CN103457793A - Method, device and system for measuring multicast time delay - Google Patents

Abstract

A method for measuring multicast delay includes: sending a first multicast path query message to a downstream network element, capturing key frames in a multicast data stream on a multicast source group path, and recording the captured key frames ID and the first capture time; send the second multicast path query message to the downstream network element, and the downstream network element captures the key frames in the multicast data stream on the multicast source group path, and records the captured key frames The identification and the second capture time of the key frame, and send the identification of the key frame and the second capture time through the multicast path query response message; receive the multicast path query response message sent by the downstream network element; use the key frame identification, The time difference between the first capture time and the second capture time calculation and the time when the downstream network element captures the key frame. The invention can measure the in-band multicast time delay, which is beneficial to the maintenance and upgrade of the subsequent multicast network.

Description

Method, device and system for measuring multicast delay

technical field

The invention relates to the communication field, in particular to a multicast delay measurement method, device and system.

Background technique

Multicast in the Internet Protocol (IP) network realizes the replication of IP datagrams from one point to many points. Compared with the point-to-point communication method of unicast, the multicast source in multicast technology only sends one copy of the data packet, and then the data packet will be copied and distributed only where it needs to be copied and distributed, and there is only one copy in each network link data flow. Multicast can reduce the burden on the server and save bandwidth, but the current multicast technology does not measure the in-band multicast delay, which is not conducive to subsequent maintenance and upgrades.

Contents of the invention

The embodiment of the present invention provides a multicast delay measurement method, device and system for measuring in-band multicast delay.

The first aspect of the present invention provides a method for measuring multicast delay, including:

sending a first multicast path query message to a downstream network element, and capturing key frames in the multicast data stream on the multicast source group path, and recording the key frames captured and the first capturing time, Wherein, the first multicast path query message includes the multicast source group path information and a start measurement command;

sending a second multicast path query message to the downstream network element, where the second multicast path query message includes the multicast source group path information and an end measurement command;

receiving a multicast path query response message sent by the downstream network element, wherein the multicast path query response message is sent by the downstream network element after receiving the second multicast path query message, the The multicast path query response message includes the identifier of the key frame captured by the downstream network element after receiving the first multicast path query message and the second key frame captured by the downstream network element take time;

Using the identifier of the key frame, the first capture time, and the second capture time to calculate a time difference from the downstream network element capturing the key frame.

In the first possible implementation of the first aspect, the method for measuring multicast delay provided by the present invention may further include:

The maximum time difference, the minimum time difference and the average time difference between each downstream network element capturing the key frame are determined by using the time difference between capturing the key frame and the downstream network element.

With reference to the first possible implementation of the first aspect, in the second possible implementation, the method for measuring multicast delay provided by the present invention may further include:

Sending the maximum time difference, the minimum time difference and the average time difference to a terminal for display.

In a third possible implementation manner of the first aspect, the key frame may be an I frame.

The second aspect of the present invention provides a method for measuring multicast delay, including:

receiving a first multicast path query message sent by the measurement initiating network element, wherein the first multicast path query message includes the multicast source group path information and a start measurement command;

After receiving the first multicast path query message, capture key frames in the multicast data stream on the multicast source group path, record the key frame identification and the second captured key frame time, wherein the measurement initiating network element captures the key frame after sending the first multicast path query message, and records the key frame identifier captured and the measurement initiating network element capturing the first grab time to said keyframe;

receiving a second multicast path query message sent by the measurement initiating network element, wherein the second multicast query message includes the multicast source group path information and an end measurement command;

After receiving the second multicast path query message, send the identification of the key frame and the second capture time to the measurement initiating network element through a multicast path query response message, and the measurement initiating network element uses The identifier of the key frame, the first capture time and the second capture time calculate the time difference between capturing the key frame.

In a first possible implementation manner of the second aspect, the key frame may be an I frame.

A third aspect of the present invention provides a measurement initiating network element device, including:

The first sending module is configured to send a first multicast path query message to a downstream network element, and capture key frames in the multicast data stream on the multicast source group path, and record the captured key frame identifier and the first capture time, wherein the first multicast path query message includes the multicast source group path information and a start measurement command;

A second sending module, configured to send a second multicast path query message to the downstream network element, wherein the second multicast path query message includes the multicast source group path information and an end measurement command;

A receiving module, configured to receive a multicast path query response message sent by the downstream network element, wherein the multicast path query response message is sent by the downstream network element after receiving the second multicast path query message The multicast path query response message includes the identifier of the key frame captured by the downstream network element after receiving the first multicast path query message and the key frame captured by the downstream network element. the second grab time of the frame;

A calculation module, configured to use the identification of the key frame received by the receiving module, the first capture time, and the second capture time to calculate the time between the key frame captured by the downstream network element Time difference.

In the first possible implementation manner of the third aspect, the measurement initiating network element device provided by the present invention may further include a judging module, configured to use the calculation module calculated and the downstream network element captured to the The time difference of the key frame determines the maximum time difference, the minimum time difference and the average time difference between each downstream network element capturing the key frame.

With reference to the first possible implementation manner of the third aspect, in a second possible implementation manner, the device further includes a third sending module, configured to transmit the maximum time difference determined by the judging module, the minimum The time difference and the average time difference are sent to the terminal for display.

In a third possible implementation manner of the third aspect, the key frame may be an I frame.

A fourth aspect of the present invention provides a downstream network element device, including:

The first receiving module is configured to receive a first multicast path query message sent by a measurement initiating network element, wherein the first multicast path query message includes the multicast source group path information and a start measurement command;

A capture module, configured to capture key frames in the multicast data stream on the multicast source group path after the first receiving module receives the first multicast path query message, and record all captured The identification of the key frame and the second capture time, wherein the measurement initiating network element captures the key frame after sending the first multicast path query message, and records the captured key frame identification and time of first crawl;

The second receiving module is configured to receive a second multicast path query message sent by the measurement initiating network element, wherein the second multicast query message includes the multicast source group path information and an end measurement command;

A sending module, configured to, after the second receiving module receives the second multicast path query message, send the identification of the key frame and the second capture to the measurement initiating network element through a multicast path query response message The measurement initiating network element calculates the time difference between capturing the key frame and the key frame by using the identifier of the key frame, the first capturing time, and the second capturing time.

In a first possible implementation manner of the fourth aspect, the key frame may be an I frame.

The fifth aspect of the present invention provides a multicast delay measurement system, including a measurement initiating network element device and at least two downstream network element devices, wherein,

The measurement initiating network element device is used to send a first multicast path query message to each of the downstream network element devices, and capture key frames in the multicast data stream on the multicast source group path, and record the captured The identification of the key frame and the first capture time, wherein the first multicast path query message includes the multicast source group path and start measurement command;

The downstream network element device is configured to capture the key frame in the multicast data stream on the multicast source group path after receiving the first multicast path query message, and record the captured Keyframe identification and second capture time;

The measurement initiating network element device is configured to send a second multicast path query message to each of the downstream network elements, wherein the second multicast path query message includes a multicast source group path and an end measurement command;

The downstream network element device is configured to, after receiving the second multicast path query message, send a multicast path query response message to the measurement initiating network element to send the identifier of the key frame and the second capture time;

The measurement initiating network element device is used to use the identifier of the key frame, the first capture time, and the second capture time of each of the downstream network elements to calculate the The time difference between the above keyframes.

The present invention performs delay measurement by extending Multicast Trace Router (MTRACE) messages. The measurement initiating network element notifies each downstream network element to capture key frames in the multicast data stream by sending an MTRACE message and specifying statistical parameters (multicast source group path, start measurement command, stop measurement command, etc.) in the MTRACE message. And reply to the measurement initiating network element with the identifier and capture time of the captured key frame through the MTRACE response message. The measurement initiating network element calculates the time difference between the measurement initiating network element and each downstream network element capturing the same key frame by using the identification of the key frame, the capture time of the own network element and the capture time of each downstream network element. The invention can measure the in-band multicast time delay, which is beneficial to the maintenance and upgrade of the subsequent multicast network.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a flow chart of a method for measuring multicast delay provided by an embodiment of the present invention;

Fig. 2 is a flow chart of a method for measuring multicast delay provided by an embodiment of the present invention;

Fig. 3 is a networking diagram of a method for measuring multicast delay provided by an embodiment of the present invention;

Fig. 4 is a networking diagram of a method for measuring multicast delay provided by an embodiment of the present invention;

FIG. 5 is a structural diagram of a measurement initiating network element device provided by an embodiment of the present invention;

FIG. 6 is a structural diagram of another measurement initiating network element device provided by an embodiment of the present invention;

FIG. 7 is a structural diagram of a measurement initiating network element device provided by an embodiment of the present invention;

FIG. 8 is a structural diagram of a downstream network element device provided by an embodiment of the present invention;

FIG. 9 is a structural diagram of a downstream network element device provided by an embodiment of the present invention;

FIG. 10 is a structural diagram of a multicast delay measurement system provided by an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. 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.

Please refer to FIG. 1. FIG. 1 is a flow chart of a method for measuring multicast delay provided by an embodiment of the present invention. This embodiment describes the technical method of the present invention from the side of the measurement initiating network element. The execution subject of this embodiment can It is a measurement initiating network element, and the measurement initiating network element may be a Provider Edge-Aggregation (PE-AGG) device or a Provider Edge (PE) device. As shown in Figure 1, the multicast delay measurement method provided in this embodiment includes:

101. Send the first multicast path query message to the downstream network element, and capture a certain key frame in the multicast data stream on the multicast source group path, and record the key frame's identifier and the first captured key frame. The acquisition time, wherein, the first multicast path query message includes the multicast source group path and the start measurement command.

Wherein, the multicast source group path is indicated by a multicast routing item (S, G), where S is a multicast source address, and G is a multicast group address.

The identifier (S, G) of the multicast source group path represents a source group information, and each device maintains the source group information. And, after each device receives the multicast data, it queries the outgoing interface of the device according to the (S, G) entry, and copies and sends the multicast data from the queried outgoing interfaces. In this way, there is a forwarding index such as ((S, G), outbound interface list) on each device, and the path relationship can be expressed in the entire network.

Wherein, the first capture time is the time when the measurement initiating network element captures the key frame.

Wherein, the identifier of the key frame may be an Internet Protocol (Internet Protocol, IP) serial number of the key frame.

When the multicast data stream is transmitted, it will be compressed by some encoding methods, such as Moving Picture Experts Group (MPEG), H.264, H.265, etc., they all set some key frames in the transport stream (such as I frame), the subsequent frames are offset on this basis to obtain the corresponding data information. Wherein, besides the I frame, the key frame may also be other continuously sent key frames.

102. Send a second multicast path query message to a downstream network element, where the second multicast path query message includes the multicast source group path information and an end measurement command.

Wherein, the downstream network element is a network element located downstream of the measurement initiating network element on the transmission path of the multicast source group.

103. Receive a multicast path query response message sent by a downstream network element, wherein the multicast path query response message is sent by the downstream network element after receiving the second multicast path query message, and the multicast path query response message It includes an identifier of a key frame captured by the downstream network element after receiving the first multicast path query message and a second capture time of the key frame captured by the downstream network element.

Wherein, the second capture time is the time when the downstream network element captures the key frame.

104. Calculate a time difference between the measurement initiating network element and each downstream network element capturing a certain key frame by using the identifier of the key frame, the first capture time, and the second capture time.

Wherein, there may be multiple downstream network elements, and the downstream network elements may be identified by the network bridge address of the downstream network elements. After receiving the MTRACE response message sent by each downstream network element, the execution subject of this embodiment identifies different downstream network elements through the bridge address, and calculates the time difference between different downstream network elements capturing the same key frame.

Optionally, before sending the first multicast path query message, the method provided in this embodiment further includes: performing clock calibration by using a Network Time Protocol (Network Time Protocol, NTP).

Optionally, this embodiment further includes determining a maximum time difference, a minimum time difference, and an average time difference between each downstream network element capturing the key frame by using a time difference between the downstream network element capturing the key frame and the downstream network element capturing the key frame. Right now,

Determine the maximum time difference and the minimum time difference among the time differences between the measurement initiating network element and each downstream network element capturing the same key frame, and the average value of the time difference between the measurement initiating network element and each downstream network element capturing the same key frame, That is, the average time difference.

Optionally, the method provided in this embodiment further includes sending the maximum time difference, the minimum time difference, and the average time difference to a terminal for display. Wherein, the terminal is a personal computer (Personal Computer, PC) or a network management server or a mobile terminal.

Optionally, the key frame in this embodiment is an I frame.

In this embodiment, delay measurement is performed by extending the MTRACE message. The measurement initiating network element notifies each downstream network element to capture key frames in the multicast data stream by sending an MTRACE message and specifying statistical parameters (multicast source group path, start measurement command, stop measurement command, etc.) in the MTRACE message. And reply to the measurement initiating network element with the identifier and capture time of the captured key frame through the MTRACE response message. The network element that initiates the measurement uses the identifier of the key frame, the capture time of this network element, and the capture time of each downstream network element to calculate the time difference between the time when each downstream network element captures the same key frame. This embodiment can measure the multicast delay on a certain section of the multicast source group path, which is beneficial to the maintenance and upgrade of the subsequent multicast network.

Please refer to FIG. 2 . FIG. 2 is a flow chart of a method for measuring multicast delay provided by an embodiment of the present invention. This embodiment describes the technical solution of the embodiment of the present invention from the side of the downstream network element. The execution subject of this embodiment is the downstream network element, and the downstream network element can be a PE device or a digital subscriber line access multiplexer (Digital Subscriber Line Access Multiplexer, DSLAM), as shown in Figure 2, the method provided in this embodiment includes:

201. Receive a first multicast path query message sent by a measurement initiating network element, wherein the first multicast path query message includes a multicast source group path message and a start measurement command.

202. After receiving the first multicast path query message, capture the key frame in the multicast data stream on the multicast source group path, and record the identifier of the key frame and the captured key frame The second capturing time, wherein, the measurement initiating network element captures the key frame after sending the first multicast path query message, and records the identifier of the key frame and the measurement initiating network element capturing the key The first grab time of the frame.

Wherein, the first capture time is the time when the measurement initiating network element captures the key frame, and the second capture time is the time when the downstream network element captures the key frame.

203. Receive a second multicast path query message sent by the measurement initiating network element, where the second multicast query message includes the multicast source group path message and an end measurement command.

Wherein, the multicast source group path is indicated by a multicast routing item (S, G), where S is a multicast source address, and G is a multicast group address.

The identifier (S, G) of the multicast source group path represents a source group information, and each device maintains the source group information. And, after each device receives the multicast data, it queries the outgoing interface of the device according to the (S, G) entry, and copies and sends the multicast data from these outgoing interfaces. In this way, there is a forwarding index such as ((S, G), outbound interface list) on each device, and the path relationship can be expressed in the entire network.

204. After receiving the second multicast path query message, send the identifier of the key frame and the second capture time to the measurement initiating network element through a multicast path query response message, and the measurement After receiving the multicast path query response message, the initiating network element uses the identifier of the key frame, the first capture time, and the second capture time to calculate the distance between the measurement initiating network element and the downstream network element. The time difference between meta capture and keyframe.

Wherein, the key frame may be an I frame.

Wherein, the identifier of the key frame may be the IP serial number of the key frame.

In this embodiment, the downstream network element records the identifier of the captured key frame and the capture time of the captured key frame according to the command carried in the extended MTRACE message, and records the identifier of the key frame and the captured key frame The capture time described above is sent to the measurement initiating network element, and the measurement initiating network element calculates the time difference between this network element and different downstream network elements according to the time when it captures the same key frame and the capture time sent by each downstream network element, so as to determine The multicast delay on a certain section of the multicast source group path is beneficial to the maintenance and upgrade of the subsequent multicast network.

Please refer to Figure 3 and Figure 4. Figure 3 and Figure 4 are networking diagrams of a multicast delay measurement method provided in this embodiment. As shown in Figure 3 and Figure 4, the measurement initiation network element is PE-AGG, and the downstream The network elements are UPE and DSLAM. As shown in Figure 3:

The PE-AGG initiates a first MTRACE message, and the first MTRACE message carries the multicast source group SG and the start measurement command.

After receiving the MTRACE message of PE-AGG, UPE and DSLAM start to capture the I frame of this source group SG, and record the IP sequence number of the captured I frame and the time of capturing the I frame.

As shown in Figure 4:

The PE-AGG initiates a second MTRACE message, and the second MTRACE message carries the multicast source group SG and the command to stop measurement.

After receiving the second MTRACE message from the PE-AGG, the UPE and the DSLAM report all recorded IP serial numbers and corresponding capture time.

After PE-AGG receives the message reported by UPE and DSLAM, it calculates the maximum time difference and the minimum time difference among the time difference between each downstream network element and its own network element receiving the same I frame, and each downstream network element receives the same I frame as its own network element. The average value of the time difference of the I frame, that is, the average time difference, is used to send to the terminal for display.

Wherein, the terminal may be a PC, a network management server, or a mobile terminal.

Wherein, the second MTRACE message is sent after at least a minimum preset time after the first MTRACE message is sent, and the minimum preset time should not be less than the sending interval of the I frame.

Please refer to FIG. 5. FIG. 5 is a structural diagram of a measurement initiating network element device provided by an embodiment of the present invention. As shown in FIG. 5, the measurement initiating network element device includes:

The first sending module 301 is configured to send a first multicast path query message to a downstream network element, and capture key frames in the multicast data stream on the multicast source group path, and record the identifier and key frame captured. The first capture time, wherein the first multicast path query message includes multicast source group path information and a start measurement command.

The second sending module 302 is configured to send a second multicast path query message to a downstream network element, wherein the second multicast path query message includes the multicast source group path information and an end measurement command;

The receiving module 303 is configured to receive a multicast path query response message sent by a downstream network element, wherein the multicast path query response message is sent by the downstream network element after receiving the second multicast path query message, and the multicast path query response message is sent by the downstream network element. The path query response message includes the identifier of the key frame captured by the downstream network element after receiving the first multicast path query message and the second capture time of the key frame captured by the downstream network element.

The calculation module 304 is configured to use the identification of the key frame received by the receiving module 303, the first capture time, and the second capture time to calculate the time difference between the time when the downstream network element captures the key frame.

FIG. 6 is a structural diagram of another measurement initiating network element device provided in this embodiment. On the basis of the embodiment in FIG. 5, a clock calibration module 305, a judging module 306 and a third sending module 307 may also be included, wherein:

The clock calibration module 305 is configured to perform clock calibration by using the network time protocol.

The judging module 306 is configured to determine the maximum time difference, the minimum time difference and the average time difference between each downstream network element capturing the key frame by using the time difference calculated by the calculation module and each downstream network element capturing the key frame.

The third sending module 307 is configured to send the maximum time difference, the minimum time difference and the average time difference determined by the judging module to the terminal for display.

Optionally, the key frame is an I frame.

The measurement initiating network element device provided in this embodiment performs delay measurement by extending the MTRACE message. The measurement initiating network element device notifies each downstream network element to capture key frames in the multicast data stream by sending an MTRACE message and specifying statistical parameters (multicast source group path, start measurement command, stop measurement command, etc.) in the MTRACE message , and reply the captured key frame identification and capture time to the measurement initiating network element through the MTRACE response message. The network element device that initiates the measurement uses the identification of the key frame, the capture time of the own network element, and the capture time of each downstream network element to calculate the time difference between the capture time of the same key frame and that of each downstream network element. This embodiment can measure the in-band multicast delay, which is beneficial to the maintenance and upgrade of the subsequent multicast network.

Please refer to FIG. 7. FIG. 7 is a structural diagram of a measurement network element initiating device provided by an embodiment of the present invention, including a memory 401 and a processor 402, wherein the memory 401 is used to store a set of program codes, and the program stored in the memory 401 The code includes an operating system and an application program, and the processor is used to read the program code stored in the memory 401 to execute:

Send the first multicast path query message to the downstream network element, and capture a key frame in the multicast data flow on the multicast source group path, and record the key frame's identifier and the first capture time , wherein the first multicast path query message includes the multicast source group path information and a start measurement command.

Sending a second multicast path query message to a downstream network element through the network interface unit and the input/output interface, wherein the second multicast path query message includes the group path information of the multicast source and an end measurement command.

Receive the multicast path query response message sent by the downstream network element through the input and output interface, wherein the multicast path query response message is sent by the downstream network element after receiving the second multicast path query message, and the multicast path query response message It includes an identifier of a key frame captured by the downstream network element after receiving the first multicast path query message and a second capture time of the key frame captured by the downstream network element.

The key frame identifier, the first capture time, and the second capture time are used to calculate the time difference between a downstream network element and a certain key frame.

For specific execution steps, refer to the embodiment in FIG. 1 , which will not be repeated here.

The measurement initiating network element device may also include a hard disk drive for storing other necessary application programs.

The measurement initiating network element device provided in this embodiment performs delay measurement by extending the MTRACE message. The measurement initiating network element device notifies each downstream network element to capture key frames in the multicast data stream by sending an MTRACE message and specifying statistical parameters (multicast source group path, start measurement command, stop measurement command, etc.) in the MTRACE message , and reply the captured key frame identification and capture time to the measurement initiating network element through the MTRACE response message. The measurement initiating network element device calculates the time difference between each downstream network element capturing the same key frame by using the identification of the key frame, the capture time of the own network element, and the capture time of each downstream network element. This embodiment can measure the in-band multicast delay, which is beneficial to the maintenance and upgrade of the subsequent multicast network.

Please refer to FIG. 8. FIG. 8 is a structural diagram of a downstream network element device provided by an embodiment of the present invention, including:

The first receiving module 501 is configured to receive a first multicast path query message sent by a measurement initiating network element, wherein the first multicast path query message includes multicast source group path information and a start measurement command;

Grabbing module 502, for after the first receiving module 501 receives the first multicast path query message, grab the key frame in the multicast data flow on the multicast source group path, record the captured key frame ID and the second capture time, wherein, the first multicast path query message includes the multicast source group path and start measurement command, and the measurement initiating network element captures the multicast source group path after sending the first multicast path query message Keyframes in the multicast data stream on the Internet, and record the identification and first capture time of the captured keyframes;

The second receiving module 503 is configured to receive a second multicast path query message sent by the measurement initiating network element, wherein the first multicast path query message includes multicast source group path information and a start measurement command;

The sending module 504 is configured to, after the second receiving module 503 receives the second multicast path query message, send the identification of the key frame and the second capture time to the measurement initiating network element through the multicast path query response message, which is initiated by the measurement After receiving the multicast path query response message, the network element calculates the time difference for capturing the key frame by using the identifier of the key frame, the first capture time and the second capture time, wherein the second multicast query message contains the multicast Source group path and end measure command.

Optionally, the key frame is an I frame.

The downstream network element device provided in this embodiment records the identifier and capture time of the captured key frame according to the command carried in the extended MTRACE message, and sends the identifier and capture time of the key frame to the measurement initiating network element , the measurement initiating network element calculates the time difference between this network element and different downstream network elements according to the time when it captures the same key frame and the capture time sent by each downstream network element, so as to determine the multicast delay, which is beneficial to the subsequent multicast network maintenance and upgrades.

Please refer to FIG. 9. FIG. 9 is a structural diagram of a measurement network element initiating device provided by an embodiment of the present invention, including a memory 601 and a processor 602, wherein the memory 601 is used to store a set of program codes, and the program stored in the memory 601 The code includes an operating system and an application program, and the processor is used to read the program code stored in the memory 601 to execute:

The first multicast path query message sent by the measurement initiating network element is received through the network interface unit and the input and output interface, wherein the first multicast path query message includes a multicast source group path message and a start measurement command.

After receiving the first multicast path query message, capture the key frame in the multicast data stream on the multicast source group path, record the identifier of the key frame and the second capture time, wherein the measurement initiation The network element captures the key frame after sending the first multicast path query message, and records the identifier of the key frame and the first capture time when the measurement initiating network element captures the key frame.

Receive the second multicast path query message sent by the measurement initiating network element through the network interface unit and the input and output interface, wherein the second multicast query message includes the group path information of the multicast source and an end measurement command.

After receiving the second multicast path query message, send the identifier of the key frame and the second capture time to the measurement initiating network element through a multicast path query response message, and the measurement initiating network After receiving the multicast path query response message, the element uses the key frame identifier, the first capture time and the second capture time to calculate the measurement initiation network element and the downstream network element capture Get the time difference of the keyframe.

For specific execution steps, refer to the embodiment in FIG. 2 and will not repeat them here.

The measurement initiating network element device may also include a hard disk drive for storing other necessary application programs.

The downstream network element device provided in this embodiment records the identifier and capture time of the captured key frame according to the command carried in the extended MTRACE message, and sends the identifier and capture time of the key frame to the measurement initiating network element , the measurement initiating network element calculates the time difference between this network element and different downstream network elements according to the time when it captures the same key frame and the capture time sent by each downstream network element, so as to determine the multicast delay, which is beneficial to the subsequent multicast network maintenance and upgrades.

Please refer to FIG. 10. FIG. 10 is a structural diagram of a multicast delay measurement system provided by an embodiment of the present invention, including a measurement initiating network element device 701 and at least two downstream network element devices 702, wherein,

The measurement initiating network element device 701 is used to send the first multicast path query message to each downstream network element device 702, and capture key frames in the multicast data stream on the multicast source group path, and record the captured key frames The identification and the first capture time, wherein, the first multicast path query message includes the multicast source group path and the start measurement command;

The downstream network element device 702 is configured to capture key frames in the multicast data stream on the multicast source group path after receiving the first multicast path query message, and record the key frame identification and the second captured key frame time;

The measurement initiating network element device 701 is configured to send a second multicast path query message to each downstream network element, wherein the second multicast path query message includes a multicast source group path and an end measurement command;

The downstream network element device 702 is configured to, after receiving the second multicast path query message, send the multicast path query response message to the measurement initiating network element to send the identification of the key frame and the second capture time;

The measurement initiating network element device 701 is configured to use the identification of the key frame, the first capture time and the second capture time of each downstream network element to calculate the time difference between each downstream network element capturing the same key frame.

In the multicast delay measurement system provided by this embodiment, the measurement initiating network element device notifies each downstream by sending an MTRACE message and specifying statistical parameters (multicast source group path, start measurement command, stop measurement command, etc.) in the MTRACE message The network element device captures the key frame in the multicast data stream, and replies the identification and capture time of the captured key frame to the measurement initiating network element through the MTRACE response message. The network element device that initiates the measurement uses the identification of the key frame, the capture time of the network element, and the capture time of each downstream network element to calculate the time difference between the capture time of the same key frame and that of each downstream network element device. This embodiment can measure the in-band multicast delay, which is beneficial to the maintenance and upgrade of the subsequent multicast network.

Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be implemented through computer programs to instruct related hardware, and the programs can be stored in a computer-readable storage medium. During execution, it may include the processes of the embodiments of the above-mentioned methods. Wherein, the storage medium may be a magnetic disk, an optical disk, a read-only memory (Read-Only Memory, ROM) or a random access memory (Random Access Memory, RAM for short).

The above disclosures are only preferred embodiments of the present invention, and certainly cannot limit the scope of rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope of the present invention.

Claims (13)

1. A method for measuring multicast delay, characterized in that, comprising: sending a first multicast path query message to a downstream network element, and capturing key frames in the multicast data stream on the multicast source group path, and recording the key frames captured and the first capturing time, Wherein, the first multicast path query message includes the multicast source group path information and a start measurement command; sending a second multicast path query message to the downstream network element, where the second multicast path query message includes the multicast source group path information and an end measurement command; receiving a multicast path query response message sent by the downstream network element, wherein the multicast path query response message is sent by the downstream network element after receiving the second multicast path query message, the The multicast path query response message includes the identifier of the key frame captured by the downstream network element after receiving the first multicast path query message and the second key frame captured by the downstream network element take time; Using the identifier of the key frame, the first capture time, and the second capture time to calculate a time difference from the downstream network element capturing the key frame. 2. The method according to claim 1, further comprising: The maximum time difference, the minimum time difference and the average time difference between each downstream network element capturing the key frame are determined by using the time difference between capturing the key frame and the downstream network element. 3. The method according to claim 2, wherein the method further comprises: Sending the maximum time difference, the minimum time difference and the average time difference to a terminal for display. 4. The method according to claim 1, wherein the key frame is an I frame. 5. A method for measuring multicast delay, characterized in that, comprising: receiving a first multicast path query message sent by the measurement initiating network element, wherein the first multicast path query message includes the multicast source group path information and a start measurement command; After receiving the first multicast path query message, capture key frames in the multicast data stream on the multicast source group path, record the key frame identification and the second captured key frame time, wherein the measurement initiating network element captures the key frame after sending the first multicast path query message, and records the key frame identifier captured and the measurement initiating network element capturing the first grab time to said keyframe; receiving a second multicast path query message sent by the measurement initiating network element, wherein the second multicast query message includes the multicast source group path information and an end measurement command; After receiving the second multicast path query message, send the identification of the key frame and the second capture time to the measurement initiating network element through a multicast path query response message, and the measurement initiating network element uses The identifier of the key frame, the first capture time and the second capture time calculate the time difference between capturing the key frame. 6. The method according to claim 5, wherein the key frame is an I frame. 7. A measurement initiating network element device, characterized in that, comprising: The first sending module is configured to send a first multicast path query message to a downstream network element, and capture key frames in the multicast data stream on the multicast source group path, and record the captured key frame identifier and the first capture time, wherein the first multicast path query message includes the multicast source group path information and a start measurement command; A second sending module, configured to send a second multicast path query message to the downstream network element, wherein the second multicast path query message includes the multicast source group path information and an end measurement command; A receiving module, configured to receive a multicast path query response message sent by the downstream network element, wherein the multicast path query response message is sent by the downstream network element after receiving the second multicast path query message The multicast path query response message includes the identifier of the key frame captured by the downstream network element after receiving the first multicast path query message and the key frame captured by the downstream network element. the second grab time of the frame; A calculation module, configured to use the identification of the key frame received by the receiving module, the first capture time, and the second capture time to calculate the time between the key frame captured by the downstream network element Time difference. 8. The device according to claim 7, characterized in that the device further comprises a judging module, configured to use the time difference between the key frame captured by the downstream network element and the time difference calculated by the calculation module to determine and Each downstream network element captures the maximum time difference, the minimum time difference and the average time difference of the key frame. 9. The device according to claim 8, further comprising a third sending module, configured to send the maximum time difference, the minimum time difference and the average time difference determined by the judging module to terminal to display. 10. The device according to claim 7, wherein the key frame is an I frame. 11. A downstream network element device, characterized in that it comprises: The first receiving module is configured to receive a first multicast path query message sent by a measurement initiating network element, wherein the first multicast path query message includes the multicast source group path information and a start measurement command; A capture module, configured to capture key frames in the multicast data stream on the multicast source group path after the first receiving module receives the first multicast path query message, and record all captured The identification of the key frame and the second capture time, wherein the measurement initiating network element captures the key frame after sending the first multicast path query message, and records the captured key frame identification and time of first crawl; The second receiving module is configured to receive a second multicast path query message sent by the measurement initiating network element, wherein the second multicast query message includes the multicast source group path information and an end measurement command; A sending module, configured to, after the second receiving module receives the second multicast path query message, send the identification of the key frame and the second capture to the measurement initiating network element through a multicast path query response message The measurement initiating network element calculates the time difference between capturing the key frame and the key frame by using the identifier of the key frame, the first capturing time, and the second capturing time. 12. The device according to claim 11, wherein the key frame is an I frame. 13. A multicast delay measurement system, characterized in that it includes a measurement initiating network element device and at least two downstream network element devices, wherein, The measurement initiating network element device is used to send a first multicast path query message to each of the downstream network element devices, and capture key frames in the multicast data stream on the multicast source group path, and record the captured The identification of the key frame and the first capture time, wherein the first multicast path query message includes the multicast source group path and start measurement command; The downstream network element device is configured to capture the key frame in the multicast data stream on the multicast source group path after receiving the first multicast path query message, and record the captured Keyframe identification and second capture time; The measurement initiating network element device is configured to send a second multicast path query message to each of the downstream network elements, wherein the second multicast path query message includes a multicast source group path and an end measurement command; The downstream network element device is configured to, after receiving the second multicast path query message, send a multicast path query response message to the measurement initiating network element to send the identifier of the key frame and the second capture time; The measurement initiating network element device is used to use the identifier of the key frame, the first capture time, and the second capture time of each of the downstream network elements to calculate the The time difference between the above keyframes.

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