WO2015180418A1 - Multicast transmission method, device and system - Google Patents

Abstract

Disclosed are a multicast transmission method, device and system. The method comprises: receiving a first checking packet comprising serial number information from a control channel of a multicast group; according to the serial number information, determining information about a multicast data packet of the multicast group which should be received; receiving the multicast data packet from a data channel of the multicast group; within a first pre-determined time, according to the received multicast data packet and the determined information about the multicast data packet which should be received, detecting whether a multicast data packet is lost; and if a multicast data packet is lost, sending a negative acknowledgement (NAK) to a sending end of the multicast group, so that the sending end resends the lost multicast data packet. By means of the multicast transmission method of the present invention, a multicast receiver can quickly and accurately discover a multicast data packet which is lost in a process of transmission using the checking packet, thereby greatly improving the reliability of multicast transmission.

Description

Multicast transmission method, device and system

This application claims priority to Chinese Patent Application No. 201410229489.X, entitled "Multicast Transmission Method, Apparatus and System", filed on May 28, 2014, the entire contents of In this application.

Technical field

The present invention relates to the field of communications, and in particular, to a multicast transmission method, apparatus, and system.

Background technique

Software-Defined Networking (SDN) is a new network innovation architecture. By separating the control plane of the network device from the data plane, it realizes flexible control of network traffic and provides innovation for core networks and applications. Good platform. In SDN, the control planes of network devices are usually centralized on one controller. The controller devices need to send control information to multiple network devices to ensure the normal operation of the network devices. Since an SDN usually includes a large number of network devices, the controller uses the multicast protocol to send control information to the network device to ensure the transmission efficiency of the control information and reduce the transmission delay of the control information.

In actual use, data packets between the controller and the network device are also likely to be transmitted across the wide area, and data packets are likely to be lost during transmission. Since the multicast protocol itself does not include an acknowledgment mechanism and a retransmission mechanism, in order to ensure the reliability of data packet transmission, it is necessary for the multicast receiver to detect whether the data packet is lost. The multicast receiver sends a Negative Acknowledgement (NAK) to the multicast sender after detecting the packet loss. After receiving the NAK, the multicast sender sends the data packet corresponding to the NAK to the multicast receiver.

In the prior art, a common method for detecting packet loss is that a multicast sender sends a data packet carrying a sequence number of a transmission sequence, and the multicast receiver determines whether there is a data packet according to whether the transmission sequence number of the data packet is lost. Is there a loss? For example, if the multicast receiver receives the data packets numbered 100 and 102, if the multicast receiver still does not have the data packet number 101, The data packet of the 101st packet may be lost, and the NAK of the data packet of the 101st is sent to the multicast sender, and the multicast sender is requested to resend the data packet of the 101st.

In the actual situation, although the multicast sender sends data packets in the order of number, after the network transmission arrives at the multicast receiver, it has been out of order. Therefore, when the multicast receiver receives the data packet No. 102, it cannot immediately judge the loss of 101. It also needs to wait for a period of time. This is to reduce the feedback efficiency and reduce the transmission efficiency of the data packet. In addition, in this manner, when a certain data packet is lost, the multicast receiver can only discover the data packet after receiving the subsequent sequence number. This will cause the multicast receiver to be unable to discover the loss of the last data packet in a certain period of time. If the last data message is lost, it is likely to be undetectable. As can be seen from the above, if the existing multicast transmission method is used, if the data packet is lost during transmission, it may be difficult to find for a long time, which may result in low reliability of multicast data transmission.

Summary of the invention

The embodiment of the invention provides a multicast transmission method, device and system, which can solve the problem that the data transmission of the existing multicast transmission method is difficult to be discovered in a long time after being lost in the transmission process, thereby making the multicast data transmission reliable. Low sexual problem.

The first aspect provides a multicast transmission method, including: receiving a first verification message from a control channel of a multicast group, where the first verification message includes sequence number information; and according to the sequence number information Determining the information of the multicast group that should receive the multicast data packet; receiving the multicast data packet from the data channel of the multicast group; and according to the received multicast data packet, in the first predetermined time, And determining the information of the multicast data packet to be received, detecting whether there is a lost multicast data packet; if there is a lost multicast data packet, sending a negative acknowledgement NAK to the sending end of the multicast group, so as to facilitate the The sender retransmits the lost multicast data packet, and the NAK includes sequence number information of the lost multicast data packet.

With reference to the first aspect, in a first possible implementation manner of the first aspect, the method further includes: if the multicast data packet corresponding to the NAK is not received, and the number of times the NAK is sent is not up Up to a preset threshold, the NAK is repeatedly sent to the transmitting end according to a predetermined retransmission frequency.

With reference to the first aspect or the first possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, the method further includes: determining, by the multicast data, the N multicast data of the multicast group to be sent. Transmitting a second parity packet for the N multicast data packets, where the second verification packet includes sequence number information of the N multicast data packets; The control channel of the multicast group sends the second check packet to the receiving end, so that the receiving end determines packet loss information according to the second check packet, and uses the data channel of the multicast group to The receiving end sends the N multicast data messages.

With reference to the second possible implementation manner of the first aspect, in a third possible implementation manner of the first aspect, the sequence number information of the N multicast data packets is: the N multicast data packets The sending sequence number; or the initial sending sequence number of the N multicast data messages and the number N of the N multicast data messages.

With reference to the second possible implementation manner of the first aspect or the third possible implementation manner of the first aspect, in a fourth possible implementation manner of the first aspect, the method further includes: if the second verification If the ACK corresponding to the second verification packet is not received within the second predetermined time after the packet is sent, the second verification packet is sent to the receiving end.

A second aspect provides a multicast transmission apparatus, where the apparatus includes: a receiving unit, configured to receive a first verification packet from a control channel of a multicast group, where the first verification packet includes a serial number a determining unit, configured to determine, according to the serial number information received by the receiving unit, information of a multicast data packet to be received by the multicast group; the receiving unit is further configured to use the multicast The data channel of the group receives the multicast data packet, and the detecting unit is configured to: according to the multicast data packet that the receiving unit has received, and the multicast datagram that should be received by the determining unit, in the first predetermined time And the sending unit, if the detecting unit detects the lost multicast data packet, sending a negative acknowledgement NAK to the sending end of the multicast group, so as to facilitate the sending And transmitting, by the terminal, the lost multicast data packet, where the NAK includes sequence number information of the lost multicast data packet.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the device further includes: a preparing unit, configured to determine N multicast data packets of the multicast group to be sent, and a generating unit, And generating, by using the N multicast data packets that are determined by the preparation unit, a second check packet, where the second check packet includes a sequence number of the N multicast data packets. The sending unit is further configured to send, by using the control channel of the multicast group, the second verification packet generated by the generating unit to the receiving end, so that the receiving end is configured according to the second school The packet is determined to be the packet loss information, and the N multicast data packets determined by the preparation unit are sent to the receiving end by using the data channel of the multicast group.

With reference to the second possible implementation of the second aspect, in a third possible implementation manner of the second aspect, the generating unit is configured to generate the N multicast data packets that are determined by the preparation unit The second verification packet of the transmission sequence number; or when the transmission sequence number of the N multicast data packets determined by the preparation unit is continuous, generating an initial transmission including the N multicast data messages The second check packet of the sequence number and the number of multicast data packets to be sent.

With reference to the second possible implementation of the second aspect or the third possible implementation manner of the second aspect, in a fourth possible implementation manner of the second aspect, the sending unit is further configured to be used in the second school And after receiving the ACK corresponding to the second verification packet, the second verification packet is sent to the receiving end again.

A third aspect provides a multicast transmission system, where the system includes a multicast sender and a multicast receiver, and the multicast sender is used to determine N multicasts of the multicast group to be sent. And generating a first check packet for the N multicast data packets, where the first check packet includes sequence number information of the N multicast data packets; The control channel of the multicast group sends the first check packet to the receiving end, so that the receiving end determines packet loss information according to the first check packet, and uses the data channel of the multicast group to The receiving end sends the N multicast data packet; the multicast receiver is configured to receive the first check packet sent by the multicast sender from a control channel of the multicast group; The sequence number information determines information of the multicast group that should receive the multicast data packet; receives the multicast data packet from the data channel of the multicast group; Detecting whether there is a lost multicast data packet according to the received multicast data packet and the determined information of the multicast data packet that should be received by the multicast sender; And transmitting a negative acknowledgement NAK to the multicast sender of the multicast group, so that the multicast sender retransmits the lost multicast data packet, where the NAK includes the lost multicast Serial number information of the data message.

The multicast transmission method provided by the embodiment of the present invention receives the first verification packet from the control channel of the multicast group, where the first verification packet includes sequence number information, and determines the group to be received according to the sequence number information. The information of the data packet is received; the multicast data packet is received from the data channel of the multicast group; and the received multicast data packet and the determined multicast data packet are received within the first predetermined time. The information is sent to detect whether there is a lost multicast data message; if there is a lost multicast data message, the negative acknowledgement NAK of the lost multicast data message is sent to the multicast sender, so that the multicast sender is heavy The lost multicast data packet is sent, so that the multicast receiver can quickly and accurately discover the multicast data packet lost during the transmission process by using the verification packet received by the control channel, thereby greatly improving the reliability of the multicast transmission. Sex.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below, and it will be apparent to those skilled in the art that In other words, other drawings can be obtained based on these drawings without paying for creative labor.

1A is a flowchart of an embodiment of a multicast transmission method according to the present invention;

1B is a flowchart of another embodiment of a multicast transmission method according to the present invention;

2A is a schematic diagram of an embodiment of a multicast transmission apparatus according to the present invention;

2B is a schematic diagram of another embodiment of a multicast transmission apparatus according to the present invention;

3 is a schematic diagram of an embodiment of a multicast transmission system according to the present invention;

4 is a schematic diagram of another embodiment of a multicast transmission apparatus according to the present invention.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

1A is a flowchart of an embodiment of a multicast transmission method according to the present invention. The embodiment includes the following steps:

Step 101: Receive a first verification packet from a control channel of the multicast group, where the first verification packet includes sequence number information.

The multicast transmission device first receives the first check packet sent by the sender from the control channel of the multicast group, where the first check packet includes sequence number information, and the group that should be received can be determined according to the sequence number information. The serial number of the broadcast data message. The multicast transmission device may be a multicast route or a multicast group member. The sender may be a multicast source or a multicast route. In this way, the sequence number information of the multicast data packet to be received is obtained from the control channel of the multicast group, which not only ensures the accuracy of the sequence number information, but also avoids the occupation of the data channel and reduces the congestion and packet loss of the data channel. To quickly obtain the serial number information.

After receiving the first verification packet, the acknowledgement (Acknowledgement, ACK for short) corresponding to the first verification packet is sent to the sending end.

Step 102: Determine, according to the serial number information, information about a multicast data packet to be received by the multicast group.

The multicast transmission device may obtain sequence number information from the first verification packet, and determine, according to the sequence number information, that the multicast transmission device should receive the data packet. For example, if the first verification message includes the initial transmission sequence number 0 and the step size 10 of the message sequence, it indicates that the data message to be received includes ten multicast data messages with sequence numbers 0 to 9.

Step 103: Receive a multicast data packet from a data channel of the multicast group.

The data channel of the multicast group receives the multicast data packet and receives the control channel from the multicast group. The first verification message can be performed simultaneously.

In step 104, it is detected whether there is a lost multicast data packet according to the received multicast data packet and the determined information of the multicast data packet to be received.

In order to quickly discover the lost data packet, the multicast transmission device needs to set a first predetermined time in advance as a deadline for detecting whether the message sequence has a lost message, wherein the first predetermined time can be set as needed. . In actual use, the sending end sends the first check packet through the control channel, and then sends the multicast data packet one by one through the data channel. The sending time of the first check packet and the last multicast data packet. There will be a send interval between them. In addition, due to the complexity of the multicast network, packets may be transmitted in the multicast network with a certain delay. Therefore, the first predetermined time may be preset according to actual conditions, and the first predetermined time may be greater than or equal to a sum of the transmission time interval and the delay.

During the first predetermined time, the multicast transmission device can detect whether there is a lost multicast data packet according to the received multicast data packet and the determined information of the multicast data packet to be received. For example, when the received multicast data packet is ten multicast data packets with sequence numbers 0 to 9, but only received within the first predetermined time, nine multicast data with sequence numbers 0 to 9 are received. Packet, then it can be determined that the multicast data packet with sequence number 9 has been lost during transmission.

Step 105: If there is a lost multicast data packet, send a negative acknowledgement NAK to the sending end of the multicast group, so that the sending end resends the lost multicast data packet, where the NAK includes the The serial number information of the lost multicast data packet.

If the multicast data packet is lost, the multicast transmission device sends the NAK of the lost multicast data packet to the sending end of the first verification packet, where the NAK includes the lost multicast data. The serial number information of the message. The transmitting end sends the lost packet to the multicast transmission device again, so as to ensure the reliability of the multicast communication. For example, when the multicast data packet whose sequence number is 9 is lost during transmission, the multicast data packet NAK with sequence number 9 can be sent to the sender. After receiving the NAK, the sender will re- Sending a multicast data packet with sequence number 9 to the multicast transmission device. Other parameters that may be included in the NAK may also be used to determine the Lost information about multicast data packets. When there are multiple data packets lost, a NAK can be generated for each lost data packet, or a NAK can be generated together.

To improve the transmission efficiency, when the multicast data packet corresponding to the NAK is not received, the NAK of the lost multicast data packet may be repeatedly sent to the sending end according to the predetermined first retransmission frequency, until the received The number of data packets corresponding to the NAK or the number of retransmissions reaches a preset threshold.

The above steps 101 to 105 may be implemented by a multicast user receiving end, or may be implemented by a multicast transmission device, for example, a multicast router.

As shown in the above embodiment, the first verification packet is received from the control channel of the multicast group, where the first verification packet includes sequence number information; and the multicast group is determined according to the sequence number information. The information of the multicast data packet should be received. When the multicast data packet is received from the data channel of the multicast group, the multicast transmission device can quickly and accurately detect whether there is a loss by using the verification packet. a multicast data packet; if there is a lost multicast data packet, sending a negative acknowledgement NAK to the transmitting end of the multicast group, so that the sending end resends the lost multicast data packet, in the NAK The serial number information of the lost multicast data packet is included, thereby greatly improving the reliability of the multicast transmission.

FIG. 1B is a flowchart of another embodiment of a multicast transmission method according to the present invention. After the foregoing step 105, the following steps may also be included:

Step 106: Determine N multicast data packets of the multicast group to be sent.

The multicast transmission device can set the batch sending period according to the local sending buffer size. When the sending period arrives, the multicast transmitting device checks the data packet to be sent in the sending buffer to determine the data packet to be sent.

Step 107: Generate a second parity packet for the N multicast data packets, where the second parity packet includes sequence number information of the N multicast data packets.

When generating the second verification packet, the sequence number of the N multicast data packets may be determined first, and then the verification packet including the sequence number is generated.

When determining the sequence number of a multicast data packet, you can directly send the multicast data packet. The sequence number is used as the sequence number of the multicast data packet. Alternatively, the multicast data packet may be assigned a corresponding sequence number, and the sequence number may be written into the multicast data packet. For example, when the sequence number of the multicast data packet is X, X may be used as the sequence number of the multicast data packet, or a serial number Y may be re-assigned to the multicast data packet.

After the sequence number of the N multicast data packets is determined, the second check packet is generated, where the second check packet may include each multicast data in the N multicast data packets. The serial number of the text. When the number of data packets in the packet sequence is large, and the serial number is continuous, the first verification packet may only include the data packet in the packet sequence. The initial sequence number of the text and the step size of the message sequence, that is, the initial transmission sequence number of the N multicast data messages and the number N of the N multicast data messages. The receiving end can infer the sequence numbers of all data messages in the message sequence according to the initial sending sequence number and the step size. For example, when the sequence of the multicast data packet to be sent includes 10 multicast data packets with sequence numbers 0 to 9, the first verification packet may include 10 serial numbers of 0 to 9, and It may include only the initial sequence number 0 of the message sequence and the step size 10 of the message sequence.

Step 108: Send the second verification packet to the receiving end by using the control channel of the multicast group, so that the receiving end determines packet loss information according to the second verification packet.

After the second verification packet is generated, the multicast transmission device may send the second verification packet to the receiving end by using the control channel of the multicast group. The receiving end may be a multicast route or a multicast group member. The receiving end may use the second verification packet to determine the information of the multicast data packet to be received, and determine the multicast data packet lost during the transmission according to the received multicast data packet. For the specific process, refer to step 101 to step 105, which are not described here.

If the ACK corresponding to the second verification packet is not received within the second predetermined time after the sending of the second verification packet, the second verification packet is sent to the receiving end again. If the second check packet is lost in the transmission process, the second check packet may be sent to the receiving end again. When the second verification packet is sent to the receiving end, the unicast mode may be adopted.

Step 109: Send the N multicast data packets to the receiving end by using the data channel of the multicast group.

After the second verification packet is sent to the receiving end by the control channel of the multicast group, or after the second verification packet is sent, the multicast transmission device passes the data of the multicast group. The channel sends the N multicast data packets to the receiving end. The process of sending multicast data packets to the receiving end through the data channel is not described here.

The receiving end may determine, according to the second verification packet, whether the N multicast data messages are all received. If one of the multicast data packets is not received by the receiving end, the receiving end may send a NAK corresponding to the multicast data packet to the multicast transmission device. After receiving the NAK, the multicast transmission device sends the multicast data packet corresponding to the NAK to the receiving end.

The above steps 106 to 109 may be implemented by a multicast source or by a multicast transmission device, for example, a multicast router.

With the multicast transmission method of the embodiment, the multicast transmission device can use the first verification packet to receive the multicast data packet by using the first verification packet received from the control channel of the multicast group. And accurately discovering the multicast data packets that are lost during the transmission process, thereby greatly improving the reliability of the multicast transmission; and generating the second verification packet when the multicast data packet is sent to the receiving end of the multicast user. The receiving end can quickly and accurately discover the multicast data packets lost during the transmission.

1A and 1B, the above steps 101 to 109 can be implemented by a multicast transmission device, for example, a multicast router.

Corresponding to the multicast transmission method of the present invention, the present invention also provides a multicast transmission apparatus and a multicast transmission system.

2A is a schematic diagram of an embodiment of a multicast transmission apparatus according to the present invention.

The multicast transmitting apparatus includes a receiving unit 201, a determining unit 202, a detecting unit 203, and a transmitting unit 204.

The receiving unit 201 is configured to receive a first verification packet from a control channel of the multicast group, where the first verification packet includes sequence number information.

The determining unit 202 is configured to determine, according to the sequence number information received by the receiving unit 201, information about the multicast data packet to be received by the multicast group.

The receiving unit 201 is further configured to receive a multicast data packet from a data channel of the multicast group.

The detecting unit 203 is configured to detect, according to the multicast data packet that the receiving unit 201 has received, and the information that the determining unit 202 determines that the multicast data packet should be received, in the first predetermined time. There is a lost multicast data message.

The sending unit 204, if the detecting unit 203 detects the lost multicast data packet, sends a negative acknowledgement NAK to the transmitting end of the multicast group, so that the sending end resends the lost multicast datagram. The NAK includes sequence number information of the lost multicast data packet.

The sending unit 204 is further configured to: when the multicast data packet corresponding to the NAK is not received, and the number of times of sending the NAK does not reach a preset threshold, send the packet to the sending end according to a predetermined retransmission frequency. The NAK.

The sending unit 204 is further configured to: after the receiving unit 201 receives the first verification message, send the ACK corresponding to the first verification message to the sending end.

As shown in FIG. 2B, the apparatus may further include: a preparation unit 205, and a generation unit 206.

The preparation unit 205 is configured to determine N multicast data packets of the multicast group to be sent.

The generating unit 206 is configured to generate a corresponding second check packet for the N multicast data packets that are determined by the preparation unit 205, where the second check packet includes the N groups The serial number information of the broadcast data message.

Specifically, the generating unit 206 may be configured to generate a second verification packet that includes a transmission sequence number of the N multicast data packets determined by the preparation unit 205. The second verification packet including the initial transmission sequence number of the N multicast data packets and the number of multicast data packets to be sent is generated when the transmission sequence number of the N multicast data packets is determined to be 205. .

The sending unit 204 is further configured to send, by using the control channel of the multicast group, the second verification packet generated by the generating unit 206 to the receiving end, so that the receiving end is configured according to the second school The packet is determined to be the packet loss information, and the N multicast data packets determined by the preparation unit 205 are sent to the receiving end by using the data channel of the multicast group.

The sending unit 204 is further configured to: if the ACK corresponding to the second verification packet is not received in the second predetermined time after the sending of the second verification packet, re-send to the receiving end Sending the second verification packet. The sending unit 204 may use the multicast mode or the unicast mode when the second check packet is sent to the multicast receiver.

The receiving unit 201 is further configured to receive a NAK sent by the receiving end. The sending unit 204 is further configured to: when the receiving unit 201 receives the NAK from the receiving end, send the multicast data packet corresponding to the NAK to the receiving end.

In this embodiment, when receiving the multicast data packet, the multicast transmission device can quickly discover the multicast data packet lost during the transmission process by using the first verification packet, thereby greatly improving the reliability of the multicast transmission. The multicast transmission device may also be configured to send a multicast data packet, and generate a second verification packet when the multicast data packet is sent, so that the multicast receiver can quickly discover the group lost during the transmission. Broadcast data messages create conditions.

3 is a schematic diagram of an embodiment of a multicast transmission system according to the present invention.

The system shown in FIG. 3 includes a multicast sender 301 and a multicast receiver 302.

The multicast sender 301 is configured to determine N multicast data packets to be sent, and generate a corresponding first check packet, the first check packet, for the N multicast data packets. Include the serial number information of the N multicast data packets; send the first check packet to the receiving end by using the control channel of the multicast group; and pass the data channel of the multicast group to the receiving end Sending the N multicast data packets. In this embodiment of the present invention, the multicast sender may be a multicast source or a multicast router. The sequence number information of the N multicast data packets may be the transmission sequence number of the N multicast data packets; when the transmission sequence numbers of the N multicast data messages are consecutive, the N The sequence number information of the multicast data packet may be an initial transmission sequence number and location of the N multicast data packets. The number N of N multicast data packets.

The multicast receiver 302 is configured to receive the first check packet from a control channel of the multicast group, and determine, according to the sequence number information, information that should receive the multicast data packet; from the multicast group The data channel receives the multicast data packet; and determines whether there is a lost multicast data packet according to the received multicast data packet and the determined information of the multicast data packet to be received within a predetermined time; The multicast data packet is lost, and the NAK of the lost multicast data packet is sent to the multicast sender 301, so that the multicast sender 301 retransmits the lost multicast data packet. In this embodiment of the present invention, the multicast receiver may be a multicast receiving end device or a multicast router.

The multicast sender 301 is further configured to: if the ACK corresponding to the first verification packet is not received within the second predetermined time after the sending of the first verification packet, The receiving end sends the first verification packet.

The multicast sender 301 is further configured to resend the first verification packet to the receiving end in a unicast manner.

The multicast sender 301 is further configured to: if the NAK from the receiving end is received, send the multicast data packet corresponding to the NAK to the receiving end.

The multicast receiver 302 is further configured to: if the multicast data packet corresponding to the NAK is not received, and the number of times of sending the NAK does not reach a preset threshold, repeat to the sending end according to a predetermined retransmission frequency. Send the NAK.

The multicast receiver 302 is further configured to: after receiving the first verification message, send an acknowledgement ACK corresponding to the first verification message to the sending end.

The multicast sender 301 may be a multicast source or a multicast transmission device, such as a multicast router. The multicast receiver 302 may be a multicast user receiver or a multicast transmission device, such as a multicast router. According to the above description, the multicast transmission device participating in the multicast group, such as a multicast router, can implement segmented packet discovery and retransmission of multicast data packet transmission, which not only improves packet loss detection and retransmission. Efficiency can also avoid the impact of packet loss on the receiving end and improve the experience of multicast users.

FIG. 4 is a schematic structural diagram of another multicast transmission apparatus according to an embodiment of the present invention.

As shown in FIG. 4, the multicast transmission device includes a processor 401, a memory 402, and a communication interface 403. The processor 401, the memory 402, and the communication interface 403 are connected by a bus 404.

The bus 404 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is shown in Figure 4, but it does not mean that there is only one bus or one type of bus.

The memory 402 is used to store programs. In particular, the program can include program code, the program code including computer operating instructions. The memory 402 may include a random access memory (RAM) memory, and may also include a non-volatile memory (Non-Volatile Memory), such as at least one disk storage.

The processor 401 executes a program stored in the memory 402, and is configured to: receive, by using the communication interface 403, a first verification packet from a control channel of the multicast group, where the first verification packet includes sequence number information; Determining, according to the serial number information, information about the multicast data packet to be received by the multicast group; receiving, by using the communication interface 403, the multicast data packet from the data channel of the multicast group; Detecting whether there is a lost multicast data packet according to the received multicast data packet and the determined information of the multicast data packet to be received; if there is a lost multicast data packet, the communication interface 403 is used to notify the group. The sender of the broadcast group sends a negative acknowledgement NAK, so that the sender retransmits the lost multicast data packet, and the NAK includes the sequence number information of the lost multicast data packet. In this way, the multicast data packets lost during the transmission process can be quickly and accurately found, thereby greatly improving the reliability of the multicast transmission.

The processor 401 is further configured to: if the multicast data packet corresponding to the NAK is not received, and the number of times of sending the NAK does not reach a preset threshold, send the message to the server according to a predetermined retransmission frequency. The NAK is repeatedly transmitted.

The processor 401 is further configured to: after receiving the first verification message, send, by using the communication interface 403, the acknowledgement ACK corresponding to the first verification message to the sending end.

The processor 401 is further configured to determine N multicast data packets of the multicast group to be sent, and generate a second second check packet for the N multicast data packets, where the The second check packet includes the sequence number information of the N multicast data packets, and the second check packet is sent to the receiving end by using the control channel of the multicast group by using the communication interface 403. The receiving end determines the packet loss information according to the second verification packet, and sends the N multicast data packets to the receiving end by using the data channel of the multicast group through the communication interface 403. The sequence number information of the N multicast data packets may be the transmission sequence number of the N multicast data packets; when the transmission sequence numbers of the N multicast data messages are consecutive, the N The sequence number information of the multicast data packet may be: an initial transmission sequence number of the N multicast data packets and a quantity N of the N multicast data packets. In this way, when the multicast data packet is sent to the receiving end of the multicast user, the second check packet is generated, so that the receiving end can quickly and accurately discover the multicast data packet lost during the transmission.

The processor 401 is further configured to: if the ACK corresponding to the second verification packet is not received in the second predetermined time after the sending of the second verification packet, re-send through the communication interface 403 Sending the second verification packet to the receiving end. When the second verification packet is sent to the receiving end, the unicast mode may be adopted.

The processor 401 is further configured to: if the NAK from the receiving end is received, send the multicast data message corresponding to the NAK to the receiving end by using the communication interface 403.

The processor 401 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP processor, etc.), or a digital signal processor (DSP) or an application specific integrated circuit ( ASIC), off-the-shelf programmable gate array (FPGA) or other programmable logic device.

It will be apparent to those skilled in the art that the techniques in the embodiments of the present invention can be implemented by means of software plus a necessary general hardware platform. Based on such understanding, the technical solution in the embodiments of the present invention may be in the form of a software product in essence or in part contributing to the prior art. It is embodied that the computer software product can be stored in a storage medium, such as a ROM/RAM, a magnetic disk, an optical disk, etc., and includes a plurality of instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to execute the present invention. The methods described in various embodiments or portions of the embodiments are invented.

The various embodiments in the specification are described in a progressive manner, and the same or similar parts between the various embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the device and the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiment.

The embodiments of the invention described above are not intended to limit the scope of the invention. Any modifications, equivalent substitutions and improvements made within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims (10)

A multicast transmission method, the method comprising: Receiving, by the control channel of the multicast group, the first verification packet, where the first verification packet includes sequence number information; Determining, according to the serial number information, information about the multicast data packet to be received by the multicast group; Receiving a multicast data packet from the data channel of the multicast group; Detecting whether there is a lost multicast data packet according to the received multicast data packet and the determined information of the multicast data packet to be received; Sending a negative acknowledgement NAK to the sender of the multicast group, so that the sender retransmits the lost multicast data packet, and the NAK includes the lost multicast. Serial number information of the data message. The method of claim 1 wherein the method further comprises: If the multicast data packet corresponding to the NAK is not received, and the number of times the NAK is sent does not reach the preset threshold, the NAK is repeatedly sent to the sending end according to a predetermined retransmission frequency. The method of claim 1 or 2, wherein the method further comprises: Determining N multicast data packets of the multicast group to be sent; Generating a corresponding second check packet for the N multicast data packets, where the second check packet includes sequence number information of the N multicast data packets; Sending, by the control channel of the multicast group, the second check packet to the receiving end, so that the receiving end determines packet loss information according to the second check packet; Sending, by the data channel of the multicast group, the N multicast data packets to the receiving end. The method of claim 3, wherein the sequence number information of the N multicast data messages is: Sending sequence numbers of the N multicast data packets; or The initial transmission sequence number of the N multicast data packets and the number N of the N multicast data packets. The method of claim 3 or 4, wherein the method further comprises: If the ACK corresponding to the second verification packet is not received within the second predetermined time after the sending of the second verification packet, the second verification packet is sent to the receiving end again. Text. A multicast transmission device, characterized in that the device comprises: a receiving unit, configured to receive a first verification packet from a control channel of the multicast group, where the first verification packet includes sequence number information; a determining unit, configured to determine information about the multicast data packet to be received by the multicast group according to the serial number information received by the receiving unit; The receiving unit is further configured to receive a multicast data packet from a data channel of the multicast group; a detecting unit, configured to detect, according to the multicast data packet that the receiving unit has received, and the information that the determining unit determines to receive the multicast data packet, whether the lost multicast data exists in the first predetermined time Message a sending unit, if the detecting unit detects a lost multicast data packet, sending a negative acknowledgement NAK to the transmitting end of the multicast group, so that the sending end resends the lost multicast data packet, The sequence number information of the lost multicast data packet is included in the NAK. The device of claim 6 wherein said device further comprises: a preparation unit, configured to determine N multicast data packets of the multicast group to be sent; a generating unit, configured to generate a second second verification packet for the N multicast data packets that are determined by the preparation unit, where the second verification packet includes the N multicast data packets Serial number information; The sending unit is further configured to send, by using a control channel of the multicast group, the second check packet generated by the generating unit to the receiving end, so that the receiving end is configured according to the second check report. And determining, by the data channel of the multicast group, the N multicast data packets determined by the preparation unit by using the data channel of the multicast group. The device of claim 7 wherein: The generating unit is specifically configured to generate a second verification packet that includes a transmission sequence number of the N multicast data packets determined by the preparation unit, or the N identifiers that are determined by the preparation unit When the sequence number of the multicast data packet is consecutive, the second check packet containing the initial transmission sequence number of the N multicast data packets and the number of multicast data packets to be sent is generated. The device according to claim 7 or 8, wherein The sending unit is further configured to: after receiving the ACK corresponding to the second verification message, in a second predetermined time after the sending of the second verification message, send the ACK to the receiving end again The second verification message. A multicast transmission system, characterized in that the system comprises a multicast sender and a multicast receiver, The multicast sender is configured to determine N multicast data packets of the multicast group to be sent, and generate a corresponding first check packet for the N multicast data packets, where the The first verification packet is sent to the receiving end by the control channel of the multicast group, so that the receiving end is configured according to the sequence number information of the N multicast data packets. The first verification packet determines the packet loss information; and the N multicast data packet is sent to the receiving end by using the data channel of the multicast group; The multicast receiver is configured to receive, by the control channel of the multicast group, the first check packet sent by the multicast sender, and determine, according to the sequence number information, a receivable group of the multicast group. Receiving information of the data packet; receiving the multicast data packet from the data channel of the multicast group; receiving the multicast data according to the received multicast data packet and determining the received multicast data in the first predetermined time The information of the multicast data packet sent by the user is detected whether there is a lost multicast data packet; if there is a lost multicast data packet, a negative acknowledgement NAK is sent to the multicast sender of the multicast group, so as to facilitate The multicast sender retransmits the lost multicast data packet, and the NAK includes sequence number information of the lost multicast data packet.

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