WO2022002043A1 - Data retransmission method, network device, and computer readable storage medium - Google Patents

Abstract

A data retransmission method, a network device, and a computer readable storage medium. The method comprises: receiving a first retransmission request from a set top box device, the first retransmission request being used for requesting this home gateway to retransmit a lost data packet (S210); and searching for the lost data packet from data packets pre-cached in this home gateway, and sending a retransmission response message to the set top box device, the retransmission response message carrying the searched lost data packet (S220).

Description

Data retransmission method, network device and computer-readable storage medium

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Patent Application No. 202010614878.X, filed with the China Patent Office on June 30, 2020, the entire contents of which are incorporated herein by reference.

technical field

The present disclosure relates to, but is not limited to, the field of communication technology.

Background technique

Video images are usually transmitted by on-demand and multicast-based video streams. The transmission of multicast data streams generally uses the User Datagram Protocol (UDP) packetization method, but the transmission of video signals based on the UDP protocol is not reliable. , When the quality of the Internet network is poor, the loss of data packets will cause the video data to be incomplete, resulting in video packet loss and stuck, unable to restore the full content of the video signal, especially when the multicast HD is transmitted in the wireless Internet (Wireless Fidelity, WIFI) environment. Video packet loss and freezing during video services will seriously affect the user's video playback experience.

SUMMARY OF THE INVENTION

The present disclosure provides a data retransmission method, a network device, and a computer-readable storage medium.

In a first aspect, the present disclosure provides a data retransmission method, comprising: receiving a first retransmission request from a set-top box device, where the first retransmission request is used to request a home gateway to retransmit a lost data packet; The gateway searches for the lost data packet in the data packets pre-cached, and sends a retransmission response message to the set-top box device, where the retransmission response message carries the found lost data packet.

In a second aspect, the present disclosure provides a data retransmission method, comprising: when packet loss of a received multicast data packet is detected, sending a first retransmission request to a designated gateway device, where the first retransmission request is used for Request the gateway device to retransmit the lost data packet; receive the retransmission response message from the gateway device, and obtain the lost data packet carried in the retransmission response message, wherein the lost data packet is the data packet found in the local cache of the gateway device.

In a third aspect, the present disclosure provides a network device, comprising: one or more processors; a memory on which one or more programs are stored, and when the one or more programs are executed by the one or more processors, a The or multiple processors implement the data retransmission method of the first aspect or the second aspect of the present disclosure.

In a fourth aspect, the present disclosure provides a computer-readable storage medium, the storage medium stores a computer program, and when the computer program is executed by a processor, any one of the data retransmission methods in the present disclosure is implemented.

Description of drawings

FIG. 1 shows a schematic flowchart of a conventional set-top box device multicast retransmission.

FIG. 2 shows a schematic flowchart of the data retransmission method of the present disclosure.

FIG. 3 shows a schematic flowchart of the gateway device of the present disclosure caching multicast stream data.

FIG. 4 shows a schematic flowchart of data retransmission in the multicast-to-unicast scenario of the present disclosure.

FIG. 5 shows a schematic diagram of the packet format of the frame format of the retransmission response packet of the gateway device of the present disclosure.

FIG. 6 shows a schematic flowchart of a gateway device of the present disclosure processing a retransmission request sent by a set-top box.

FIG. 7 shows a schematic flowchart of the data retransmission method of the present disclosure.

FIG. 8 shows a schematic diagram of a pass-through packet format of a set-top box feedback message of the present disclosure.

FIG. 9 shows a schematic diagram of the message format of the specific payload of the set-top box feedback message in FIG. 8 .

FIG. 10 shows a schematic flowchart of the data retransmission method of the present disclosure.

FIG. 11 shows a schematic flowchart of the data retransmission method of the present disclosure.

FIG. 12 is a schematic flowchart of the implementation of multicast data stream retransmission of a set-top box device through a home gateway according to the present disclosure.

FIG. 13 shows a schematic structural diagram of a data retransmission apparatus provided by the present disclosure.

FIG. 14 shows a schematic structural diagram of a data retransmission apparatus provided by the present disclosure.

FIG. 15 shows a schematic structural diagram of a data retransmission apparatus provided by the present disclosure.

FIG. 16 shows a schematic structural diagram of a data retransmission apparatus provided by the present disclosure.

17 is a block diagram illustrating an exemplary hardware architecture of a computing device capable of implementing the data retransmission method and apparatus according to the present disclosure.

detailed description

In order to make the objectives, technical solutions and advantages of the present disclosure clearer, the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments in the present disclosure and the features of the embodiments can be arbitrarily combined with each other unless there is conflict.

Video images are usually transmitted by on-demand and multicast-based video streams. The transmission of multicast data streams generally uses the User Datagram Protocol (UDP) packetization method, but the transmission of video signals based on the UDP protocol is not reliable. , When the quality of the Internet network is poor, the loss of data packets will cause the video data to be incomplete, resulting in video packet loss and stuck, unable to restore the full content of the video signal, especially when the multicast HD is transmitted in the wireless Internet (Wireless Fidelity, WIFI) environment. Video packet loss and freezing during video services will seriously affect the user's video playback experience.

In order to solve the problem of incomplete video data in the process of video transmission in the Internet, a cache area is usually established at the service source based on the video signal stream, and the video signal stream is cached in the cache area. The packet is re-requested to the cache area to be resent. However, multicast retransmission at the source end of the video server will increase the load on the server and the transmission network. When a large number of Set-Top-Box (STB) terminal devices request retransmission concurrently, network congestion will be caused in extreme cases. , which affects the user experience.

FIG. 1 shows a schematic flowchart of a traditional set-top box device multicast retransmission method. As shown in FIG. 1 , the multicast retransmission method may include the following steps S101 to S106.

In step S101, as shown in "multicast join" in FIG. 1, the set-top box device sends a multicast join message to the multicast server.

In this step, the home gateway can transparently transmit the multicast join message through the Layer 2 bridging mode, or forward the corresponding multicast join message to the multicast server as a Layer 3 multicast routing agent.

In step S102, as shown in "Send Multicast Stream" in Fig. 1, the multicast server sends the Real Time Transport Protocol (RTP) multicast stream corresponding to the multicast group to the set-top box device and multicast packet loss transfer server.

In step S103, as shown in "Save stream" in Fig. 1, the multicast packet loss retransmission server synchronously saves the multicast data stream of the corresponding channel.

In step S104, as shown in Figure 1 as "found packet loss, request retransmission", the set-top box device receives the multicast data stream and performs packet loss check. Request retransmission of lost packets from the multicast packet loss retransmission server.

In step S105, as shown in "Retransmit Lost Packet" in FIG. 1, the multicast packet loss retransmission server receives the packet retransmission request, and retransmits the corresponding lost multicast data packet.

In step S106, as shown in "completely assembled, decoded and outputted for playback" in Fig. 1, the set-top box can be completely reassembled according to the currently received retransmission packet and the previously received normal packet, and decoded and outputted to the TV for playback.

Through the above steps S101-S106, a buffer area is established on the multicast retransmission server side, and the video signal stream received from the multicast server is buffered in the buffer area. The data packets are retransmitted to the cache area of the multicast retransmission server, so as to solve the problem that the video data is incomplete due to network problems during the transmission of the video in the Internet.

In this multicast retransmission method, when there are a large number of set-top box terminal devices concurrently requesting retransmission, the retransmission request issued by the source end of the video server (for example, the multicast retransmission server) will increase the load of the server and the transmission network. In extreme cases, it will cause network congestion and affect user experience.

The present disclosure provides a data retransmission method, which can cache the multicast data stream locally in the gateway device, and the set-top box device preferentially requests retransmission from the gateway device, which can effectively reduce the load of retransmitted packets by the multicast server and reduce network retransmission. time delay.

FIG. 2 shows a schematic flowchart of the data retransmission method of the present disclosure. As shown in FIG. 2 , the data retransmission method in the present disclosure may be applied to a home gateway, and may include the following steps S210 and S220.

In step S210, a first retransmission request from the set-top box device is received, and the first retransmission request is used to request the home gateway to retransmit the lost data packet.

In step S220, the lost data packet is searched from the data packets pre-cached by the home gateway, and a retransmission response message is sent to the set-top box device, and the retransmission response message carries the found lost data packet.

According to the data retransmission method of the present disclosure, the gateway device caches the multicast data locally, and the set-top box device preferentially requests the gateway device to retransmit lost data packets, which can effectively reduce the load of the multicast server retransmitted packets and reduce network retransmission. time delay.

In one embodiment, the data packets in the cache of the home gateway, according to the different networking methods and video playback services, the wide area network (Wide Area Network, WAN) side multicast data stream, including the first original code stream data packet and the third Two original code stream data packets, wherein the first original code stream data packet and the second original code stream data packet are multicast data packets carrying real-time transmission protocol-based RTP header information, and the first original code stream data packet comes from The Internet TV (Over The Top, OTT) connected by routing is a multicast service plane that carries multicast services through the Internet routing channel for home gateways. Internet Protocol TV (Internet Protocol TV, IPTV) private network multicast service plane.

In the embodiment of the present disclosure, when the home gateway forwards the received downlink multicast data stream to the set-top box device, the multicast data stream learned by multicast is synchronously cached locally according to the multicast address and destination port number. , in the specific implementation, the gateway locally pre-configures and delivers the corresponding multicast virtual local area network (Virtual Local Area Network, VLAN) to the kernel according to the needs of the business. When the gateway receives the STB uplink join message, it will This multicast learning entry includes multicast VLAN, multicast group, packet source port and other information. Subsequent received downlink multicast streams are hashed according to the multicast group. Hash operation, and forward to the corresponding source port according to the multicast entry information learned from the upstream, and record the RTP header part information after the UDP packet header corresponding to the multicast group at the same time. It can buffer the multicast data stream of the department, and supports the buffering of multiple different multicast groups at the same time.

In the embodiment of the present disclosure, the gateway device may be a home gateway device, and an optical network unit (Optical Network Unit, ONU) is used as a home gateway device accessed by an STB, and while forwarding basic multicast protocol packets and data packets, It has the function of a small content distribution network (CDN). Since the home gateway device is the latest gateway device connected to the set-top box, the home gateway device is given priority to request retransmission of lost data packets locally, which can effectively reduce the network of the video server. load, reduce network congestion, and improve video transmission quality during wireless 4K access.

In one embodiment, before step S210, the method further includes: step S11, when receiving different service request messages from the set-top box device, sending different service request messages to the corresponding multicast server; step S12, Locally, the home gateway caches and forwards the downlink data packets received from the corresponding multicast server in a predetermined manner, wherein the predetermined manner corresponds to different service request messages and playback modes of the set-top box device.

FIG. 3 shows a schematic flowchart of the gateway device of the present disclosure caching multicast stream data. In Figure 3, the set-top box bridges the multicast data stream of the IPTV network-side multicast server through a wired local area network (Local Area Network, LAN) port or a wireless WLAN port, and the process of caching the multicast stream data may specifically include the following steps S301 to S304.

In step S301, the set-top box device sends an uplink multicast protocol join message through the wireless WLAN port.

In this step, the set-top box device can access the IPTV network-side multicast server in a bridging manner through a wired LAN port or a wireless WLAN port.

In step S302, the home gateway device learns the added multicast group and source port according to the uplink multicast protocol join message, and forwards it to the IPTV bridge WAN to connect to the network side multicast server.

In this step, the home gateway can listen to the Snooping module through the Internet Group Management Protocol (The Internet Group Management Protocol, IGMP) multicast, and listen to the uplink multicast protocol join message of the set-top box device.

In step S303, the home gateway device receives the downlink multicast data stream sent by the WAN side server, and distinguishes the packet group and the RTP destination port number for local multicast data stream caching.

In this step, when the packet loss pre-detection sub-module of the home gateway finds that the sequence numbers of the RTP packets are discontinuous, it can actively request the server for pre-retransmission.

In step S304, the home gateway device forwards the received downlink multicast data stream to the set-top box terminal device of the wireless WLAN port.

In this step, the home gateway device may forward the downstream multicast data stream to the corresponding LAN port or wireless WLAN port according to the learned upstream rule, so as to forward it to the set-top box terminal device.

Through the above steps S301-S304, the home gateway device can send the received multicast data packet of the downstream corresponding multicast group to the set-top box device, And it can synchronously cache the received multicast data packets of different multicast groups into the home gateway.

In this embodiment, after receiving the downlink multicast data stream and forwarding it to the set-top box device, the home gateway can distinguish the packet group and the destination port number for local caching, so as to be used for subsequent retransmission requests according to the received set-top box device, Find and send the missing packet from the local cache to the set-top box device.

As can be seen from the above description, if the service request message is a multicast join message, the above step S11 may specifically include: step S11-01, according to the received multicast join message of the set-top box device, the corresponding multicast Group information, message source port device information, and multicast VLAN information pre-configured in the home gateway are added as corresponding multicast learning entries; step S11-02, according to the home gateway's networking and network protocol TV IPTV service Plane deployment information to forward the multicast join message to the corresponding multicast server of the bridging service plane or the multicast server of the routing service plane. The above-mentioned step S12 may specifically include: step S12-01, sending the received downlink multicast data packet to the set-top box device; step S12-02, sending the downlink multicast data packet according to different multicast addresses and based on real-time transmission protocol RTP. The destination port number is cached in the preset cache queue of the home gateway by means of cyclic coverage.

In one embodiment, if the first retransmission request is an unacknowledged NACK feedback message based on the Real-time Transport Control Protocol (RTCP) sent by the set-top box device, and the data packets pre-cached by the home gateway are Multicast packets buffered by different multicast groups, RTP destination port numbers and original packet sequence numbers.

In this embodiment, in the above step S220, the step of searching for lost data packets from the data packets pre-cached by the home gateway may include: step S221, parsing the RTCP-based NACK feedback message, and obtaining the NACK feedback message carried in the NACK feedback message. Multicast group information, destination port number, serial number of the lost data packet and packet loss sequence mask, the packet loss sequence mask is used to determine that the set-top box device has packet loss; step S222, according to the multicast group carried in the NACK feedback message information, destination port number, and sequence number of the lost packet, and find the lost packet from the multicast packets cached locally by the gateway device.

Correspondingly, in this embodiment, the retransmission response packet carries the retransmission packet identifier, and the retransmission packet identifier is used to identify the retransmission response packet; in the above step S220, the step of sending the retransmission response packet to the set-top box device, Step S223 may be included, generating a retransmission response message according to the found lost data packet, the retransmission response message carrying the RTP-based header information, the original packet sequence number of the lost data packet, and the lost data packet in the original RTP data. The payload in the packet is used to obtain the original content of the lost data packet; in step S224, a retransmission response message is sent to the set-top box device through the RTP data retransmission channel between the home gateway and the set-top box device.

In this embodiment, the retransmission message is sent by an RTCP message. Once the set-top box device finds that there is a packet loss, it will use immediate feedback to actively report it. When the home gateway receives the RTCP-based NACK retransmission request message sent by the set-top box device, Analyze the received RTCP retransmission message, obtain the corresponding multicast group, RTP port number, packet loss sequence number, and packet loss sequence mask information, and use the parsed information to query the multicast data packets in the local cache.

In the embodiment of the present disclosure, the cache size of the gateway device is the size of the cache space required to perform caching for a fixed duration according to the video rate of the specified resolution video, for example, the size of the cache space required for 2-second caching according to the 4K video rate of 25-35 Mbps. In practical application scenarios, the cache size can be appropriately expanded according to actual business requirements and the storage configuration capability of the home gateway.

In the embodiment of the present disclosure, after step S11, the method further includes: step S13, when it is detected that the sequence numbers of the received downlink multicast data packets are discontinuous, sending a pre-retransmission to a designated packet loss retransmission server request, the pre-retransmission request is used to request the packet loss retransmission server to retransmit the multicast data packets corresponding to the received discontinuous sequence numbers; step S14, receive the discontinuous sequence sent by the packet loss retransmission server The multicast data packet corresponding to the number.

In this embodiment, it is generally considered that the packet loss rate is small when transmitting in a wired manner. Therefore, the present disclosure can propose a method for multicast retransmission in a wireless access manner for gateways and set-top box devices. When the packet loss pre-detection sub-module of the home gateway finds that the sequence numbers of the RTP packets are discontinuous, it can actively request pre-retransmission from the server to improve the efficiency of data retransmission.

In this embodiment, the home gateway device and the set-top box device can use multicast or unicast communication mode. If the set-top box device is a pure unicast service scenario, it is sent in the way of on-demand, and the gateway generally bridges the transparent transmission or routing mode. For NAT translation, pure unicast application scenarios are not within the scope of the embodiments of the present disclosure.

FIG. 4 shows a schematic flowchart of data retransmission in the multicast-to-unicast scenario of the present disclosure. In Figure 4, the set-top box accesses the multicast data stream of the OTT network side multicast server through a wired local area network (Local Area Network, LAN) port or a wireless WLAN port and through a routing device.

As shown in FIG. 4, in one embodiment, the data retransmission method may include the following steps S401 to S406.

In step S401, the set-top box device sends an HTTP (Hypertext Transfer Protocol, Hypertext Transfer Protocol) request message carrying the address information of the multicast program through the wireless WLAN port.

In this step, the multicast screen projection command reference of the HTTP request message is exemplarily given, for example:

http://192.168.1.1:9090/IGMP:224.1.1.2:2024

and, http://192.168.1.1:9090/RTP:224.1.1.2:2024

The home gateway can implement the multicast-to-unicast proxy udpxy module, and can extract "IGMP:224.1.1.2:2024" and "RTP:224.1.1.2:2024" from the multicast screen projection command reference, and generate HTTP according to the extracted content. The multicast join message based on the multicast protocol corresponding to the request message.

In step S402, the udpxy module in the home gateway for realizing the multicast-to-unicast proxy function translates the HTTP request message into a multicast join message and sends it to the OTT multicast server of the Internet routing WAN connection plane.

In this step, when the home gateway device receives the multicast join message sent by the LAN side or the WLAN side, it can also act as a proxy to forward the multicast join message through the IGMP multicast proxy Proxy module.

In step S403, for the multicast-to-unicast playback mode, the home gateway receives the OTT multicast data stream on the WAN side, strips off the header of the Point-to-Point Protocol over Ethernet (PPPoE), and obtains the corresponding UDP Multicast data flow.

In step S404, the home gateway performs local slice storage on the received UDP multicast data stream.

In step S405, the home gateway converts the received WAN side multicast data stream into a Transmission Control Protocol (Transmission Control Protocol, TCP) unicast data stream.

In step S406, the home gateway forwards the unicast data stream to the set-top box device on the WLAN side.

In this step, when the normal multicast stream does not undergo unicast conversion, the forwarding process is that the home gateway forwards the protocol stack Layer 3 multicast route learned upstream to the corresponding br0 bridge device port (ie the source port), and, The home gateway forwards the received downlink multicast data stream to the corresponding learned wired and wireless access bridge ports (ie, destination ports) of the LAN-side set-top box.

In one embodiment, the udpxy module receives packets of the multicast data stream to the udpxy process according to the UDP destination port number, and the udpxy user mode process performs RTP multicast stream caching, and further converts the multicast data stream into the unicast of the TCP protocol. The stream is forwarded to the LAN side set-top box.

Through the above steps S401-S406, in the multicast-to-unicast application scenario, the home gateway converts the device-supported multicast data stream on the WAN side to the TCP unicast stream on the LAN side, and may include multicast-to-unicast udpxy playback methods or HLS playback through HTTP proxy. The home gateway device performs data retransmission according to the set-top box TCP unicast retransmission request.

In another application scenario of the present disclosure, the set-top box device can adopt the streaming media (HTTP Live Streaming, HLS) playback mode based on the HTTP protocol. In this application scenario, the home gateway can carry the received multicast program address information. The HTTP request message is converted into a multicast join message; and from the downstream media file data packet received by the multicast server of the corresponding routing service plane, the transport stream TS media file is obtained, and the TS is forwarded through HTTP proxy. The media files are sent to the set-top box device; based on the multimedia data processing service MTS, the TS media files are locally sliced and stored.

In the application scenario of streaming media HLS playback based on HTTP protocol, HLS is a real-time streaming transmission protocol based on HTTP protocol. ) description file, M3U represents a list file of audio files; the other part is TS media files, so for HLS mode, the home gateway can cache TS media files locally, and store them in slices through MTS mode.

It can be seen from the above description that, in one embodiment, if the service request message is a hypertext transfer protocol HTTP request message, the above step S11 may include: step S11-11, which carries the address information of the multicast program in the received message. The HTTP request message is converted into a multicast join message; step S11-12, the converted multicast join message is sent to the multicast server of the routing service plane corresponding to the multicast program address information.

When the set-top box device adopts the multicast-to-unicast playback mode, the above step S12 may include: step S12-11, converting the downlink multicast data packet received from the multicast server of the corresponding routing service plane into a TCP unicast broadcast data packets, and send the TCP unicast data packets to the set-top box device; step S12-12, remove the Ethernet transmission point-to-point protocol PPPoE header and the Internet Protocol (Internet Protocol, IP) header from the downlink multicast data packets, and obtain the corresponding UDP group UDP multicast data streams are stored locally in slices.

If the set-top box device adopts the playback mode of proxy streaming media based on the HTTP protocol, the above step S12 may include: step S12-21, obtaining the transport stream from the downstream media file data packets received by the multicast server of the corresponding routing service plane The TS media file is forwarded to the set-top box device by means of HTTP proxy; step S12-22, based on the multimedia data processing service MTS, the TS media file is locally sliced and stored.

In the above-mentioned embodiments, for the application scenario of multicast-to-unicast playback, and the application scenario of HLS-based playback based on HTTP protocol, the home gateway and the set-top box device communicate through the TCP protocol, and the TCP-based unicast can be implemented. replay.

Specifically, in the application scenario of multicast-to-unicast playback, the first retransmission request sent by the set-top box device to the gateway device may be a unicast retransmission request based on the TCP protocol, and the data packets pre-cached by the home gateway are local Slicing the stored UDP data packets, in the above step S220, the step of searching for the lost data packets from the data packets pre-buffered by the home gateway specifically refers to searching for the lost data packets from the UDP multicast data stream, and sending the data packets through the TCP Unicast retransmission to the set-top box device.

Specifically, in the application scenario of HLS playback based on the HTTP protocol, the first retransmission request sent by the set-top box device to the gateway device may be a unicast retransmission request based on the TCP protocol, and the data packet pre-cached by the home gateway For the TS media file stored in the local slice, in the above-mentioned step S220, the step of searching for the lost data packet from the data packet pre-cached by the home gateway specifically refers to searching for the lost data packet from the TS media file, and by TCP unicast retransmission to the set-top box device.

FIG. 5 shows a schematic diagram of the packet format of the frame format of the retransmission response packet of the gateway device of the present disclosure. As can be seen from Figure 5, the message format of the retransmission response message between the home gateway and the set-top box device can be extended by defining a private message, and the retransmission response message carries the RTP header information and the missing data packet The original packet sequence number and the payload of the lost packet in the original RTP packet. In the specific implementation, the multicast port (Multicast Port) contained in the response message is the destination port number of the multicast RTP stream minus 1 (the RTP port number and the RTCP port number are generally a pair).

In one embodiment, if the search for the lost data packet from the multicast data packets pre-cached by the home gateway fails, the method further includes: step S230, sending a second retransmission request to a designated packet loss retransmission server, The second retransmission request is used to request the packet loss retransmission server to retransmit the lost data packet; step S231, receive the lost packet sent by the packet loss retransmission server.

In this embodiment, if the local cache of the home gateway does not find the lost data packet that the set-top box device requests for retransmission, the home gateway acts as a proxy to continue to request retransmission to the upper-layer multicast retransmission server, so as to achieve WIFI connection Enter the purpose of playing 4K video smoothly, and at the same time can reduce the load of the video server.

FIG. 6 shows a schematic flowchart of a gateway device of the present disclosure processing a retransmission request sent by a set-top box. As shown in FIG. 6 , the gateway device processing the retransmission request sent by the set-top box may include the following steps S601 to S605.

In step S601, the gateway device receives the RTCP retransmission request message sent by the set-top box device.

In step S602, the gateway device parses the received RTCP retransmission, and obtains the corresponding multicast group, RTP port number, packet loss sequence number, and packet loss sequence mask information.

In this step, the packet sequence number (Packet ID, PID), as the packet loss sequence number, can be used to indicate the start sequence number of the currently lost packet; the bitmask of the subsequent lost packets (Bitmask of Lost Packets, BLP), BLT can be 16 bits (bits); BLP allows the loss of any of the following 16 RTP packets to be reported immediately after the RTP packet indicated by the PID. That is, according to the starting sequence number of the currently lost packet and the BLP, the subsequent packet loss sequence number for retransmission is calculated, and the set-top box requests a retransmission, and the home gateway can respond to multiple data packets.

In step S603, the gateway device obtains the multicast RTP original code stream data packets buffered at the local kernel layer 2 or layer 3.

In step S604, if the local cache of the gateway device fails to find the sequence number of the lost packet, it acts as a proxy to request retransmission of the lost packet from the multicast packet loss retransmission server.

In step S605, the gateway device performs RTP packets again according to the frame format communicated with the set-top box device and responds to the STB client.

Through the above-mentioned method for implementing multicast RTP data stream retransmission control through the home gateway in steps S601-S605, the multicast server load, retransmission delay and network congestion can be effectively reduced by this method.

According to the data retransmission method of the present disclosure, when receiving a retransmission request directly initiated by the set-top box device to the home gateway when packet loss occurs, the home gateway searches for the loss of retransmission requested by the set-top box device through the locally cached multicast stream in advance The data includes and resends the data packets found in the local cache to the set-top box device, effectively reducing the RTCP retransmission packet load of the multicast server and reducing the network retransmission delay.

FIG. 7 shows a schematic flowchart of the data retransmission method of the present disclosure. The data retransmission method can be applied to a set-top box device. As shown in FIG. 7 , the method can include the following steps S710 and S720.

In step S710, when it is detected that the received multicast data packet is lost, a first retransmission request is sent to the designated gateway device, and the first retransmission request is used to request the gateway device to retransmit the lost data packet.

In step S720, the retransmission response message of the gateway device is received, and the lost data packet carried in the retransmission response message is obtained, wherein the lost data packet is the data packet found in the local cache of the gateway device.

In this embodiment, when the set-top box device detects that the received downlink multicast data packet is lost, it directly sends a retransmission request to the gateway device, thereby obtaining the lost data packet found in the local cache by the gateway device.

In one embodiment, the first retransmission request is an unacknowledged NACK feedback message based on the real-time transmission control protocol RTCP. In this embodiment, step S710 may specifically include: detecting that the received multicast data packet is lost, and When the packet loss rate is within the predetermined packet loss rate range, send an RTCP-based NACK feedback message to the specified gateway device, where the NACK feedback message carries the specified multicast group, destination port number and the sequence number of the lost data packet .

In this embodiment, if the STB multicast channel data of the set-top box device detects packet loss through the packet loss retransmission module, and the packet loss rate is within the predetermined packet loss rate range, it sends an RTCP NACK retransmission request message to the home gateway. message; after receiving the NACK retransmission request message, the home gateway replies to the retransmitted data packet through a data retransmission channel such as an RTP channel.

In this implementation manner, the transmission communication mode for retransmitting data packets between the gateway and the STB, such as communication by specifying IP and private port number UDP connectionless mode.

The communication between the home gateway and the STB can use UDP to communicate in a connectionless mode. As an example, for example, the fixed IP is 192.168.1.1 and a specified private port. Generally, the set-top box accesses the OTT corresponding to the IGMP Proxy routing proxy mode. In this scenario, the set-top box obtains the small network address (ie the small network segment address, such as 192.168.1.x) assigned by the gateway;

As another example, for a scenario where a set-top box is connected to an IPTV server in a bridging manner, the set-top box may use two virtual MACs, one of which is a virtual Media Access Control (MAC) address and the gateway to communicate in the above-mentioned UDP manner, and the other virtual MAC address. The MAC address obtained is the large network address (that is, the large network segment address) of the IPTV private network service plane.

The following describes a schematic diagram of the message format of the feedback message sent by the set-top box device by using FIG. 8 and FIG. 9 . FIG. 8 shows a schematic diagram of a packet format of a set-top box feedback message according to an embodiment of the present disclosure; FIG. 9 shows a schematic diagram of a packet format of a specific payload of the set-top box feedback message in FIG. 8 .

In FIG. 8 , the retransmission request message of the set-top box device is sent by using an RTCP message. Once the set-top box device finds that there is packet loss, it can immediately feed back the retransmission request message to the gateway device. In the RTCP header of the retransmission request message, FMT and PT can be used to determine the type of the message, and the feedback control information (Feedback control Information, FCI) is the specific payload of this type of message. As an example, as shown in FIG. 8 , when FMT=1 and PT=205, it means that the packet is a NACK packet.

In Figure 9, the NACK message indicated by the FCI includes: the packet sequence number (Packet ID, PID), which is used to indicate the sequence number of the lost packet; the packet loss sequence mask, (Bitmask Of Following Lost Packets, BLP), It is a mask of 16 packets starting from the PID. The BLP is 1, which indicates that the set-top box device has lost packets. The BLP is 0, which means that the set-top box device has not reported packet loss.

In this embodiment, when the set-top box device finds packet loss, it sends a retransmission request to the gateway device through the packet format of the feedback message sent by the set-top box device shown in Figures 8 and 9, and the retransmission request carries the lost packet. The sequence number of the packet and the packet loss sequence mask.

In one embodiment, before step S710, before it is detected that the received multicast data packet is lost, the method further includes: step S701, sending a multicast join message to the gateway device, and the multicast join message is used for Request to join the multicast group, and the multicast join message carries the multicast source port device information and the multicast group information requested to join; Step S702, receive the multicast data packet of the multicast group requested to join sent by the gateway device.

In one embodiment, if the set-top box device adopts the playback mode of multicast-to-unicast udpxy or the playback mode of proxy streaming media based on the HTTP protocol, the step of receiving the retransmission response message of the gateway device in S720 may specifically include: The HTTP proxy of the text transmission protocol receives the unicast data packets based on the transmission control protocol TCP forwarded by the gateway device, and obtains the lost data packets carried in the TCP unicast data packets.

In this embodiment, in the application scenario where the set-top box adopts the multicast-to-unicast playback mode, the home gateway can convert the downlink multicast data stream into a TCP unicast data stream through the udpxy module, and convert the converted TCP unicast data stream into a TCP unicast data stream. The data stream is sent to the set-top box device to implement TCP unicast retransmission directly between the gateway and the set-top box; in the application scenario where the set-top box device adopts the HTTP protocol proxy-based streaming media playback mode, the TS media file is forwarded by HTTP proxy. To the set-top box device, in both scenarios, TCP unicast retransmission can be supported directly between the gateway and the set-top box, without the need for direct retransmission between the set-top box and the multicast server.

In one embodiment, the retransmission response packet is a packet received through an RTP data channel between the set-top box device and the gateway device, and the retransmission response packet carries a retransmission packet identifier, which is used to identify the retransmission response message; in this embodiment, after step S720, the method may further include: step S730, acquiring the header information based on real-time transmission protocol RTP and the original packet sequence number of the lost data packet carried in the retransmission response message , and the payload of the lost data packet in the original RTP data packet; Step S731, parse the header information based on RTP, if the header information contains the retransmission packet identifier, then parse out the retransmitted packet from the payload in the original packet Lost data packets; Step S732, assemble the currently received lost data packets and the received non-lost data packets to obtain the assembled data packets, and decode the assembled data packets to play the decoded data.

According to the data retransmission method of the embodiment of the present disclosure, after detecting that there is packet loss, the set-top box device initiates a retransmission request to the home gateway, and receives the lost data message retransmitted by the gateway device and re-sends it to the set-top box. multicast packets. In the data retransmission method, compared with sending a retransmission request to the multicast server after detecting packet loss, the load of the multicast server, the retransmission delay and the network congestion can be effectively reduced.

FIG. 10 shows a schematic flowchart of the data retransmission method of the present disclosure. The data retransmission method may be applied to a multicast server. As shown in FIG. 10 , the data retransmission method may include the following steps S810 and S820.

In step S810, a multicast join message sent by the designated gateway device is received, where the multicast join message is a multicast join message sent by the set-top box device to the gateway device, or a request based on the hypertext transfer protocol HTTP sent by the set-top box device The multicast join message obtained by converting the message;

In step S820, the multicast data packet of the multicast group requested to join is sent to the designated packet loss retransmission server and the gateway device, wherein the sent multicast data packet is locally cached in the gateway device, and the sent multicast The data packets are used in the gateway device to retransmit data lost by the set top box device to the set top box device.

In the data retransmission method, when the home gateway receives a multicast join message that the set-top box device requests to join the multicast group, it obtains the corresponding multicast group and message source port device information, and according to the multicast VLAN configured by the current gateway Add the corresponding multicast learning entry, and further forward the multicast join message to the corresponding bridging or routing service plane according to the networking of the home gateway and the deployment of the IPTV service plane, such as the bridging B plane (corresponding to the IPTV private network) or A plane for Internet routing (corresponding to OTT application scenarios). As an example, the source port may be determined according to a device identifier corresponding to a buffer area (Struct sk_buffer, skb) received by the kernel, such as an Ethernet port eth0 or a wireless LAN port wlan0.

After receiving the multicast join packet sent by the gateway device, the multicast server sends the downlink multicast data packet corresponding to the multicast group to the packet loss retransmission server and the gateway device, so that the gateway device locally caches the downlink multicast data packet , and is used to retransmit the data packets lost by the set-top box device to the set-top box device. Therefore, when a packet loss occurs on the set-top box device side, the gateway device retransmits the lost data packets to the set-top box device without receiving and processing a large number of data packets through the multicast server. This can effectively reduce the load of multicast servers, retransmission delay and network congestion.

It is to be understood that the present disclosure is not limited to the specific configurations and processes described in the above embodiments and shown in the figures. For the convenience and brevity of description, the detailed description of the known method is omitted here, and the specific working process of the system, module and unit described above can refer to the corresponding process in the foregoing method implementation, which will not be repeated here.

FIG. 11 shows a schematic flowchart of the data retransmission method of the present disclosure. The data retransmission method may be applied to a multicast retransmission server. As shown in FIG. 11 , the data retransmission method may include the following steps S910 to S930.

In step S910, the multicast data packet sent by the multicast server is received and saved.

In step S920, a second retransmission request sent by the designated gateway device is received, and the second retransmission request is used to request the packet loss retransmission server to retransmit the data packets lost by the designated set-top box device, and the gateway device currently caches the data packets in the local cache. The data packets lost by the set-top box device are not included in the broadcast data packets.

In step S930, from the saved multicast data packets, find and send the lost data packets to the multicast server, and the lost data packets are forwarded to the set-top box device in the multicast server.

In the data retransmission method, when the multicast packet loss retransmission server receives the retransmission request from the gateway device to retransmit the lost data packet of the specified set-top box device, it sends the lost data packet to the multicast server. The request is sent by the gateway device when the locally cached multicast data packets do not contain the data packets lost by the set-top box device. Compared with each time the set-top box device loses packets, the multicast packet loss retransmission server will receive and process it. The retransmission request sent by the set-top box device reduces the network delay of the retransmission, and at the same time can reduce the load of the multicast server and the network congestion.

It is to be understood that the present disclosure is not limited to the specific configurations and processes described in the above embodiments and shown in the figures. For the convenience and brevity of description, the detailed description of the known method is omitted here, and the specific working process of the system, module and unit described above can refer to the corresponding process in the foregoing method implementation, which will not be repeated here.

FIG. 12 is a schematic flowchart of implementing STB multicast data stream retransmission through a home gateway according to the present disclosure. In this embodiment, the method includes the following steps S1001-a to S1010.

In step S1001-a, the set-top box sends a multicast join message.

In step S1001-b, the home gateway forwards the corresponding multicast join message to the multicast server in a bridging manner or in a multicast routing proxy manner.

In step S1002, the multicast server sends the RTP data stream corresponding to the multicast group to the home gateway and the multicast packet loss retransmission server.

In step S1003, the multicast packet loss retransmission server synchronously saves the multicast data stream of the corresponding channel.

In step S1004, the home gateway device receives the downlink multicast data stream, forwards it to the LAN-side set-top box, and caches it locally.

In this step, the set-top box in the embodiment of the present disclosure may use a wireless or wired access manner, and the data stream retransmission method may mainly be directed to the wireless access manner of the set-top box.

In this step, the home gateway device may perform local caching according to the zoned multicast group and the RTP destination port number.

In step S1005, after receiving the multicast data stream, the set-top box device detects that there is packet loss, and initiates an RTCP request to the local home gateway to retransmit the lost data packet.

In this step, the set-top box device performs RTP packet loss check. If it is a multicast with FEC (forward error correction) function, FEC recovery is performed first. When FEC cannot be recovered and it is confirmed that there is packet loss in the stream, the The gateway initiates an RTCP request to retransmit the lost data packet, and its content contains the RTCP standard header and the privately defined extension field frame format content.

In step S1006, the home gateway device receives the RTCP packet retransmission request, and sends the lost multicast data packet found in the local cache to the set-top box device.

In this step, the home gateway device acquires the multicast group data packets cached at the local kernel layer 2 or layer 3, and if the acquisition is successful, it retransmits the corresponding lost group according to the private frame format of the retransmission response packet defined between it and the set-top box. broadcast data packets to the set-top box.

In step S1007, if the local cache fails to find the packet loss sequence number, the home gateway device, as the local proxy of the multicast server, continues to request the multicast packet loss retransmission server to retransmit the lost packets.

In step S1008, the multicast packet loss retransmission server receives the packet retransmission request, and retransmits the corresponding lost multicast data packet to the home gateway.

In step S1009, after receiving the retransmission packet of the service response, the home gateway device decodes it and forwards it to the set-top box device again according to the private frame format of the response packet defined with the set-top box device.

In step S1010, the set-top box device reassembles the complete retransmission packet according to the currently received retransmission packet and the normal packet that has been received before, decodes the output and then plays it on the TV.

Through the above steps S1001-S1010, the multicast data stream is cached locally on the home gateway, and when the set-top box device detects packet loss, it will first request the home gateway for RTCP retransmission, the retransmission delay is small, and the multicast server RTCP can be effectively reduced Retransmit packet load and reduce network retransmission delay.

The data retransmission apparatus according to the present disclosure will be described in detail below with reference to the accompanying drawings. FIG. 13 shows a schematic structural diagram of a data retransmission apparatus provided by the present disclosure. As shown in FIG. 13 , the data retransmission apparatus can be applied to a home gateway device, and includes the following modules: a first retransmission request receiving module 1110, configured to receive a first retransmission request from a set-top box device, and the first retransmission request uses In order to request the home gateway to retransmit the lost data packets; the lost packet retransmission module 1120 is configured to search for the lost data packets from the data packets pre-cached by the home gateway, send a retransmission response message to the set-top box device, and retransmit the response The message carries the found lost packets.

In the specific embodiment of the present disclosure, it can be a scheme that multicast data packets are processed in the chip of the CPU, and then the data packets can be buffered and forwarded at the second or third layer of the kernel. For some chips, the multicast data packets are not For processing in the CPU, the hard-accelerated forwarding scheme of the chip can be used directly, and the transmission efficiency is higher.

In one embodiment, the apparatus for data retransmission in the home gateway device may further include: a service request forwarding module, configured to receive different service request packets from the set-top box device before receiving the first retransmission request from the set-top box device When different service request messages are sent to the corresponding multicast server; the message buffering and forwarding module is configured to cache the downlink data packets received from the corresponding multicast server locally in the home gateway in a predetermined manner and forwarding, wherein the predetermined mode corresponds to different service request messages and playback modes of the set-top box device.

In one embodiment, if the service request message is a multicast join message, the service request forwarding module is specifically configured to, according to the received multicast join message of the set-top box device, convert the obtained corresponding multicast group information, The device information of the packet source port and the multicast VLAN information pre-configured on the home gateway are added as the corresponding multicast learning entries; according to the networking of the home gateway and the network protocol TV IPTV service plane deployment information, the multicast is added The message is forwarded to the corresponding multicast server bridging the service plane or the multicast server of the routing service plane; the message buffering and forwarding module is specifically configured to send the received downlink multicast data packets to the set-top box device; the downlink multicast data The packets are buffered in the preset buffer queue of the home gateway by means of cyclic coverage according to different multicast addresses and destination port numbers based on the real-time transmission protocol RTP.

In one embodiment, the size of the cached storage space is the size of the storage space determined in advance according to the service requirements corresponding to the received multicast data packets. The rate and cache time are determined.

In one embodiment, the service request message is a hypertext transfer protocol HTTP request message, and the service request forwarding module is specifically configured to convert the received HTTP request message carrying the address information of the multicast program into a multicast join message; send the converted multicast join message to the multicast server of the routing service plane corresponding to the address information of the multicast program.

In one embodiment, the apparatus for data retransmission in the home gateway device may further include: a pre-retransmission request sending module, configured to, after forwarding the multicast join message according to the multicast source port in the multicast join message, detect When the sequence numbers of the received downlink multicast data packets are discontinuous, send a pre-retransmission request to the designated packet loss retransmission server. The pre-retransmission request is used to request the packet loss retransmission server. The multicast data packets corresponding to the consecutive sequence numbers are retransmitted; the pre-retransmission data packet receiving module is configured to receive the multicast data packets corresponding to the discontinuous sequence numbers sent by the packet loss retransmission server.

In one embodiment, if the set-top box device adopts the playback mode of multicast-to-unicast udpxy, the message buffering and forwarding module in the home gateway device is specifically configured to: receive from the multicast server of the corresponding routing service plane The downlink multicast data packets are converted into TCP unicast data packets, and the TCP unicast data packets are sent to the set-top box device; from the downlink multicast data packets, the Ethernet transmission point-to-point protocol PPPoE header and IP header are removed to obtain the corresponding UDP multicast data stream, and store UDP multicast packets in local slices.

In one embodiment, if the set-top box device adopts the playback mode of proxy streaming media based on the HTTP protocol, the message buffering and forwarding module in the home gateway device is specifically configured to: In the downlink media file data packet, the transport stream TS media file is obtained, and the TS media file is forwarded to the set-top box device by means of HTTP proxy; based on the multimedia data processing service MTS, the TS media file is locally sliced and stored.

In one embodiment, the first retransmission request is an unacknowledged NACK feedback message based on the real-time transmission control protocol (RTCP) sent by the set-top box device, and the multicast data packets pre-buffered by the home gateway are based on different multicast groups, destination port numbers Multicast packets that are buffered with the original packet sequence number.

In this embodiment, the lost packet retransmission module 1120 in the home gateway device is specifically configured to: parse the RTCP-based NACK feedback message to obtain the multicast group information, destination port number, lost data packets carried in the NACK feedback message The packet loss sequence mask is used to determine the packet loss of the set-top box device; according to the multicast group information, destination port number and the sequence number of the lost data packet carried in the NACK feedback message, the Look for lost packets in the multicast packets cached locally by the gateway device.

In one embodiment, the retransmission response packet carries a retransmission packet identifier, and the retransmission packet identifier is used to identify the retransmission response packet; the lost packet retransmission module 1120 in the home gateway device is specifically configured to The retransmission response message is generated by the data packet, and the retransmission response message carries the header information based on the real-time transmission protocol RTP, the original packet sequence number of the lost data packet, and the payload of the lost data packet in the original RTP data packet; The RTP data retransmission channel between the home gateway and the set-top box device sends a retransmission response message to the set-top box device.

In one embodiment, if the first retransmission request is a unicast retransmission request based on the TCP protocol, and the set-top box device adopts a multicast-to-unicast playback mode, the lost packet retransmission module 1120 in the home gateway device, specifically It is also configured to search for lost data packets from the UDP multicast data packets pre-cached by the home gateway; and, if the first retransmission request is a unicast retransmission request based on the TCP protocol, and the set-top box device adopts the HTTP protocol proxy flow If the media is played, the lost packet retransmission module 1120 in the home gateway device is further configured to search for lost data packets from the TS media files pre-cached by the home gateway.

In one embodiment, the data retransmission apparatus in the home gateway device may further include: a second retransmission request sending module, configured to send a message to the home gateway if it fails to search for the missing data packet from the multicast data packets pre-cached by the home gateway. The designated packet loss retransmission server sends a second retransmission request, and the second retransmission request is used to request the packet loss retransmission server to retransmit the lost data packets; the lost packet receiving module receives the lost packets sent by the packet loss retransmission server. data pack.

According to the data retransmission apparatus of the embodiment of the present disclosure, when receiving a retransmission request directly initiated by the home gateway when the set-top box device loses packets, the home gateway searches for the set-top box device to request retransmission through the locally cached multicast stream in advance The lost data includes, and the data packets found in the local cache are resent to the set-top box device, which effectively reduces the RTCP retransmission packet load of the multicast server and reduces the network retransmission delay.

The data retransmission apparatus according to the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. FIG. 14 shows a schematic structural diagram of a data retransmission apparatus provided by the present disclosure. As shown in FIG. 14 , the data retransmission apparatus can be applied to a set-top box device, and includes the following modules: a retransmission request sending module 1210, configured to detect that the received multicast data packet is lost, and send the first data to the designated gateway device. A retransmission request, the first retransmission request is used to request the gateway device to retransmit the lost data packet; the lost packet receiving module 1220 is configured to receive the retransmission response packet of the gateway device, and obtain the lost packet carried in the retransmission response packet The lost data packets are those found in the local cache of the gateway device.

In one embodiment, the first retransmission request is an unacknowledged NACK feedback message based on the real-time transmission control protocol RTCP, and the retransmission request sending module 1210 is specifically configured to: detect that the received multicast data packet is lost, and the packet is lost. When the packet loss rate is within the predetermined packet loss rate range, send an RTCP-based NACK feedback message to the specified gateway device, where the NACK feedback message carries the specified multicast group, destination port number and the sequence number of the lost data packet.

In one embodiment, if the multicast data packet received by the set-top box device carries the forward error correction check (FEC) code, the retransmission request sending module 1210 is specifically configured as follows when detecting that the received multicast data packet is lost: Perform FEC decoding according to the FEC code carried by the multicast data to recover the lost data packets; if the lost data packets fail to be recovered, it is determined that the received downlink multicast data packets are lost.

In one embodiment, the data retransmission apparatus in the set-top box device may further include: a multicast join message sending module, configured to send a multicast join message to the gateway device before detecting that the received multicast data packet is lost. The multicast join message is used to request to join the multicast group, and the multicast join message carries the multicast source port and the multicast group requested to join; the multicast packet receiving module is configured to receive the request to join sent by the gateway device. The multicast packets of the multicast group.

In one embodiment, if the set-top box device adopts the playback mode of multicast-to-unicast udpxy or the playback mode of proxy streaming media based on the HTTP protocol, the lost packet receiving module 1220 in the set-top box device is used to receive the retransmission response of the gateway device. When sending a message, the specific configuration is as follows: through the hypertext transfer protocol HTTP proxy, receiving the unicast data packet based on the transmission control protocol TCP forwarded by the gateway device, and obtaining the lost data packet carried in the TCP unicast data packet.

In this embodiment, in the application scenario where the set-top box adopts the multicast-to-unicast playback mode and the application scenario where the playback mode based on HTTP protocol proxy streaming media is adopted, it is possible to support the direct TCP single-streaming between the gateway and the set-top box. It does not require direct retransmission between the set-top box and the multicast server.

In one embodiment, the retransmission response message received by the set-top box device is a message received through the RTP data channel between the set-top box device and the gateway device, and the retransmission response message carries a retransmission packet identifier, and the retransmission packet identifier Used to identify retransmission response packets.

In this embodiment, the data retransmission apparatus in the set-top box device may further include: a message information acquisition module, configured to acquire the real-time transmission protocol RTP-based header information carried in the retransmission response message, and the original data of the lost data packet. The packet sequence number, and the payload of the lost data packet in the original RTP packet; the header information parsing module is configured to parse the RTP-based header information. The retransmitted lost data packets are obtained by parsing the payload in After the data packet, to play the decoded data.

According to the data retransmission apparatus according to the embodiment of the present disclosure, after the set-top box device detects that there is a packet loss, it initiates a retransmission request to the home gateway, and receives the lost data packet retransmitted by the gateway device and re-sends it to the set-top box, so as to obtain a complete package after assembly. multicast packets. In the data retransmission method, compared with sending a retransmission request to the multicast server after detecting packet loss, the load of the multicast server, the retransmission delay and the network congestion can be effectively reduced.

The data retransmission apparatus according to the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. FIG. 15 shows a schematic structural diagram of a data retransmission apparatus provided by the present disclosure. As shown in FIG. 15 , the data retransmission apparatus can be applied to a multicast server, and includes the following modules.

The multicast join message receiving module 1310 is configured to receive a multicast join message sent by a specified gateway device, where the multicast join message is a multicast join message sent by the set-top box device to the gateway device, or based on the multicast join message sent by the set-top box device. The multicast join message obtained by converting the request message of the hypertext transfer protocol HTTP.

The multicast data packet sending module 1320 is configured to send the multicast data packet of the multicast group requesting to join to the designated packet loss retransmission server and the gateway device, wherein the sent multicast data packet is locally cached in the gateway device, And the sent multicast data packet is used in the gateway device to retransmit the data packet lost by the set-top box device to the set-top box device.

According to the data retransmission device of the embodiment of the present disclosure, after receiving the multicast join message sent by the gateway device, the multicast server sends the downlink multicast data packet corresponding to the multicast group to the packet loss retransmission server and the gateway device, so as to The gateway device locally caches the downlink multicast data packet and is used to retransmit the data packet lost by the set-top box device to the set-top box device. Therefore, when packet loss occurs on the set-top box device side, the gateway device retransmits the lost data packet to the set-top box device, There is no need to receive and process a large number of data retransmission requests through the multicast server, thereby effectively reducing the multicast server load, retransmission delay and network congestion.

The data retransmission apparatus according to the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. FIG. 16 shows a schematic structural diagram of a data retransmission apparatus provided by the present disclosure. As shown in FIG. 16 , the data retransmission apparatus can be applied to a multicast retransmission server, and can include the following modules.

The multicast data packet receiving module 1410 is configured to receive and save the multicast data packet sent by the multicast server;

The second retransmission request receiving module 1420 is configured to receive a second retransmission request sent by the specified gateway device. The second retransmission request is used to request the retransmission of the data packets lost by the specified set-top box device, and the gateway device currently caches the data packets locally. The multicast data packets do not contain data packets lost by the set-top box device;

The lost packet sending module 1430 is configured to find and send the lost data packet from the saved multicast data packets to the gateway device, and the lost data packet is forwarded to the set-top box device in the gateway device.

In one embodiment, the apparatus for data retransmission may further include: a pre-retransmission request receiving module, configured to receive a pre-retransmission request sent by the gateway device, where the pre-retransmission request is used to request the discontinuous sequence received by the gateway device The pre-retransmission data receiving module is configured to send the found multicast data packets corresponding to the discontinuous sequence numbers from the saved multicast data packets to the gateway. equipment.

According to the data retransmission apparatus according to the embodiment of the present disclosure, when the server for packet loss retransmission receives the retransmission request from the gateway device to retransmit the lost data packet of the specified set-top box device, it sends the lost data packet to the multicast server. The transmission request is sent by the gateway device when the locally cached multicast data packets do not contain the data packets lost by the set-top box device. Compared with each time the set-top box device loses packets, the packet loss retransmission server will receive and process the set-top box. The retransmission request sent by the device reduces the network delay of retransmission, and at the same time reduces the load of the multicast server and network congestion.

It is to be understood that the present disclosure is not limited to the specific configurations and processes described in the above embodiments and shown in the figures. For the convenience and brevity of description, the detailed description of the known method is omitted here, and the specific working process of the system, module and unit described above can refer to the corresponding process in the foregoing method implementation, which will not be repeated here.

17 is a structural diagram illustrating an exemplary hardware architecture of a computing device capable of implementing the data retransmission method and apparatus according to an embodiment of the present disclosure.

As shown in FIG. 17 , the computing device 1500 includes an input device 1501 , an input interface 1502 , a central processing unit 1503 , a memory 1504 , an output interface 1505 , and an output device 1506 . The input interface 1502, the central processing unit 1503, the memory 1504, and the output interface 1505 are connected to each other through the bus 1510, and the input device 1501 and the output device 1506 are respectively connected to the bus 1510 through the input interface 1502 and the output interface 1505, and then to the computing device 1500. connections to other components.

Specifically, the input device 1501 receives input information from the outside, and transmits the input information to the central processing unit 1503 through the input interface 1502; the central processing unit 1503 processes the input information based on the computer-executable instructions stored in the memory 1504 to generate output information, temporarily or permanently store the output information in the memory 1504, and then transmit the output information to the output device 1506 through the output interface 1505; the output device 1506 outputs the output information to the outside of the computing device 1500 for the user to use.

In one embodiment, the computing device shown in FIG. 17 may be implemented as a gateway device, and the gateway device may include: a memory configured to store a program; a processor configured to execute the program stored in the memory to The data retransmission method described in the above embodiment is executed.

In one embodiment, the computing device shown in FIG. 17 may be implemented as a set-top box device, and the set-top box device may include: a memory configured to store a program; a processor configured to execute the program stored in the memory to The data retransmission method described in the above embodiment is executed.

In one embodiment, the computing device shown in FIG. 17 may be implemented as a multicast server, and the multicast server may include: a memory configured to store a program; a processor configured to execute the program stored in the memory , so as to execute the data retransmission method described in the above embodiments.

In one embodiment, the computing device shown in FIG. 17 may be implemented as a multicast packet loss and retransmission server, and the multicast packet loss and retransmission server may include: a memory configured to store a program; a processor, configured by It is configured to run the program stored in the memory to execute the data retransmission method described in the above embodiments.

The above descriptions are merely exemplary embodiments of the present disclosure, and are not intended to limit the protection scope of the present disclosure. In general, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic, or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor or other computing device, although the present disclosure is not limited thereto.

Embodiments of the present disclosure may be implemented by the execution of computer program instructions by a data processor of a mobile device, eg, in a processor entity, or by hardware, or by a combination of software and hardware. The computer program instructions may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state setting data, or source code written in any combination of one or more programming languages or object code.

The block diagrams of any logic flow in the figures of the present disclosure may represent program steps, or may represent interconnected logic circuits, modules, and functions, or may represent a combination of program steps and logic circuits, modules, and functions. Computer programs can be stored on memory. The memory may be of any type suitable for the local technical environment and may be implemented using any suitable data storage technology, such as but not limited to read only memory (ROM), random access memory (RAM), optical memory devices and systems (Digital Versatile Discs). DVD or CD disc) etc. Computer-readable media may include non-transitory storage media. The data processor may be of any type suitable for the local technical environment, such as, but not limited to, a general purpose computer, special purpose computer, microprocessor, digital signal processor (DSP), application specific integrated circuit (ASIC), programmable logic device (FGPA) and processors based on multi-core processor architectures.

The foregoing has provided the detailed description of exemplary embodiments of the present disclosure, by way of illustrative and non-limiting example. However, various modifications and adjustments to the above embodiments will be apparent to those skilled in the art when considered in conjunction with the accompanying drawings and claims, without departing from the scope of the present disclosure. Accordingly, the proper scope of the present disclosure will be determined with reference to the claims.

Claims (18)

1. A data retransmission method, comprising:

   receiving a first retransmission request from the set-top box device, where the first retransmission request is used to request the home gateway to retransmit the lost data packet;

   The lost data packet is searched from the data packets pre-cached by the home gateway, and a retransmission response message is sent to the set-top box device, and the retransmission response message carries the found lost data packet.
2. The method of claim 1, wherein, before the receiving the first retransmission request from the set-top box device, the method further comprises:

   When receiving different service request messages from the set-top box device, send the different service request messages to the corresponding multicast server;

   In the local home gateway, the downlink data packets received from the corresponding multicast server are cached and forwarded in a predetermined manner, wherein the predetermined manner is different from the different service request packets and the set-top box equipment. corresponding to the playback method.
3. The method according to claim 2, wherein, if the service request message is a multicast join message, when the different service request message from the set-top box device is received, the different service request message Send to the corresponding multicast server, including:

   According to the received multicast join message of the set-top box device, the corresponding acquired multicast group information, message source port device information, and multicast virtual local area network (VLAN) information pre-configured on the home gateway are added as corresponding multicast learning entry;

   According to the networking of the home gateway and the network protocol television (IPTV) service plane deployment information, the multicast join message is forwarded to the corresponding bridging service plane multicast server or routing service plane multicast server;

   The local home gateway caches and forwards the downlink data packets received from the corresponding multicast server in a predetermined manner, including:

   sending the received downlink multicast data packet to the set-top box device;

   The downlink multicast data packets are buffered in the preset buffer queue of the home gateway by means of cyclic coverage according to different multicast addresses and destination port numbers based on Real Time Transport Protocol (RTP).
4. The method according to claim 2, wherein, if the service request message is a hypertext transfer protocol (HTTP) request message, when different service request messages from a set-top box device are received, the different service request messages are The service request message sent to the corresponding multicast server, including:

   Convert the received HTTP request message carrying the address information of the multicast program into a multicast join message;

   The converted multicast join message is sent to the multicast server of the routing service plane corresponding to the multicast program address information.
5. The method according to claim 4, wherein, if the set-top box device adopts a multicast-to-unicast playback mode, the local home gateway, for the downlink data packets received from the corresponding multicast server, Cache and forward in predetermined ways, including:

   Convert the downlink multicast packet received from the multicast server of the corresponding routing service plane into a Transmission Control Protocol (TCP) unicast packet, and send the TCP unicast packet to the set-top box device;

   From the downlink multicast data packet, remove the Point-to-Point Protocol over Ethernet (PPPoE) header and the Internet Protocol (IP) header to obtain the corresponding User Datagram Protocol (UDP) multicast data stream, and transmit the UDP multicast data stream. Data packets are stored locally in slices.
6. The method according to claim 4, wherein, if the set-top box device adopts the playing mode of proxy streaming media based on the Hypertext Transfer Protocol (HTTP) protocol, the local home gateway, on the The downlink data packets received by the server are buffered and forwarded in a predetermined manner, including:

   From the downstream media file data packet received by the multicast server of the corresponding routing service plane, obtain a transport stream (TS) media file, and forward the TS media file to the set-top box device by means of an HTTP proxy;

   Based on the Multimedia Data Processing Service (MTS), the TS media file is locally sliced and stored.
7. The method according to any one of claims 2-5, wherein after sending the different service request packets to the corresponding multicast server, the method further comprises:

   When it is detected that the sequence numbers of the received downlink multicast data packets are discontinuous, a pre-retransmission request is sent to the designated packet loss retransmission server, and the pre-retransmission request is used to request the packet loss retransmission server. The multicast data packets corresponding to the received discontinuous sequence numbers are retransmitted;

   Receive the multicast data packets corresponding to the discontinuous sequence numbers sent by the packet loss retransmission server.
8. The method according to claim 1, wherein, if the first retransmission request is a real-time transmission control protocol (RTCP)-based non-acknowledgement (NACK) feedback message sent by the set-top box device; Find the lost data packet in the pre-cached data packet, including:

   Parse the RTCP-based NACK feedback message, and obtain the multicast group information, destination port number, sequence number of the lost data packet, and packet loss sequence mask carried in the NACK feedback message, and the packet loss sequence mask uses for determining that the set-top box device has packet loss;

   According to the multicast group information, the destination port number and the serial number of the lost data packet carried in the NACK feedback message, the lost data packet is searched from the multicast data packets cached locally by the gateway device.
9. The method according to claim 8, wherein the retransmission response packet carries a retransmission packet identifier, and the retransmission packet identifier is used to identify the retransmission response packet; the retransmission response packet is sent to the set-top box device. Send a response message, including:

   A retransmission response message is generated according to the found lost data packet, and the retransmission response message carries RTP-based header information, the original packet sequence number of the lost data packet, and the lost data packet in the The payload in the original RTP data packet, the payload is used to obtain the original content of the lost data packet;

   The retransmission response message is sent to the set-top box device through the RTP data retransmission channel between the home gateway and the set-top box device.
10. The method according to any one of claims 1-5, wherein,

    If the first retransmission request is a unicast retransmission request based on the TCP protocol, and the set-top box device adopts the multicast-to-unicast playback mode, the search for the Lost data packets, including: searching for the lost data packets from the UDP multicast data packets pre-cached by the home gateway;

    If the first retransmission request is a unicast retransmission request based on the TCP protocol, and the set-top box device adopts the HTTP protocol proxy streaming media playback mode, search for the lost data packet from the data packets pre-cached by the home gateway. The data packets include: searching for the lost data packets from the TS media files pre-cached by the home gateway.
11. The method according to any one of claims 1-5, wherein, if the search for the lost data packet from the multicast data packets pre-cached by the home gateway fails, the method further comprises:

    sending a second retransmission request to the designated packet loss retransmission server, where the second retransmission request is used to request the packet loss retransmission server to retransmit the lost data packet;

    Receive the lost data packet sent by the lost packet retransmission server.
12. A data retransmission method, comprising:

    When detecting that the received multicast data packet is lost, send a first retransmission request to the designated gateway device, where the first retransmission request is used to request the gateway device to retransmit the lost data packet;

    Receive the retransmission response message of the gateway device, and obtain the lost data packet carried in the retransmission response message, wherein the lost data packet is found in the local cache of the gateway device data pack.
13. The method of claim 12, wherein the first retransmission request is a real-time transmission control protocol (RTCP)-based non-acknowledgement (NACK) feedback message, and the detected packet loss occurs when the received multicast data packet is lost. , send the first retransmission request to the specified gateway device, including:

    When it is detected that the received multicast data packet is lost, and the packet loss rate is within the range of the predetermined packet loss rate, send the (RTCP)-based NACK feedback message to the designated gateway device, wherein the NACK feedback message It carries the specified multicast group information, destination port number and sequence number of lost data packets.
14. The method according to claim 12 or 13, wherein, before the detected packet loss of the received multicast data packet, the method further comprises:

    Send a multicast join message to the gateway device, where the multicast join message is used to request to join a multicast group, and the multicast join message carries the multicast source port device information and the multicast group requested to join information;

    Receive a multicast data packet of the multicast group that is requested to join and sent by the gateway device.
15. The method according to claim 12, wherein, if the local set-top box device adopts a multicast-to-unicast playback mode or an HTTP protocol-based proxy streaming media playback mode, the receiving the retransmission response message of the gateway device, Obtaining the lost data packet carried in the retransmission response message, including:

    Receive the TCP unicast data packet sent by the gateway device through a hypertext transfer protocol HTTP proxy, and obtain the lost data packet carried in the TCP unicast data packet.
16. The method according to claim 12 or 13, wherein the retransmission response message is a message received through an RTP data channel between the local set-top box device and the gateway device, and the retransmission response message carries a retransmission packet identifier, where the retransmission packet identifier is used to identify the retransmission response message; after receiving the retransmission response message from the gateway device, the method further includes:

    Obtain the real-time transport protocol (RTP)-based header information carried in the retransmission response message, the original packet sequence number of the lost data packet, and the payload of the lost data packet in the original RTP data packet;

    Parsing the RTP-based header information, if the header information includes the retransmission packet identifier, parse the retransmitted lost data packet from the payload in the original packet;

    The currently received lost data packets and the received non-lost data packets are assembled to obtain the assembled data packets, and the assembled data packets are decoded to play the decoded data.
17. A network device comprising:

    one or more processors;

    a memory having stored thereon one or more programs which, when executed by the one or more processors, cause the one or more processors to implement claims 1-11, or claims The data retransmission method described in any one of 12-16.
18. A computer-readable storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, realizes the data reproduction according to any one of claims 1-11 or 12-16. pass method.

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