CN113872916A

CN113872916A - Data retransmission method, network device, and computer-readable storage medium

Info

Publication number: CN113872916A
Application number: CN202010614878.XA
Authority: CN
Inventors: 邬立保; 武云飞
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2020-06-30
Filing date: 2020-06-30
Publication date: 2021-12-31
Also published as: WO2022002043A1

Abstract

The application provides a data retransmission method, a network device and a computer readable storage medium, wherein the method comprises the following steps: receiving a first retransmission request from the set top box equipment, wherein the first retransmission request is used for requesting the home gateway to retransmit a lost data packet; searching for a lost data packet from data packets cached in advance by the home gateway, and sending a retransmission response message to the set top box equipment, wherein the retransmission response message carries the searched lost data packet.

Description

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

Technical Field

The present application relates to the field of communications technologies, and in particular, to a data retransmission method, a network device, and a computer-readable storage medium.

Background

Video images are generally transmitted in video streaming in an on-demand and multicast-based manner, a User data packet Protocol (UDP) packet manner is generally adopted for transmitting multicast data streams, but transmission of video signals based on the UDP Protocol is not reliable, and when internet network quality is poor, video data is incomplete due to loss of data packets, so that video packet loss and blockage are caused, and all contents of the video signals cannot be restored.

In order to solve the problem of incomplete video data in the transmission process of videos in the internet, a cache region is usually established at a service source end based on a video signal code stream, the video signal code stream is cached in the cache region, and a data packet missing from the signal code stream is requested to be retransmitted to the cache region again. However, when multicast retransmission is performed at the source end of the video server, the load of the server and the transmission network is increased, and when a large number of Set-Top-Box (STB) terminal devices concurrently request retransmission, network congestion is caused in an extreme case, which affects user experience.

Disclosure of Invention

The application provides a data retransmission method, a network device and a computer readable storage medium.

In a first aspect, an embodiment of the present application provides a data retransmission method, including: receiving a first retransmission request from a set top box device, wherein the first retransmission request is used for requesting the home gateway to retransmit a lost data packet; searching the lost data packet from the data packets cached in advance by the home gateway, and sending a retransmission response message to the set top box device, wherein the retransmission response message carries the searched lost data packet.

In a second aspect, an embodiment of the present application provides a data retransmission method, including: when detecting that a received multicast data packet is lost, sending a first retransmission request to a specified gateway device, wherein the first retransmission request is used for requesting the gateway device to retransmit the lost data packet; and receiving a retransmission response message of the gateway device to 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, an embodiment of the present application provides a network device, including: one or more processors; a memory having one or more programs stored thereon, which when executed by the one or more processors, cause the one or more processors to implement the data retransmission method of the first aspect or the second aspect in the embodiments of the present application.

In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, where a computer program is stored, and when being executed by a processor, the computer program implements any one of the data retransmission methods in the embodiment of the present application.

According to the data retransmission method, the network device and the computer-readable storage medium in the first aspect of the embodiments of the present application, when the home gateway receives a retransmission request directly initiated to the home gateway when a packet loss occurs in the set top box device, the home gateway searches for missing data included in the retransmission request of the set top box device through a multicast code stream cached locally in advance, and retransmits the data message found in the local cache to the set top box device, thereby effectively reducing a multicast server retransmission message load and reducing a network retransmission delay.

According to the data retransmission method, the network device and the computer-readable storage medium in the second aspect of the embodiments of the present application, after detecting that there is a packet loss, the set-top box device initiates a retransmission request to the home gateway, receives the lost data packet retransmitted by the gateway device, and retransmits the lost data packet to the set-top box, so as to obtain an assembled complete multicast data packet. In the data retransmission method, compared with the method that a retransmission request is sent to the multicast server after packet loss is detected, the load, retransmission delay and network congestion conditions of the multicast server can be effectively reduced.

With regard to the above embodiments and other aspects of the present application and implementations thereof, further description is provided in the accompanying drawings description, detailed description and claims.

Drawings

Fig. 1 shows a flow diagram of multicast retransmission of a conventional set-top box device.

Fig. 2 is a flowchart illustrating a data retransmission method according to an embodiment of the present application.

Fig. 3 is a schematic flowchart illustrating a process of caching multicast stream data by a gateway device according to an embodiment of the present application.

Fig. 4 shows a schematic flow chart of data retransmission in a scenario of switching multicast to unicast according to an embodiment of the present application.

Fig. 5 is a message format diagram illustrating a frame format of a retransmission response packet of a gateway device according to an embodiment of the present application.

Fig. 6 is a flowchart illustrating a gateway device processing a retransmission request sent by a set top box according to an embodiment of the present application.

Fig. 7 is a flowchart illustrating a data retransmission method according to another embodiment of the present application.

Fig. 8 shows a packet passing message format diagram of a set top box feedback message according to an embodiment of the present application.

Fig. 9 is a message format diagram of a specific payload of the set-top box feedback message in fig. 8.

Fig. 10 is a flowchart illustrating a data retransmission method according to yet another embodiment of the present application.

Fig. 11 is a flowchart illustrating a data retransmission method according to yet another embodiment of the present application.

Fig. 12 is a schematic flowchart of implementing retransmission of multicast data stream by a set-top box device through a home gateway according to an exemplary embodiment of the present application.

Fig. 13 is a schematic structural diagram of a data retransmission apparatus according to an embodiment of the present invention.

Fig. 14 is a schematic structural diagram of a data retransmission apparatus according to an embodiment of the present invention.

Fig. 15 is a schematic structural diagram of a data retransmission apparatus according to an embodiment of the present invention.

Fig. 16 is a schematic structural diagram of a data retransmission apparatus according to an embodiment of the present invention.

Fig. 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 embodiments of the present invention.

Detailed Description

To make the objects, technical solutions and advantages of the present application more apparent, embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

Fig. 1 shows a flow diagram of a multicast retransmission method of a conventional set-top box device. As shown in fig. 1, the multicast retransmission method may include the following steps.

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 may transparently transmit the multicast join message in a two-layer bridge mode, or may forward the corresponding multicast join message to the multicast server as a three-layer multicast routing agent.

S102, as shown in "sending multicast code stream" in fig. 1, the multicast server sends a Real Time Protocol (RTP) multicast code stream corresponding to the multicast group to the set-top box device and the multicast packet loss retransmission server.

S103, as shown in "save code stream" in fig. 1, the multicast packet loss retransmission server synchronously saves the multicast data stream of the corresponding channel.

S104, as shown in "find there is a packet loss and request retransmission" in fig. 1, the set-top box device receives the multicast data stream, performs packet loss check, and requests the multicast packet loss retransmission server to retransmit the lost data packet when finding that there is a packet loss in the received multicast data stream.

S105, as shown in "retransmitting the lost packet" in fig. 1, the multicast packet loss retransmission server receives the retransmission packet request, and retransmits the corresponding lost multicast data packet.

S106, as shown in "assemble complete, decode output play" in fig. 1, the set-top box can reassemble completely according to the currently received retransmission packet and the previously received normal packet, and play the packet to the television after decoding output.

Through the steps S101 to S105, a cache region is established at the multicast retransmission server, the video signal code stream received from the multicast server is cached in the cache region, and the set-top box device can request the cache region of the multicast retransmission server to resend the data packet with the missing serial number in the transmission process of the signal code stream, so as to solve the problem of incomplete video data caused by the network problem in the transmission process of the video in the internet.

In the multicast retransmission method, when a large number of set top box terminal devices concurrently request retransmission, for a retransmission request sent by a video server source end (for example, a multicast retransmission server), loads of a server and a transmission network are increased, and network congestion is caused in an extreme case, which affects user experience.

The embodiment of the application provides a data retransmission method, which can locally cache multicast data streams in gateway equipment, and the set top box equipment preferentially requests the gateway equipment for retransmission, so that the load of retransmission messages of a multicast server can be effectively reduced, and the network retransmission delay can be reduced.

Fig. 2 is a flowchart illustrating a data retransmission method according to an embodiment of the present application. As shown in fig. 1, the data retransmission method in the embodiment of the present application may be applied to a home gateway, and may include the following steps.

S210, 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 a lost data packet.

S220, searching for the lost data packet from the data packets cached in advance by the home gateway, and sending a retransmission response message to the set top box equipment, wherein the retransmission response message carries the searched lost data packet.

According to the data retransmission method of the embodiment of the application, the gateway device caches the multicast data locally, the set top box device preferentially requests the gateway device to retransmit the lost data packet, and therefore the load of the multicast server for retransmitting the message can be effectively reduced, and the network retransmission delay is reduced.

In an embodiment, according to a difference between a networking mode and a video playing service, a data packet in a home gateway cache multicasts a data stream on a WAN side, including a first original code stream data packet and a second original code stream data packet, where The first original code stream data packet and The second original code stream data packet are multicast data packets carrying real-time transport Protocol RTP header information, and The first original code stream data packet is from an Internet television (Over The Top, OTT) accessed in a routing mode, for a home gateway, a multicast service plane for carrying a multicast service through an Internet routing channel, and The second original code stream data packet is from a network Protocol television (Internet Protocol TV, IPTV) private network multicast service plane accessed in a bridging mode.

In the embodiment of the application, 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 and stored locally in a mode of a multicast address and a destination port number, when the specific implementation is realized, the gateway locally pre-configures and sends a corresponding multicast Virtual Local Area Network (VLAN) to the kernel according to the service requirement, when the gateway receives an STB uplink join message, adds a multicast learning item according to the received uplink join message and the multicast VLAN configuration, the added multicast learning item comprises multicast VLAN, a multicast group, a message source port and other information, the subsequent reception of the downlink multicast stream is Hash operation according to the multicast group, and forwards the multicast item information learned by uplink to the corresponding source port, and simultaneously records the RTP header part information after the multicast group corresponds to the UDP data packet header, the cached data packet can be purposefully cached only with the multicast data stream of the RTP packet head, and simultaneously, the caching of a plurality of different multicast group program sources is supported.

In this embodiment of the present application, the gateway device may be a home gateway device, where an Optical Network Unit (ONU) is used as a home gateway device accessed by the STB, and has a function of a small Content Distribution Network (CDN) while forwarding a basic multicast protocol packet and a data packet, and the home gateway device is a closest gateway device accessed by the set top box and preferentially requests to retransmit a lost data packet locally at the home gateway device, so that Network load of a video server can be effectively reduced, Network congestion is reduced, and video transmission quality during wireless 4K access is improved.

In one embodiment, before step S210, the method further comprises: s11, when receiving different service request messages from the set-top box equipment, sending the different service request messages to the corresponding multicast server; and S12, local to the home gateway, caching and forwarding the downlink data packets received from the corresponding multicast server in a predetermined mode, wherein the predetermined mode corresponds to different service request messages and the playing mode of the set-top box device.

Fig. 3 is a schematic flowchart illustrating a process of caching multicast stream data by a gateway device according to an embodiment of the present application. In fig. 3, the set-top box bridges and accesses the multicast data stream of the multicast server on the IPTV Network side through a wired Local Area Network (LAN) port or a wireless WLAN port, and the process of caching the multicast data stream may specifically include the following steps.

S301, the set-top box device sends an uplink multicast protocol joining message through a wireless WLAN interface.

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

And S302, the home gateway equipment adds the packet into the multicast group and the source port which are learned to be added according to the uplink multicast protocol, and forwards the packet to the multicast server at the WAN connection network side of the IPTV bridge.

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

And S303, the home gateway equipment receives the downlink multicast data stream sent by the WAN side server, and distinguishes the multicast group and the RTP destination port number to cache the local multicast data stream.

In this step, when the packet loss pre-detection sub-module of the home gateway finds that the sequence number of the RTP packet is not continuous, it can actively request the server side for pre-retransmission.

And S304, the home gateway equipment forwards the received downlink multicast data stream to the set top box terminal equipment of the wireless WLAN port.

In this step, the home gateway device may forward the downlink multicast data stream to the corresponding LAN port or wireless WLAN port according to the learned uplink rule, and then forward to the set-top box terminal device.

Through the steps S301 to S304, the home gateway device may forward the received multicast join message that the set-top box device requests for uplink to the multicast server, and send the received multicast data packet of the downlink corresponding multicast group to the set-top box device, and may synchronously cache the received multicast data packets of different multicast groups in the home gateway.

In this embodiment, after receiving the downlink multicast data stream and forwarding the downlink multicast data stream to the set top box device, the home gateway may distinguish the multicast group and the destination port number to perform local cache, so as to subsequently search for and send the lost data packet to the set top box device from the local cache according to the received retransmission request of the set top box device.

As can be seen from the above description, if the service request packet is a multicast join packet, the step S11 may specifically include: s11-01, according to the received multicast join message of the set-top box device, adding the obtained corresponding multicast group information, message source port device information and multicast VLAN information configured in the home gateway in advance as corresponding multicast learning items; and S11-02, according to the configuration information of the networking and IPTV service planes of the home gateway, forwarding the multicast join message to a multicast server of a corresponding bridging service plane or a multicast server of a routing service plane. The step S12 may specifically include: s12-01, sending the received downlink multicast data packet to the set-top box device; and S12-02, caching the downlink multicast data packet into a preset cache queue of the home gateway in a circulating coverage mode according to different multicast addresses and a destination port number based on a real-time transport protocol (RTP).

In an embodiment, if the first retransmission request is a non-acknowledgement NACK feedback message based on a Real-time Transport Control Protocol (RTCP) sent by the set-top box device, and a data packet cached in advance by the home gateway is a multicast data packet cached according to different multicast groups, RTP destination port numbers, and original packet sequence numbers.

In this embodiment, in step S220, the step of searching for a lost data packet from data packets cached in advance by the home gateway may specifically include: s221, analyzing the NACK feedback message based on RTCP to obtain multicast group information, a destination port number, a serial number of a lost data packet and a packet loss sequence mask carried in the NACK feedback message, wherein the packet loss sequence mask is used for determining that the set top box equipment has packet loss; and S222, searching the lost data packet from the multicast data packet locally cached by the gateway equipment 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.

Correspondingly, in this embodiment, the retransmission response packet carries a retransmission packet identifier, and the retransmission packet identifier is used to identify the retransmission response packet; in the step S220, the step of sending the retransmission response packet to the set-top box device may specifically include step S223 of generating a retransmission response packet according to the found lost data packet, where the retransmission response packet carries header information based on RTP, an original packet sequence number of the lost data packet, and a payload of the lost data packet in the original RTP data packet, and the payload is used to obtain an original content of the lost data packet; and S224, sending a retransmission response message to the set-top box equipment through an RTP data retransmission channel of the home gateway and the set-top box equipment.

In this embodiment, the retransmission packet is sent by using an RTCP message, once a set-top box device finds that there is a packet loss, the set-top box device actively reports the packet by immediate feedback, and the home gateway analyzes the received RTCP retransmission packet after receiving an NACK retransmission request packet based on the RTCP sent by the set-top box device, and acquires a corresponding multicast group, an RTP port number, a packet loss sequence number, and packet loss sequence mask information, so as to query a multicast data packet in a local cache by using information obtained by analysis.

In the embodiment of the present application, the cache size of the gateway device is a cache with a fixed duration according to the video rate of the specified resolution, for example, a cache space size required for 2-second cache according to the 4K video rate of 25 to 35 Mbps. In an actual application scenario, the cache size may be expanded appropriately according to actual service requirements and storage configuration capabilities of the home gateway.

In the embodiment of the present application, after step S11, the method further includes: s13, when detecting that the serial number of the received downlink multicast data packet is discontinuous, sending a pre-retransmission request to a designated packet loss retransmission server, wherein the pre-retransmission request is used for requesting the packet loss retransmission server to retransmit the multicast data packet corresponding to the discontinuous serial number; and S04, receiving the multicast data packet corresponding to the discontinuous serial number sent by the packet loss retransmission server.

In this embodiment, when the transmission is performed in the wired manner, it is generally considered that the packet loss rate is relatively low, and therefore, the present application may provide a multicast retransmission method for a gateway and a set top box device in the wireless access manner. When the packet loss pre-detection submodule of the home gateway finds that the serial number of the RTP packet is discontinuous, the packet loss pre-detection submodule can actively request for pre-retransmission to the server side, and the data retransmission efficiency is improved.

In this embodiment, the home gateway device and the set top box device may use a multicast or unicast communication method, and if the set top box device is in a pure unicast service scenario, the home gateway device and the set top box device transmit in an on-demand manner, and the gateway generally performs NAT conversion in a bridge transparent transmission or routing manner, and the pure unicast application scenario is not within the scope of the embodiment of the present invention.

Fig. 4 shows a schematic flow chart of data retransmission in a scenario of switching multicast to unicast according to an embodiment of the present application. In fig. 4, the set-top box accesses a multicast data stream of a multicast server on an OTT Network side through a wired 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, the set-top box device sends an HTTP request message carrying multicast program address information through a wireless WLAN port.

In this step, the multicast screen cast command giving the HTTP request message exemplarily refers to, 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 realize a multicast-to-unicast proxy udp x module, extract the IGMP 224.1.1.2:2024 and the RTP 224.1.1.2:2024 from the multicast screen projection command reference, and generate a multicast join message based on a multicast protocol corresponding to the HTTP request message according to the extracted content.

And S402, the home gateway udp xy module for realizing the function of converting multicast to unicast proxy translates the HTTP request message into a multicast join message and sends the multicast join message 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 may also serve as a Proxy, and forward the multicast join message through the IGMP multicast Proxy module.

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

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

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

S406, the home gateway forwards the unicast data stream to the set top box device at 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 normal multicast stream to the corresponding br0 bridge device port (i.e. source port) according to the uplink learned protocol stack three-layer multicast route, and the home gateway forwards the received downlink multicast data stream to the corresponding learned LAN side set-top box wired and wireless access bridge port (i.e. destination port).

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

Through the above steps S401 to S406, in the application scenario of converting multicast to unicast, the home gateway converts the device-supported WAN side multicast data stream into a LAN side TCP unicast stream, and may include a multicast to unicast udp playing mode or an HTTP proxy HLS playing mode. And the home gateway equipment retransmits the data according to the TCP unicast retransmission request of the set top box.

In another application scenario of the present application, the set-top box device may adopt a playing mode of a Streaming media (HTTP Live Streaming, HLS) based on an HTTP protocol, and in the application scenario, the home gateway may convert a received HTTP request packet carrying multicast program address information into a multicast join packet; acquiring a transport stream TS media file from a downlink media file data packet received by a multicast server of a corresponding routing service plane, and forwarding the TS media file to set-top box equipment in an HTTP proxy mode; and based on a multimedia data processing service (MTS), the TS media file is locally sliced and stored.

In an application scenario of an HTTP protocol-based streaming media HLS playing mode, HLS is a real-time streaming protocol implemented based on the HTTP protocol, and a transmission content may include two parts, where one part is a description file, for example, an Extended M3U Playlist (Extended M3U Playlist, M3U8) description file, and M3U represents a list file of audio files; and the other part is a TS media file, so for the HLS mode, the TS media file can be locally cached by the home gateway, and the TS media file is sliced and stored in the MTS mode.

As can be seen from the above description, in an embodiment, if the service request message is a hypertext transfer protocol HTTP request message, the step S11 may specifically include: s11-11, converting the received HTTP request message carrying the multicast program address information into a multicast adding message; s11-12, the multicast join message obtained by conversion 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 a play mode of converting multicast to unicast, the step S12 may specifically include: s12-11, converting the downlink multicast data packet received from the multicast server of the corresponding routing service plane into a TCP unicast data packet, and sending the TCP unicast data packet to the set top box device; s12-12, removing the Ethernet transmission point-to-point Protocol PPPoE header and the Internet Protocol (IP) header from the downlink multicast data packet to obtain the corresponding UDP multicast data stream, and performing local slice storage on the UDP multicast data packet.

If the set-top box device adopts a playing mode based on HTTP protocol proxy streaming media, the step S12 may specifically include: s12-21, obtaining a transport stream TS media file from a downlink media file data packet received by a multicast server of a corresponding routing service plane, and forwarding the TS media file to set-top box equipment in an HTTP proxy mode; s12-22, based on the multimedia data processing service MTS, the TS media file is stored in local slices.

In the above embodiment, for an application scenario in which multicast is converted into unicast playing and an application scenario in which HLS mode playing is implemented based on HTTP protocol, the home gateway and the set top box device communicate via TCP protocol, and unicast retransmission based on TCP can be implemented.

Specifically, in an application scenario of switching multicast to unicast playing, the first retransmission request sent by the set-top box device to the gateway device may be a unicast retransmission request based on a TCP protocol, where a data packet pre-cached by the home gateway is a UDP data packet stored in a local slice, and in step S220, the step of searching for a lost data packet from the data packet pre-cached by the home gateway specifically refers to searching for a lost data packet from a UDP multicast data stream, and retransmitting the lost data packet to the set-top box device through the TCP unicast.

Specifically, in an application scenario of playing in an HLS manner implemented 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, where a data packet pre-cached by the home gateway is a TS media file stored in a local slice, and in step S220, the step of searching for a lost data packet from the data packet pre-cached by the home gateway, specifically, searching for a lost data packet from the TS media file, and retransmitting the lost data packet to the set-top box device in a unicast manner through the TCP.

Fig. 5 is a message format diagram illustrating a frame format of a retransmission response packet of a gateway device according to an embodiment of the present application. As can be seen from fig. 5, the message format of the retransmission response message between the home gateway and the set-top box device may adopt a defined private message extension mode, and the retransmission response message carries header information of the RTP, an original packet sequence number of the lost data packet, and a payload of the lost data packet in the original RTP data packet. In a specific implementation, a Multicast Port (Multicast Port) included in the response message is a destination Port number minus 1 of the Multicast RTP stream (the RTP Port number and the RTCP Port number are generally a pair).

In an embodiment, if finding a lost packet from multicast packets cached in advance by the home gateway fails, the method further includes: s230, sending a second retransmission request to a specified packet loss retransmission server, wherein the second retransmission request is used for requesting the packet loss retransmission server to retransmit lost data packets; s231, receiving the lost data 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 requested to be retransmitted by the set top box device, the home gateway continues to request retransmission to the upper multicast retransmission server as a proxy, so as to achieve the purpose of smoothly playing the 4K video under WIFI access, and at the same time, reduce the load of the video server.

Fig. 6 is a flowchart illustrating a gateway device processing a retransmission request sent by a set top box according to an embodiment of the present application. As shown in fig. 6, the gateway device processing the retransmission request sent by the set-top box may include the following steps.

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

S602, the gateway device analyzes the received RTCP retransmission and acquires the corresponding multicast group, RTP port number, packet loss sequence number and packet loss sequence mask information.

In this step, a Packet sequence number (Packet ID, PID), which is a Packet loss sequence number, may be used to indicate a Packet start sequence number currently lost; a bit mask (BLP), which may be 16 bits (bits), of the subsequent Lost packet; BLP allows the loss of any of the next 16 RTP packets to be reported immediately after the RTP packet indicated by the PID. That is, the subsequent retransmission packet loss serial number is calculated according to the current lost packet starting serial number and the BLP, and the home gateway can respond to a plurality of data packets when the set-top box retransmits the request once.

S603, the gateway device obtains the multicast RTP original code stream data packet cached in the second layer or the third layer of the local kernel.

S604, if the local cache of the gateway device fails to find the packet loss sequence number, the gateway device serves as a proxy to request the multicast packet loss retransmission server to retransmit the lost packet.

And S605, the gateway equipment carries out RTP packet again according to the frame format communicated with the set-top box equipment and responds to the STB client.

Through the above S601-S605, the method for controlling the retransmission of the multicast RTP data stream by the home gateway can effectively reduce the load of the multicast server, the retransmission delay and the network congestion.

According to the data retransmission method provided by the embodiment of the application, when the home gateway receives a retransmission request directly sent to the home gateway when the set top box equipment loses packets, lost data requested to be retransmitted by the set top box equipment is searched through a multicast code stream cached locally in advance, and a data message searched in the local cache is retransmitted to the set top box equipment, so that the multicast server RTCP retransmission message load is effectively reduced, and the network retransmission time delay is reduced.

Fig. 7 is a flowchart illustrating a data retransmission method according to another embodiment of the present application. The data retransmission method can be applied to a set-top box device, and as shown in fig. 7, the method can include the following steps.

S710, when detecting that a packet loss occurs in a received multicast data packet, sending a first retransmission request to a designated gateway device, where the first retransmission request is used to request the gateway device to retransmit the lost data packet.

S720, receiving the retransmission response message of the gateway device, and obtaining 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 this embodiment, when detecting that a packet loss occurs in a received downlink multicast data packet, the set-top box device directly sends a retransmission request to the gateway device, so as to obtain the lost data packet found in the local cache by the gateway device.

In an embodiment, the first retransmission request is a non-acknowledgement NACK feedback message based on a real-time transport control protocol RTCP, in this embodiment, S710 may specifically include: and when detecting that the received multicast data packet is lost and the packet loss rate is within a preset packet loss rate interval range, sending a NACK feedback message based on RTCP to the appointed gateway equipment, wherein the NACK feedback message carries an appointed multicast group, a destination port number and the sequence number of the lost data packet.

In the embodiment, if the set top box equipment STB multicast channel data detects packet loss through a packet loss retransmission module and the packet loss rate is within a preset packet loss rate interval range, sending a NACK retransmission request message of RTCP to a home gateway; after receiving the NACK retransmission request message, the home gateway replies a retransmission data packet through a data retransmission channel, for example, an RTP channel.

In this embodiment, the gateway and the STB communicate with each other in a transmission communication mode, such as a UDP connectionless mode with a specific IP and a private port number.

When the communication between the home gateway and the STB can adopt a connection-free mode for communication by using UDP, as an example, for example, the fixed IP is 192.168.1.1 and a certain specified private port, the set-top box generally adopts such a scheme in an OTT access scenario corresponding to an IGMP Proxy routing Proxy mode, and at this time, the set-top box acquires a small network address (i.e., a small network segment address, for example, 192.168.1.x) allocated by the gateway;

as another example, for a set-top box and a bridging IPTV server scenario, the set-top box may employ two virtual MACs, where one virtual Media Access Control (MAC) address communicates with the gateway in the UDP manner, and the other virtual MAC address obtains a large network address (i.e., a large network segment address) of the IPTV private network service plane.

The following describes a message format schematic diagram of the set top box device sending the feedback message through fig. 8 and fig. 9. Fig. 8 is a schematic diagram illustrating a packet passing message format of a set top box feedback message according to an embodiment of the present application; fig. 9 is a message format diagram of a specific payload of the set-top box feedback message in fig. 8.

In fig. 8, the retransmission request packet of the set-top box device is sent by using an RTCP message, and once the set-top box device finds that there is a packet loss, the set-top box device can immediately feed back the packet to the gateway device through the retransmission request packet. In the RTCP header of the retransmission request message, the FMT and the PT may be used to determine the type of the message, and the Feedback Control Information (FCI) is the specific load of the type of the message. As an example, as shown in fig. 8, when FMT is 1 and PT is 205, it represents that this message is a NACK message.

In fig. 9, the NACK message indicated by the FCI includes: packet sequence number (Packet ID, PID) for indicating the sequence number of the lost Packet; a packet loss sequence mask (BLP) is a mask Of 16 Packets starting from the PID, where the BLP is 1 to identify that the set-top box device has a packet loss, and the BLP is 0 to indicate that the set-top box device has not reported a packet loss.

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

In one embodiment, before step S710, before detecting that a packet loss occurs in the received multicast data packet, the method further includes: s11, sending 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 multicast source port device information and multicast group information requested to join; and S12, receiving the multicast data packet of the multicast group requested to join sent by the gateway device.

In an embodiment, if the set-top box device adopts a playing mode of multicast-to-unicast udp or a playing mode based on HTTP protocol proxy streaming media, the step of receiving the retransmission response packet of the gateway device in S720 may specifically include: and receiving a unicast data packet which is forwarded by the gateway equipment and is based on a Transmission Control Protocol (TCP) through a hypertext transfer protocol (HTTP) proxy to obtain a lost data packet carried in the TCP unicast data packet.

In this embodiment, in an application scenario where the set-top box adopts a play mode of multicast to unicast, the home gateway may convert the downlink multicast data stream into a TCP unicast data stream through the udp xy module, and send the converted TCP unicast data stream to the set-top box device, so as to implement direct TCP unicast retransmission between the gateway and the set-top box; in an application scene that the set-top box device adopts a playing mode based on HTTP proxy streaming media, the TS media file is forwarded to the set-top box device in an HTTP proxy mode, under the two scenes, TCP unicast retransmission can be directly carried out between a gateway and the set-top box, and direct retransmission between the set-top box and a multicast server is not needed.

In one embodiment, the retransmission response message is a message received through an RTP data channel between the 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; in this embodiment, after step S720, the method may further include: s730, acquiring header information based on a real-time transport protocol (RTP) carried in the retransmission response message, an original packet sequence number of the lost data packet and a payload of the lost data packet in the original RTP data packet; s731, analyzing header information based on RTP, and if the header information contains retransmission packet identification, analyzing from the effective load in the original packet to obtain a retransmission lost data packet; s732, assembling the currently received lost data packet and the received data packet that has not been lost to obtain an assembled data packet, and decoding the assembled data packet to play the decoded data.

According to the data retransmission method of the embodiment of the application, after detecting that packet loss exists, the set top box device initiates a retransmission request to the home gateway, receives the lost data message retransmitted by the gateway device and retransmits the lost data message to the set top box, and obtains an assembled complete multicast data packet. In the data retransmission method, compared with the method that a retransmission request is sent to the multicast server after packet loss is detected, the load, retransmission delay and network congestion conditions of the multicast server can be effectively reduced.

Fig. 10 is a flowchart illustrating a data retransmission method according to yet another embodiment of the present application. The data retransmission method can be applied to a multicast server, as shown in fig. 10, and the data retransmission method can include the following steps.

S810, receiving a multicast adding message sent by a specified gateway device, wherein the multicast adding message is a multicast adding message sent by a set top box device to the gateway device or a multicast adding message obtained by converting a request message based on a hypertext transfer protocol (HTTP) sent by the set top box device;

and S820, sending the multicast data packet of the multicast group requested to join to a designated packet loss retransmission server and gateway equipment, wherein the sent multicast data packet is locally cached in the gateway equipment, and the sent multicast data packet is used for retransmitting the data lost by the set top box equipment to the set top box equipment in the gateway equipment.

In the data retransmission method, when a home gateway receives a multicast join message that a set-top box device requests to join a multicast group, the home gateway acquires corresponding multicast group and message source port device information, adds a corresponding multicast learning item according to a multicast VLAN configured by the current gateway, and further forwards the multicast join message to a corresponding bridging or routing service plane, such as a bridging B plane (corresponding to an IPTV private network) or an Internet access plane a plane (corresponding to an OTT application scenario), according to the networking of the home gateway and the deployment situation of the IPTV service plane. As an example, the source port may be determined according to a device identifier corresponding to a buffer area (Struct sk _ buffer, skb) of the kernel receive packet, such as ethernet port eth0 or wlan port wlan 0.

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 that the gateway device locally caches the downlink multicast data packet and retransmits the data packet lost by the set top box device to the set top box device.

It is to be understood that the invention is not limited to the particular arrangements and instrumentality described in the above embodiments and shown in the drawings. For convenience and brevity of description, detailed description of a known method is omitted here, and for the specific working processes of the system, the module and the unit described above, reference may be made to corresponding processes in the foregoing method embodiments, which are not described herein again.

Fig. 11 is a flowchart illustrating a data retransmission method according to yet another embodiment of the present application. The data retransmission method can be applied to a multicast retransmission server, as shown in fig. 11, and the data retransmission method can include the following steps.

S910, receiving and storing the multicast data packet sent by the multicast server.

And S920, receiving a second retransmission request sent by the specified gateway device, where the second retransmission request is used to request the packet loss retransmission server to retransmit the data packet lost by the specified set top box device, and the multicast data packet currently cached by the gateway device in the local cache does not include the data packet lost by the set top box device.

S930, searching and sending the lost data packet to the multicast server from the stored multicast data packets, and forwarding the lost data packet to the set-top box device in the multicast server.

In the data retransmission method, when the multicast packet loss retransmission server receives a retransmission request of the gateway device for requesting retransmission of a data packet lost by the specified set top box device, the lost data packet is sent to the multicast server, and because the retransmission request is sent under the condition that the multicast data packet lost by the set top box device is not contained in the multicast data packet currently cached locally by the gateway device, compared with the case that the set top box device loses the packet each time, the multicast packet loss retransmission server receives and processes the retransmission request sent by the set top box device, the network time delay of retransmission is reduced, and meanwhile, the load and the network congestion of the multicast server can be reduced.

Fig. 12 is a schematic flowchart of implementing retransmission of the STB multicast data stream through the home gateway according to an exemplary embodiment of the present application. In this embodiment, the method includes the following steps.

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

And S1001-b, the home gateway transparently transmits the corresponding multicast adding message to a multicast server in a bridging mode or serves as a multicast routing agent mode.

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

S1003, the multicast packet loss retransmission server synchronously stores the multicast data stream of the corresponding channel.

And S1004, the home gateway equipment receives the downlink multicast data stream, forwards the downlink multicast data stream to the set top box on the LAN side, and performs local cache.

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

In this step, the home gateway device may perform local caching by distinguishing the multicast group from the RTP destination port number.

S1005, after receiving the multicast data stream, the set-top box device detects a 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 the multicast packet has a Forward Error Correction (FEC) function, FEC recovery is performed first, and when the FEC cannot be recovered and it is determined that there is packet loss in the code stream, an RTCP request is initiated to the local home gateway to retransmit the lost data packet, where the content includes an RTCP standard header and privately defined extended field frame format content.

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

In the step, the home gateway device obtains the multicast group data packet cached in the second layer or the third layer of the local kernel, and if the obtaining is successful, the corresponding lost multicast data packet is retransmitted to the set top box according to the retransmission response packet private frame format defined between the home gateway device and the set top box.

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

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

S1009, the home gateway device receives the retransmission packet of the service response, decodes the retransmission packet, and then retransmits the retransmission packet to the set top box device according to the private frame format of the response packet defined by the set top box device.

S1010, the set-top box device reassembles the retransmission packet received currently and the normal packet received before completely, and the retransmission packet is decoded and output and then played for the television.

Through the steps S1001-S1010, the multicast data stream is cached locally in the home gateway, when the set-top box device detects packet loss, the set-top box device preferentially requests the home gateway for RTCP retransmission, the retransmission time delay is small, and the load of the RTCP retransmission message of the multicast server can be effectively reduced and the network retransmission time delay can be reduced.

The following describes a data retransmission apparatus according to an embodiment of the present application in detail with reference to the accompanying drawings. Fig. 13 is a schematic structural diagram of a data retransmission apparatus according to an embodiment of the present invention. As shown in fig. 13, the data retransmission apparatus may 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, where the first retransmission request is used to request a home gateway to retransmit a lost data packet;

and a lost packet retransmission module 1120, configured to search for a lost data packet from data packets cached in advance by the home gateway, and send a retransmission response packet to the set top box device, where the retransmission response packet carries the searched lost data packet.

In the specific embodiment of the present application, a scheme of processing multicast data packets in a chip of a CPU may be adopted, and subsequently, data packet caching and forwarding may be performed in a second layer or a third layer of a kernel, and for a part of chip multicast data packets, a hard acceleration forwarding scheme that may directly go through the chip instead of being processed in the CPU may be adopted, so that transmission efficiency is higher.

In one embodiment, the data retransmission apparatus in the home gateway device may further include: the service request forwarding module is used for sending different service request messages to corresponding multicast servers when receiving different service request messages from the set-top box equipment before receiving the first retransmission request from the set-top box equipment; and the message caching and forwarding module is used for caching and forwarding the downlink data packet received from the corresponding multicast server in a predetermined mode locally at the home gateway, wherein the predetermined mode corresponds to different service request messages and the playing mode of the set-top box equipment.

In an embodiment, if the service request packet is a multicast join packet, the service request forwarding module is specifically configured to add, according to the received multicast join packet of the set top box device, the acquired corresponding multicast group information, packet source port device information, and multicast VLAN information configured in advance at the home gateway as a corresponding multicast learning entry; according to the configuration information of the networking and IPTV service planes of the home gateway, forwarding the multicast adding message to a multicast server of a corresponding bridging service plane or a multicast server of a routing service plane; the message caching and forwarding module is specifically used for sending the received downlink multicast data packet to the set top box device; and caching the downlink multicast data packet into a preset cache queue of the home gateway in a circulating covering mode according to different multicast addresses and a target port number based on a real-time transport protocol (RTP).

In one embodiment, the size of the storage space of the cache is a storage space size determined in advance according to a service requirement corresponding to the received multicast data packet, and the service requirement is determined by the resolution, the transmission rate and the cache time of the video data in the transmitted multicast data packet.

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

In one embodiment, the data retransmission apparatus in the home gateway device may further include: a pre-retransmission request sending module, configured to send a pre-retransmission request to a specified packet loss retransmission server when detecting that a serial number of a received downlink multicast data packet is discontinuous after forwarding a multicast join packet according to a multicast source port in the multicast join packet, where the pre-retransmission request is used to request the packet loss retransmission server to retransmit a multicast data packet corresponding to the received discontinuous serial number; and the pre-retransmission data packet receiving module is used for receiving the multicast data packet corresponding to the discontinuous serial number sent by the packet loss retransmission server.

In one embodiment, if the set-top box device adopts a playing mode of converting multicast to unicast udp, the message caching and forwarding module in the home gateway device is specifically configured to: converting a downlink multicast data packet received from a multicast server of a corresponding routing service plane into a TCP unicast data packet, and sending the TCP unicast data packet to set top box equipment; and removing the PPPoE header and the IP header from the downlink multicast data packet to obtain a corresponding UDP multicast data stream, and performing local slice storage on the UDP multicast data packet.

In one embodiment, if the set-top box device adopts a playing mode based on HTTP protocol proxy streaming media, the message caching and forwarding module in the home gateway device is specifically configured to: acquiring a transport stream TS media file from a downlink media file data packet received by a multicast server of a corresponding routing service plane, and forwarding the TS media file to set-top box equipment in an HTTP proxy mode; and based on a multimedia data processing service (MTS), the TS media file is locally sliced and stored.

In an embodiment, the first retransmission request is a non-acknowledgement NACK feedback message based on a real-time transport control protocol RTCP sent by the set-top box device, and the multicast data packet cached in advance by the home gateway is a multicast data packet cached according to different multicast groups, destination port numbers and original packet sequence numbers.

In this embodiment, the lost packet retransmission module 1120 in the home gateway device is specifically configured to: analyzing the NACK feedback message based on RTCP to obtain multicast group information, a destination port number, a serial number of a lost data packet and a packet loss sequence mask carried in the NACK feedback message, wherein the packet loss sequence mask is used for determining that the set top box equipment has packet loss; and searching the lost data packet from the multicast data packets cached locally by the gateway equipment according to the multicast group information, the destination port number and the sequence number of the lost data packet carried in the NACK feedback message.

In one embodiment, the retransmission response message carries a retransmission packet identifier, and the retransmission packet identifier is used for identifying the retransmission response message; a lost packet retransmission module 1120 in the home gateway device, configured to generate a retransmission response packet according to the found lost data packet, where the retransmission response packet carries header information based on a real-time transport protocol RTP, an original packet sequence number of the lost data packet, and a payload of the lost data packet in the original RTP data packet; and sending a retransmission response message to the set-top box equipment through an RTP data retransmission channel of the home gateway and the set-top box equipment.

In an embodiment, if the first retransmission request is a unicast retransmission request based on a TCP protocol, and the set-top box device adopts a playing mode from multicast to unicast, the lost packet retransmission module 1120 in the home gateway device is specifically further configured to search for a lost packet from a UDP multicast packet 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 a playing mode that uses HTTP protocol to proxy streaming media, the lost packet retransmission module 1120 in the home gateway device is further specifically configured to: and searching lost data packets from TS media files cached in advance 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 second retransmission request to a specified packet loss retransmission server if finding a lost data packet from multicast data packets cached in the home gateway in advance fails, where the second retransmission request is used to request the packet loss retransmission server to retransmit the lost data packet; and the lost data packet receiving module is used for receiving the lost data packet sent by the lost packet retransmission server.

According to the data retransmission device in the embodiment of the application, when the home gateway receives a retransmission request directly sent to the home gateway when the set top box equipment loses packets, lost data requested to be retransmitted by the set top box equipment is searched through a multicast code stream cached locally in advance, and a data message searched in the local cache is retransmitted to the set top box equipment, so that the multicast server RTCP retransmission message load is effectively reduced, and the network retransmission time delay is reduced.

The following describes a data retransmission apparatus according to an embodiment of the present invention in detail with reference to the accompanying drawings. Fig. 14 is a schematic structural diagram of a data retransmission apparatus according to an embodiment of the present invention. 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 send a first retransmission request to a designated gateway device when detecting that a packet loss occurs in a received multicast data packet, where 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 a retransmission response packet of the gateway device, and obtain a lost data packet carried in the retransmission response packet, where the lost data packet is a data packet found in the local cache of the gateway device.

In an embodiment, the first retransmission request is a non-acknowledgement NACK feedback message based on a real-time transport control protocol RTCP, and the retransmission request sending module 1210 is specifically configured to: and when detecting that the received multicast data packet is lost and the packet loss rate is within a preset packet loss rate interval range, sending a NACK feedback message based on RTCP to the appointed gateway equipment, wherein the NACK feedback message carries an appointed multicast group, a destination port number and the sequence number of the lost data packet.

In an embodiment, if the multicast data packet received by the set top box device carries a forward error correction check FEC code, the retransmission request sending module 1210 is specifically configured to, when detecting that a packet loss occurs to the received multicast data packet: performing FEC decoding according to FEC encoding carried by multicast data to recover lost data packets; and if the recovery of the lost data packet fails, determining that the received downlink multicast data packet is lost.

In one embodiment, the data retransmission apparatus in the set-top box device may further include: a multicast adding message sending module, configured to send a multicast adding message to the gateway device before detecting that a packet loss occurs in a received multicast data packet, where the multicast adding message is used to request to add to a multicast group, and the multicast adding message carries a multicast source port and a multicast group requested to be added; and the multicast data packet receiving module is used for receiving the multicast data packet of the multicast group which is sent by the gateway equipment and requires to be added.

In an embodiment, if the set-top box device adopts a playing mode of multicast-to-unicast udp or a playing mode based on HTTP protocol proxy streaming media, the lost packet receiving module 1220 in the set-top box device is specifically configured to: and receiving a unicast data packet which is forwarded by the gateway equipment and is based on a Transmission Control Protocol (TCP) through a hypertext transfer protocol (HTTP) proxy to obtain a lost data packet carried in the TCP unicast data packet.

In this embodiment, in both an application scenario in which the set-top box adopts a multicast-to-unicast playing mode and an application scenario in which the set-top box adopts an HTTP protocol proxy streaming media-based playing mode, TCP unicast retransmission can be directly performed between the gateway and the set-top box, and direct retransmission between the set-top box and the multicast server is not required.

In one embodiment, the retransmission response packet received by the set-top box device 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, where the retransmission packet identifier is used to identify the retransmission response packet.

In this embodiment, the data retransmission apparatus in the set-top box device may further include: the message information acquisition module is used for acquiring header information based on a real-time transport protocol (RTP), a sequence number of an original packet of a lost data packet and a payload of the lost data packet in the original RTP data packet, wherein the header information is carried in a retransmission response message; the header information analysis module is used for analyzing header information based on RTP, and if the analyzed header information based on RTP contains a retransmission packet identifier, analyzing from a payload in an original packet to obtain a retransmitted lost data packet; and the data packet assembling module is used for assembling the currently received lost data packet and the received data packet which is not lost to obtain an assembled data packet, and decoding the assembled data packet to play the data obtained by decoding.

According to the data retransmission device in the embodiment of the application, after detecting that packet loss exists, the set top box equipment initiates a retransmission request to the home gateway, receives the lost data message retransmitted by the gateway equipment and retransmits the lost data message to the set top box, and obtains an assembled complete multicast data packet. In the data retransmission method, compared with the method that a retransmission request is sent to the multicast server after packet loss is detected, the load, retransmission delay and network congestion conditions of the multicast server can be effectively reduced.

The following describes a data retransmission apparatus according to an embodiment of the present invention in detail with reference to the accompanying drawings. Fig. 15 is a schematic structural diagram of a data retransmission apparatus according to an embodiment of the present invention. As shown in fig. 15, the data retransmission apparatus may be applied to a multicast server and includes the following modules.

A multicast join message receiving module 1310, 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 a set top box device to the gateway device, or a multicast join message obtained by converting a request message based on a hypertext transfer protocol HTTP sent by the set top box device.

A multicast data packet sending module 1320, configured to send a multicast data packet of the multicast group requested to join to a designated packet loss retransmission server and a gateway device, where 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 a data packet lost by the set top box device to the set top box device.

According to the data retransmission device in the embodiment of the application, after receiving the multicast adding 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 that the gateway device locally caches the downlink multicast data packet and is used for retransmitting the data packet lost by the set top box device to the set top box device.

The following describes a data retransmission apparatus according to an embodiment of the present invention in detail with reference to the accompanying drawings. Fig. 16 is a schematic structural diagram of a data retransmission apparatus according to an embodiment of the present invention. As shown in fig. 16, the data retransmission apparatus may be applied to a multicast retransmission server, and may include the following modules.

A multicast data packet receiving module 1410, configured to receive and store a multicast data packet sent by a multicast server;

a second retransmission request receiving module 1420, configured to receive a second retransmission request sent by a designated gateway device, where the second retransmission request is used to request retransmission of a data packet lost by the designated set-top box device, and a multicast data packet currently cached by the gateway device in a local cache does not include the data packet lost by the set-top box device;

the lost packet sending module 1430 is configured to search and send a lost packet from the stored multicast packets to the gateway device, where the lost packet is forwarded to the set-top box device in the gateway device.

In one embodiment, the data retransmission apparatus may further include: the pre-retransmission request receiving module is used for receiving a pre-retransmission request sent by the gateway equipment, and the pre-retransmission request is used for requesting to retransmit the multicast data packet corresponding to the discontinuous serial number received by the gateway equipment; and the pre-retransmission data receiving module is used for sending the multicast data packet corresponding to the searched discontinuous serial number to the gateway equipment from the stored multicast data packet.

According to the data retransmission device in the embodiment of the application, when the packet loss retransmission server receives a retransmission request of the gateway device for requesting retransmission of a data packet lost by the specified set top box device, the lost data packet is sent to the multicast server, and because the retransmission request is sent by the gateway device under the condition that the multicast data packet currently cached locally does not contain the data packet lost by the set top box device, compared with the case that the set top box device loses the packet each time, the packet loss retransmission server receives and processes the retransmission request sent by the set top box device, the network time delay of retransmission is reduced, and meanwhile, the load of the multicast server and the network congestion can be reduced.

As shown in fig. 17, computing device 1500 includes an input device 1501, an input interface 1502, a central processor 1503, memory 1504, an output interface 1505, and an output device 1506. The input interface 1502, the central processor 1503, the memory 1504, and the output interface 1505 are connected to each other via a bus 1510, and the input device 1501 and the output device 1506 are connected to the bus 1510 via the input interface 1502 and the output interface 1505, respectively, and are further connected to other components of the computing device 1500.

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

In one embodiment, the computing device shown in fig. 17 may be implemented as a gateway device that may include: a memory configured to store a program; a processor configured to execute the program stored in the memory to perform the data retransmission method described in the above embodiments.

In one embodiment, the computing device shown in fig. 17 may be implemented as a set-top box device that may include: a memory configured to store a program; a processor configured to execute the program stored in the memory to perform 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 server that may include: a memory configured to store a program; a processor configured to execute the program stored in the memory to perform 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 retransmission server, which may include: a memory configured to store a program; a processor configured to execute the program stored in the memory to perform the data retransmission method described in the above embodiments.

The above description is only exemplary embodiments of the present application, and is not intended to limit the scope of the present application. In general, the various embodiments of the application 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 which may be executed by a controller, microprocessor or other computing device, although the application is not limited thereto.

Embodiments of the application may be implemented by a data processor of a mobile device executing computer program instructions, for example 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 related instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages.

Any logic flow block diagrams in the figures of this application 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. The computer program may be stored on a memory. The memory may be of any type suitable to 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 storage devices and systems (digital versatile disks, DVDs, or CD discs), etc. The computer readable medium may include a non-transitory storage medium. The data processor may be of any type suitable to the local technical environment, such as but not limited to general purpose computers, special purpose computers, microprocessors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), programmable logic devices (FGPAs), and processors based on a multi-core processor architecture.

The foregoing has provided by way of exemplary and non-limiting examples a detailed description of exemplary embodiments of the present application. Various modifications and adaptations to the foregoing embodiments may become apparent to those skilled in the relevant arts in view of the following drawings and the appended claims without departing from the scope of the invention. Therefore, the proper scope of the invention is to be determined according to the claims.

Claims

1. A method of data retransmission, the method comprising:

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

searching the lost data packet from the data packets cached in advance by the home gateway, and sending a retransmission response message to the set top box device, wherein the retransmission response message carries the searched lost data packet.

2. The method of claim 1, wherein prior to said receiving the first retransmission request from the set-top box device, the method further comprises:

when receiving different service request messages from set top box equipment, sending the different service request messages to corresponding multicast servers;

and locally at the home gateway, caching and forwarding the downlink data packets received from the corresponding multicast server in a predetermined mode, wherein the predetermined mode corresponds to the different service request messages and the playing mode of the set-top box device.

3. The method according to claim 2, wherein if the service request packet is a multicast join packet, when receiving a different service request packet from a set-top box device, sending the different service request packet to a corresponding multicast server, includes:

adding the acquired corresponding multicast group information, the information of the message source port equipment and the multicast Virtual Local Area Network (VLAN) information configured in the home gateway in advance into corresponding multicast learning items according to the received multicast adding message of the set top box equipment;

according to the configuration information of the networking and IPTV service planes of the home gateway, forwarding the multicast adding message to a multicast server of a corresponding bridging service plane or a multicast server of a routing service plane;

the caching and forwarding the downlink data packet received from the corresponding multicast server in a predetermined manner locally at the home gateway includes:

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

and caching the downlink multicast data packet into a preset cache queue of the home gateway in a circulating covering mode according to different multicast addresses and a target port number based on a 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 receiving a different service request message from a set-top box device, sending the different service request message to a corresponding multicast server, comprises:

converting the received HTTP request message carrying the multicast program address information into a multicast adding message;

and sending the multicast adding message obtained by conversion to a multicast server of a routing service plane corresponding to the multicast program address information.

5. The method of claim 4, wherein if the set-top box device adopts a multicast-to-unicast udp y playing mode, the caching and forwarding the downlink data packet received from the corresponding multicast server in a predetermined mode locally at the home gateway includes:

converting a downlink multicast data packet received from a multicast server of a corresponding routing service plane into a Transmission Control Protocol (TCP) unicast data packet, and sending the TCP unicast data packet to the set top box equipment;

and removing the Ethernet transmission point-to-point protocol PPPoE header and the Internet protocol IP header from the downlink multicast data packet to obtain a corresponding UDP multicast data stream, and performing local slice storage on the UDP multicast data packet.

6. The method of claim 4, wherein if the set-top box device adopts a playing mode based on HTTP protocol proxy streaming media, the caching and forwarding the downlink data packet received from the corresponding multicast server in a predetermined mode locally at the home gateway includes:

acquiring a transport stream TS media file from a downlink media file data packet received by a multicast server of a corresponding routing service plane, and forwarding the TS media file to the set top box device in an HTTP proxy mode;

and based on a multimedia data processing service (MTS), carrying out local slice storage on the TS media file.

7. The method according to any of claims 2-5, wherein after sending the different service request message to the corresponding multicast server, the method further comprises:

when detecting that the serial number of the received downlink multicast data packet is discontinuous, sending a pre-retransmission request to a specified packet loss retransmission server, wherein the pre-retransmission request is used for requesting the packet loss retransmission server to retransmit the multicast data packet corresponding to the received discontinuous serial number;

and receiving the multicast data packet corresponding to the discontinuous serial number sent by the packet loss retransmission server.

8. The method of claim 1, wherein if the first retransmission request is a non-acknowledgement NACK feedback message based on real-time transport control protocol RTCP sent by the set-top box device; the searching for the lost data packet from the data packets cached in advance by the home gateway includes:

analyzing the RTCP-based NACK feedback message to obtain multicast group information, a destination port number, a sequence number of a lost data packet and a packet loss sequence mask carried in the NACK feedback message, wherein the packet loss sequence mask is used for determining that the set top box equipment has packet loss;

and searching the lost data packet from the multicast data packets cached locally by the gateway equipment according to the multicast group information, the destination port number and the sequence number of the lost data packet carried in the NACK feedback message.

9. The method according to claim 8, wherein the retransmission response packet carries a retransmission packet identifier, and the retransmission packet identifier is used for identifying the retransmission response packet; the sending of the retransmission response packet to the set-top box device includes:

generating a retransmission response message according to the found lost data packet, wherein the retransmission response message carries header information based on RTP, an original packet sequence number of the lost data packet, and a payload of the lost data packet in an original RTP data packet, and the payload is used for acquiring original content of the lost data packet;

and sending the retransmission response message to the set-top box equipment through an RTP data retransmission channel of the home gateway and the set-top box equipment.

10. The method according to any one of claims 1 to 5,

if the first retransmission request is a unicast retransmission request based on a TCP protocol and the set-top box device adopts a playing mode of converting multicast to unicast, the searching for the lost data packet from the data packets cached in advance by the home gateway includes: searching the lost data packet from UDP multicast data packets cached in advance by the home gateway;

if the first retransmission request is a unicast retransmission request based on a TCP protocol and the set-top box device adopts an HTTP protocol proxy streaming media playing mode, searching for the lost data packet from data packets cached in advance by the home gateway includes: and searching the lost data packet from the TS media file cached in the home gateway in advance.

11. The method according to any of claims 1-5, wherein if finding the missing data packet from the multicast data packets cached in advance by the home gateway fails, the method further comprises:

sending a second retransmission request to a specified packet loss retransmission server, wherein the second retransmission request is used for requesting the packet loss retransmission server to retransmit the lost data packet;

and receiving the lost data packet sent by the packet loss retransmission server.

12. A method of data retransmission, the method comprising:

when detecting that a received multicast data packet is lost, sending a first retransmission request to a specified gateway device, wherein the first retransmission request is used for requesting the gateway device to retransmit the lost data packet;

and receiving a retransmission response message of the gateway device to 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.

13. The method according to claim 12, wherein the first retransmission request is a non-acknowledgement NACK feedback message based on real-time transport control protocol RTCP, and when detecting that a packet loss occurs in a received multicast data packet, the sending of the first retransmission request to a specified gateway device comprises:

and when detecting that the received multicast data packet is lost and the packet loss rate is within a preset packet loss rate interval range, sending the NACK feedback message based on the RTCP to the appointed gateway equipment, wherein the NACK feedback message carries appointed multicast group information, a destination port number and the sequence number of the lost data packet.

14. The method according to claim 12 or 13, wherein before said detecting packet loss of the received multicast data packet, the method further comprises:

sending a multicast adding message to the gateway device, wherein the multicast adding message is used for requesting to add a multicast group, and the multicast adding message carries multicast source port device information and multicast group information requested to be added;

and receiving the multicast data packet of the multicast group requested to join, which is sent by the gateway equipment.

15. The method according to claim 12, wherein if the local set-top box device adopts a playing mode of multicast-to-unicast udp or a playing mode based on HTTP protocol proxy streaming media, the receiving a retransmission response packet of the gateway device to obtain the lost packet carried in the retransmission response packet includes:

and receiving a TCP unicast data packet sent by the gateway equipment through a hypertext transfer protocol (HTTP) proxy to 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 packet is a packet received through an RTP data channel between a local set-top box device and the gateway device, and the retransmission response packet carries a retransmission packet identifier, and the retransmission packet identifier is used for identifying the retransmission response packet; after receiving the retransmission response packet of the gateway device, the method further includes:

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

analyzing the RTP-based header information, and if the header information contains the retransmission packet identifier, analyzing the payload in the original packet to obtain the retransmitted lost data packet;

and assembling the currently received lost data packet and the received data packet which is not lost to obtain an assembled data packet, and decoding the assembled data packet to play the decoded data.

17. A network device, comprising:

one or more processors;

memory having one or more programs stored thereon that, when executed by the one or more processors, cause the one or more processors to implement the data retransmission method of any of claims 1-11 or claims 12-16.

18. A computer-readable storage medium, characterized in that the storage medium stores a computer program which, when executed by a processor, implements the data retransmission method of any one of claims 1-11 or claims 12-16.