JP6044263B2 - Communication quality measurement system and method - Google Patents

Description

  The present invention relates to a communication quality measurement system and method, and can be applied to communication quality measurement on a network such as NGN (Next Generation Network).

  Conventionally, methods for measuring evaluation values for evaluating network quality can be broadly classified into two types: “active measurement” and “passive measurement”.

  In passive measurement, a measurement device is installed on a network to be evaluated, measurement information (for example, circulating traffic) is acquired (captured), and the data is processed to obtain quality information. In the passive measurement, it is possible to measure the communication quality of the user traffic itself flowing on the network to be evaluated. However, the measurement cannot be performed unless communication (traffic) occurs in the network to be evaluated.

  With active measurement, the measurement device itself communicates (for example, communication such as test traffic) on the network to be measured, and measures the parameters (for example, delay time, etc.) related to the communication quality of the network at that time . As described above, in the active measurement, it is necessary to support a communication function as a measurement device, but it is possible to install a measurement device at an arbitrary point and perform measurement at an arbitrary time. Examples of existing techniques related to active measurement include the techniques described in Non-Patent Document 1 and Patent Document 1.

  Non-Patent Document 1 describes that in NGN, an active probe (measuring device) is arranged at each UNI point (User-Network Interface) and the communication quality of the NGN is measured by active measurement between the active probes. ing.

  Japanese Patent Application Laid-Open No. 2004-151561 describes that measurement relating to communication quality is efficiently performed for a network that provides a plurality of applications having different quality classes such as NGN. Specifically, in Patent Document 1, the measurement items are set for each application (quality class) in the measurement device, and traffic necessary for quality evaluation is generated simply by selecting the measurement target application during measurement. Thus, a system that can perform quality evaluation related to the network is described.

JP 2011-30051 A

Edited by Nippon Telegraph and Telephone Corporation, “NGN End-End Quality Measurement System”, [Online], INTERNET, [October 10, 2012 search], <URL: http://www.ntt.co.jp/RD/OFIS /active/2010pdf/hot/nw/01.html>

  However, the conventional measurement techniques disclosed in Patent Document 1 and Non-Patent Document 1 have a problem that accurate measurement of communication quality related to a communication session involving media conversion has not been studied in detail. For example, when measuring communication quality (for example, measurement of communication delay time) between a fixed-line phone corresponding to “G.711” and a mobile phone corresponding to “G.729”, in the related art, for example, One example is to sequentially check the packet transmission time and the packet reception time per unit from the start time. However, in the case of the above example, the number of packets differs before and after media conversion depending on the division period and codec difference. Therefore, in the conventional technology, a delay (hereinafter referred to as “packet transfer delay”) that occurs accurately at the end-to-end (End to End). There is a problem that it is not possible to obtain "time". Such a problem occurs not only in audio media but also in moving image media due to the frame rate, codec difference, and the like.

  The above-described problem occurs particularly in a network that provides FMC (Fixed Mobile Convergence) or IPTV service that closely links mobile communication and wired communication.

  Therefore, there is a demand for a communication quality measurement system and method capable of measuring communication quality even in a network where communication media conversion is performed.

According to a first aspect of the present invention, a frame sequence of media data sent from a first communication device is converted into a frame sequence of communication media of a type corresponding to the second communication device, and the second communication device is used. In a communication quality measurement system for measuring a parameter relating to communication quality with respect to a network including a media conversion device to be sent to the network, And a second measurement device arranged at a second measurement point on the network. (2) The first measurement device is directed to the second measurement device via the media conversion device. Media frame sending means for sending a frame sequence of the first type of communication media, and (3) the second measuring device from the first measuring device via the media converting device, A media frame receiving means for receiving a frame sequence of two types of communication media; and a measuring means for performing measurement processing on each received frame. (4) a frame measured by the measuring means of the second measuring device Storage means for storing measurement data including measurement results for each, and (5) each frame transmitted from the first measurement device using the measurement data stored by the storage means, and the second measurement A frame correspondence acquisition means for obtaining a corresponding combination with each frame received by the apparatus; and (6) each combination of frames for which a correspondence relation is obtained by the frame correspondence relation acquisition means is stored by the storage means. from the measured data, and the communication quality calculation means for calculating a parameter related to the communication quality between said first measurement point and said second measurement point, (7) the first measurement The apparatus further comprises control information transmitting means for transmitting control information related to a session of a frame sequence to be transmitted via the media conversion device, and (8) the second measurement device is connected to the first measurement device. Further comprising frame transmission timing acquisition means for acquiring the transmission timing of each frame transmitted from the first measurement device based on the received control information, (9) the storage means at least the second measurement The reception timing of each frame received by the device and a part or all of the control information received by the second measurement device are stored as a part of measurement data. (10) The communication quality calculation means For each combination of frames for which the correspondence is obtained by the relationship acquisition means, the transmission timing at the first measurement device and the reception timing at the second measurement device. (11) The communication quality calculation means determines that the communication quality calculation means determines that if there is a section in which the frame loss rate in the second measuring device exceeds a predetermined value, It shifts to the process which calculates the frame transfer delay time which concerns on the following area, without calculating the frame transfer delay time which concerns on.

According to a second aspect of the present invention, a frame sequence of media data sent from the first communication device is converted into a frame sequence of communication media of a type corresponding to the second communication device, and the second communication device is used. Measuring a parameter relating to communication quality with respect to a network including a media conversion device for sending to a first measuring device arranged at a first measurement point on the network; In a communication quality measurement method performed by a communication quality measurement system comprising a second measurement device arranged at a second measurement point, (1) media frame sending means, media frame receiving means, measurement means, storage means, frame correspondence acquisition means, the communication quality calculation means, the control information transmitting unit, a frame transmission timing acquiring means comprises, (2) the media frame transmission The stage sends a frame sequence of the first type of communication media from the first measuring device to the second measuring device via the media converting device, and (3) receiving the media frame Means receives the frame sequence of the second type of communication media from the first measurement device via the media conversion device by the second measurement device; and (4) the measurement means includes the above perform measurement processing for each frame the media frames received by the receiving means, (5) the storing means accumulates the measured data including the measurement result for each frame of said measuring means has measured, (6) the frame correspondence acquisition The means uses the measurement data accumulated by the accumulation means to correspond between each frame transmitted from the first measurement apparatus and each frame received by the second measurement apparatus. (7) The communication quality calculation means calculates the first measurement point and the first measurement point from the measurement data accumulated by the accumulation means for each combination of frames for which the correspondence relation is obtained by the frame correspondence relation acquisition means. (8) The control information transmission means calculates a frame sequence to be transmitted from the first measurement device via the media conversion device. (9) The frame transmission timing acquisition means transmits the control information from the first measurement device based on the control information received from the first measurement device by the second measurement device. (10) The storage means acquires at least the reception timing of each frame received by the second measuring device and the second measurement. A part or all of the control information received by the apparatus is accumulated as part of the measurement data. (11) The communication quality calculation means, for each combination of frames for which the correspondence relation is obtained by the frame correspondence relation acquisition means, A frame transfer delay time is obtained based on the transmission timing in the first measurement device and the reception timing in the second measurement device. (12) The communication quality calculation means is the second measurement device. If there is a section in which the frame loss rate exceeds a predetermined value, the process proceeds to the process of calculating the frame transfer delay time for the next section without calculating the frame transfer delay time for the section. It is characterized by that.

  According to the present invention, it is possible to provide a communication quality measurement system capable of measuring communication quality even in a network where communication media conversion is performed.

It is the block diagram shown about the functional structure of the measuring apparatus (each component which comprises a communication quality measurement system) which concerns on embodiment. It is the block diagram shown about the whole structure of the network used as the measuring object by the communication quality measurement system which concerns on embodiment, and a communication quality measurement system. It is the flowchart shown about operation | movement of the communication quality measurement system which concerns on embodiment. It is the flowchart shown about the operation | movement which transmits a packet with the measuring apparatus of the packet transmission side which concerns on embodiment. 5 is a flowchart illustrating an operation when a packet is received by the measurement apparatus on the packet reception side according to the embodiment. It is explanatory drawing shown about the specification of the communication media (codec) corresponding with the communication quality measurement system which concerns on embodiment. It is the timing chart (the 1) shown about the analysis process of the packet transfer delay time performed in the analysis part which concerns on embodiment. It is the timing chart (the 2) shown about the analysis process of the packet transfer delay time performed in the analysis part which concerns on embodiment. It is the flowchart shown about the operation | movement at the time of the analysis part which concerns on embodiment performs the analysis process of the packet transfer delay time for 1 area.

(A) Main Embodiment Hereinafter, an embodiment of a communication quality measurement system and method according to the present invention will be described in detail with reference to the drawings.

(A-1) Configuration of Embodiment FIG. 2 is a block diagram showing the configuration of the communication quality evaluation system 2 for measuring the network 1 and the communication quality related to the network 1.

  As shown in FIG. 2, the network 1 is a network system constructed as NGN. On the network 1, a session control device 3 that performs at least call control between SIP terminals and a media conversion device 4 that performs media conversion (for example, codec conversion) in media communication between SIP terminals are arranged.

  The session control device 3 is a call control device that performs call control between communication devices. In this embodiment, it is assumed that the session control device 3 performs call control using SIP / SDP (Session Initiation Protocol / Session Description Protocol). As the session control device 3, for example, an existing SIP server (call control device) compatible with SIP / SDP can be applied.

  Then, it is assumed that ONUs 5 (5-1, 5-2) for accommodating the user network are arranged at the end portion of the network 1. It is assumed that the user side (lower side) interface of each of the ONUs 5-1 and 5-2 is UNI.

  The measuring devices 20 (20-1 and 20-2) are connected to the UNIs of the ONUs 5-1 and 5-2, respectively. It is assumed that the communication quality evaluation system 2 of this embodiment includes two measuring devices 20-1 and 20-2. That is, in the communication quality evaluation system 2, between the first measurement point on the network 1 (UNI point under ONU5-1) and the second measurement point on the network 1 (UNI point under ONU5-2). Measurement related to communication quality of Note that the position (measurement point position) where the measurement apparatus 20 is arranged and the connection interface to the network 1 are not limited.

  Each of the measuring devices 20-1 and 20-2 performs a measurement on the communication quality between the opposing measuring device 20 based on the communication function as the SIP terminal and the signal (packet) to be transmitted and received. In this embodiment, the measurement devices 20-1 and 20-2 perform media communication via the media conversion device 4 under call control of the session control device 3, and measure communication quality related to the media communication (for example, , Packet transfer delay time). Here, it is assumed that the measuring devices 20-1 and 20-2 function as SIP terminals that perform telephone communication using different communication media (voice codecs).

  Specifically, the measuring device 20-1 is a G.M. It is assumed that telephone communication (media communication) corresponding to the codec 711 can be performed. The measuring device 20-2 is a G.M. Assume that telephone communication (media communication) corresponding to the 729 codec can be performed. Accordingly, the media conversion device 4 performs codec conversion (media conversion) processing between the measurement device 20-1 and the measurement device 20-2.

  As described above, the network 1 has a configuration in which the media conversion device 4 can realize, for example, a communication environment or the like based on a technology that closely links mobile communication and wired communication (Fixed Mobile Convergence). .

  Next, the internal configuration of the measuring devices 20-1 and 20-2 will be described with reference to FIG. Here, the measurement apparatuses 20-1 and 20-2 will be described as having the same configuration.

  For example, the measurement device 20 is realized by installing the measurement program of the embodiment (a program corresponding to each component in FIG. 1) in an information processing device (communication device) having a processor, a memory, a network interface, and the like. It may be. Note that the information processing performed by the measurement device 20 may be executed by being distributed to a plurality of information processing devices.

  The measurement apparatus 20 includes a session control unit 201, a packet generation unit 202, a quality measurement unit 203, a session disconnection unit 204, an application information input unit 205, an application information setting unit 206, and an analysis unit 207.

  The test information storage unit 205 stores an application as an identifier of the application for each application capable of performing measurement test processing related to communication quality (hereinafter referred to as “communication quality measurement test processing”) in the measurement device 20. A name and information defining the content of the test communication quality measurement test process of the application (hereinafter referred to as “test information”) are stored. Details of the test information of each application will be described later.

  When an application name (application identifier) is input based on a user operation or the like, the test information input unit 206 converts the application name into each component (session control unit 201, packet generation) that performs a communication quality measurement test process. Unit 202, quality measurement unit 203, session disconnection unit 204, and analysis unit 207) to start the communication quality measurement test process. Each component supplied with the application name acquires necessary information from the test information storage unit 205 among the test information corresponding to the application name, and starts the communication quality measurement test process. The trigger and timing at which the measurement apparatus 20 starts the communication quality measurement test process is not limited. In this embodiment, the test information input of each of the measurement apparatuses 20-1 and 20-2 is input by a user operation. Description will be made assuming that the communication quality measurement test process is started when the application name is input to the unit 206.

  In the communication quality measurement system 2 (measuring devices 20-1 and 20-2) of this embodiment, the network 1 provides services of a plurality of quality classes as in the system described in Patent Document 1. As a premise, it is assumed that the packet generation and the quality measurement can be performed collectively by targeting a plurality of quality classes and a plurality of applications.

  The session control unit 201 has a session control function, and includes a session information reading unit 201a and a session generation unit 201b. Specifically, the session control unit 201 transmits / receives a call control signal (SIP message) to / from the session control device 3 using SIP / SDP, and performs a session (call) of media communication with the measuring device 20 as an opposing SIP terminal. ). When the session control unit 201 connects the session (for example, when an INVITE message is transmitted), the session control unit 201 notifies the session control device 3 of the contents and conditions of the media communication used for the current session using SDP. To do. Based on this information, the session control apparatus 3 performs quality call determination and necessary resource allocation in the network 1 to perform specific call control.

  The packet generation unit 202 has a traffic generation function and includes a packet information reading unit 202a, a packet generation unit 202b, and an end determination unit 202c. Specifically, the packet generation unit 202 generates traffic (packet string for transmitting media data) to be measured in the communication quality evaluation system 2 after the session is started with the measuring device 20 as the opposite SIP terminal. . At this time, the packet generation unit 202 not only simply transmits and receives packets, but also the quality may change depending on the traffic characteristics. Therefore, the generated traffic depends on the target service / application. There is a need. For example, as a codec, G. In the case of IP telephones using H.711, IP telephone terminals often send 200-byte packets every 20 msec. Therefore, the packet generator 202 needs to transmit packets at the same interval and size. It is.

  The quality measurement unit 203 has a measurement function related to quality evaluation, and includes a measurement information reading unit 203a, a measurement execution unit 203b, an end determination unit 203c, and a measurement data storage unit 203d. Examples of parameters (indexes) related to the communication quality of the network 1 include items recommended in the ITU-T recommendation, such as packet transfer delay time, packet transfer delay fluctuation, and packet loss rate. In this embodiment, the quality measuring unit 3 will be described as measuring at least a packet transfer delay time as a parameter related to the communication quality of the network 1.

  The session disconnection unit 204 has a function of disconnecting the media communication session connected to the measurement apparatus 20.

  The analysis unit 207 has a function of analyzing the measurement data stored in the quality measurement unit 203 (measurement data storage unit 203d). Specific processing contents of the analysis unit 207 will be described later.

(A-2) Operation | movement of embodiment Next, operation | movement of the communication quality evaluation system 2 (measuring apparatus 20-1, 20-2) of this embodiment which has the above structures is demonstrated.

  First, in the test information storage unit 205 of the measuring apparatuses 20-1 and 20-2, a set of information such as session information, packet information, and quality measurement item information is stored in advance as test information for each application to be measured. (S101).

  Here, the test information storage unit 205 of the measurement apparatus 20-1 stores the measurement apparatus as session information corresponding to a telephone communication application (hereinafter, the name of the application is referred to as “telephone communication application”). It is assumed that information indicating that telephone communication is performed with a predetermined condition (for example, a predetermined band, a QoS class) is set with the terminal 20-2. The test information storage unit 205 of the measuring device 20-1 stores predetermined conditions (for example, predetermined traffic characteristics, DSCP values, etc.) via the media conversion device 4 as packet information corresponding to a telephone communication application. And the measuring device 20-2, G. It is assumed that information indicating that transmission / reception of communication media packets (packets in which test audio data is inserted) using the codec 711 is performed is set. Further, the test information storage unit 205 of the measuring device 20-1 is set to measure at least the measurement item of the media packet transfer delay time as the quality measurement item information corresponding to the telephone communication application. And

  In addition, here, the test information storage unit 205 of the measuring device 20-2 performs telephone communication with the measuring device 20-1 under predetermined conditions as session information corresponding to the telephone communication application. It is assumed that the information shown is set. Further, in the test information storage unit 205 of the measuring device 20-2, as packet information corresponding to the application for telephone communication, the G.G. It is assumed that information indicating transmission / reception of communication media packets using the 729 codec is set. Further, the test information storage unit 205 of the measuring apparatus 20-2 is set to measure at least the measurement item of the transfer delay time of the media packet as the quality measurement item information corresponding to the telephone communication application. And

  In the measurement apparatuses 20-1 and 20-2, as in the case of Patent Document 1, items other than the packet transfer delay time may be defined as the quality measurement item information. Since various measurement methods can be applied to the item of, detailed description relating to processing other than the packet transfer delay time is omitted below.

  Thereafter, “telephone communication application” is designated as the application name for the test information input unit 206 of the measuring devices 20-1 and 20-2 by the operation of the user (for example, a system administrator or the like), and the communication quality It is assumed that a measurement test process start operation has been performed (S102).

  Then, the test information input unit 206 of the measurement apparatuses 20-1 and 20-2 uses the input application name (telephone communication application) as each component (session control unit 201, packet generation unit) that performs the communication quality measurement test process. 202, the quality measurement unit 203, the session disconnection unit 204, and the analysis unit 207) to start the communication quality measurement test process (S103). As a result, the measurement apparatuses 20-1 and 20-2 start the communication quality measurement process related to the telephone communication application. At this time, the measurement devices 20-1 and 20-2 hold the contents of the SDP at the time of transmission / reception with the opposite measurement device 20, and hold them in the measurement data storage unit 203d as part of the measurement data. And

  First, in the measurement apparatuses 20-1 and 20-2, session information corresponding to the input application name is read from the test information storage unit 205 by the session control unit 201 (session information reading unit 201 a). In the measurement apparatuses 20-1 and 20-2, the session control unit 201 (session generation unit 201 b) makes a session request by SIP to the session control apparatus 3 based on the read session information. It is assumed that a telephone communication application session is established between the measuring devices 20-1 and 20-2 (S104).

 In the measurement apparatuses 20-1 and 20-2, packet information corresponding to the input application name is read from the test information storage unit 205 by the packet generation unit 202 (packet generation unit 202 b). Based on the packet information, the packet generation unit 202 (packet generation unit 202b) starts generating and transmitting a media packet related to the established telephone application session (S105).

  In the measurement apparatuses 20-1 and 20-2, the quality measurement item information corresponding to the input application name is read from the test information storage unit 205 by the quality measurement unit 203 (measurement information reading unit 203 a). Then, in the measurement devices 20-1 and 20-2, the quality measurement unit 203 (measurement information reading unit 203a) uses the quality measurement item information (packet transfer delay time) to determine the media packet from the opposite measurement device 20 Reception and communication quality measurement are started (S106).

  In the measurement apparatuses 20-1 and 20-2, when the packet generation unit 202 (end determination unit 202c) detects the end timing of the communication quality measurement test process, the packet generation unit 202 performs packet generation and quality measurement. The communication quality measurement process by the unit 203 ends (S107). The timing of termination determination by the termination determination unit 202c is not limited, and may be, for example, after a lapse of a certain time (which may be set as test information) after the packet generation / transmission processing is started.

  In the measurement devices 20-1 and 20-2, the measurement data including the measurement results (reception times of the received test packets) stored in the quality measurement unit 203 (measurement data storage unit 203d) is analyzed. Is supplied to the unit 207 (S108), and the session disconnection unit 204 executes test session disconnection processing (S109).

  In the measurement apparatuses 20-1 and 20-2, the analysis unit 207 performs an analysis process on the measurement data stored in the measurement data storage unit 203d (S110). The analysis unit 207 communicates between the measurement device 20 and the measurement device 20 facing each other based on the input test information, the contents of the SDP stored as part of the measurement data in the measurement data storage unit 203d, and the like. It is assumed that the specification is grasped and the measurement data is analyzed based on the grasped communication specification.

  Note that the output method of the processing results (packet transfer delay time sequence, etc.) performed by the analysis unit 207 is not limited. For example, the processing result is output to an information recording medium (HDD, DVD-ROM, etc.) and stored. Alternatively, the data may be transmitted and output to another device (for example, a server on the network 1).

  With the above flow, the communication quality measurement test process is executed in the measurement apparatuses 20-1 and 20-2.

  Next, in the packet generation unit 202 (packet generation unit 202b) of the measurement devices 20-1 and 20-2, from the start of packet generation / transmission processing in step S105 described above until the end in step S107 described above. Will be described with reference to the flowchart of FIG.

  As shown in FIG. 4, the packet generation unit 202 (packet generation unit 202b) generates a packet based on the acquired packet information until the end determination unit 202c determines that the communication quality measurement test process is ended. And the process which repeatedly performs a transmission process is performed (S201, S202). At this time, the content of the media data transmitted by the packet generator 202 (packet generator 202b) is not limited. For example, dummy audio data for testing may be repeatedly transmitted.

  Note that the interval (packetization cycle) at which the packet generator 202 (packet generator 202b) transmits the test packet is determined by the codec specifications and settings of the communication media to be transmitted. In this embodiment, the packet generation unit 202 (packet generation unit 202b) will be described as transmitting test data using RTP / RTCP (Real-time Transport Protocol / RTP Control Protocol). That is, the packet generation unit 202 (packet generation unit 202b) transmits an RTP packet with media data (voice data) inserted therein as a test packet for each packetization period. Further, the packet generation unit 202 (packet generation unit 202b) transmits an RTCP packet for performing RTP communication control as a test packet every predetermined period.

  FIG. 6 is an explanatory diagram showing the specifications and settings of each codec to which the measuring devices 20-1 and 20-2 correspond.

  In FIG. 6, the G.C. 711 and G. 729 specifications are shown.

  G. Reference numeral 711 denotes a codec having a transfer rate of 64 kbps, and the payload length of the RTP packet is 160 bytes or 320 bytes. Therefore, G. In 711, when the payload length is 160 bytes, the packetization period is 20 msec, and when the payload length is 320 bytes, the packetization period is 40 msec. G. 729 is a codec with a transfer rate of 8 kbps, and the payload length of the RTP packet is 20 bytes or 40 bytes. Therefore, G. In 729, when the payload length is 20 bytes, the packetization period is 20 msec, and when the payload length is 40 bytes, the packetization period is 40 msec.

  Note that the packetization period information may be notified between the measuring apparatuses 20-1 and 20-2 using, for example, the SDP of the SIP message at the time of session connection.

  In addition, when performing the communication quality measurement test process, the measurement execution unit 203b also stores information on the packet transmission start time and the packetization cycle in the opposing measurement device 20 as part of the measurement data in the measurement data storage unit 203d. It shall be accumulated.

  Next, in the quality measurement unit 203 (measurement execution unit 203b, measurement data storage unit 203d) of the measurement devices 20-1 and 20-2, after the measurement process is started in step S106 described above, in step S107 described above. The process until the end will be described with reference to the flowchart of FIG.

  As shown in FIG. 5, the quality measurement unit 203 (measurement execution unit 203b) performs test packets (RTP packet and RTCP packet) related to the communication quality measurement test process until it is determined that the communication quality measurement test process is finished. ) Is received (acquisition time is received), and the process of repeatedly executing the process of accumulating in the measurement data accumulating unit 203d as measurement data is performed together with the information related to the test packet (S301 to S304). .

  The quality measurement unit 203 (measurement execution unit 203b) stores at least the sequence number of the RTP packet received as a test packet in the measurement data storage unit 203d as part of the measurement data. The quality measurement unit 203 (measurement execution unit 203b) accumulates at least control information inserted in the RTCP packet received as a test packet in the measurement data storage unit 203d as part of the measurement data.

  Next, the contents of the analysis process performed by the analysis unit 207 performed in step S110 described above will be described.

  In addition, between the measuring apparatuses 20-1 and 20-2, as described above, both the packetization period and the test packet (RTP packet) are obtained in advance by exchanging signals (INVITE message or the like) at the time of prior setting or call control. ) Transmission start timing is assumed to be known. That is, it is assumed that the measuring devices 20-1 and 20-2 can grasp the timing at which each RTP packet is transmitted from the opposing measuring device 20.

  Then, the analysis unit 207 associates the transmission timing of each packet (RTP packet) in the opposing measuring apparatus 20 with each received packet (RTP packet). Then, the analysis unit 207 calculates a packet transfer delay time (End to End delay time) related to the received packet.

  The analysis unit 207 calls the packet transmission time (RTP packet transmission time) on the opposite measuring device 20 side (hereinafter also referred to as “packet transmission side”) and the measurement device 20 (hereinafter also referred to as “packet reception side”). ), The multiple-to-multiple or single-to-multiple linking is performed in consideration of the packetization periods on the input side and the output side.

  Here, as an example, G.I. The packetization period of the measurement apparatus 20-1 corresponding to 711 is 20 msec, G.711. Assume that the packetization period of the measuring device 20-2 corresponding to H.729 is 40 msec.

  FIG. 7 is a timing chart illustrating processing executed by the analysis unit 207 of the measurement device 20-2 when the measurement device 20-1 is the packet transmission side and the measurement device 20-2 is the packet reception side. .

  In FIG. 7, as an example, the packet transmission start time (transmission time of the first RTP packet) on the packet transmission side (measurement device 20-1) is set as the timing T101. 7, timings T102, T103, T104, T105, T106,... After the timing T101 indicate packet transmission times (RTP packet transmission times) on the packet transmission side, respectively. That is, the interval between the timings T101 to T106 is 20 msec. 7, each of timings T201, T202, T203,... Indicates a packet reception time (RTP packet reception time) on the packet reception side (measurement device 20-2). The time between each of the timings T201 to T203 is approximately 40 msec when no delay fluctuation or the like occurs. The sequence numbers of the received packets at timings T201, T202, and T203 are 1, 2, and 3, respectively. In FIG. 7, in order to simplify the explanation, the sequence numbers are represented in the form of 1, 2, 3,..., But the sequence number format (initial value, added value, etc.) is not limited.

  In the case of the example in FIG. 7, since the packetization cycle on the packet transmission side is 20 msec and the packetization cycle on the packet reception side is 40 msec, the analysis unit 207 of the measuring device 20-2 transmits two packets on the packet transmission side. The time is associated with one packet reception time on the packet reception side. That is, in the example of FIG. 7, in the analysis unit 207 of the measuring apparatus 20-2, for example, a set of packet transmission times at timings T101 and T102 is associated with a packet reception time at timing T201.

  In the case of the example in FIG. 7, since the packetization cycle on the packet transmission side and the packetization cycle on the packet reception side have a relationship of 1: 2, the analysis unit 207 sets the packetization cycle on the packet transmission side to 2 If it is doubled, the packet can be linked to the packet on the packet receiving side. As described above, if the packet transmission period is a multiple of one on the packet transmission side and the packet reception side, the analysis unit 207 multiplies the other packetization period by the multiple to thereby associate the packets. Is possible. Even when the packetization period is not a multiple of one on the packet transmission side and the packet reception side, the analysis unit 207 can link packets by obtaining the least common multiple of the two packetization periods. . For example, when the packetization cycle on the packet transmission side is 30 msec and the packetization cycle on the packet reception side is 20 msec (in the case of a 3: 2 relationship), the least common multiple is 60 msec. The association between the two packets on the side and the three packets on the packet receiving side can be obtained.

  As a method for associating the packet transmission time on the packet transmission side with the packet reception time on the packet reception side in the analysis unit 207 on the packet reception side, among RTCP packets supplied from the packet transmission side, SR (Sender Report) ) May be used (hereinafter referred to as “RTCP-SR packet”). The SR inserted in the RTCP-SR packet includes information on the sequence number of the RTP packet to be supplied to the packet receiving side (for example, information on the leading sequence number and the number of packets). The analysis unit 207 can associate the packet transmission time on the packet transmission side with the packet reception time on the packet reception side based on the contents of the RTCP-SR packet and the sequence number of the reception packet. Note that the media conversion device 4 converts each RTP packet and the contents (sequence number, etc.) of the RTP packet into a format suitable for the measurement device 20 on the packet reception side by media conversion.

  And in the analysis part 207 of the measuring apparatus 20-2, after performing the same connection about the above packet reception times, about each connection (linkage of packet transmission time and packet reception time; combination), Calculate the packet transfer delay time. For example, regarding the association between the packet transmission time at timings T101 and T102 and the packet reception time at timing T201, the difference d101 between the timing T102, which is the last packet transmission time, and the timing T201 is used as the packet related to the association. It may be calculated as a transfer delay.

  FIG. 8 is a timing chart showing processing executed by the analysis unit 207 of the measurement device 20-1 when the measurement device 20-2 is the packet transmission side and the measurement device 20-1 is the packet reception side. . In the case of the example in FIG. 8, since the packetization cycle on the packet transmission side is 40 msec and the packetization cycle on the packet reception side is 20 msec, the analysis unit 207 of the measurement apparatus 20-1 The two packet reception times on the packet reception side are associated with each other. Then, the analysis unit 207 of the measuring apparatus 20-1 for example, for each association, the difference between the packet transmission time and the packet reception time of the first received packet (for example, the difference d201 between the timing T301 and the timing T401 in FIG. 8). ) Is calculated as the packet transfer delay time.

  In addition, when the packet linking process is detected, the analysis unit 207 detects a packet loss on the packet receiving side (when the packet sequence number on the packet receiving side is not continuous), the packet is lost on the packet receiving side. You may make it skip the link process which concerns on a packet. For example, in the example of FIG. 7, when the packet related to the timing T202 (sequence number 2) is lost and cannot be received (when information is not accumulated in the measurement data accumulation unit 203d), the analysis unit 207 Linking related to timings T103 and T104 is skipped, and a grouping process of a packet transmission time at timings T105 and T106 and a packet reception time at timing T204 is performed.

  In this embodiment, the analysis unit 207 on the packet reception side assumes that communication quality is worse than a predetermined level and quality measurement is not possible for any section where packet loss occurs at a rate higher than a predetermined level. Assume that the packet transfer delay time is not calculated. The packet receiving side analysis unit 207 treats the reception interval of RTCP-SR packets as one section, and calculates the packet loss rate (number of RTP packets transmitted on the packet transmitting side / number of RTP packets received on the packet receiving side) for each section. To do. That is, the analysis unit 207 on the packet reception side handles a period from the reception time of the first RTCP-SR packet to the reception time of the second RTCP-SR packet received next as one section.

  The SR inserted into the RTCP-SR packet includes information on the sequence number of the RTP packet to be supplied to the packet receiving side in the section (for example, information on the top sequence number and the number of RTP packets in the section). Therefore, the packet receiving side analysis unit 207 can detect the packet loss based on the contents of the RTCP-SR packet and the sequence number of the received packet.

  Specifically, the packet receiving side analysis unit 207 of this embodiment determines the processing method for each section and calculates the transfer delay time (the packet transmission time and the packet reception time) according to the flowchart shown in FIG. (Including linking process). The analysis unit 207 on the packet receiving side executes the process shown in FIG. 9 for each section.

  First, when the analysis unit 207 on the packet reception side acquires information stored in the measurement data storage unit 203d for one section, the packet loss number on the packet reception side in the section is counted (S401).

  If the counted packet loss number is 0 in step S401, the packet receiving side analysis unit 207 performs the linking process and the transfer delay time calculating process as shown in FIGS. S403).

  The packet receiving side analysis unit 207 determines the packet related to the first received packet (RTP packet) in the section based on the packet transmission start time on the packet transmitting side and the processing information related to the section processed so far. The transmission time can be grasped.

  On the other hand, when the counted packet loss number is 1 or more in step S401, the packet receiving side analysis unit 207 calculates the packet loss rate in the section (S402).

  If the packet loss rate is 0.1% or less in step S402 described above, the packet receiving side analysis unit 207 excludes the packet transmission time associated with the lost packet, and the above-described FIG. The linking process and the transfer delay time calculation process as shown in FIG. 8 are performed (S404).

  On the other hand, if the packet loss rate is greater than 0.1% in step S402 described above, the analysis unit 207 on the packet receiving side does not calculate the packet transfer delay time for the relevant section, and performs processing for the next section. Shall be transferred to. Note that the analysis unit 207 on the packet reception side may count the number of sections in which the packet loss rate is greater than 0.1% and output it as a part of the processing result.

  In general, the packet loss rate (packet loss rate) of an IP packet is required to be 0.1% or less between NGN UNI and UNI.

(A-3) Effects of Embodiment According to this embodiment, the following effects can be achieved.

  The communication quality measurement system 2 obtains a link (combination) between the packet transmission time on the packet transmission side and the packet reception time on the packet reception side even when the packetization period is different between the packet transmission side and the packet reception side. The packet transfer delay time can be obtained for each application. In other words, in the communication quality measurement system 2, the packet transmission period is different between the packet transmission side and the packet reception side because the analysis unit 207 can grasp the packet transmission time on the packet transmission side by taking advantage of the active measurement. However, the packet transfer delay time can be obtained.

  In particular, in a network (for example, NGN) to which FMC technology that closely links mobile communication and wired communication is applied, communication between terminals with different corresponding communication media is performed. The communication quality measurement system 2 (measuring devices 20-1 and 20-2) that can obtain the above is very useful.

(B) Other Embodiments The present invention is not limited to the above-described embodiments, and may include modified embodiments as exemplified below.

(B-1) In the communication quality measurement system 2 of the above embodiment, the example of measuring the quality related to communication between the fixed telephone (G.711) and the mobile phone (G.721) has been described. The type of communication media (encoding method and specification type) is not limited. For example, in the communication quality measurement system 2, communication between fixed telephones (for example, communication between G.711 and G.722) between the above-described fixed telephone and mobile phone (G.711 and G.721). Of course, it may be replaced with communication between mobile phones (for example, communication between AMR-NB and AMR-WB).

(B-2) In the communication quality measurement system 2 of the above-described embodiment, the communication quality measurement test process (linking process or the like) between IP packets (between RTP packets) is performed. The frame to be is not limited to an IP packet. For example, the communication quality measurement system 2 may perform a communication quality measurement test process (link process or the like) between an ATM network cell and an IP network IP packet. In this case, the communication quality measurement system 2 needs to know at least the cell transmission start time and the cell transmission interval in the ATM network.

(B-3) Although the above embodiment has been described as the configuration in which the analysis unit 207 is arranged inside the measurement apparatus 20, the arrangement position of the analysis unit 207 is not limited. For example, it may be realized by installing an analysis processing program for performing processing of the analysis unit 207 in an arbitrary information processing apparatus (terminal such as a PC) on the network 1. By disposing the analysis unit 207 outside the measurement apparatus 20, the configuration (CPU, memory amount, etc.) of each measurement apparatus 20 can be suppressed to a small scale. In addition, when it is set as the structure which arrange | positions the analysis part 207 inside the measurement apparatus 20 like said embodiment, the number of apparatuses in the communication quality measurement system 2 can be reduced.

(B-4) The analysis unit 207 in the above embodiment has described the process of acquiring each packet transmission time of the packet transmitted by the packet transmission side based on the packet transmission start time and the packetization period on the packet transmission side. The method by which the analysis unit 207 acquires the packet transmission time is not limited to this. For example, the packet transmission side measurement device 20 may acquire the packet transmission time of each packet and supply the packet transmission time to the analysis unit 207 on the packet reception side. The method of supplying the packet transmission time from the measuring device 20 on the packet transmission side to the analysis unit 207 on the packet reception side is not limited. For example, the packet transmission time may be accumulated in the measurement device 20 on the packet transmission side, and supplied when the analysis processing is performed in the analysis unit 207 on the packet reception side.

(B-5) Even when a packet loss occurs, the analysis unit 207 of the above embodiment can perform packet association processing between the packet transmission side and the packet reception side based on the contents of the RTCP-SR packet. Although it has been explained that it is possible, the linking may be performed by other methods. For example, if the analysis unit 207 knows in advance the linking method (linking rules) (for example, the sequence number always starts with 1 and is incremented by 1), the sequence number is confirmed. It is possible to link only by doing.

(B-6) In the above embodiment, a case has been described in which the communication quality measurement system 2 performs a communication quality measurement test process on audio communication media. However, the communication quality measurement system 2 is not limited to audio, and is related to moving image (video) communication media. Of course, the communication quality measurement test process may be performed.

  When media data of a moving image is transmitted using a protocol such as RTP, packets constituting the packet sequence of the media data form a one-frame image using a plurality of packets, unlike the case of voice. In this case, the marker bit flag of the normal RTP header part is “1” in the last RTP packet of one frame worth of packets. Specifically, the quality measuring unit 203 monitors the marker bit flag of the RTP packet to be received, and when the RTP packet for one frame is received when the packet having the marker bit “1” is received. And the next RTP packet can be recognized as the second frame.

  Therefore, in this case, the quality measuring unit 203 needs to acquire a reception time (frame reception time) every time a packet for one frame is received.

  In the analysis unit 207 of the above-described embodiment, the packetization period is used for linking packets between the packet transmission side and the packet reception side for the packet sequence constituting the audio media data. In this case, it is necessary to replace with the frame rate (framing cycle). The frame rate is usually expressed as a numerical value per second, and expressed in units of fps (Frames Per Second). Therefore, the analysis unit 207 on the packet reception side transmits the frame transmission time on the packet transmission side (for example, transmission of the last RTP packet of one frame worth of packets) based on the frame rate on the packet transmission side and the frame rate on the packet reception side. Time) and the frame reception time on the packet receiving side (for example, the reception time of the first RTP packet of the packet for one frame) can be calculated as the packet transfer delay time. Further, in this case, in the packet receiving side analysis unit 207, as in the case of the above-described embodiment (in the case of a telephone communication application), the least common multiple of either the frame rate of the packet transmission side and the packet reception side or any one of them is multiplied. Multiple-to-multiple / single-to-multiple linking can be performed.

(B-7) In the measurement apparatuses 20-1 and 20-2 of the above-described embodiment, the communication quality measurement test process is performed for bidirectional communication, but only in one direction (for example, from the measurement apparatus 20-1). Communication quality measurement test processing (only communication to the measuring device 20-2) may be performed.

  DESCRIPTION OF SYMBOLS 1 ... Network, 2 ... Communication quality measuring system 20, 20-1, 20-2 ... Measuring apparatus, 201 ... Session control part, 201a ... Session information reading part, 201b ... Session production | generation part, 202 ... Packet production | generation part, 202a ... packet information reading unit, 202b ... packet generation unit, 202c ... end determination unit, 203 ... quality measurement unit, 203a ... measurement information reading unit, 203b ... measurement execution unit, 203c ... end determination unit, 203d ... measurement data storage unit, 204 ... Session disconnection unit, 205 ... Test information storage unit, 206 ... Test information input unit, 207 ... Analysis unit, 3 ... Session control device, 4 ... Media conversion device, 5-1, 51-2, ONU.

Claims (3)

A media conversion device for converting a frame sequence of media data transmitted from the first communication device into a frame sequence of a communication medium of a type supported by the second communication device and transmitting the frame sequence to the second communication device In a communication quality measurement system for measuring parameters related to communication quality for a network comprising:
A first measurement device disposed at a first measurement point on the network; and a second measurement device disposed at a second measurement point on the network;
The first measuring device has media frame sending means for sending a frame sequence of the first type of communication media to the second measuring device via the media conversion device,
The second measurement device includes: a media frame receiving unit that receives a frame sequence of a second type of communication media from the first measurement device via the media conversion device; and a measurement process for each received frame. Measuring means for performing
Storage means for storing measurement data including measurement results for each frame measured by the measurement means of the second measurement device;
Frame correspondence relationship for obtaining a corresponding combination between each frame transmitted from the first measurement device and each frame received by the second measurement device using the measurement data accumulated by the accumulation means Acquisition means;
For each combination of frames for which the correspondence relationship has been obtained by the frame correspondence relationship acquisition means, the communication quality between the first measurement point and the second measurement point is determined from the measurement data accumulated by the accumulation means. Communication quality calculating means for calculating parameters;
The first measurement device further includes control information transmission means for transmitting control information related to a session of a frame sequence to be transmitted via the media conversion device,
The second measurement apparatus further includes a frame transmission timing acquisition means for acquiring a transmission timing of each frame transmitted from the first measurement apparatus based on the control information received from the first measurement apparatus,
The storage means stores at least a reception timing of each frame received by the second measurement device and a part or all of control information received by the second measurement device as a part of measurement data,
The communication quality calculation means includes a transmission timing at the first measurement apparatus and a reception timing at the second measurement apparatus for each combination of frames for which the correspondence relation is obtained by the frame correspondence relation acquisition means. Based on the frame transfer delay time,
If there is a section in which the frame loss rate in the second measuring device exceeds a predetermined value, the communication quality calculation means does not calculate the frame transfer delay time related to the section, and A communication quality measurement system, which shifts to a process of calculating a frame transfer delay time related to a section . The network supports multiple application services,
The first measuring device includes:
Communication information storage means for storing an identifier of the application and communication condition information of the application for each application supported by the network;
The communication quality according to claim 1 , further comprising: a transmission control unit that, when an application identifier is input, causes the media frame transmission unit to perform frame transmission under communication conditions corresponding to the application of the identifier. Measuring system. A media conversion device for converting a frame sequence of media data transmitted from the first communication device into a frame sequence of a communication medium of a type supported by the second communication device and transmitting the frame sequence to the second communication device For a network comprising: a first measurement device arranged at a first measurement point on the network; and a second measurement point on the network. In a communication quality measurement method performed by a communication quality measurement system comprising a second measurement device arranged,
Media frame sending means, media frame receiving means, measuring means, storage means, frame correspondence relationship obtaining means, communication quality calculating means, control information sending means, frame sending timing obtaining means,
The media frame sending means sends a frame sequence of the first type of communication media from the first measuring device to the second measuring device via the media converting device,
The media frame receiving means receives a frame sequence of the second type of communication media from the first measurement device via the media conversion device by the second measurement device,
The measurement means performs measurement processing on each frame received by the media frame reception means,
Said storage means stores the measured data including the measurement result for each frame of said measuring means has measured,
The frame correspondence acquisition means uses the measurement data accumulated by the accumulation means to send between each frame transmitted from the first measurement apparatus and each frame received by the second measurement apparatus. Find the corresponding combination,
The communication quality calculation means includes, for each combination of frames for which the correspondence relation is obtained by the frame correspondence relation acquisition means, from the measurement data accumulated by the accumulation means, the first measurement point and the second measurement point. calculating a parameter related to the communication quality between,
The control information transmission means transmits control information related to a session of a frame sequence to be transmitted from the first measurement device via the media conversion device,
The frame transmission timing acquisition means acquires the transmission timing of each frame transmitted from the first measurement device based on the control information received by the second measurement device from the first measurement device,
The storage means stores at least a reception timing of each frame received by the second measurement device and a part or all of control information received by the second measurement device as a part of measurement data,
The communication quality calculation means includes a transmission timing at the first measurement apparatus and a reception timing at the second measurement apparatus for each combination of frames for which the correspondence relation is obtained by the frame correspondence relation acquisition means. Based on the frame transfer delay time,
If there is a section in which the frame loss rate in the second measuring device exceeds a predetermined value, the communication quality calculation means does not calculate the frame transfer delay time related to the section, and A communication quality measuring method, which shifts to a process of calculating a frame transfer delay time related to a section .

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