CN1716945A - Method for detecting medium flow service quality - Google Patents

Abstract

This invention discloses a method for testing the medium flow service quality, which enables MGC to get the current medium flow service quality timely so as to timely regulate the transfer of the medium flow in the process of transferring medium flows. MGC sends the request information for detecting current value to MG in a preset fixed period to get the current service quality of the medium flow not obtaining it only after the MGC is dismantled.

Description

Media streaming service quality detection method

technical field

The invention relates to the communication field, in particular to a media stream service quality detection technology.

Background technique

With the continuous development of communication technology, various services of the Internet, mobile communication network, and fixed-line communication network continue to infiltrate and merge. Application Protocol, WAP) and video conferencing and other emerging business types. However, since the Internet, mobile communication network and fixed telephone communication network adopt different network architectures, it is not necessary to fully integrate all services of these three networks. It cannot be processed according to the processing process of the above-mentioned emerging business, but requires a new processing mechanism. Next Generation Network (Next Generation Network, referred to as "NGN") is a new type of network, which can fully integrate services such as voice, data, fax and video, so that various services of the Internet, mobile communication network and fixed telephone communication network can be Interconnection and intercommunication are realized on the network layer, so the current NGN network has become a main mechanism for integrating the above three networks.

The core idea of NGN is to separate media from services and media from control, that is, media transmission has nothing to do with service types and service control, and service bearer does not need to consider the form of the bearer network and the type of user terminal. It is necessary to configure and define service characteristics to meet the needs of users. NGN can be divided into four layers functionally: access layer, transmission and media layer, control layer and application layer.

Among them, the access layer is used to access various services of users. It should be able to connect high-speed transmission lines upwards and support multiple service interfaces downwards; the transmission and media layers are used to provide unified and comprehensive services with guaranteed quality of service and large bandwidth. platform; the control layer is the control core of the NGN network, which is used to complete the control, management, connection, routing, billing, authentication and other functions of the entire network, and has the ability to develop interfaces; the business layer is the development and comprehensive service access The platform is used to provide various value-added services, multimedia services and third-party services, etc.

In NGN, the core part is the control layer, which uses softswitch technology to provide call control and connection control functions for services with real-time requirements in NGN. Since the softswitch technology only exchanges the Internet transport layer addresses of the calling party and the called party through the system, without any circuit switching unit to establish an end-to-end connection, as long as the addresses of the calling party and the called party are given, , it can be processed in a fixed form without depending on the type of specific business, so the separation of business transmission and business type can be realized.

The softswitch that implements the softswitch function in NGN is the softswitch, which is mainly composed of three parts: Media Gateway (MG for short), Media Gateway Controller (MGC for short), and signaling gateway (MGC for short). Signal Gateway, referred to as "SG").

Among them, MG is used for media stream conversion and connection between different networks, such as the connection between the public switched telephone network and the Internet, or the connection between the mobile communication network and the Internet;

The MGC controls the establishment and release of the MG connection according to the received signaling. It is the start and end point of the signaling message and can control the entire network through various protocols. Currently, the communication protocols between MGC and MG are H.248/Media Gateway Control (H.248/MeGaCo for short) protocol and Media Gateway Control Protocol (MGCP for short). ”) Two protocols. Those skilled in the art can know that MGCP is a protocol based on User Datagram Protocol (User Datagram Protocol, referred to as "UDP") transmission, and H.248/MeGaCo is based on Transmission Control Protocol (Transport Control Protocol, referred to as "TCP") and UDP transmission protocol. H.248's message encoding is based on text and binary, while MGCP's message encoding is based on text.

The SG is used to convert different signaling.

Fig. 1 is a schematic diagram of the networking structure of MG and MGC in NGN, as shown in the figure. This structure is mainly composed of user 10, user 20, media gateway (MG) 30, media gateway (MG) 40 and media gateway controller (MGC) 50.

Those skilled in the art should know that two connection models are defined in the H.248/MeGaCo protocol: terminal and context. The terminal can be a physical terminal with semi-permanent existence or a temporary terminal released after temporary application. The context is the connection between some terminals, which is used to describe the topology relationship between the terminals and the parameters of media mixing or exchange, so that the protocol has better flexibility and scalability. Generally speaking, a terminal can only belong to one context, and a context can contain multiple terminals. The physical terminal can be a Time Division Multiplex (TDM for short) channel or an analog line; the temporary terminal can be a real-time transport protocol (Real-time transport protocol) for carrying voice, data, video signals or various mixed signals. -time Transport Protocol, referred to as "RTP") stream. In the specific use process, the characteristics of the terminal can be represented by parameters such as attributes, events, signals, and statistics. In order to shield the problem of terminal diversity, various characteristic parameters of the terminal can be combined into a package.

MG30 and MG40 are respectively used to connect user 10 and user 20, and convert the type of media stream between user 10 and user 20.

MGC50 is used to control the establishment and release of the connection between MG30 and MG40, and complete the functions of call control, service provision, service exchange, resource management, billing, authentication and authorization, address resolution, voice processing control, control and management of various temporary terminals, etc. .

In the specific implementation process, MGC50 controls and manages MG30 and MG40 using the H.248/MeGaCo protocol, and RTP media streams are transmitted between MG30 and MG40. Those skilled in the art should know that the RTP media stream can adopt different encoding and decoding methods, such as G.711, G.723, G.729, T.38 and so on.

Since the Internet is used as the bearer medium of various services in NGN, when the Internet has a long delay and a high packet loss rate, it will seriously affect the quality of service (Quality of Service, referred to as "QoS") of the media stream, such as voice Voice quality during communication, fax completion rate or video clarity, etc. Therefore, it is necessary to know the QoS status of media streams transmitted between MGs during the transmission process, so as to evaluate the overall QoS of the network, or dynamically adjust the call control strategy.

In the prior art, statistical parameters of the Network packet and the RTP packet in the H.248 protocol are usually used to reflect the quality of service. Those skilled in the art should know that the above statistical parameters include the number of bytes sent and received, the number of packets sent and received, the number of lost packets, network delay and so on.

The specific process of obtaining the service quality of the current media stream in the prior art is as follows. The MGC first receives a call request from the MG and establishes a connection for the current media stream. At the same time, the MG where the media stream is located counts the parameters of the Network packet and the RTP packet. If the call of the media stream ends, the MGC issues a request to remove the call, and the MG where the media stream resides stops counting the parameters after receiving the call to remove the command, and returns the parameters that have been counted to the MGC. The MGC receives the returned parameters, and adjusts the transmission of the media stream according to the values of the parameters. For example, when the returned parameter indicates that the bandwidth is insufficient, a codec method that requires less bandwidth can be used.

In practical application, the above-mentioned solution has the following problems: because the technical solution of the prior art returns the statistical parameters reflecting the quality of service of the media stream only when the media stream call ends, the real-time performance is poor, and the media currently being transmitted cannot be analyzed. Adjust the quality of streaming service.

The main reason for this situation is that only when the media streaming call ends, the statistical parameters representing the quality of service of the media streaming are returned.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a media stream quality of service detection method, so that in the process of media stream transmission, the MGC can obtain the service quality of the current media stream in real time, thereby adjusting the transmission of the media stream in real time .

To achieve the above object, the present invention provides a method for detecting media streaming service quality, comprising the following steps:

After the temporary terminal representing the media stream is added to the context, the A media gateway periodically obtains the quality of service information of the media stream and records it on the temporary terminal representing the media stream;

The B media gateway controller sets the detection duration and detection cycle as required, and during the detection duration, sends a detection current value request message to the temporary terminal representing the media flow in the media gateway in each detection cycle, so that The above detection current value request message contains statistical parameters;

C. The media gateway responds to the current value detection request message from the media gateway controller periodically, selects the quality of service information that needs to be reported on the temporary terminal representing the media stream according to the statistical parameters, and together with the calculated The activation duration is reported to the media gateway controller together.

Wherein, the statistical parameters include the number of bytes sent, the number of bytes received, the number of packets sent, the number of packets received, the number of lost packets, and the current packet loss rate of the media stream periodically obtained by the media gateway through the real-time transmission control protocol. , current jitter, current delay or any combination thereof; and

One of or any combination of packet loss rate, jitter, and delay average, maximum value, and minimum value obtained by the media gateway through comparison calculation; and

The detection period set in the step B is greater than or equal to the real-time transmission control protocol sampling period.

The activation duration is the difference between the current reporting time and the activation time of the media stream.

In the step C, the media gateway clears the average value of the packet loss rate, jitter, and delay after each response to the detection current value request message, and before the next response to the detection current value request message, re- Comparing and calculating the average value, maximum value and minimum value of the packet loss rate, jitter and time delay, and recording it as a part of the quality of service information on the temporary terminal representing the media stream.

In the step B, when the detection duration has just started, the media gateway controller immediately starts the first detection, sends a first detection current value request message to the temporary terminal representing the media stream in the media gateway, and

The temporary terminal responds to the first detection current value request message, selects the service quality information that needs to be reported according to the statistical parameters in the request, and reports it to the media gateway control together with the calculated activation duration device.

In the step B, when the detection period ends, or when the temporary terminal representing the media flow in the media gateway is deleted or moved out before the detection period ends, the media gateway controller immediately Start the final detection, send a final detection current value request message to the temporary terminal representing the media flow in the media gateway, and

The temporary terminal responds to the last detected current value request message, selects the quality of service information that needs to be reported according to the statistical parameters in the request, and reports it to the media gateway control together with the calculated activation duration. device.

In the step B, the detection duration and the detection period are positive integers, and the detection duration is longer than the detection period.

Through comparison, it can be found that the difference between the technical solution of the present invention and the prior art is that during the media stream transmission process, the MGC sends a detection current value request message to the MG at a fixed period to obtain the current service quality of the media stream, instead of only The quality of service is obtained after the MGC removes the media stream, so the real-time performance is better.

The difference in this technical solution has brought obvious beneficial effects, that is, the MGC can send a detection current value request message to the MG at a fixed period, and the current service quality of the media stream can be obtained, so as to adjust the media stream transmission in real time. In addition, the present invention also expands the H.248 protocol so that the user can define the service quality parameters of the current media stream as required.

Description of drawings

Figure 1 is a schematic diagram of the network structure of MG and MGC in NGN;

Fig. 2 is a flow chart of MG side processing for periodic detection of media stream service quality according to an embodiment of the present invention;

Fig. 3 is a flow chart of processing at the MGC side for periodic detection of media stream service quality according to an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings.

According to the principle of the present invention, in order to obtain the statistical parameters reflecting the service quality of the current media stream in real time, so as to control the transmission of the current media stream, a fixed detection cycle and detection duration can be set in the MGC. During the use process, the MGC continuously sends a detection value request command to the temporary terminal representing the current media stream on the MG, triggering the MG to continuously return the statistical parameters of the media stream service quality to the MGC, thereby realizing real-time control.

Fig. 2 is a flow chart of the MG side processing for periodic detection of media stream service quality according to a real-time example of the present invention, as shown in the figure. First enter step 210, load the temporary terminal on the MG, those skilled in the art should know that the temporary terminal can be added into the context by using the add command of H.248. When adding, the current time can be used as the activation moment of the media stream.

Then enter step 220, the MG starts the mechanism of collecting service quality information, obtains the service quality statistical parameters of the current media stream, and records them on the temporary terminal corresponding to the media stream. Those skilled in the art should know that the service quality statistical parameters of the current media stream can be obtained in a fixed period through the Real-time Transport Control Protocol (Real-time Transport Control Protocol, "RTCP"). Those skilled in the art should know that the statistical parameters of the quality of service are the number of bytes sent, the number of bytes received, the number of packets sent, the number of packets received, the number of lost packets, the current packet loss rate, the current jitter, and the current time delay. One or several combinations, the average value of packet loss rate, jitter and delay can be obtained through the calculation inside the MG.

Then enter step 230, the MG receives the current value detection request message periodically sent by the MGC, and responds to it, specifically, according to the statistical parameters in the above request message, the temporary terminal corresponding to the media stream Select the quality of service information to be reported, and report it to the MGC together with the calculated activation duration. Since the MGC sends the detection current value request message in a fixed period, the delay of the detection value message for each period may be different depending on the network condition, so the response of the MG to the detection value message is not returned in a fixed period, so the above response In addition to including statistical parameters reflecting the current media streaming service quality, it should also include the activation duration. Those skilled in the art should know that the activation duration is the difference between the reporting time when the MG where the current media stream resides receives the detection value message and the media stream activation time, that is, the activation duration of the current media stream.

Then enter step 240, the MG clears the service quality information valid only for the last detection period, and starts to perform service quality statistics for the new detection period. Since the MG has to respond to each received detection current value request message, and to ensure that the current response is for the current detection cycle, after the return of the QoS parameters of the last detection cycle, it is necessary to clear only the Statistical parameter values that were valid in the last detection period, and start to collect statistical parameter values of service quality in the new detection period at the same time, and record them on the temporary terminal corresponding to the media stream.

The above describes the processing flow of the MG side when periodically detecting the quality of service of the media stream in the present invention, and the processing process of the MGC side will be described in detail below. Fig. 3 is a flow chart of the MGC side processing for periodically detecting the quality of service of the media stream according to an embodiment of the present invention, as shown in the figure.

After the MG starts the mechanism for collecting media stream service quality information, the MGC first enters step 310, and sets the detection duration and detection cycle as required. Those skilled in the art should know that both the detection duration and detection period should be positive integers, and the detection duration should be greater than the detection period, and the detection period should be greater than or equal to the sampling period of RTCP. If the RTCP sampling period is close to or equal to the detection period, then the content of the period detection is the content of the latest RTCP information sampling.

Then enter step 320, the MGC sends a detection current value request message to the MG to query the service quality of the current media stream. Those skilled in the art should know that the request message for detecting the current value should be accompanied by a statistics descriptor, which is used to indicate the service quality statistics parameters to be returned. In the present invention, the statistical parameters include the number of bytes sent, the number of bytes received, the number of packets sent, the number of packets received, the number of lost packets, the current packet loss rate, the current jitter, the current One of the time delays or any combination thereof; and one of the packet loss rate, jitter, average value, maximum value, and minimum value of the time delay obtained by the MGC through comparison and calculation, or any combination thereof.

Then enter step 330, the MGC receives the media stream quality of service information returned by the MG. Those skilled in the art can know that the parameters returned by the current detection cycle obtained by the MGC can be compared and calculated with the corresponding parameters returned by the previous detection cycle, so as to obtain the situation of the current detection cycle.

Then enter step 340, the MGC controls the transmission of the media stream according to the obtained media stream quality of service information. If the network bandwidth is not enough, you can use low-bandwidth encoding for the media stream. In addition, various graphs reflecting the quality of service situation can also be drawn according to the returned information of the quality of service parameters at different activation durations.

Then enter step 350, MGC judges whether the current detection duration has exceeded or whether the current media stream is over, if the detection duration has exceeded or the temporary terminal representing the media stream has been deleted or removed from the context within the detection duration, then end Detection process; if the activation duration has not exceeded the detection duration and the current media stream has not ended, then enter step 330 to start the next detection process.

In actual use, the system may need to know the quality of service status before the detection start time, so when the detection starts, the first detection process can be started immediately. When the detection duration is exceeded or the temporary terminal representing the media stream is deleted or removed from the context within the detection duration, the last detection process can be started to obtain the current media stream service on the MG within the detection period that has not yet been completed. Statistical parameter of quality. The above-mentioned initial first detection and final detection are both triggered by a non-fixed duration, which needs to be triggered by adding a new operation command, and the processing process is relatively complicated. For example, the last detection process may be triggered by a detection duration end command or a media stream removal command. Specifically, when the detection duration has just started, the media gateway controller immediately starts the first detection, sends a request for the first detection of the current value to the temporary terminal in the media gateway representing the media stream, and the temporary terminal responds to the first detection of the current value request, according to The statistical parameters in the request are used to select the quality of service information to be reported, and report to the media gateway controller together with the calculated activation duration. On the other hand, when the detection duration ends, or when the temporary terminal representing the media stream is deleted or moved out of the context before the detection duration ends, the media gateway controller immediately starts the final The temporary terminal of the flow sends the request for the last detection of the current value, and the temporary terminal responds to the request of the last detection of the current value, selects the service quality information to be reported on it according to the statistical parameters in the request, and reports it together with the calculated activation time to the media gateway controller.

Since different media streams may require different QoS, in the original H.248 protocol, the QoS statistical parameters returned include the number of packets sent, the number of packets received, packet loss rate, jitter, and delay. In order to better monitor the media stream, the H.248 protocol can be extended, and the basic extended parameters of the H.248 protocol will be described in detail below. It mainly includes Maximum Packets Loss Rate (Maximum Packets Loss Rate, referred to as "maxplr"), Minimum Packets Loss Rate (Minimplr for short), Maximum Jitter (Maximum Jitter, referred to as "maxj"), Minimum Jitter (Minimum Jitter, "minj" for short), maximum delay (Maximum delay, "maxd" for short), minimum delay (Minimum delay, "mind" for short).

Among them, the maximum packet loss rate is a parameter used to define the maximum packet loss rate in the current detection period of the media stream. The parameter identifier is maxplr or 0×0009, and the type is a double-precision integer, which may be a 32-bit integer or a 32-bit decimal .

The minimum packet loss rate is a parameter used to define the minimum packet loss rate in the current detection period of the media stream. The parameter identifier is minplr or 0×0010, the type is a double-precision integer, and the value may be a 32-bit integer or a 32-bit decimal.

The maximum jitter is a parameter used to define the maximum jitter in the current detection period of the media stream. The parameter identifier is maxj or 0×0011, the type is an integer, and the value may be a 32-bit non-negative integer.

The minimum jitter is a parameter used to define the minimum jitter in the current detection period of the media stream. The parameter identifier is minj or 0×0012, the type is an integer, and the value may be a 32-bit non-negative integer.

The maximum delay is a parameter used to define the maximum delay of the current detection cycle of the media stream. The parameter identifier is maxd or 0×0013, the type is an integer, and the value may be a 32-bit non-negative integer.

The minimum delay is a parameter used to define the minimum delay of the current detection period of the media stream. Its parameter identifier is mind or 0×0014, the type is an integer, and the value may be a 32-bit non-negative integer.

Although the present invention has been illustrated and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein, and without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (7)

1. a method for detecting medium flow service quality is characterized in that, comprises following steps:

The A media gateway is obtained each quality of service information of this Media Stream after the ephemeral terminations of representing Media Stream is added into context, and is recorded on the ephemeral terminations of representing this Media Stream;

The B Media Gateway Controller is provided with as required and detects duration and sense cycle, and in during described detection duration, representing the ephemeral terminations of this Media Stream to issue in described media gateway in each sense cycle detects the currency request message, contains statistical parameter in the described detection currency request message;

The described media gateway response cycle of C ground is from the detection currency request message of described Media Gateway Controller, representing the quality of service information of selecting needs to report on the ephemeral terminations of this Media Stream according to described statistical parameter, and, report described Media Gateway Controller together together with the activation duration that calculates.

2. method for detecting medium flow service quality according to claim 1, it is characterized in that, described statistical parameter comprise the described Media Stream that media gateway periodically obtains by RTCP Real-time Transport Control Protocol the transmission byte number, receive byte number, send the bag number, receiver packet number, lost package number, present packet loss, current shake, Yanzhong a kind of or their combination in any when current; And

A kind of in mean value, maximum and the minimum value of the packet loss of described media gateway by relatively calculate obtaining, shake, time delay or their combination in any; And

The described sense cycle that is provided with among the described step B is more than or equal to the RTCP Real-time Transport Control Protocol sampling period.

3. method for detecting medium flow service quality according to claim 1 is characterized in that, described activation duration is current report poor with described Media Stream activation moments constantly.

4. method for detecting medium flow service quality according to claim 2, it is characterized in that, among the described step C, described media gateway is removed the mean value of packet loss, shake, time delay after responding described detection currency request message each time, and at next this responds before the described detection currency request message, again relatively calculate mean value, maximum and the minimum value of packet loss, shake, time delay, and, be recorded on the ephemeral terminations of representing this Media Stream as the part of described quality of service information.

5. method for detecting medium flow service quality according to claim 1 is characterized in that, also comprises following steps at described step B:

When described detection duration had just begun, described Media Gateway Controller started immediately first and to detect, and represented the ephemeral terminations of this Media Stream to issue in described media gateway and detected the currency request message first; And

The described currency request message that detects first of described ephemeral terminations response, according to the statistical parameter in the described request, the quality of service information that selection thereon need report, and, report described Media Gateway Controller together together with the activation duration that calculates.

6. method for detecting medium flow service quality according to claim 1 is characterized in that, in described step B, also comprises following steps:

When described detection duration finishes, or the ephemeral terminations of representing this Media Stream in the described media gateway was deleted from context before described detection duration finishes or when moving away, described Media Gateway Controller starts last detection immediately, in described media gateway, represent the ephemeral terminations of this Media Stream to issue last detection currency request message, and

Described ephemeral terminations responds described last detection currency request message, according to the statistical parameter in the described request, and the quality of service information that selection thereon need report, and, report described Media Gateway Controller together together with the activation duration that calculates.

7. method for detecting medium flow service quality according to claim 1 is characterized in that, among the described step B, described detection duration and sense cycle are positive integers, and described detection duration is greater than described sense cycle.

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