JP2001127795A - Network quality evaluation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a network quality evaluation device that can properly identify its location when deterioration in the communication quality is clarified. SOLUTION: The network quality evaluation device that extracts packer data from a plurality of positions of a communication network and evaluates the communication quality of the network on the basis of the extracted data, transmits the communication network test packet data for measuring the communication quality to the communication network by using detection of deteriorated communication quality as a trigger.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network quality evaluation apparatus, and more particularly to an improvement of an apparatus for extracting and evaluating communication packets of a communication network at a plurality of locations.

[0002]

2. Description of the Related Art There is the Internet as a familiar communication network. On the Internet, not only textual information but also voice and image information can be exchanged as data.The services include data transmission services such as e-mail, net news, file transfer (ftp), remote login (telnet), Gopher, There are also information retrieval services such as WWW. According to the Internet, information can be exchanged instantaneously without being restricted by companies, countries, etc.,
It is widely used in various fields, such as individuals, companies, government agencies, educational institutions, and research institutions.

[0003] In the Internet, if the communication quality of the communication network does not sufficiently satisfy the quality required by the service to be used, packet data may be lost or delay time may fluctuate. In such a case, the received sound may be interrupted, or in the case of moving image information, the movement of the received moving image may be unnatural.

However, in the Internet, since a plurality of terminals and services share the route of the communication network, the communication quality is degraded when the number of users accessing simultaneously increases as compared with the case where the number of users is small. In addition, the bandwidth of a line constituting a communication network is generally designed so that a trunk portion is wide and a branch line portion is narrow. However, when actually operated, the branch line portion may be overloaded.

[0005] In any case, the provider must provide more stable services to the user from the standpoint of providing a part of the communication network for a fee. It is necessary to accurately analyze the cause. Further, it is desirable that the user can accurately grasp the quality of various services in real time in order to determine whether the quality of various services used on the Internet is commensurate with the usage fee of the communication network.

FIG. 7 is a block diagram showing an example of a conventional network quality evaluation device. In the figure, a communication network ISP1 is provided by a provider.
In the communication network ISP1, lines are connected to each other via a plurality of routers R. A company (head office) 2 and a company (branch) 3 as users are connected to the communication network ISP1 via a router R, and a probe manager 4 is also connected via the router R. In addition, other users and communication networks are also connected via a router, but they are not shown.

The probe P1 has a function of extracting packet data from the communication network, and is connected to a port of the router R from which the packet data is to be extracted, if necessary. The probe P1 apparently operates as a through circuit to extract packet data without disturbing communication, a physical layer circuit 6 for converting the extracted packet data into a logic signal, and a noticeable specified communication packet. A filter circuit 7 including a packet filter and a data filter for extracting only necessary information, a memory control circuit 9 for storing information extracted by the filter circuit 7 together with a time stamp in a memory 8, and an external communication circuit 10 for storing information stored in the memory 8 And a control circuit 11 for controlling transmission to the probe manager 4 via the control circuit 11.

In the configuration shown in FIG. 7, the probe manager 4 connects the packet information of interest extracted by the probe P1 connected to the port of the router R of the company (head office) 2 to the port of the router R of the company (branch office) 3. The same packet information of interest extracted by the probe P1 is fetched and the packet information of the two is collated, and packet loss, delay time, delay fluctuation between the company (head office) 2 and the company (branch office) 3 are determined. Measures communication quality items such as throughput.

[0009]

However, in such a conventional apparatus, even if the measurement result of the probe manager 4 indicates that the communication quality has deteriorated, the communication network I
It is not possible to specify which part of SP1 has a cause of deteriorating the communication quality.

The present invention focuses on such a problem, and an object of the present invention is to realize a network quality evaluation device capable of accurately specifying a location where communication quality has deteriorated when it becomes clear. is there.

[0011]

According to a first aspect of the present invention, there is provided a network for extracting packet data from a plurality of locations in a communication network and evaluating communication quality of the network based on the extracted data. In the quality evaluation device, test packet data for measuring communication quality is transmitted to a communication network, triggered by detection of deterioration of communication quality.

[0012] Thus, when the deterioration of the communication quality is detected, the cause can be immediately investigated.

[0013] A second aspect of the present invention is characterized in that the test packet data uses the same packet data as when the deterioration of the communication quality is detected.

Thus, the cause of the deterioration of the communication quality can be determined in a state in which the conditions that caused the deterioration are reproduced.

A third aspect of the present invention is characterized in that, as the test packet data, predetermined packet data suitable for specifying an estimated cause of deterioration is used.

[0016] Thus, when the cause of the deterioration of the communication quality can be empirically and statistically estimated, it can be quickly investigated.

[0017] Claim 4 of the present invention claims 1 to 3.
In the network quality evaluation device described above, a time stamp is added to the test packet data.

Thus, the cause of the deterioration of the communication quality can be determined and the delay time characteristic can be easily measured.

According to a fifth aspect of the present invention, there is provided a network quality evaluation apparatus for extracting packet data from a plurality of locations in a communication network and displaying a change in network quality over time based on the extracted data. , A predetermined event is displayed on the quality time change display screen.

Thus, the delay time data displayed on the quality time change display screen can be read by using the predetermined event as a clue, and it is determined whether the delay time is caused by a normal disturbance of the delay time or the occurrence of the predetermined event. The data can be easily decoded. The event to be displayed may be a mark or a list.

According to a sixth aspect of the present invention, in the network quality evaluation device according to the fifth aspect, the predetermined event is a route change.

Thus, it is possible to easily determine whether the data displayed on the quality time change display screen is due to the disorder of the normal delay time or the data resulting from the route change occurring relatively infrequently.

According to a seventh aspect of the present invention, there is provided a network quality evaluation apparatus for extracting packet data from a plurality of locations in a communication network and evaluating communication quality of the network based on the extracted data. It is characterized in that one circuit is used in a time-division manner.

Thus, the circuit configuration of the entire apparatus can be simplified, and the cost can be reduced. In this case, the packet data includes bidirectional communication and data from a plurality of locations.

[0025] Claim 8 of the present invention is claims 1 to 7.
In the above described network quality evaluation device, the measurement port is of a through type.

Thus, measurement can be performed without disturbing the data transmission system.

The ninth aspect of the present invention is the first to seventh aspects.
In the described network quality evaluation device, the measurement port is a mirror type.

Thus, by connecting to a mirror port or a normal communication port of a router or a switch, it is possible to connect to a network without physically disconnecting a line.

According to a tenth aspect of the present invention, in the network quality evaluation device according to the first to seventh aspects, the measurement port can be switched between a through type and a mirror type.

Thus, measurement can be performed at an appropriate port according to the network situation.

According to an eleventh aspect of the present invention, in a network quality evaluation apparatus for extracting packet data from a plurality of locations in a communication network and evaluating the communication quality of the network based on the extracted data, a communication quality measurement result is displayed as a list. In addition, although the quality is worse than the quality limit set value, the display form of the measurement result is made different from the others.

Thus, the measurement result of the quality deterioration can be easily identified. The display form includes a display color and a display shape.

[0033]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an example of an embodiment of the present invention. In the present invention, the probe P2 having the same configuration as the conventional one is also connected to the port of each router R in the communication network ISP1. However, these probes P2 are equivalent to packets whose packet length, quality class, and the like indicate communication quality deterioration based on quality deterioration occurrence packet information transmitted when the probe manager 4 detects deterioration in communication quality. It has a function of generating and outputting a test packet. The probe P1 may have a function of generating and outputting a test packet similar to the probe P2.

The operation of FIG. 1 will be described. As in the prior art, the probe manager 4 checks the packet information of interest extracted by the probe P1 connected to the router R port of the company (head office) 2 and the probe P1 connected to the router R port of the company (branch office) 3. The same packet information of interest extracted in step (1) is fetched and the two packet information are collated, and the packet loss between the company (head office) 2 and the company (branch office) 3 is determined.
Measures communication quality items such as delay time, delay fluctuation, and throughput.

The probe manager 4 detects the deterioration of the communication quality, takes in the information of the communication packet in which the deterioration has occurred from one of the probes P1, and transmits the information to each probe P2. Each probe P2 generates a test packet as described above based on this packet information and outputs it to the communication network ISP1.

That is, in each probe P2, since the test packet passes through the tap circuit 5, it is taken into the memory 8 together with the time stamp as in each probe P1. The data on these test packets taken into the memory 8 of each probe P2 is transmitted to the probe manager 4.

The probe manager 4 selects and verifies the information of the two probes P2 by sequentially switching the combinations of the routers R in the communication network ISP1,
The communication quality in each combination of the routers R is measured. For example, the delay time and the fluctuation of the delay time can be measured by comparing the reception time on the receiving side with the time stamp added to the packet data.

As described above, when the deterioration of the communication quality is detected, packet communication is performed between the probes P2 in the communication network ISP1 using the same test packet as the communication packet having the deteriorated communication quality. The communication quality between the routers R can be measured in almost real time, and the routers R that deteriorate the communication quality can be measured.
Can be accurately specified, and the cause analysis can be performed efficiently.

As a result, when the quality fluctuates for each service, the provider can accurately analyze and grasp the cause of each. In addition, the user can accurately grasp the quality of various services used on the Internet in real time, and obtain data for determining contract conditions with the provider.

It should be noted that the test packet is not necessarily limited to the packet based on the packet data when the quality is deteriorated. For example, the test packet may be arbitrarily created by the probe manager 4 for testing.

Also, a list of communication quality measurement results for each combination of routers R thus measured is displayed, and although the quality is worse than the quality limit set value, the display color of the measurement result is different from the others. By making it different, the defective part can be clearly indicated.

The measuring ports of the probes P1 and P2 may be of a through type for continuously passing packet data or a mirror port type using a mirror port for copying and transmitting packet data. Alternatively, any one of the two may be switchably set according to the situation.

In the through type, the line is temporarily cut off when connecting to the network, but after connection, all the packet data can be extracted while continuously passing the packet data without interruption, and the mirror port type However, when connecting to a network, there is a case where it is not necessary to physically disconnect the line, but all packet data flowing through the line may not completely flow through the mirror port. On the other hand, if the switching type is used, both advantages can be combined.

By the way, the communication path is changed according to the communication traffic situation in the communication network ISP1, but a large delay fluctuation occurs with the change of the path.
When detecting delay fluctuations in measuring communication quality,
The delay fluctuation is caused by communication network I such as router R
If it is possible to identify on the measurement result display screen whether it is caused by the inside of the apparatus constituting the SP1 or due to the above-mentioned route change, useless man-hours for finding the cause can be omitted.

FIG. 2 is a block diagram of a probe P to which such a path information analysis function is added, and portions common to FIG. 1 are denoted by the same reference numerals. In FIG. 2, a path information analysis circuit 12 is connected between the filter circuit 7 and the memory control circuit 9.

The operation of FIG. 2 will be described. For example, OSPF (O
In the case of using the pen short path first (routing protocol), routing packets are exchanged between nodes in the network, and each node performs route calculation using topology information and link matrix information obtained from the information. Therefore, the probe P in FIG. 2 also captures packet data for delay measurement and also captures a routing packet, and detects that a route change has occurred.

When the occurrence of a route change is detected, it is specified that a delay time has occurred due to the route change, such as “R1” or “R2” in FIG. As a result, it is possible to identify the delay time and the delay fluctuation in the normal operation state without the path change.

The probe for detecting a route change may be integrated with a probe for performing ordinary delay measurement, or may be individually and independently provided.

Further, the connection position of the probe for detecting the route change is not limited to the user part, but may be any port in the communication network ISP1.

FIG. 3 shows an example in which a route change is detected by a routing packet. However, the present invention can be applied to detection of other events by using a packet relating to a special event arbitrarily designated by a user (operator). Packets related to special events, such as those sent when a router fails or those sent when traffic exceeds the maximum set value, are used.When these packets are detected, they are specific to each event indicating that fact. Are displayed as "R1" and "R2" in FIG.

As described above, by displaying the predetermined event mark on the quality time change display screen, it is possible to identify whether the measurement result of the delay time or the delay fluctuation is related to a special event or in the normal operation state.

FIG. 4 shows a specific example of a probe for extracting packet data of full-duplex communication, in which a system having the same configuration is provided in each of the two directions. In FIG. 4, T _X (transmitting) side data processing system and R _X (receiving) side data processing system of the measured packet of the measured packet is connected in parallel with the same configuration in the tap circuit 14. Each data processing system includes a physical layer circuit 15, a sampling control circuit 1
6, a packet filter 17, a data filter 18, a memory controller 19, and a memory 20. The measurement data output from each memory controller 19 is sent to the probe manager 2 via the external communication circuit 21.
2 is transmitted. The operation of each unit is the same as that of each unit in FIG. 1 except that the sampling control circuit 16 samples packet data in a certain section, and a description thereof will be omitted.

[0053] According to the configuration of FIG. 4, but the T _X (transmitting) side to be measured packets and R _X (receiving) side to be measured packets can be simultaneously parallel processing, the circuit scale of the apparatus becomes large That is inevitable.

[0054] Therefore, in the circuit of Figure 5 is used in a time-division alternatively one data processing system in a full duplex communication of T _X (transmitting) side to be measured packets and R _X (receiving) side to be measured packet In this case, the circuit scale is reduced to approximately half to reduce the cost.

In FIG. 5, the tap circuit 14 has T
A switching circuit 24 for alternately selecting a packet to be measured on the _X (transmission) side and a packet to be measured on the R _X (reception) side is connected.
An output terminal of the switching circuit 24 is connected to a data processing system including a physical layer circuit 15, a sampling control circuit 16, filter circuits 17 and 18 including a packet filter and a data filter, a memory controller 19, and a memory 20. I have. Then, the measurement data output from the memory controller 19 is transmitted to the probe manager 22 via the external communication circuit 21.

In the configuration shown in FIG. 5, if the measurement is performed for one minute at intervals of, for example, 10 minutes, the following time relationship is obtained. Time (HH: MM) switching circuit sampling measurement time 00: 00:00: 05 R _X side 00: 01~00: 02 00: 05~00 : 10 T X side 00:06 to 00:07 00: 10-00 : 15 R _X side 00: 11~00: 12 00: 15~00 : 20 T X side 00: 16~00: 17 00: 20~00 : 25 R X side 00:21 to 00:22 00: 25 00:30 T _X side 00:26 to 00:27 - - - - - - - - - in other words, the sampling measurement of full duplex communication alternately.

Only the necessary packet information designated by the filter circuits 17 and 18 is selected from the sampled packet data, and is stored in the memory 20 via the memory controller 19 together with the time stamp. Then, the data stored in the memory 20 is transmitted to the probe manager 23 via the external communication circuit 21 and the communication quality is analyzed and displayed as described above.

FIG. 6 shows an example of a configuration for extracting packet data at multiple points based on the circuit of FIG. 5. Output terminals of tap circuits 25 to 27 disposed at multiple points are connected in parallel to a switching circuit 24. ing.

In the configuration shown in FIG. 6, if the measurement is performed for one minute at intervals of, for example, 10 minutes, the following time relationship is obtained. Time (HH: MM) switching circuit sampling measurement time 00:00 to 00:01 staff deg circuit 25R _X side 00:00 to 00:01 00:01 to 00:02 staff deg circuit 25T _X side 00:01 to 00:02 00 : 02-00: 03 Tuff circuit 26R _X side 00: 02-00: 03 00: 03-00: 04 Tuff circuit 26T _X side 00: 03-00: 04 ・ ・ ・ ・ ・ ・ 00: 08-00: 09 Tuff circuit 27R _X side 00: 08-00: 09 00: 09-00: 10 Tuff circuit 27TX _X side 00: 09-00: 10 00: 10-00: 11 Tuff circuit 25R _X side 00: 10-00: 11 00:11 to 00:12 staff deg circuit 25T _X side 00:11 to 00:12 00:12 to 00:13 staff deg circuit 26R _X side 00:12 to 00:13 00:13 to 00:14 staff deg circuit 26T _X side 00:13 to 00:14 ············· That is, as in FIG.

Although examples of full-duplex communication have been described with reference to FIGS. 5 and 6, the present invention is not limited to full-duplex communication but can be applied to half-duplex communication.

Although FIGS. 5 and 6 show examples of a through-type port using a tap circuit, a tap circuit becomes unnecessary in the case of a mirror-type port.

The switching circuit 24 may be connected after the physical layer circuit 15, and in that case, the switching circuit 24 may have both the switching function and the sampling function.

[0063]

As described above, according to the first aspect of the present invention,
According to the above, in a network quality evaluation device that extracts packet data from a plurality of locations in a communication network and evaluates the communication quality of the network based on the extracted data, when the deterioration of the communication quality is detected, the cause is immediately investigated. be able to. According to claim 2 of the present invention,
The cause of the deterioration of the communication quality can be determined in a state where the conditions that caused the deterioration are reproduced. According to the third aspect of the present invention, when the cause of deterioration of communication quality can be empirically and statistically estimated, it can be quickly investigated. According to the fourth aspect of the present invention, it is possible to determine the cause of the deterioration of the communication quality and measure the delay time characteristic. According to the fifth aspect of the present invention, the quality time data displayed on the quality time change display screen can be read by using an event such as a predetermined mark as a clue. It is easy to decipher the data as to whether the data is caused by the above. According to the sixth aspect of the present invention, it is easy to determine whether the data displayed on the quality time change display screen is due to the disorder of the normal delay time or the route change that occurs relatively infrequently. Can be identified.
According to claim 7 of the present invention, the circuit configuration of the entire device can be simplified, and the cost can be reduced. According to the eighth aspect of the present invention, the measurement can be performed without disturbing the data transmission system. According to the ninth aspect of the present invention, it is possible to connect to a network without physically disconnecting a line. According to the tenth aspect of the present invention, the measurement can be performed at an appropriate port according to the network situation. According to the eleventh aspect of the present invention, it is possible to easily identify the measurement result of the communication quality deterioration. As described above, the network quality evaluation device according to the present invention can grasp and analyze the communication quality in almost real time, which is extremely useful for both the provider of the network and the user of the network.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of an embodiment of the present invention.

FIG. 2 is a block diagram showing another example of the embodiment of the present invention.

FIG. 3 is a display example of a measurement result.

FIG. 4 is a block diagram showing another example of the embodiment of the present invention.

FIG. 5 is a block diagram showing another example of the embodiment of the present invention.

FIG. 6 is a block diagram showing another example of the embodiment of the present invention.

FIG. 7 is a block diagram illustrating an example of a conventional network quality evaluation device.

[Explanation of symbols]

 1 ISP 2 Company (Head Office) 3 Company (Branch) 4,22 Probe Manager P, P1, P2 Probe

Claims (11)

[Claims] 1. A network quality evaluation device that extracts packet data from a plurality of locations in a communication network and evaluates communication quality of the network based on the extracted data. A network quality evaluation device for transmitting test packet data for measurement. 2. The network quality evaluation device according to claim 1, wherein packet data equivalent to a case where deterioration of communication quality is detected is used as the test packet data. 3. The network quality evaluation device according to claim 1, wherein predetermined packet data suitable for specifying an estimated cause of deterioration is used as the test packet data. 4. The network quality evaluation device according to claim 1, wherein a time stamp is added to the test packet data. 5. A network quality evaluation device for extracting packet data from a plurality of locations in a communication network and displaying a change in network quality over time based on the extracted data, by detecting packet data specific to a predetermined event. A network quality evaluation device for displaying a predetermined event on a quality time change display screen. 6. The network quality evaluation device according to claim 5, wherein the predetermined event is a route change. 7. A network quality evaluation device that extracts packet data from a plurality of locations in a communication network and evaluates the communication quality of the network based on the extracted data. A network quality evaluation device characterized by being used for division. 8. The network quality evaluation device according to claim 1, wherein the measurement port is of a through type. 9. The network quality evaluation device according to claim 1, wherein the measurement port is a mirror type. 10. The network quality evaluation device according to claim 1, wherein the measurement port is switchable between a through type and a mirror type. 11. A network quality evaluation device that extracts packet data from a plurality of locations in a communication network and evaluates the communication quality of the network based on the extracted data. A network quality evaluation device characterized in that the display form of the measurement result is different from that of the others, although the quality is worse than that of other devices.