CN104168457B - Method and device for playing multiple media streams on demand - Google Patents

Abstract

The present invention provides a multi-channel media stream on-demand method and device. The method includes: using the first service link to send a target channel media stream service establishment notification message to the video surveillance client, and the service establishment notification message carries the private key of the video surveillance device. Network IP address, expected private network port number, and public network IP address converted by the NAT gateway device, expected public network port number; receive the service diversion report sent by the video surveillance client to the public network IP address and expected public network port number document, establishing a second service link between the video surveillance equipment and the video surveillance client, the diversion message carrying the target channel identifier; using the second service link, sending the media stream of the target channel to the video surveillance client end. Utilizing the invention reduces the hole punching process of STUN traversal and improves the efficiency of monitoring services.

Description

A multi-channel media stream on-demand method and device

technical field

The invention relates to the technical field of video monitoring, in particular to a multi-channel media stream on-demand method and device.

Background technique

In order to save the number of public network IP addresses and protect private network security, operators will deploy NAT (Network Address Translation, Network Address Translation) gateway devices at the egress of private networks. The addresses are converted to each other. Among them, the NAT gateway device can convert multiple private network IP addresses into the same public network IP address, and only need to use different port numbers after conversion to distinguish the corresponding private network IP addresses. As shown in Figure 1, the NAT gateway device can convert (IP1, Port1), (IP2, Port2), (IP3, Port3) in the private network to (IPA, PortA1), (IPA, PortA2) and (IPA, PortA3).

Taking the video surveillance field as an example, the video surveillance client and the video surveillance device may be located in different private networks, and may be located under a certain NAT gateway device. When P2P signaling interaction and media data transmission are to be performed between the video surveillance client and the video surveillance device, STUN (Simple Traversal of UDP over NATs, UDP simple traversal of NAT) detection and STUN traversal process are required to communicate.

Assuming that there is a camera under the video surveillance device, when the video surveillance client wants to view the live media stream data corresponding to the camera, first, perform STUN detection. Through the detection, the video surveillance device can learn the private network IP address of the video surveillance device and the corresponding public network IP address and public network port number of the local port number that sends the current live stream of the camera after conversion by the NAT gateway device. For example, suppose the private network IP address of the video surveillance device is b, and the current local port number is b1, the corresponding (B, B1) after the conversion of (b, b1) by the NAT gateway device is obtained after the STUN detection. Similarly, the video surveillance client obtains its private network IP address and a public network IP address and port number (C, C1) converted by the NAT gateway device connected to it through STUN detection. After the STUN detection, STUN traversal is performed, mainly the public network IP address and public network port number of the opposite end obtained by the video surveillance client and the video surveillance device according to the detection (the information can be detected by both parties of the video server), through hole punching For example, after the video surveillance client opens up the service link with (B, B1) of the video surveillance device above, the video surveillance device and the video surveillance client can start communicating and transmitting live media streams data.

The above is an example of a monitoring client ordering one live stream. If multiple cameras are performing live ordering services at the same time, STUN detection and STUN traversal need to be repeated. Repeating the STUN detection process will introduce more additional delays. The real-time requirements of the monitoring service are affected, and the efficiency of the monitoring service is very low.

Contents of the invention

In view of this, the present invention provides a multi-channel media stream on-demand method and device to improve monitoring efficiency.

The embodiment of the present invention provides a multi-channel media stream on-demand method, which is applied to video monitoring equipment located in the monitoring network. The video monitoring equipment manages multiple channels, and each channel corresponds to an image acquisition device. The monitoring group The network also includes a video monitoring client and a network address translation NAT gateway device, the video monitoring client and the video monitoring device are located in different private networks, and are respectively connected to the public network through the NAT gateway device, and the method includes:

receiving a target channel media stream service request message, and receiving a multiplexed first service link notification message, where the first service link is an established transmission link between the video surveillance device and the video surveillance client;

Use the IP address and port number of the video surveillance equipment side of the first service link as the source IP address and source port number, and use the IP address and port number of the video surveillance client side of the first service link as the destination IP Address and destination port number, send the target channel media flow service establishment notification message to the video monitoring client, the service establishment notification message carries the private network IP address and the expected private network port number of the video monitoring device, so The desired private network port number is the expected private network port number used by the video monitoring device to send the target channel media stream, and the target channel identifier, and the private network IP address after being converted by the egress NAT gateway device of the video monitoring device The corresponding public network IP address, the desired public network port number corresponding to the desired private network port number;

receiving the service diversion message sent by the video surveillance client to the public network IP address and the desired public network port number, establishing a second service link between the video surveillance device and the video surveillance client, the The diversion message carries the target channel identifier;

Using the second service link, send the media stream of the target channel to the video surveillance client.

The embodiment of the present invention also provides a multi-channel media stream on-demand method, which is applied to a video monitoring client located in a monitoring network. The monitoring network also includes a video monitoring device and a NAT gateway device. The video monitoring device manages A plurality of channels, each channel corresponds to an image acquisition device, the video monitoring client and the video monitoring device are located in different private networks, and are respectively connected to the public network through a NAT gateway device, and the method includes:

Sending a message requesting to obtain the media stream of the target channel of the video monitoring device;

receiving the target channel media stream service establishment notification message sent by the video surveillance device multiplexing the first service link, the first service link being the established transmission link between the video surveillance client and the video surveillance device The service establishment notification message carries the target channel identifier, the private network IP address of the video monitoring device and the expected private network port number for the video monitoring device to send the media stream of the target channel, and the exit port number of the video monitoring device The NAT gateway device converts the public network IP address obtained by the private network IP address and the desired public network port number obtained by converting the desired private network port number;

After determining that the target channel identifier in the service establishment notification message is a channel identifier requesting to obtain a media stream, a flow diversion message is sent to the public network IP address and the expected public network port number to establish the video monitoring the second service link between the client and the video monitoring device;

The target channel media stream data sent by the video monitoring device based on the second service link is received.

The embodiment of the present invention also provides a multi-channel media stream on-demand method, which is applied to a video surveillance network. The video surveillance network includes a video surveillance client, a video surveillance device, a video surveillance server, and a NAT gateway device. The video surveillance device Manage a plurality of channels, each channel corresponds to an image acquisition device, the video monitoring server is located in the public network, the video monitoring client and the video monitoring device are located in different private networks, and are respectively connected to the public network through a NAT gateway device, so The methods described include:

The video monitoring client sends a request message to the video monitoring server to obtain the media stream service of the target channel of the video monitoring device;

The video monitoring server queries the monitoring relationship table, checks whether the video monitoring client and the video monitoring device have established a media monitoring relationship, if not, then the video monitoring client and the video monitoring device perform NAT UDP Simple traversal of STUN detection and STUN traversal, establishing a transmission link between the video surveillance client and the video surveillance device, the video surveillance device sends the target channel media stream to the video surveillance client, if Yes, continue;

The video monitoring server sends a message for multiplexing the first service link to the video monitoring device and the video monitoring client, and sends the target channel media stream service request message requested by the video monitoring client to the video monitoring device;

The video monitoring device receives the target channel media stream service request message, and receives the multiplexed first service link notification message, and the first service link is the established transmission link between the video monitoring device and the video monitoring client link;

The video surveillance device uses the IP address and port number of the video surveillance device side of the first service link as the source IP address and source port number, and uses the IP address and port number of the video surveillance client side of the first service link As the purpose IP address and purpose port number, send the target channel media stream service establishment notification message to the video monitoring client, and the service establishment notice message carries the private network IP address and the desired private network port of the video monitoring device number, and the target channel identification, the desired private network port number is the desired private network port number used by the video surveillance equipment to send the target channel media stream;

The NAT gateway device at the exit where the video monitoring device is located fills in the service establishment notification message with the public network IP address obtained by the conversion of the private network IP address and the desired public network port number obtained by the conversion of the desired private network port number;

The video surveillance client receives the service establishment notification message, and if the channel identifier carried in the message is the same as the requested channel identifier, then the public network IP address in the service establishment notification message and the It is expected that the public network port number sends a service diversion message, and establishes a second service link between the video surveillance device and the video surveillance client, and the diversion message carries a target channel identifier;

The video surveillance device sends the media stream of the target channel to the video surveillance client by using the second service link.

The embodiment of the present invention also provides a video monitoring device, located in a video monitoring network, the video monitoring device manages multiple channels, each channel corresponds to an image acquisition device, and the monitoring network also includes a video monitoring client And network address translation NAT gateway equipment, described video surveillance client and video surveillance equipment are positioned at different private networks, are connected with public network through NAT gateway equipment respectively, comprise:

A receiving unit, configured to receive a target channel media stream service request message, and receive a multiplexed first service link notification message, the first service link being established by the video surveillance device and the video surveillance client transmission link;

A sending unit, configured to use the IP address and port number of the video surveillance device side of the first service link as the source IP address and source port number, and use the IP address and port number of the video surveillance client side of the first service link The port number is used as the destination IP address and the destination port number to send the target channel media stream service establishment notification message to the video surveillance client, and the service establishment notification message carries the private network IP address of the video surveillance device, the expected private network Network port number, the desired private network port number is the expected private network port number used by the video monitoring device to send the target channel media stream, and the target channel identifier, and is converted by the egress NAT gateway device of the video monitoring device The public network IP address corresponding to the private network IP address, and the desired public network port number corresponding to the desired private network port number;

An establishment unit, configured to receive a service diversion packet sent by the video surveillance client to the public network IP address and the desired public network port number, and establish a second service between the video surveillance device and the video surveillance client link, the diversion message carries a target channel identifier;

The sending unit is further configured to use the second service link to send the media stream of the target channel to the video surveillance client.

The embodiment of the present invention also provides a video surveillance client, which is located in a video surveillance network. The surveillance network also includes a video surveillance device and a NAT gateway device. The video surveillance device manages multiple channels, and each channel corresponds to An image acquisition device, the video monitoring client and the video monitoring device are located in different private networks, and are respectively connected to the public network through a NAT gateway device, including:

A sending unit, configured to send a message requesting to obtain the media stream of the target channel of the video monitoring device;

A receiving unit, configured to receive a target channel media stream service establishment notification message sent by the video monitoring device by multiplexing the first service link, the first service link being the video monitoring client and the video monitoring device The transmission link that has been established, the service establishment notification message carries the target channel identifier, the private network IP address of the video monitoring device and the desired private network port number for the video monitoring device to send the media stream of the target channel, and the The public network IP address obtained by converting the private network IP address and the desired public network port number obtained by converting the desired private network port number through the NAT gateway device at the exit of the video surveillance equipment;

An establishment unit, configured to send a diversion message to the public network IP address and the desired public network port number after determining that the target channel identifier in the service establishment notification message is a channel identifier requesting to obtain a media stream , establishing a second service link between the video surveillance client and the video surveillance device;

The receiving unit is further configured to receive target channel media stream data sent by the video monitoring device based on the second service link.

An embodiment of the present invention provides a video monitoring network, the video monitoring network includes a video monitoring client, a video monitoring device, a video monitoring server and a NAT gateway device, the video monitoring device manages multiple channels, and each channel corresponds to a Image acquisition equipment, the video monitoring server is located in the public network, the video monitoring client and the video monitoring equipment are located in different private networks, respectively connected to the public network through a NAT gateway device, including:

The video monitoring client is used to send a request message to the video monitoring server to obtain the media stream service of the target channel of the video monitoring device;

The video monitoring server is used to query the monitoring relationship table, check whether the video monitoring client and the video monitoring device have established a media monitoring relationship, if not, then the video monitoring client and the video monitoring device perform UDP of NAT simply traverses STUN detection and STUN traversal, establishes a transmission link between the video surveillance client and the video surveillance device, and the video surveillance device sends the target channel media stream to the video surveillance client end, if yes, continue;

The video monitoring server is further configured to send a packet multiplexing the first service link to the video monitoring device and the video monitoring client, and send the target channel media stream service request requested by the video monitoring client to the video monitoring device message;

A video monitoring device, configured to receive a target channel media stream service request message, and receive a multiplexed first service link notification message, the first service link is the video monitoring device and the video monitoring client Established transmission link;

The video surveillance device is further configured to use the video surveillance device side IP address and port number of the first service link as the source IP address and source port number, and use the video surveillance client side of the first service link The IP address and port number of the destination IP address and the destination port number are used as the destination IP address and the destination port number, and the target channel media stream service establishment notification message is sent to the video monitoring client, and the service establishment notification message carries the private network IP address of the video surveillance device Address, expected private network port number, and target channel identification, the expected private network port number is the expected private network port number used by the video surveillance equipment to send the target channel media stream;

The NAT gateway device at the exit where the video monitoring device is located is used to fill in the service establishment notification message with the public network IP address obtained through the conversion of the private network IP address and the desired public IP address obtained through the conversion of the desired private network port number. network port number;

The video surveillance client is further configured to receive the service establishment notification message, and if the channel identifier carried in the message is the same as the requested channel identifier, then report to the public in the service establishment notification message The network IP address and the desired public network port number send a service diversion message, establish a second service link between the video surveillance device and the video surveillance client, and the diversion message carries a target channel identifier;

The video monitoring device is further configured to use the second service link to send the media stream of the target channel to the video monitoring client.

The embodiment of the present invention provides a multi-channel media stream on-demand method and device. The video monitoring device and the video monitoring client perform STUN traversal through punching packets to establish the first service link. Subsequently, for the video monitoring device and the video The business of the monitoring client can reuse the first service link to transmit data packets between devices. When the video monitoring device sends a service establishment notification message to the video monitoring client, the private network IP address of the video monitoring device and The private network port number corresponding to the sending target channel is added to the service establishment notification message, and the NAT gateway device performs conversion when receiving the message, and adds the converted public network IP address and public network port number to the service establishment notification message. In the notification message, the service establishment notification message is sent to the video surveillance client, and the video surveillance client establishes the second service with the video surveillance device according to the converted public network IP address and public network port number on the video surveillance device side. link, and use the second service link to obtain the data of the target channel, which reduces the hole punching process of STUN traversal and improves the efficiency of monitoring services.

Description of drawings

Fig. 1 is a schematic diagram of network address translation of a NAT gateway device provided by the prior art;

Fig. 2 is the application scenario diagram of the multi-channel media stream on-demand method provided by the embodiment of the present invention;

Fig. 3 is a flow chart of a method provided by an embodiment of the present invention;

Fig. 4 is a flow chart of a method provided by another embodiment of the present invention;

Fig. 5 is a flow chart of a method provided by another embodiment of the present invention;

Fig. 6 is a hardware environment architecture diagram of the operation of the video surveillance equipment provided by the embodiment of the present invention;

Fig. 7 is a schematic structural diagram of a video monitoring device provided by an embodiment of the present invention;

Fig. 8 is a hardware environment architecture diagram of the operation of the video surveillance client provided by the embodiment of the present invention;

Fig. 9 is a schematic structural diagram of a video monitoring device provided by an embodiment of the present invention;

Fig. 10 is a schematic structural diagram of a video surveillance network provided by an embodiment of the present invention.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In order to make the multi-channel media stream on-demand method provided by the embodiment of the present invention easier to understand, an optional application scenario of the on-demand method is first described in conjunction with FIG. 2. As shown in FIG. 2, the monitoring system mainly includes: front-end equipment and back-end equipment. Among them, the front-end equipment can be camera, manual or electric lens, pan/tilt, protective cover, listener, alarm detector and multi-function decoder, etc., which are mainly used to monitor the target objects on the scene within the scope of its own monitoring, as shown in Figure 2 Out of IPC1, IPC2 and IPC3, only IPC (IP camera, network camera) is used here to represent the front-end equipment of the monitoring system. Wherein, the back-end device can be a central control device or a sub-control device, etc., and the video surveillance device shown in Figure 2 is the back-end device, and the back-end device can be an NVR (Network Video Recorder or Network Video Recorder) or a DVR (Digital Video Recorder). VideoRecorder hard disk video recorder), the back-end equipment is mainly used to receive the scene images collected by each front-end equipment, so that when the video surveillance client obtains the data of a certain channel, it uses the business link with the video surveillance client to use the channel The data is sent to the video surveillance client.

Among them, as shown in Figure 2, the video surveillance device accesses and manages multiple cameras, and each camera corresponds to a channel of the video surveillance device. For example, if the video surveillance client obtains the data of the first channel, it means that the video surveillance client It is necessary to obtain the live image collected by IPC1. The service link is a link established between the video surveillance device and the video surveillance client, and is used to realize the transmission of information data between the video surveillance device and the video surveillance client.

Since the video surveillance device in Figure 2 is on the private network side of NAT gateway device A, and the video surveillance client is on the private network side of NAT gateway device B, it is first necessary to perform STUN detection. Through detection, the video surveillance device can learn its own The private network IP address and the private network port number that sends the current code stream are converted by the NAT gateway device A to the corresponding public network IP address IPA and public network port number PortA. Similarly, the video surveillance client knows its own private network IP address , The private network port number receiving the current code stream is converted by the NAT gateway device B to the corresponding public network IP address IPB and public network port number PortB.

When the video surveillance client obtains the data of a certain channel, the video surveillance device and the video surveillance client need to obtain the peer’s public network IP address and public network port number according to STUN traversal. After the traversal is successful, use the service established during the traversal The link obtains the data of the certain channel.

On the basis of the above process, the embodiments of the present invention can acquire media stream data of multiple channels separately or simultaneously by using only one STUN traversal process, so as to improve monitoring efficiency.

Embodiment one

As shown in Figure 3, it is a schematic flow diagram of a multi-channel media stream on-demand method provided by the embodiment of the present invention. The method of the embodiment of the present invention is executed by a video monitoring device, and the video monitoring device manages multiple channels, and each channel Corresponding to an image acquisition device, the monitoring network also includes a video monitoring client and a NAT gateway device. The video monitoring client and the video monitoring device are located in different private networks, and are respectively connected to the public network through a NAT gateway device. The following steps may be included :

Step 301: Receive a target channel media stream service request message, and receive a multiplexed first service link notification message, where the first service link is an established transmission link between the video surveillance device and the video surveillance client.

Wherein, the first service link is a link established by using STUN traversal technology. Take the service link a in Figure 2 as the first service link. This service link a is used to transmit the media stream data collected by IPC1 between the video surveillance equipment and the video surveillance client, and the notification message carries the services that need to be multiplexed. The link identifier of link a, for example, "a" indicates the service link.

When the video monitoring client requests to view the IPC2 live code stream, then the IPC2 at this time corresponds to the second channel of the video monitoring device, and the second channel is the target channel.

The video surveillance device receives a request from the video surveillance client for the second channel of media stream data. For example, the video surveillance client wants to view the live broadcast of the IPC2 at this time. The video monitoring device also receives the notification message of multiplexing the first service link a.

Step 302: Use the IP address and port number of the video surveillance device side of the first service link as the source IP address and source port number, and use the IP address and port number of the video surveillance client side of the first service link as the destination IP address and destination port number, send the target channel media stream service establishment notification message to the video surveillance client, the service establishment notification message carries the private network IP address of the video surveillance device, the desired private network port number, and the desired private network The network port number is the expected private network port number used by the video monitoring device to send the media stream of the target channel, the target channel identifier, and the public network IP corresponding to the private network IP address converted by the egress NAT gateway device of the video monitoring device Address, desired public network port number corresponding to the desired private network port number.

Because the existing technology needs to use STUN detection and STUN traversal process to establish service links when the data collected by each IPC connected to the video surveillance equipment is broadcast on demand, the delay of monitoring is serious, and the efficiency of monitoring services is very low. Therefore, the embodiment of the present invention has established the service link a, and when the video surveillance client and the video surveillance device transmit the service link corresponding to the second IPC2 code stream, use the established service link a to send video The monitoring client sends a service establishment notification message, which carries the private network IP address of the video surveillance device and the expected private network port number (IP2, Port2) corresponding to the transmission target channel code stream, and the service establishment notification message When passing through the NAT gateway device A, the NAT gateway device A converts (IP2, Port2) into a public network IP address and a desired public network port number (IPA, PortA2), and adds the (IPA, PortA2) in the service establishment notification report The text is sent to the video surveillance client, so that the video surveillance client establishes a service link b with the video surveillance device according to the service establishment notification message, thereby reducing the hole punching process of STUN traversal and improving the efficiency of the surveillance service.

Wherein, the service establishment notification message sent by the video surveillance equipment also carries the target channel identifier channel2, so that when the video surveillance client receives the service establishment notification message, it can judge whether it is requested by itself according to the target channel identifier channel2 The channel information of the target channel for obtaining data. Since the video surveillance client requests to obtain IPC2 data, the target channel identifier channel2 in the service establishment notification message is the channel through which the video surveillance client requests to obtain data.

Step 303: Receive the traffic diversion packet sent by the video surveillance client to the public network IP address and the expected public network port number, establish a second service link between the video surveillance device and the video surveillance client, and the traffic diversion packet Carry the target channel ID.

Step 304: Using the second service link, send the media stream of the target channel to the video surveillance client.

The video surveillance device is receiving the service diversion packet sent by the video surveillance client. The destination IP address and destination port number (IPA, PortA2) of the diversion packet are respectively the private network IP address of the video surveillance device and the expected channel corresponding to the target channel. The public network IP address converted from the private network port number (IP2, Port2) and the expected public network port number (IPA, PortA2), when the video surveillance device receives the service drainage packet sent by the video surveillance client, use the traffic drainage packet The IP address and IP port number of the video monitoring client side carried in the file, and according to (IP2, Port2), establish the corresponding service link of the video monitoring client and the video monitoring device to transmit the second media stream data IPC2 live media stream b. The video monitoring device uses the service link b to send the media stream data collected by the IPC2 to the video monitoring client.

The embodiment of the present invention utilizes a service link established by STUN to send a service establishment notification message to the video surveillance client, thereby establishing a service link corresponding to the video surveillance client and the video surveillance device transmitting the second channel media stream, The service establishment notification message carries the private network IP address of the video surveillance device and the expected private network port number of the media stream corresponding to the target channel for the video surveillance client to obtain the data allocated by the video surveillance device, and the received This message is the converted public network IP address and expected public network port number, and the video monitoring client establishes a second service link with the video monitoring device based on the converted public network IP address and expected public network port number on the video monitoring device side and use the second service link to obtain the data of the target channel, which reduces the hole punching process of STUN traversal and improves the efficiency of monitoring services.

Embodiment two

As shown in Figure 4, it is a schematic flow diagram of a multi-channel media stream on-demand method provided by the embodiment of the present invention. The method of the embodiment of the present invention is executed by the video surveillance client and applied to the video surveillance located in the surveillance network Client, the monitoring network also includes video monitoring equipment and NAT gateway equipment, the video monitoring equipment manages multiple channels, each channel corresponds to an image acquisition device, the video monitoring client and video monitoring equipment are located in different private networks, Connecting to the public network through a NAT gateway device may include the following steps:

Step 401: Send a message requesting to obtain the media stream of the target channel of the video monitoring device.

Step 402: Receive the target channel media stream service establishment notification message sent by the video surveillance device by multiplexing the first service link. The first service link is the established transmission link between the video surveillance client and the video surveillance device The service establishment notification message carries the target channel identifier, the private network IP address of the video monitoring device and the expected private network port number of the video monitoring device sending the media stream of the target channel, and the NAT gateway device that converts the video monitoring device through the video monitoring device. The public network IP address obtained from the private network IP address and the desired public network port number obtained by converting the desired private network port number.

The target channel media stream takes the video surveillance client requesting to obtain the data collected by the second channel channel2 connected to the video surveillance device as an example. After receiving the service establishment notification message sent by the video surveillance device, the service establishment Determine whether the target channel identifier channel2 carried in the notification message is the same as the target channel channel2 that the user requests to obtain data. If the judgment results are the same, then determine that the service establishment notification message is correct. If the judging results are not the same, it is determined that the service notification message is wrong, and the message requesting to obtain the media stream of the target channel of the video monitoring device is resent to the video monitoring server until the judging results are the same.

Step 403: After determining that the target channel identifier in the service establishment notification message is the channel identifier for requesting to obtain media streams, send a flow diversion message to the public network IP address and the expected public network port number, and establish the video surveillance client end and the second service link of the video surveillance equipment.

Step 404: Receive the target channel media stream data sent by the video monitoring device based on the second service link.

The video monitoring client sends a traffic diversion message to the video surveillance device according to the service establishment notification message, wherein the public network IP address and the expected public network port number carried in the service establishment notification message are used as the destination IP address of the traffic diversion message, Destination port number. The diversion message also carries the target channel identifier channel2, so that the video surveillance device receives the diversion message and sends the data corresponding to the target channel identifier channel2 to the video surveillance client according to the target channel identifier channel2.

After the video monitoring device receives the flow diversion message, a service link b between the video monitoring client and the video monitoring device to transmit the media stream of the target channel is established. Received through the service link b when receiving the target channel media stream data sent by the video surveillance equipment.

In the embodiment of the present invention, the video surveillance client receives the service establishment notification message sent by the video surveillance device, because the service establishment notification message carries the private network IP address of the video surveillance device, the desired private network port number corresponding to the target channel, and After the converted public network IP address and expected public network port number, the video monitoring client establishes a service link corresponding to the target channel with the video monitoring device according to the converted public network IP address and expected public network port number, thereby using The service link corresponding to the target channel obtains the data of the target channel, thereby reducing the hole punching process of STUN traversal and improving the efficiency of monitoring services.

Embodiment three

5 is a flow chart of another multi-channel media stream on demand provided by the embodiment of the present invention, which is applied to a video surveillance network. The video surveillance network includes a video surveillance client, a video surveillance device, a video surveillance server, and a NAT gateway device. The video surveillance device manages multiple channels, and each channel corresponds to an image acquisition device. The video surveillance server is located in the public network, and the video surveillance client and video surveillance device are located in different private networks, respectively connected to the public network through a NAT gateway device. The method can include:

Step 501: the video surveillance client sends a request message to the video surveillance server to obtain the media stream service of the target channel of the video surveillance device.

The service request message carries the channel identifier, user identifier, video surveillance client identifier, and video surveillance device identifier of the target channel for which the video surveillance client requests to obtain data.

For example, as shown in FIG. 2 , the video surveillance client requests to obtain the data of IPC2 corresponding to the second channel of the video surveillance device, and the channel identifier of the target channel of the monitoring request to obtain data carried in the data acquisition request is channel2.

Step 502: The video monitoring server queries the pre-stored media monitoring relationship table according to the user ID and the ID of the video monitoring device to check whether the media monitoring relationship has been established between the video monitoring client and the video monitoring device, and if yes, continue.

Wherein, the user identifier may be an account number and password for logging in on the video surveillance client. Depending on the user ID, the permissions corresponding to the user ID are also different. For example, the account number can be: zhanghao; the password can be ****. The authority of the video monitoring server for the account and password is that the media monitoring relationship table can be searched according to the user ID. The authority to other accounts and passwords is prohibited from searching the media monitoring relationship table.

When the video monitoring server checks the media monitoring relationship table, if the media monitoring relationship table includes the service link identification corresponding to the identification of the video monitoring client and the identification of the video monitoring equipment, it indicates that the video monitoring client and the video monitoring A service link has been established between devices.

If the media monitoring relationship table does not include the service link identifier corresponding to the identifier of the video surveillance client and the identifier of the video surveillance device, indicating that no service link has been established between the video surveillance client and the video surveillance device, then use The STUN detection technology establishes a service link between the video surveillance client and the video surveillance device, and the video surveillance server records and saves the information of the service link established by using the STUN detection technology in the media monitoring relationship table.

In the embodiment of the present invention, the media monitoring relationship table is as shown in Table 1:

Table 1:

As shown in Table 1, when the video monitoring server searches the media monitoring relationship table according to the video monitoring client identification and video monitoring device identification carried in the data acquisition request, if the media monitoring relationship table includes the video information carried in the data acquisition request The ID of the surveillance client and the ID of the video surveillance device indicate that a service link has been established between the video surveillance client and the video surveillance device; otherwise, it indicates that no service link has been established between the video surveillance client and the video surveillance device .

Taking the video surveillance client identified as video surveillance client 1 and the video surveillance device 1 having established a service link, and only establishing the service link a as an example, the established service link is The service link established between the video surveillance client and the video surveillance device using the STUN traversal technology. It is used to enable the video surveillance client to obtain the media stream data of the IPC1 corresponding to the first channel of the video surveillance device according to the established service link a.

Or there are multiple established service links, and these multiple service links can be established through other methods other than STUN detection and traversal, for example, they can be established through the solution of the present invention, and the established service link method is not limited here.

Step 503: The video surveillance server sends a packet multiplexing the first service link to the video surveillance device and the video surveillance client, and sends a target channel media stream service request packet requested by the video surveillance client to the video surveillance device.

Wherein, the message of multiplexing the first service link sent by the video surveillance server to the video surveillance device and the video surveillance client carries the identifier of the first service link.

Since the video monitoring client does not receive the message returned by the video monitoring server regarding the service request message within the preset time period, it will continue to send the service request message to the video monitoring server. Therefore, the video surveillance server needs to send a packet multiplexing the first service link to the video surveillance client. After receiving the packet sent by the video surveillance server to multiplex the first service link, the video surveillance client will wait for a message sent by the video surveillance device using the established service link.

Step 504: The video surveillance device receives the target channel media stream service request message, and receives the notification message of the multiplexed first service link, the first service link is the established transmission link between the video surveillance device and the video surveillance client link.

Step 505: The video surveillance device uses the IP address and port number of the video surveillance device side of the first service link as the source IP address and source port number, and uses the IP address and port number of the video surveillance client side of the first service link number as the destination IP address and destination port number, and send the target channel media stream service establishment notification message to the video surveillance client, and the service establishment notification message carries the private network IP address of the video surveillance device, the expected private network port number, And target channel identification, the expected private network port number is the private network port number expected to be used by the video monitoring device to send the media stream of the target channel.

Step 506: NAT gateway device A receives the service establishment notification message sent by the video surveillance device, and converts the private network IP address of the video surveillance device carried in the service establishment notification message and the desired private network port number corresponding to the target channel, And the converted public network IP address and the expected public network port number are filled in the service establishment notification message, and the service establishment notification message is sent to the NAT gateway device B connected to the video surveillance client, so that the NAT Gateway device B sends the service establishment notification message to the video surveillance client.

At the same time, the NAT gateway device saves the mapping relationship between the private network IP address, the expected private network port number and the public network IP address, and the expected public network port number, so that the subsequent completion of the public network IP address, the expected public network port number to the private network IP address , The address translation of the expected private network port number.

Step 507: The video monitoring client receives the service establishment notification message, if the channel identifier carried in the message is the same as the requested channel identifier, then the public network IP address in the service establishment notification message and the expected public IP address in the service establishment notification message are the same. The service diversion packet sent by the network port number establishes a second service link between the video surveillance device and the video surveillance client, and the diversion packet carries a target channel identifier.

Among them, the public network IP address and public network port number of the diversion message sent by the video surveillance client are converted by the NAT gateway device on the video surveillance device side, according to the internally stored public network and private network address conversion table, to the corresponding IP address of the video surveillance device. private network IP address and desired private network port number. Specifically, after the video monitoring client receives the service establishment notification message, it converts the public network IP address and the expected public network port number through the NAT gateway device according to the private network IP address of the video monitoring device and the desired private network port number corresponding to the target channel. The network port number, the video monitoring client sends a traffic diversion message, and establishes a service link b for the second channel with the video monitoring device. Every time a service link is established between the video surveillance client and the video surveillance device, both the video surveillance client and the video surveillance device send information about the established service link to the video surveillance server, and the video surveillance server sends information about the established service link to the video surveillance server. The information is stored in the media monitoring relationship table.

Step 508: the video surveillance device sends the media stream of the target channel to the video surveillance client by using the second service link.

The above-mentioned process is all based on the process of the video monitoring client ordering the data of one channel. When the video monitoring client is simultaneously ordering the data of two or more channels, the embodiment of the present invention is based on the video monitoring client simultaneously ordering the data of the two channels. For example, the difference between this method and the data of ordering one channel in Figure 7 may include:

In step 501, in the request message sent by the video surveillance client to the video surveillance server to obtain the media stream service of the target channel of the video surveillance device, the channel identifiers of the two target channels that request to obtain the media stream data may be carried, or may be The video surveillance client sends two service request packets to the video surveillance server respectively.

In step 503, the video monitoring server may send a service request message to the video monitoring device, and the service request message may carry the target channel identifier of the media stream requested by the video monitoring client. Alternatively, two service request messages may be sent, and each service request message carries the identifier of the target channel for the media stream requested by the corresponding video surveillance client.

In step 505, the service establishment notification message sent by the video monitoring device may include the IP address of the video monitoring device corresponding to the two target channels, the expected private network port number corresponding to each target channel, and the public network IP address. Address and desired public network port number. It may also be that the video monitoring device sends two service establishment notification messages.

In steps 506 and 507, after receiving the service establishment notification message, the video surveillance client sends traffic diversion messages to corresponding video surveillance devices according to the service establishment notification message. After receiving the diversion message, the video surveillance device uses the corresponding service link to return the media stream data.

According to the above solution, the video surveillance device and the video surveillance client implement STUN traversal through hole-punching packets to establish the first service link, use the first service link to transmit data packets between devices, and send When the video surveillance client sends a service establishment notification message, the private network IP address of the video surveillance device and the desired private network port number corresponding to the target channel where the video surveillance client needs to obtain data are added to the service establishment notification message, and The NAT gateway device performs conversion when receiving the message, and adds the converted public network IP address and expected public network port number to the service establishment notification message, so as to send the service establishment notification message to the video surveillance client , the video surveillance client sends a traffic diversion packet to the video surveillance device according to the converted public network IP address and the expected public port number on the video surveillance device side, and establishes a first session with the video surveillance client after the video device receives the traffic diversion packet. Two service links, and use the second service link to return the media stream data of the target channel, reducing the hole punching process of STUN traversal, and according to the solution of the present invention, the data of multiple channels can be ordered at the same time, which improves the efficiency of monitoring services .

As shown in Figure 6 and Figure 7, the embodiment of the present invention provides a video monitoring device, located in the video monitoring network, the video monitoring device manages multiple channels, each channel corresponds to an image acquisition device, and the monitoring network also Including the video surveillance client and the network address translation NAT gateway device, the video surveillance client and the video surveillance device are located in different private networks, respectively connected to the public network through the NAT gateway device. The device embodiments can be implemented by software, or by hardware or a combination of software and hardware. From the hardware level, as shown in Figure 6, it is a hardware structural diagram of the device where the video surveillance device in the embodiment of the present invention is located, except for the CPU, memory, network interface, and non-volatile memory shown in Figure 6 , the device where the device in the embodiment is located may also generally include other hardware, such as a forwarding chip responsible for processing packets, and the like. Taking software implementation as an example, as shown in Figure 7, as a device in a logical sense, it is formed by reading the corresponding computer program instructions in the non-volatile memory into the memory for operation by the CPU of the device where it is located. The video surveillance equipment 70 provided in this embodiment includes:

The receiving unit 701 is configured to receive a target channel media stream service request message, and receive a multiplexed first service link notification message, the first service link is the video surveillance device and the video surveillance client Established transmission link;

The sending unit 702 is configured to use the IP address and port number of the video surveillance device side of the first service link as the source IP address and source port number, and use the IP address of the video surveillance client side of the first service link and the port number as the destination IP address and the destination port number, send the target channel media stream service establishment notification message to the video monitoring client, and the service establishment notification message carries the private network IP address, expected Private network port number, the desired private network port number is the expected private network port number used by the video monitoring device to send the target channel media stream, and the target channel identifier, and the egress NAT gateway device of the video monitoring device The public network IP address corresponding to the converted private network IP address, and the desired public network port number corresponding to the desired private network port number;

The establishment unit 703 is configured to receive the service diversion message sent by the video surveillance client to the public network IP address and the desired public network port number, and establish a second connection between the video surveillance device and the video surveillance client. A service link, where the diversion message carries a target channel identifier;

The sending unit is further configured to use the second service link to send the media stream of the target channel to the video surveillance client.

As shown in Figure 8 and Figure 9, the embodiment of the present invention provides a video surveillance client, which is located in a video surveillance network, wherein the surveillance network also includes a video surveillance device and a NAT gateway device, and the video surveillance device manages A plurality of channels, each channel corresponds to an image acquisition device, the video monitoring client and the video monitoring device are located in different private networks, and are respectively connected to the public network through a NAT gateway device. The device embodiments can be implemented by software, or by hardware or a combination of software and hardware. From the hardware level, as shown in Figure 8, it is a hardware structural diagram of the device where the video surveillance device is located in the embodiment of the present invention, except for the CPU, memory, network interface, and non-volatile memory shown in Figure 8 , the device where the device in the embodiment is located may also generally include other hardware, such as a forwarding chip responsible for processing packets, and the like. Taking software implementation as an example, as shown in Figure 9, as a device in a logical sense, it is formed by reading the corresponding computer program instructions in the non-volatile memory into the memory for operation by the CPU of the device where it is located. The video surveillance client 90 includes:

A sending unit 901, configured to send a message requesting to obtain the media stream of the target channel of the video monitoring device;

The receiving unit 902 is configured to receive the target channel media stream service establishment notification message sent by the video surveillance device by multiplexing the first service link, the first service link being the video surveillance client and the video surveillance The transmission link that has been established by the device, the service establishment notification message carries the target channel identifier, the private network IP address of the video monitoring device, the expected private network port number for the video monitoring device to send the media stream of the target channel, and the The NAT gateway device at the egress of the video surveillance equipment converts the public network IP address obtained by the private network IP address and the desired public network port number obtained by converting the desired private network port number;

The establishment unit 903 is configured to send a flow diversion report to the public network IP address and the desired public network port number after determining that the target channel identification in the service establishment notification message is a channel identification requesting to obtain a media stream document, establishing a second service link between the video surveillance client and the video surveillance device;

The receiving unit 902 is further configured to receive target channel media stream data sent by the video surveillance device based on the second service link.

As shown in Figure 10, the embodiment of the present invention provides a video surveillance network, the video surveillance network includes a video surveillance client, a video surveillance device, a video surveillance server and a NAT gateway device, the video surveillance device manages multiple channels, each channel Corresponding to an image acquisition device, the video surveillance server is located in the public network, and the video surveillance client and video surveillance device are located in different private networks, respectively connected to the public network through a NAT gateway device. The video surveillance network 100 includes:

The video surveillance client 1001 is configured to send a request message to the video surveillance server to obtain a media stream service request for the target channel of the video surveillance device;

The video monitoring server 1002 is used to query the monitoring relationship table, check whether the video monitoring client and the video monitoring device have established a media monitoring relationship, if not, then the video monitoring client and the video monitoring device Perform NAT UDP simple traversal STUN detection and STUN traversal, establish a transmission link between the video surveillance client and the video surveillance device, and the video surveillance device sends the target channel media stream to the video surveillance Client, if yes, continue;

The video monitoring server 1002 is further configured to send a packet multiplexing the first service link to the video monitoring device and the video monitoring client, and send the target channel media stream service requested by the video monitoring client to the video monitoring device request message;

The video monitoring device 1003 is configured to receive a target channel media stream service request message, and receive a multiplexed first service link notification message, the first service link being the video monitoring device and the video monitoring client established transmission links;

The video surveillance device 1003 is further configured to use the video surveillance device side IP address and port number of the first service link as the source IP address and source port number, and use the video surveillance client of the first service link The IP address and port number of the side are used as the destination IP address and the destination port number, and the target channel media stream service establishment notification message is sent to the video surveillance client, and the service establishment notification message carries the private network of the video surveillance device IP address, expected private network port number, and target channel identification, the expected private network port number is the expected private network port number used by the video surveillance equipment to send the target channel media stream;

The NAT gateway device 1004 at the exit where the video monitoring device is located is configured to fill in the service establishment notification message with the public network IP address obtained through the conversion of the private network IP address and the desired IP address obtained through the conversion of the expected private network port number. Public network port number;

The video monitoring client 1001 is further configured to receive the service establishment notification message, and if the channel identifier carried in the message is the same as the requested channel identifier, send the The public network IP address and the service diversion message sent by the desired public network port number establish a second service link between the video surveillance device and the video surveillance client, and the diversion message carries a target channel identifier;

The video monitoring device 1003 is further configured to use the second service link to send the media stream of the target channel to the video monitoring client.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection.

Claims (6)

1. A multi-channel media stream on-demand method is applied to a video surveillance device located in a monitoring network. The video surveillance device manages a plurality of channels, and each channel corresponds to an image acquisition device. The monitoring network also includes a video Monitoring client and network address translation NAT gateway equipment, described video surveillance client and video surveillance equipment are positioned at different private networks, are connected with public network by NAT gateway equipment respectively, it is characterized in that, described method comprises: receiving a target channel media stream service request message, and receiving a notification message for multiplexing a first service link, where the first service link is an established transmission between the video surveillance device and the video surveillance client link; Use the IP address and port number of the video surveillance equipment side of the first service link as the source IP address and source port number, and use the IP address and port number of the video surveillance client side of the first service link as the destination IP Address and destination port number, send the target channel media flow service establishment notification message to the video monitoring client, the service establishment notification message carries the private network IP address and the expected private network port number of the video monitoring device, so The desired private network port number is the expected private network port number used by the video monitoring device to send the target channel media stream, and the target channel identifier, and the private network IP address after being converted by the egress NAT gateway device of the video monitoring device The corresponding public network IP address, the desired public network port number corresponding to the desired private network port number; receiving the service diversion message sent by the video surveillance client to the public network IP address and the desired public network port number, establishing a second service link between the video surveillance device and the video surveillance client, the The diversion message carries the target channel identifier; Using the second service link, send the media stream of the target channel to the video surveillance client. 2. A multi-channel media stream on-demand method is applied to a video monitoring client in a monitoring network, and the monitoring network also includes a video monitoring device and a NAT gateway device, and the video monitoring device manages a plurality of channels, each Each channel corresponds to an image acquisition device, and the video monitoring client and the video monitoring device are located in different private networks, and are respectively connected to the public network through a NAT gateway device, and it is characterized in that the method includes: Sending a message requesting to obtain the media stream of the target channel of the video monitoring device; receiving the target channel media stream service establishment notification message sent by the video surveillance device multiplexing the first service link, the first service link being the established transmission link between the video surveillance client and the video surveillance device The service establishment notification message carries the target channel identifier, the private network IP address of the video monitoring device and the expected private network port number for the video monitoring device to send the media stream of the target channel, and the exit port number of the video monitoring device The NAT gateway device converts the public network IP address obtained by the private network IP address and the desired public network port number obtained by converting the desired private network port number; After determining that the target channel identifier in the service establishment notification message is a channel identifier requesting to obtain a media stream, a flow diversion message is sent to the public network IP address and the expected public network port number to establish the video monitoring the second service link between the client and the video monitoring device; The target channel media stream data sent by the video monitoring device based on the second service link is received. 3. A multi-channel media stream on-demand method is applied to a video monitoring network, and the video monitoring network includes a video monitoring client, a video monitoring device, a video monitoring server and a NAT gateway device, and the video monitoring device manages a plurality of channels, Each channel corresponds to an image acquisition device, the video monitoring server is located in the public network, the video monitoring client and the video monitoring device are located in different private networks, and are respectively connected to the public network through a NAT gateway device, it is characterized in that the Methods include: The video monitoring client sends a request message to the video monitoring server to obtain the media stream service of the target channel of the video monitoring device; The video monitoring server queries the monitoring relationship table, checks whether the video monitoring client and the video monitoring device have established a media monitoring relationship, if not, then the video monitoring client and the video monitoring device perform NAT UDP Simple traversal of STUN detection and STUN traversal, establishing a transmission link between the video surveillance client and the video surveillance device, the video surveillance device sends the target channel media stream to the video surveillance client, if Yes, continue; The video monitoring server sends a message for multiplexing the first service link to the video monitoring device and the video monitoring client, and sends the target channel media stream service request message requested by the video monitoring client to the video monitoring device; The video monitoring device receives the target channel media stream service request message, and receives the notification message for multiplexing the first service link, and the first service link is the video monitoring device and the video monitoring client. Established transmission link; The video surveillance device uses the IP address and port number of the video surveillance device side of the first service link as the source IP address and source port number, and uses the IP address and port number of the video surveillance client side of the first service link As the purpose IP address and purpose port number, send the target channel media stream service establishment notification message to the video monitoring client, and the service establishment notice message carries the private network IP address and the desired private network port of the video monitoring device number, and the target channel identification, the desired private network port number is the desired private network port number used by the video surveillance equipment to send the target channel media stream; The NAT gateway device at the exit where the video monitoring device is located fills in the service establishment notification message with the public network IP address obtained by the conversion of the private network IP address and the desired public network port number obtained by the conversion of the desired private network port number; The video surveillance client receives the service establishment notification message, and if the channel identifier carried in the message is the same as the requested channel identifier, then the public network IP address in the service establishment notification message and the It is expected that the public network port number sends a service diversion message, and establishes a second service link between the video surveillance device and the video surveillance client, and the diversion message carries a target channel identifier; The video surveillance device sends the media stream of the target channel to the video surveillance client by using the second service link. 4. A video monitoring device, located in a video monitoring network, the video monitoring device manages a plurality of channels, each channel corresponds to an image acquisition device, and the video monitoring network also includes a video monitoring client and network address translation NAT gateway equipment, described video surveillance client and video surveillance equipment are positioned at different private networks, are connected with public network through NAT gateway equipment respectively, it is characterized in that, comprises: A receiving unit, configured to receive a target channel media stream service request message, and receive a notification message for multiplexing a first service link, where the first service link is the video surveillance device and the video surveillance client The established transmission link at the end; A sending unit, configured to use the IP address and port number of the video surveillance device side of the first service link as the source IP address and source port number, and use the IP address and port number of the video surveillance client side of the first service link The port number is used as the destination IP address and the destination port number to send the target channel media stream service establishment notification message to the video surveillance client, and the service establishment notification message carries the private network IP address of the video surveillance device, the expected private network Network port number, the desired private network port number is the expected private network port number used by the video monitoring device to send the target channel media stream, and the target channel identifier, and is converted by the egress NAT gateway device of the video monitoring device The public network IP address corresponding to the private network IP address, and the desired public network port number corresponding to the desired private network port number; An establishment unit, configured to receive a service diversion packet sent by the video surveillance client to the public network IP address and the desired public network port number, and establish a second service between the video surveillance device and the video surveillance client link, the diversion message carries a target channel identifier; The sending unit is further configured to use the second service link to send the media stream of the target channel to the video surveillance client. 5. A video monitoring client, located in a video monitoring network, the video monitoring network also includes a video monitoring device and a NAT gateway device, the video monitoring device manages multiple channels, and each channel corresponds to an image acquisition device , the video monitoring client and the video monitoring device are located in different private networks, respectively connected to the public network through a NAT gateway device, characterized in that, comprising: A sending unit, configured to send a message requesting to obtain the media stream of the target channel of the video monitoring device; A receiving unit, configured to receive a target channel media stream service establishment notification message sent by the video monitoring device by multiplexing the first service link, the first service link being the video monitoring client and the video monitoring device The transmission link that has been established, the service establishment notification message carries the target channel identifier, the private network IP address of the video monitoring device and the desired private network port number for the video monitoring device to send the media stream of the target channel, and the The public network IP address obtained by converting the private network IP address and the desired public network port number obtained by converting the desired private network port number through the NAT gateway device at the exit of the video surveillance equipment; An establishment unit, configured to send a diversion message to the public network IP address and the desired public network port number after determining that the target channel identifier in the service establishment notification message is a channel identifier requesting to obtain a media stream , establishing a second service link between the video surveillance client and the video surveillance device; The receiving unit is further configured to receive target channel media stream data sent by the video monitoring device based on the second service link. 6. A video monitoring network, the video monitoring network includes a video monitoring client, a video monitoring device, a video monitoring server and a NAT gateway device, the video monitoring device manages a plurality of channels, and each channel corresponds to an image acquisition device, The video monitoring server is located in the public network, and the video monitoring client and the video monitoring equipment are located in different private networks, and are respectively connected to the public network through a NAT gateway device, which is characterized in that, comprising: The video monitoring client is used to send a request message to the video monitoring server to obtain the media stream service of the target channel of the video monitoring device; The video monitoring server is used to query the monitoring relationship table, check whether the video monitoring client and the video monitoring device have established a media monitoring relationship, if not, then the video monitoring client and the video monitoring device perform UDP of NAT simply traverses STUN detection and STUN traversal, establishes a transmission link between the video surveillance client and the video surveillance device, and the video surveillance device sends the target channel media stream to the video surveillance client end, if yes, continue; The video monitoring server is further configured to send a packet multiplexing the first service link to the video monitoring device and the video monitoring client, and send the target channel media stream service request requested by the video monitoring client to the video monitoring device message; A video monitoring device, configured to receive a target channel media stream service request message, and receive a notification message for multiplexing a first service link, where the first service link is the video monitoring device and the video monitoring The transmission link established by the client; The video surveillance device is further configured to use the video surveillance device side IP address and port number of the first service link as the source IP address and source port number, and use the video surveillance client side of the first service link The IP address and port number of the destination IP address and the destination port number are used as the destination IP address and the destination port number, and the target channel media stream service establishment notification message is sent to the video monitoring client, and the service establishment notification message carries the private network IP address of the video surveillance device Address, expected private network port number, and target channel identification, the expected private network port number is the expected private network port number used by the video surveillance equipment to send the target channel media stream; The NAT gateway device at the exit where the video monitoring device is located is used to fill in the service establishment notification message with the public network IP address obtained through the conversion of the private network IP address and the desired public IP address obtained through the conversion of the desired private network port number. network port number; The video surveillance client is further configured to receive the service establishment notification message, and if the channel identifier carried in the message is the same as the requested channel identifier, then report to the public in the service establishment notification message The network IP address and the desired public network port number send a service diversion message, establish a second service link between the video surveillance device and the video surveillance client, and the diversion message carries a target channel identifier; The video monitoring device is further configured to use the second service link to send the media stream of the target channel to the video monitoring client.