port on the serial server through the corresponding transmission channel. . In the specific implementation, the host runs the virtual serial port management software, and sends a configuration command to notify the serial server to establish a data transmission channel. The serial server sets the serial port according to the configuration parameters in the configuration command, and associates the serial port with the virtual serial port on the host. And call reliable

UDP interface, create a link, and then notify the virtual serial port management software on the host, so that the serial port and the virtual serial port are established on the serial server and the host side. After the serial server receives the serial port data through the serial port, Determining, according to the corresponding relationship of the local maintenance, the virtual serial port to which the serial port data is sent, and then sending the serial port data to the network side through the network port, after the host receives the serial port data from the network side through the network port, according to local maintenance The corresponding relationship is sent to the corresponding virtual serial port. Similarly, the host side determines the serial port to which the data of the virtual serial port is sent according to the corresponding relationship, and then passes the data of the virtual serial port to the network port. After being sent to the network side, the serial server receives the data of the virtual serial port from the network side through the network port, and sends the data of the virtual serial port to the corresponding serial port according to the corresponding relationship of the local maintenance, thereby implementing the serial port server. The transmission channel between the physical serial port and the virtual serial port established by the host.

For the data of the upper application communicating through the transmission channel, what is seen is a reliable communication link, which is carried by UDP. As for the network environment under the link, it is not visible to the upper layer, and the present invention does not need to be considered.

When performing step S102, the method may include: encapsulating the data into a UDP packet, where the UDP packet includes a packet sequence number. When the data encapsulation is performed, a reliable UDP header may be added to the UDP packet, where the packet sequence number for ensuring that the UDP packet is correctly transmitted in sequence is included. When performing step S103, the method further includes: after receiving the response, obtaining the packet sequence number from the packet. If the packet sequence number is the same as the packet sequence number of the transmitted data, it is considered that a response corresponding to the transmitted data is received. And when the step S104 is performed, the method further includes: after receiving the UDP packet sent by the peer end, obtaining a packet sequence number from the peer end, and sending a response including the packet sequence number to the peer end.

In another embodiment, the reliable UDP header may further include other information for further ensuring reliable transmission of the UDP packet. For example, you can also include a package type to verify the package type. For example, it is also possible to include flow control related information such as >3⁄4 text length, transmission flow control information, and the like. For another example, the response sequence number may also be included, and after receiving the UDP packet, the response sequence number is obtained. A response including the response sequence number is returned, thereby verifying whether the response is a response corresponding to the UDP packet. When step S102 is performed, data that does not meet the requirements may be filtered by adding control information at the application level, thereby further ensuring reliability of data transmission. The control information may be information such as a checksum. Correspondingly, when performing step S104, the method further includes: after receiving the UDP packet sent by the peer end, verifying, according to the control information in the UDP packet, the data in the UDP packet, if the verification succeeds, The corresponding response is sent to the peer.

The invention is mainly applied to transmitting serial port data between a physical serial port of a serial port data server and a virtual serial port established by a host. Considering that the data sent by the serial server is in addition to the serial port data, there are other Ethernet-related data, server management data and other data. In order to isolate the serial port data from the data, preferably, a specific virtual local area network VLAN can be used. The identifier identifies the serial port data. Correspondingly, when performing step S102, the virtual local area network (VLAN) VLAN identifier is used to identify the serial port data. After performing the step S104, after receiving the serial port data, if it is determined that the VLAN identifier is included, the corresponding serial port data is sent. Response.

The communication between the serial port server and the host device may be bidirectional, that is, the data may be sent from the serial server to the host, or the host may send data to the serial server, which is applicable to the foregoing method.

To further illustrate the embodiments of the present invention, referring to FIG. 2, the figure shows a process of data transmission between a serial port server and a host according to an embodiment of the present invention. After the transmission channel between the two is established, the serial server will be sent. Data caching, and then encapsulating the data, includes: encapsulating the data into a UDP packet, adding a control information header to the UDP packet, adding a reliable UDP header to the UDP packet, adding the UDP packet to the UDP packet The UDP header then sends the encapsulated UDP packet to the network side. After receiving the UDP packet, the host side strips the UDP header, determines whether the order of the data packet is correct according to the reliable UDP header, and determines according to the control information header. Whether the data encapsulated in the UDP packet meets the requirements. If the order of the UDP packets is correct and the content meets the requirements, the corresponding response is returned. After the serial server sends the data, it can monitor whether the corresponding response can be received within a preset time. If not, the retransmission mechanism is started. As shown in Figure 3, the data is resent, ensuring that the host side receives it correctly. The process of sending data to the serial server by the host is the same and will not be described here. In order to implement the foregoing method, the embodiment of the present invention further provides a data transmission apparatus, which is used for communication between a serial port server and a host, as shown in FIG. 4, including:

a data sending module, configured to: cache the data when transmitting data; and package the data by using a reliable user data packet protocol (RUDP); and send a preset after sending the data Resending the encapsulated data without receiving a response corresponding to the transmitted data within the time range;

A data receiving response module configured to transmit a response corresponding to the received data after receiving the data.

The data sending module is configured to encapsulate data into a UDP packet when the data is encapsulated by RUDP, and the UDP packet includes a packet sequence number. After receiving the UDP packet, the data receiving response module obtains the packet sequence number from the packet, and sends a response including the packet sequence number. After receiving the response, the data sending module obtains the packet sequence number from the packet, and if the packet sequence number is the same as the packet sequence number of the data transmitted, it is considered that the response corresponding to the transmitted data is received.

Preferably, the UDP packet further includes control information. After receiving the UDP packet sent by the peer end, the data receiving response module further verifies the data in the UDP packet according to the control information in the UDP packet, and if the verification succeeds, the UDP packet is sent. Corresponding response.

The data refers to serial port data. Preferably, the data sending module further uses the virtual local area network (VLAN) VLAN identifier to identify the serial port data when transmitting the serial port data. After receiving the serial port data, the data receiving response module sends a response corresponding to the serial port data if it is determined that the VLAN identifier is included therein. The data sending module is further configured to: establish, by using a network port, a correspondence between a physical serial port on the serial port server and a virtual serial port of the host; and establish a physical serial port on the serial port server according to the corresponding relationship A transmission channel between the virtual serial port on the host. The data sending module and the receiving response module of the present invention are loaded on the serial server, and the data sending module and the receiving response module of the present invention are also loaded on the host, which can effectively ensure the reliable transmission of the serial data between the two by the hierarchical control mode. Sex.

Of course, the invention may have other various embodiments without departing from the spirit and spirit of the invention. All such changes and modifications are intended to be included within the scope of the appended claims.

Industrial applicability

Compared with the prior art, the present invention can achieve reliable transmission by adding a reliability mechanism between the virtual serial port and the corresponding physical serial port.

Claims

Claim

A data transmission method, configured for communication between a serial port server and a host, the method comprising: caching the data when transmitting data to the opposite end; and encapsulating the data by using a reliable user data packet protocol RUDP Transmitting; resending the encapsulated data if a response corresponding to the transmitted data is not received within a preset time range after transmitting the data; and after receiving the data sent by the opposite end, The peer sends a response corresponding to the received data.

2. The method of claim 1 wherein

The step of encapsulating the data by using RUDP includes: encapsulating the data into a user data packet protocol UDP packet, where the UDP packet includes a packet sequence number;

The step of sending a response to the peer end includes: after receiving the UDP packet sent by the peer end, obtaining a packet sequence number from the received UDP packet, and sending a response including the packet sequence number to the peer end;

The method further includes: after receiving the response, obtaining a packet sequence number from the received response, and if the obtained packet sequence number is the same as the packet sequence number of the transmitted data, it is considered that a response corresponding to the transmitted data is received.

3. The method of claim 2, wherein

The UDP packet further includes control information;

4. The method of claim 1, wherein

The data refers to serial port data;

The step of sending a response corresponding to the received data to the peer end includes: after receiving the serial port data, if it is determined that the received serial port data includes a VLAN identifier, the response corresponding to the serial port data is sent to the opposite end.

5. The method of claim 1 further comprising:

Establishing, by the network port, a correspondence between a physical serial port on the serial server and a virtual serial port of the host;

6. A data transmission device, configured to communicate between a serial port server and a host, the data transmission device comprising:

a data sending module, configured to: cache the data when transmitting data; and send the data after the data is encapsulated by a reliable user data packet protocol RUDP; and, a preset time range after the data is sent If the response corresponding to the transmitted data is not received, the encapsulated data is resent;

7. The apparatus according to claim 6, wherein

8. The apparatus according to claim 7, wherein

The UDP packet further includes control information;

9. The apparatus according to claim 6, wherein

The data refers to serial port data;

10. The apparatus according to claim 6, wherein