JP2004032714A - Apparatus and method for measuring communication quality - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measuring apparatus for measuring the amount of traffic, with high time resolution. <P>SOLUTION: The measuring apparatus comprises an integration section for integrating the packet length of a packet, having predetermined header information to packets being successively inputted for accumulating an integral value at an accumulation section; and an integral value read section for reading the integral value from the accumulation section at a predetermined time interval for outputting. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technique for measuring traffic for a packet flow flowing on a network for packet communication. In particular, the present invention relates to a technique for measuring traffic at short time intervals and grasping communication quality.
[0002]
[Prior art]
A conventional communication quality measurement device for packet communication aims to measure the communication quality at the network level, and measures the traffic volume of the entire line, the traffic volume of each protocol and each layer over a long period of time. Has been provided as a main function.
[0003]
However, with the above-mentioned conventional method, it is impossible to identify a packet flow generated by an application using a network, analyze the influence of the packet flow in the network, and measure the communication quality required for the response. Met.
[0004]
That is, since the conventional communication quality measuring device aims to measure the traffic volume for a long time, the time resolution of the traffic is set to 1 second or more. Therefore, it was not possible to grasp the traffic characteristics of a specific application such as a streaming service.
[0005]
The bandwidth required for a network by an image or audio streaming service depends on the encoding method, and is discussed in terms of an average bandwidth per second. However, software that sends the encoded information to the network performs data transmission processing independently of the encoding processing. In addition, the operation cycle of software depends on the time unit of the task management system of the operating system in which it is executed, and is generally several milliseconds to several tens of milliseconds. That is, quality control of streaming data transmitted to the network requires measurement of traffic transition with higher time resolution than before.
[0006]
[Non-patent document 1]
Kihong Park, "ON THE EFFECT AND CONTROL OF SELF-SIMILAR NETWORK TRAFFIC: S SIMULATION PERSPECTIVE", Proceedings of the 1997 Winter Simulation Communication. 989-996
[0007]
[Problems to be solved by the invention]
The problem to be solved by the present invention is to provide a technique that enables measurement of a traffic amount with high time resolution.
[0008]
[Means for Solving the Problems]
The object is to integrate a packet length of a packet having predetermined header information with respect to a packet sequentially input to the measuring device, and to accumulate the accumulated value in a storage unit at a predetermined time interval. The problem is solved by providing an integrated value reading unit that reads out and outputs the integrated value from the storage unit.
[0009]
According to the present invention, the integrated value is accumulated and read out at a predetermined time interval. Therefore, by shortening the readout time interval (1 second or less), the traffic amount can be measured with high time resolution. It can be done in time. On the other hand, in the related art, a large amount of packet data is stored in the measuring device and processed, so that it is not possible to measure the traffic amount with high time resolution in real time.
[0010]
Further, by resetting the value stored in the storage unit every time the integrated value is read from the storage unit at the time interval, the difference calculation becomes unnecessary and high-speed processing can be performed.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
As an embodiment of the present invention, a description will be given of a communication quality measuring apparatus capable of measuring a traffic amount per unit time of a packet flow at a time interval of 1 second or less. In describing the communication quality measuring apparatus, first, the reason why the measurement time interval is set to 1 second or less, more specifically, 10 μsec or more and 1 second or less will be described in detail.
[0012]
An application that transfers moving images and audio in real time requires a time constraint of 1 second or less, unlike a general application in which a processing timeout is determined in a unit of seconds.
[0013]
Taking the real-time transfer of a moving image as an example, for example, in an NTSC signal of a TV, about 30 frames are sent and displayed per second. For this reason, the transfer time allowed for one screen is less than 30 milliseconds, and unless the screen can be received regularly every 30 milliseconds, the application cannot correctly display a moving image. In order to measure a group of packets carrying screen information sent at intervals of 30 milliseconds, a time accuracy of at least 1 millisecond is required. In the future, considering higher-speed network lines that will appear, measurement at more detailed time intervals is required.
[0014]
Furthermore, when developing an application, it is necessary to grasp the network bandwidth used by the developed application. With the widespread use of MPUs with remarkably high speed, there is a high possibility that the application will be an application that sends burst packets unexpectedly by the application developer.
[0015]
Some of the packets included in the bursty packet group exceeding the network allowance cannot be accommodated in the buffers of the node devices constituting the network, resulting in packet loss. At this time, retransmission is performed as a function of the OS, which is the operating environment of the application. However, if a burst occurs again, the same phenomenon is repeated, and the result exceeds the restriction necessary to secure the real-time performance of the application. It becomes.
[0016]
In order to prevent these problems, it will be essential in the future to measure the packet group at detailed time intervals on the application development side and to design the application with high network transparency.
[0017]
The conventional measurement method aims at monitoring the long-term behavior of network traffic, and performs measurement in units of one second or more. As described above, it is impossible to grasp the burst characteristics of the packet flow specific to the application.
[0018]
Here, a method is also conceivable in which all communication data is captured by using the function of capturing all communication data of the conventional traffic monitor device, and post-processing is performed on all communication data after the capture.
[0019]
FIG. 1 shows a configuration of a virtual device using a conventional traffic monitor device for implementing such a method.
[0020]
This device comprises a conventional traffic monitoring device 1, a processing unit 2 for displaying a high time resolution, and a secondary storage device 3 for storing packets. In the conventional traffic monitor device 1, packets in the line are temporarily stored in the high-speed primary storage unit 13 via the line interface unit 11 and the writing unit 12, and then the packets are transmitted via the reading unit 14 and the secondary storage interface 15. Output to the secondary storage device 3. Thereafter, the processing unit 2 reads and analyzes the packets stored in the secondary storage device 3 as offline processing, and displays the traffic transition on the display unit 23.
[0021]
In such a configuration, the time that can be observed at one time depends on the capacity of the primary storage unit 13 of the conventional traffic monitor device 1 to be used. For example, in the case of a line having a usage rate close to 1 Gbps, the time can be less than several seconds. Absent. Further, since all stored packet information is transferred between a plurality of storage devices, continuous measurement cannot be performed in real time.
[0022]
Hereinafter, embodiments of the present invention will be described.
[0023]
FIG. 2 is a diagram showing a schematic configuration of the communication quality measuring device according to the embodiment of the present invention. The communication quality measuring device includes a selection and extraction mechanism 31 for extracting a specific packet flow from a large number of packet flows flowing on a network, a packet length integration mechanism 32 for integrating the packet length values of the extracted packets, An integrated value periodic reading mechanism 33 for periodically reading out the integrated value of the packet length obtained by the mechanism at a predetermined time interval and displaying or storing the integrated value, a display mechanism 34, and a storage unit 35 are provided. are doing. The operation of the communication quality measuring device is as follows.
[0024]
The packet selected by the selection and extraction mechanism 31 is copied and input to the packet length accumulation mechanism 32. The packet length integrating mechanism 32 integrates the packet length of each packet using a counter corresponding to the header of the input packet, and accumulates the integrated value in a memory in the packet length integrating mechanism. The processing up to this point is executed as needed according to the arrival of the packet. That is, the selection / extraction mechanism 31 and the packet length accumulation mechanism 32 perform the sequential processing in synchronization with the arrival of the packet.
[0025]
The operation of the integrated value periodic reading mechanism 33 will be described with reference to FIG. After the initialization (step S1), a time interrupt wait state is set (step S2). Then, in response to a time interruption every predetermined time (1 ms), the integrated value accumulated in the memory in the packet length integrating mechanism is periodically read, and transferred to the main memory in the integrated value periodic reading mechanism. Then, the value of the memory in the packet length integrating mechanism for storing the integrated value is initialized (set to 0) (step S2). Then, the integrated value periodic reading mechanism 33 sends the read integrated value from the main memory to the display mechanism 34 and stores it in the storage unit 35 as a file (step S4). The display mechanism 34 displays, for example, traffic transition of a specific type of packet with time on the horizontal axis and integrated value on the vertical axis. Further, it is also possible to apply a process to the integrated value to facilitate the evaluation of the burst characteristics, and display the processed data.
[0026]
Further, instead of displaying the integrated value on the display mechanism 34 or storing it in the storage unit 35, the integrated value may be transmitted to a remote monitoring device or the like via the network 40 and displayed there, as shown in FIG. .
[0027]
That is, the configuration shown in FIG. 4 has a network sending mechanism 41 instead of the display mechanism 34 and the storage unit 35. Then, the network receiving mechanism 42 and the display mechanism 43 are connected via the network 40.
[0028]
As shown in the flow of FIG. 5, in this configuration, the integrated value reading mechanism 33 sends the read integrated value to the network 40 via the network sending mechanism 41 (Step S14). The receiving side keeps waiting in the display data waiting state, and displays the integrated value on the display mechanism 43 when the network receiving mechanism 42 receives the integrated value (step S15) (step S16). In addition, it is also possible to perform processing for facilitating the burst characteristic evaluation on the integrated value, and transmit the processed data via a network.
[0029]
More specifically, the communication quality measuring device of the present embodiment has a functional configuration shown in FIG. The line interface 51, the header information extraction unit 52, and the packet information search unit 53 shown in FIG. 6 correspond to the selection and extraction mechanism 31 in FIG. 2, the accumulation mechanism 54 and the counter unit 56 correspond to the packet length accumulation mechanism 32, The interval reading section 55 corresponds to the integrated value reading mechanism 33. The operation of the configuration shown in FIG. 6 is as follows.
[0030]
The packet input via the line interface 51 is input to a header information extraction unit 52, where the header information is extracted. Then, the packet information search unit 53 uses the header information to search for an identifier of a counter of the counter unit 56 corresponding to the header information. If the search for the identifier is successful, the header information extraction unit 52 passes the packet length and the identifier to the integrating mechanism 54, and the integrating mechanism 54 integrates the packet length using a counter corresponding to the identifier. The processing up to this point is executed as needed according to the arrival of the packet.
[0031]
The information of the counter section 56 is read periodically by the fixed time interval reading section 55, and the counter is reset each time the information is read. The reading interval is a time (at least 1 ms) during which the behavior of the application can be observed, as described above. Then, the read counter value is displayed on the display unit 58 via the display / accumulation processing unit 57, and is accumulated in the measurement result accumulation unit 59.
[0032]
Next, an example of a method for measuring communication quality using the communication quality measuring device of the present invention will be described.
[0033]
FIG. 7 is a diagram illustrating a configuration example when measuring communication quality using the communication quality measuring device 60 of the present invention. In this configuration, the communication quality measuring device 60 measures the packet flow f1 immediately after being transmitted from the data transmission server 61 and the packet flow f2 immediately before the data receiving client 63 after passing through the network 62, and compares the measurement results. I do. By measuring and evaluating the difference in burst characteristics between the entrance and the exit of the network, how the burst characteristics of the packet flow transmitted from the data transmission server 61 are affected by the transfer in the network 62 Can be observed. Note that the packet flow f1 immediately after the data transmission server 61 can be considered as a packet flow unique to an application on the premise of a network in an ideal state where there is no packet flow outside the measurement target.
[0034]
At this time, the application of the data transmission server 61 adds tag information necessary for identifying a burst transfer portion to each packet and outputs the packet to the network 62. It is also possible to simultaneously output a measurement packet to the network at a level that does not affect the application.
[0035]
The above change in the burst characteristics can be observed by comparing the traffic transition display with time on the horizontal axis and the integrated value on the vertical axis at the entrance and the exit of the network.
[0036]
In addition, the above-mentioned burst characteristics are obtained by calculating the throughput (average communication amount per unit time) of the burst transfer portion of the packet and the interval at which the burst transfer appears from the integrated value of the packet length periodically read from the integrated value periodic reading mechanism. It can also be obtained by calculating the inter-burst time.
[0037]
FIG. 8 is a diagram illustrating a state of a certain packet flow before and after passing through a network. The packet included in each burst transfer portion includes tag information for identification, and the burst transfer portion is identified based on the tag information. As another method of identifying the burst transfer portion, a threshold value relating to the communication amount per unit time may be provided, and when the communication amount equal to or more than the threshold value continues for a predetermined time, the burst transfer portion may be identified.
[0038]
FIG. 9 shows an example of an evaluation method when the throughput of the burst transfer portion of the packet and the inter-burst time, which is the interval at which the burst transfer appears, are used. The throughput (average value of the communication amount per unit time) for each burst transfer portion shown in FIG. 8 is plotted on a two-dimensional plane with the vertical axis and the inter-burst time as the horizontal axis to obtain a characteristic diagram (evaluation plane). . By obtaining such an evaluation plane for the entrance and the exit of the network, it becomes possible to measure the characteristics that the network gives to the application.
[0039]
When the network is evaluated by comparing the traffic characteristics before and after passing through the network as described above, the communication quality measuring device can be configured as shown in FIG. That is, the configuration of FIG. 2 is provided with a reference data comparison mechanism 71 and a reference data storage unit 72. The reference data accumulating unit 72 previously accumulates, as reference data, burst characteristics of a packet flow unique to an application on the premise of a network in an ideal state where there is no packet flow outside the measurement target. This reference data can be obtained, for example, by measuring the packet flow f1 in the configuration of FIG.
[0040]
The reference data comparison unit 71 compares the burst characteristics of the packet flow obtained by the integrated value periodic reading unit 33 with the reference data stored in the reference data storage unit 72, and analyzes the difference. In this case, the display mechanism 34 can display the output of the integrated value periodic reading mechanism 33 and the output of the reference data comparing mechanism 71. The burst characteristic used for the comparison may be a time transition of the traffic amount, or may be obtained by a method as shown in FIG.
[0041]
Next, with reference to FIG. 11, a more detailed configuration close to hardware implementation of the communication quality measuring device of the present invention will be described below. Hereinafter, a configuration in the case of having a reference data comparison mechanism and a display mechanism will be described.
[0042]
As shown in FIG. 11, the communication quality measuring apparatus includes an input-side line interface 81, an output-side line interface 82, a duplicator 83, a selected packet length extractor 84, an integrated value storage memory 85, and an integrated value storage memory address. It has a search table 86, an adder 87, an initialization value register 88, an arbitration circuit 89, an interface circuit 90, an MPU 91, a main memory 92, a secondary storage device 93, a real-time interrupt generation device 94, and a display device 95. The line interfaces 81 and 82, the duplicator 83, and the selected packet length extractor 84 correspond to, for example, the selection and extraction mechanism 31 shown in FIG. 10, and include an integrated value accumulation memory 85, an integrated value accumulation memory address search table 86, an adder 87, an initialization value register 88 and an arbitration circuit 89 correspond to the packet length integration mechanism 32, the main memory 92 or the secondary storage device 93 corresponds to the reference data storage section 72, and the MPU 91, the main memory 92, the real time The interrupt generator 94 and the program stored in the main memory 92 correspond to the integrated value periodic reading mechanism 33 and the reference data comparing mechanism 71, and the display device 95 corresponds to the display mechanism 34. Next, the function of each unit shown in FIG. 11 will be described.
[0043]
The duplicator 83 duplicates a packet. The selected packet length extractor 84 extracts a specific packet from the duplicated packet and calculates the packet length. The integrated value storage memory 85 stores the integrated value of the packet length at an address corresponding to the header information of the packet. The integrated value memory address search table 86 searches the header information of the packet for the address where the integrated value stored in the integrated value storage memory 85 is stored, and returns the address to the selected packet length extractor 84.
[0044]
The adder 87 adds the packet length of the packet extracted by the selected packet length extractor 84 to the accumulated value accumulated so far in the accumulated value accumulation memory 85. The initialization value register 88 stores an initialization value used when the integrated value accumulation memory 85 is initialized. The arbitration circuit 89 arbitrates access to the integrated value accumulation memory 85.
[0045]
In FIG. 11, reference numeral 96 denotes a packet stream duplicated by the duplicator 83; 97, an extracted packet length; 98, an address of the integrated value storage memory 85 obtained from the integrated value memory address search table 86; It is a bus that connects the interface circuit 90, the MPU 91, the main memory 92, the secondary storage device 93, the real-time interrupt generation circuit 94, and the display device 95, which are essential for performing the processing.
[0046]
Next, the operation of the present apparatus will be described together with the details of each of the above components.
The line interface 81 connects to a line (network), converts a packet transmitted as a physical signal into a signal that can be logically processed, and transfers the signal to the duplicator 83. The duplicator 83 duplicates the packet signal in perfect form, and outputs one to the line interface 82 and the other to the selected packet length extractor 84. The line interface 82 performs a process reverse to that of the line interface 81 on the packet signal received from the duplicator 83 and outputs the packet signal to the line.
[0047]
The packet (96) duplicated by the duplicator 83 is passed to the selected packet length extractor 84.
[0048]
The operation of the selected packet length extractor 84 will be described with reference to FIG.
[0049]
When the packet arrives, the selected packet length extractor 84 extracts the header information of the packet 96 from the state of waiting for the packet arrival (step S21) (step S22). Specifically, in order to identify a series of communication (packet flow) performed by the application, a destination IP address, a source IP address, a protocol type (type of TCP / UDP), a destination port number of TCP or UDP, and a source Extract the port number. This series of header information is called a flow ID.
[0050]
The selected packet length extractor 84 calculates the packet length and requests the integrated value storage memory address search table 86 for the address of the integrated value storage memory 15 using the extracted flow ID (step S23).
[0051]
The selected packet length extractor 84 outputs the packet length 97 and the address 98 of the integrated value storage memory 85 to the adder 87 when the above-described search is successful (other than the address 0 is returned) (YES in step S24). (Step S25). If the search fails (address 0 returns) (NO in step S24), the packet is discarded (step S26), and the process returns to the operation of waiting for the packet (96) from the duplicator 83.
[0052]
FIG. 13 is a diagram showing an example of the integrated value storage memory address search table 86. In the figure, 101 is a flow ID field, 102 is an integrated value storage memory address field, 103 is a flow ID input, and 104 is an address in the integrated value storage memory 85.
[0053]
In the integrated value storage memory address search table 86, the flow ID field 101 is searched based on the flow ID 103 obtained by the selected packet length extractor 84. When the same flow ID as the flow ID 103 exists in the flow ID field 101, the address registered in the corresponding integrated value storage memory address field 102 is output as the address 104 of the integrated value storage memory 85. If it does not exist, a special address value (address 0) is output as the address 104 of the integrated value accumulation memory 85. The registered contents of the flow ID field 101 and the integrated value storage memory address field 102 can be changed by the MPU 91 via the interface circuit 90 at any time.
[0054]
In FIG. 11, an adder 87 reads data stored at the address from the integrated value storage memory 85 based on the address 98 of the integrated value storage memory 85 transferred from the selected packet length extractor 84.
[0055]
FIG. 14 shows an example of the integrated value storage memory 85, which has the same configuration as a general memory. In the figure, 201 is an address field, 202 is a data field (the data here is an integrated value), 203 is an address input, and 204 is data input / output.
[0056]
The address is a value specified by a continuous integer, and the data is arbitrary data. In the case of a read operation, data stored in the field 202 corresponding to the address 201 corresponding to the input 203 is output as 204. In the case of a write operation, data 204 is stored in a field 202 corresponding to an address 201 corresponding to an input 203.
[0057]
The adder 87 reads the data stored in the integrated value accumulation memory 85, adds the value of the packet length 97 described above thereto, and stores the data in the integrated value accumulation memory 85 again. At this time, the address used for reading and writing is given from the selected packet length extractor 84.
[0058]
The initialization value register 88 is a register that stores an initial value used when the field 202 of the integrated value accumulation memory 85 is initialized, and sets “0”. The initialization timing will be described later.
[0059]
The arbitration circuit 89 arbitrates access to the integrated value accumulation memory 85 of each of the adder 87 and the interface circuit 90. When the integrated value accumulation memory 85 is initialized, the value accumulated in the initialization value register 88 is stored at the designated address.
[0060]
The processing so far is executed in response to the arrival of the packet registered in the integrated value storage memory address search table 86. As a result, the packet length of the arriving packet is added to the value stored in the data field of the integrated value accumulation memory 85 at any time.
[0061]
The interface circuit 90 realizes access to the integrated value storage memory address search table 86 and the arbitration circuit 89. The interface circuit 90 stores the integrated value storage memory 85 and the integrated value from a program stored in the main memory 92 and processed by the MPU 91. It mediates access to the storage memory address search table 86.
[0062]
The following processing will be described with reference to FIG. Note that the processing described below is processing executed in accordance with instructions of a program stored in the main memory 22.
[0063]
At the time of initialization, the program registers the header information of the packet to be measured in the integrated value storage memory address search table 86, and then sets all data fields of the integrated value storage memory 85 to the values of the initialization value register 88. In order to perform the processing and to read the integrated value accumulation memory 85 at fixed time intervals, the real-time interrupt generation device 94 is set to generate an interrupt to the MPU 91 at fixed time intervals (step S31).
[0064]
The program waits until the real-time interrupt generator 94 generates an interrupt signal to the MPU 91 (step S32). When the real-time interrupt generator 94 generates the interrupt signal, the program shifts from the waiting state to the operation of reading the data field of the integrated value accumulation memory 85.
[0065]
At this time, the value of the data field 202 is read from the addresses (201, 104) corresponding to all of the integrated value storage memory address fields 102 registered in the integrated value storage memory address search table 86, and is stored in the designated area in the main memory 92. It is stored (step S33). In the read field, the value of the initialization value register 88 is sequentially written and initialized (step S34). Among the data stored in the main memory 92, those defined as display targets by the program are transferred to the display device 95 for display (step S35).
[0066]
By repeating the processing up to this point, it becomes possible to periodically obtain the total packet length of the packet flow based on a specific application within a certain time registered in the real-time interrupt generation device 94. By plotting the time axis on the horizontal axis and the readout value of the integrated value accumulation memory 85 on the vertical axis, it is possible to obtain the transition of the communication amount of the packet flow per unit time.
Further, the comparison process described with reference to FIGS. 8 and 9 is performed at a time interval longer than the time interval for reading out the integrated value accumulation memory 85 generated by the real-time interrupt generation device 84. That is, a time determination is performed in step S36, and a comparison process is performed when the evaluation designated time has elapsed (step S37).
[0067]
In the comparison processing, the throughput (average value of the communication amount per unit time) and the inter-burst time of the burst transfer portion of the packet are obtained, and the throughput for each burst transfer portion is represented on the vertical axis and the inter-burst time is represented on the two-dimensional axis. The plot is plotted on a plane, a characteristic diagram (evaluation plane) after passing through the network as shown in FIG. 9 is created, and the burst characteristic of the same packet flow at the time of ideal application operation before passing through the network shown in FIG. It is stored in advance in the next storage device 23 as reference data, and the throughput for each burst transfer portion is plotted on a two-dimensional plane with the vertical axis and the inter-burst time as the horizontal axis. Evaluation plane). These may be displayed on the display device 95 as they are, or their differences may be displayed. In this way, the quality of the network is measured.
[0068]
In addition, prepare reference data of traffic transition with time on the horizontal axis and integrated value on the vertical axis, and compare this with the measurement result of traffic transition with time on the horizontal axis and integrated value on the vertical axis. You may.
[0069]
The comparison between the reference data and the measurement data in this case will be described in further detail.
[0070]
The reference data is, for example, a burst transfer pattern of a packet at a constant period, which is seen in an application that distributes a moving image, a sound, or the like having real time properties over a network. Taking an example of an application for distributing a moving image based on an NTSC signal, which is a general TV signal, in a case where transmission processing is performed in units of one screen, one screen is transmitted every about 33 milliseconds. If the data amount of one screen is 1 MByte, a burst of 1 MByte occurs about every 33 milliseconds. If the capacity of the network line is 1 Gbps and the computer that executes the application has a transmission performance of 1 Gbps, a full-rate burst of the 1 Gbps line over 8 ms occurs every 30 ms. This repetition is the reference data in the case of the application. The reference data differs depending on the application, but has a specific repetition pattern when the capacity of the network line is fixed.
[0071]
When a repeatable burst pattern is distributed by the application via the network, the burst interval and burst continuous time are compared with the ideal state without the network due to the lines constituting the network and the buffer state of the node device. Changes. This is the measurement data.
[0072]
To compare the reference data and the measurement data means to create a difference between two repetition patterns. For example, a graph showing the time change of the difference is created and displayed. If the difference is large, it indicates that the effect of the network on the burst characteristics is large, and if the difference is small, it indicates that the effect is small.
[0073]
The reference data is not a burst pattern (characteristic) of the packet flow specific to the application, assuming an ideal network where there is no packet flow outside the measurement target. A burst pattern may be used. At this time, by comparing the reference data generated by the generator with the actual measurement data, it is possible to indirectly measure the influence of the packet flow unique to the application on the network. It is also possible to configure so that the post-analysis can be performed by duplicating and recording the measurement result in the nonvolatile storage means.
[0074]
Next, an example of traffic measurement using the communication quality measuring device according to the present invention will be described, including differences from the conventional device.
[0075]
16 and 17 show examples of traffic transition measurement results of packets transmitted by an MPEG-2 streaming system (apparatus A and apparatus B) having different traffic characteristics. FIG. 16 shows the result measured by the conventional device, and FIG. 17 shows the result measured by the communication quality measuring device of the present invention.
[0076]
In FIG. 16, there is almost no difference in traffic transition between the device A and the device B. On the other hand, in FIG. 17, it can be seen that the device A generates traffic that transitions stably at a maximum of 10 Mbps, while the device B generates a burst exceeding 30 Mbps at a period of 20 ms. That is, in the conventional device, since the time interval of the measurement is long, it is impossible to observe a burst at a short time interval like the traffic generated by the device B. On the other hand, since the device of the present invention can grasp traffic at short time intervals, it can observe bursts with a period of 20 milliseconds.
[0077]
FIG. 18 is a diagram illustrating an example in which distribution adjustment of a streaming distribution application is performed using the communication quality measurement device of the present invention. In other words, before the adjustment, the streaming distribution application has a traffic characteristic of repeating a burst exceeding 800 Mbps as shown in “Distributable traffic transition” in FIG. 18, and when this traffic is transmitted through the network, Packet loss was observed. Therefore, when the distribution is adjusted and the traffic shown in “Transitionable traffic transition” in FIG. 18 is transmitted, no packet loss occurs even through the network, and the distribution was successful. Such adjustment is made possible by the communication quality device of the present invention that can measure traffic at short intervals.
[0078]
It should be noted that the present invention is not limited to the embodiments described above, and various modifications and applications are possible within the scope of the claims.
[0079]
【The invention's effect】
As described above, according to the present invention, traffic measurement with high time resolution can be performed in real time. In addition, it is possible to measure in detail the influence of a series of packet flows originating from a specific application executed by a server and a client connected to the network on the network, and to control the quality of the streaming service, and Distribution adjustment can be performed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a virtual device using a conventional traffic monitor device.
FIG. 2 is a diagram showing a schematic configuration of a communication quality measuring device according to an embodiment of the present invention.
FIG. 3 is a diagram for explaining an operation of an integrated value periodic reading mechanism in the communication quality measuring device shown in FIG. 2;
FIG. 4 is a diagram illustrating a schematic configuration of a communication quality measuring device according to an embodiment of the present invention, and is a diagram illustrating a configuration when transmitting measurement data to a network.
FIG. 5 is a diagram for explaining an operation of an integrated value periodic reading mechanism in the communication quality measuring device shown in FIG. 4;
FIG. 6 is a diagram showing a functional configuration of a communication quality measuring device according to the embodiment of the present invention.
FIG. 7 is a diagram for explaining a method for measuring the influence of transfer within a network on burst characteristics of an application-specific packet flow.
FIG. 8 is a diagram illustrating a state of a packet flow before and after passing through a network.
FIG. 9 is a diagram illustrating an example of an evaluation method.
FIG. 10 is a diagram illustrating a schematic configuration of a communication quality measuring device according to an embodiment of the present invention, and is a diagram illustrating a configuration when a reference data comparison mechanism is provided.
FIG. 11 is a diagram showing a detailed configuration of a communication quality measuring device according to an embodiment of the present invention.
FIG. 12 is a diagram for explaining an operation of a selected packet length extractor 84;
FIG. 13 is a diagram illustrating an example of an integrated value storage memory address search table.
FIG. 14 is a diagram illustrating an example of an integrated value accumulation memory.
FIG. 15 is a diagram showing a flow of processing corresponding to a program stored in a main memory.
FIG. 16 is a diagram showing an example of traffic transition measured by a conventional device.
FIG. 17 is a diagram showing an example of traffic transition measured by the apparatus of the present invention.
FIG. 18 is a diagram illustrating an example in which distribution adjustment of a streaming distribution application is performed using the communication quality measurement device of the present invention.
[Explanation of symbols]
1 Conventional traffic monitoring device
2 Processing unit for displaying high time resolution
3 Secondary storage device
11 Line interface
12 Writing unit
13 High-speed primary storage unit
14 Readout unit
15, 21 Secondary storage interface
22 Traffic transition display processing unit
23 Display
31 Selection mechanism
32 Packet Length Integration Mechanism
33 Integrated value periodic reading mechanism
34, 43 display mechanism
35 storage unit
41 Network sending mechanism
42 Network receiving mechanism
51 line interface
52 Header information extraction unit
53 Packet Information Search Unit
54 Accumulator
55 Fixed time interval reading section
56 Counter section
57 display / accumulation processing unit
58 Display
59 Measurement result storage unit
60 Communication quality measurement device
61 Data transmission server
63 data receiving client,
71 Reference data comparison mechanism
72 Reference data storage mechanism
81 Input line interface
82 Output Line Interface
83 Duplicator
84 Selected packet length extractor
85 Integrated value storage memory
86 Integrated value storage memory address search table
87 adder
88 Initialization value register
89 Arbitration circuit
90 Interface circuit
91 MPU
92 Main memory
93 Secondary storage device
94 Real-time interrupt generator
95 Display device

Claims (20)

A measuring device for measuring a traffic amount of packet data flowing on a network,
An accumulating unit that accumulates a packet length of a packet having predetermined header information with respect to a sequentially input packet, and accumulates the accumulated value in an accumulating unit;
A measuring device, comprising: an integrated value reading unit that reads an integrated value from the storage unit at a predetermined time interval and outputs the integrated value. 2. The measuring device according to claim 1, wherein the measuring device initializes a value stored in the storage unit each time the integrated value is read from the storage unit at the time interval. The measuring device has a real-time interrupt unit, and when the real-time interrupt unit generates an interrupt signal, reads an integrated value from the storage unit and initializes a value stored in the storage unit. 3. The measuring device according to claim 2, wherein the measurement is started. The measuring device according to claim 1, wherein the time interval is 1 second or less. The accumulator is:
The header information of the input packet is extracted, the address of the storage unit corresponding to the header information is obtained from a table in which the header information is associated with the address, and the integrated value is stored in the obtained address. The measuring device according to claim 1. The measuring device according to claim 1, wherein the measuring device further includes a display unit that displays the integrated value or a value obtained by processing the integrated value. The measurement device according to claim 1, wherein the measurement device further includes a transmission unit that transmits the integrated value or a value obtained by processing the integrated value to another device via a network. The measuring device comprises:
A reference data storage unit for storing reference data in advance,
The measurement device according to claim 1, further comprising a reference data comparison unit that compares a measurement result obtained by the measurement device with reference data. The measuring device according to claim 8, wherein the reference data comparing unit obtains a difference between the measurement result and the reference data. 2. The measuring apparatus according to claim 1, wherein the burst characteristic of the packet flow is calculated by obtaining an average value of the communication amount per unit time of a burst transfer portion of the packet and an inter-burst time which is an interval at which the burst transfer appears from the integrated value. . A measuring method in a measuring device for measuring a traffic amount of packet data flowing on a network,
For a sequentially input packet, accumulating the packet length of the packet having predetermined header information, and accumulating the accumulated value in the accumulation unit;
Reading and outputting the integrated value from the storage unit at a time interval designated in advance. The measuring method according to claim 11, further comprising a step of initializing a value stored in the storage unit each time an integrated value is read from the storage unit at the time interval. The measurement device has a real-time interrupt unit,
13. The measurement method according to claim 12, further comprising a step of reading an integrated value from the storage unit and starting an operation of initializing a value stored in the storage unit when the real-time interrupt unit generates an interrupt signal. Method. The measuring method according to claim 11, wherein the time interval is 1 second or less. In the step of storing the integrated value in a storage unit,
The header information of the input packet is extracted, the address of the storage unit corresponding to the header information is obtained from a table in which the header information is associated with the address, and the integrated value is stored in the obtained address. The measurement method according to claim 11, wherein the measurement is performed. The measuring method according to claim 11, further comprising a step of displaying the integrated value or a value obtained by processing the integrated value. The method according to claim 11, further comprising transmitting the integrated value or a value obtained by processing the integrated value to another device via a network. The measuring method according to claim 11, further comprising a step of comparing a measurement result obtained by the measuring device with reference data. 19. The measuring method according to claim 18, wherein in the comparing step, a difference between a measurement result and reference data is obtained. 12. The method according to claim 11, further comprising: calculating a burst characteristic of a packet flow by obtaining an average value of communication traffic per unit time of a burst transfer portion of a packet and an inter-burst time which is an interval at which burst transfer appears from the integrated value. Measurement method.

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