JP2000209205A - Instrument for measuring in-network delay time - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable verification of Qos in a network and to attain an efficient operation by measuring a time from the transmission to the reception of a test packet which is determined to be one which was transmitted by own device. SOLUTION: By application kinds of the test packet inputted to a packet setting input interface part 2 is input and a transmission destination address are set in the packet by a packet setting part 3, data indicating the test packet, an ID number and the transmission address are set and transmitted to a LAN transmission line and also a transmission time is added to the data and stored in a memory 11. When a packet receiving part 6 receives a packet, it is analyzed by a packet analyzing part 7, a packet check part 8 collates the ID number with the one in the memory part 11 when data are the one indicating the test packet, a reception time is stored in the memory 11 when there is matching and the packet is returned to the transmission destination from a transmitting part 4 if it watches. A CPU 10 calculates the time from the transmission to the reception in the memory 11 and outputs it as a delay time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a local area network (LA) for interconnecting a plurality of computers.
The present invention relates to an in-network delay time measuring device for measuring an in-network delay time for each packet attribute in a network such as N).

[0002]

2. Description of the Related Art In recent years, the introduction of personal computers in companies as well as individuals has been rapidly increasing. In a company, a personal computer is usually connected to a LAN, and communication with various parties inside and outside the company via a network is performed. As the number of personal computers connected to the network increases, the traffic naturally increases, and the lack of network bandwidth has become a problem. In addition, the current LAN does not guarantee the packet delay time, and is not suitable for applications that require immediacy (such as voice communication and TV conferences) because the delay is large.

As a means for solving this problem, a QoS (Quality of Service) for efficiently operating a network bandwidth by performing priority control for each application.
service) Assurance features have begun to be offered and RSV
Standardization of procedures such as P is being made.

[0004] In recent networks, in order to realize QoS guarantee, in addition to the RSVP system, it has become common to use a LAN network device that determines a packet processing priority for each application called a layer 4 switch. ing.

[0005]

In a conventional LAN network device or a traffic monitor device such as an RMON probe, there is no means for measuring the network delay time for each application type, so that the network is efficiently operated by the QoS guarantee function. Could not be verified, ie, whether the delay time was guaranteed. Also, in order to grasp the network situation more accurately, it is necessary to measure and judge the delay situation statistically, but this has not been possible.

An object of the present invention is to provide an apparatus for measuring a network delay time for each packet attribute such as an application type, particularly in a network where QoS is guaranteed, and furthermore, a correlation between the delay time and the traffic amount. It is an object of the present invention to provide a device for measuring at regular time intervals.

[0007]

In view of the above, an embodiment of the intra-network delay time measuring apparatus according to the present invention provides a test packet transmission for transmitting a test packet having a specific packet attribute set on the network. Means for receiving a test packet transmitted on the network, determining whether the test packet is transmitted by the own device or transmitted by another device, and determining that the test packet is transmitted by the other device. In this case, the test packet receiving means for returning to the transmission source apparatus, and the delay time measurement for measuring the time elapsed from the transmission of the test packet to the reception of the test packet determined by the test packet receiving means to have been transmitted by the own apparatus. Means. If you do this,
In a LAN in which QoS is realized for each application, it is possible to measure the delay time for each application, and it is possible to verify QoS in the network.

In another embodiment of the intra-network delay time measuring apparatus according to the present invention, the apparatus further comprises traffic measuring means for measuring a traffic amount of a packet other than the test packet at regular time intervals, and wherein the test packet transmitting means comprises the test packet transmitting means. The transmission packet is transmitted at regular intervals, and the correlation between the delay time and the traffic volume is measured at regular intervals. This makes it possible to associate the delay time measured periodically with the time and the traffic at the time of measurement.
And the correlation with the traffic volume can be grasped, and the effectiveness of QoS in the network can be verified in detail.

[0009] Still another embodiment of the network delay time measuring apparatus according to the present invention further comprises address resolution means for automatically specifying addresses of a plurality of other similar devices arranged in the network. The address resolution means specifies the address of each of these devices, and then measures the delay time for each of these devices individually. In this way, it is possible to easily measure the delay time between a plurality of devices, and it is possible to verify where in the network the bottleneck of the QoS implementation exists.

[0010] Still another embodiment of the in-network delay time measuring apparatus according to the present invention comprises a standard protocol for multicast, wherein the apparatus for transmitting the test packet is a multicast server and the apparatus which is a destination of the test packet. A multicast group is formed between the respective devices so that is used as a multicast host, and the test packet is transmitted by multicast. In this way, it is possible to reduce the amount of packets flowing in the network for measuring the delay time, to effectively use the network, and to compare the delay time of the multicast packet with the result of the unicast packet. Can be verified.

Still another embodiment of the intra-network delay time measuring apparatus according to the present invention further comprises a map creating means for detecting a network topology using network configuration information included in a routing packet and creating a network topology map. The measured delay time is displayed on the network topology map. In this way, by displaying the measured delay time on a network map,
It is possible to see at a glance where in the network the delay amount is large, the operability is improved, and it is also possible to estimate the delay amount of the unmeasured route by calculating the difference between the measured routes.

[0012]

FIG. 1 is a block diagram showing an embodiment of a network delay time measuring apparatus according to the present invention. The network delay time measuring apparatus 1 includes a packet setting input interface unit 2 and a packet setting unit 3
, A packet transmitting unit 4 and a LAN interface unit 5
, A packet receiving unit 6, a packet analyzing unit 7, a packet checking unit 8, an output interface unit 9, a CPU
10 and a memory 11.

FIG. 2 schematically shows an example of a network in which a plurality of intra-network delay time measuring devices 1 of FIG. 1 are connected. In this figure, traffic monitoring devices A, B,
C and D are the same as those in the network delay time measuring apparatus 1 of FIG. 1, and are connected to the Ethernet via the HUB, respectively. These HUBs may be built in each traffic monitor device. The traffic monitoring devices A, B, C and D are connected between LANs by a layer 4 switch. This layer 4 switch guarantees the QoS of the network. E
The Ethernet performs packet transfer using the TCP / IP protocol. In the TCP / IP protocol, TCP or UD depends on the application used.
P, either TCP or UDP
The port number used to identify the application is used in. FIG. 3 schematically shows TCP and UDP packet headers. In the present invention, for example, the TC
The delay time of the application type is measured using the port number of P or UDP.

FIG. 4 is a flowchart for explaining the operation of the in-network delay time measuring device 1 of FIG. 40
Operation starts at 1. In 402, the application type and the destination address of the test packet are input to the packet setting input interface unit 2 using, for example, a keyboard. In 403, the packet setting unit 3 sets the application type, the destination address, and the like input to the packet setting input interface unit 2 in the packet, and further includes data indicating that this packet is a test packet, the ID number, and the destination. And sends it to the packet transmitting unit 4. At this time, for example, a port number for specifying the application is set in TCP or UDP as the application type. FIG.
Shows an example of a test packet. At 404, the packet transmitting unit 4 converts the test packet received from the packet setting unit 3 into
L that controls the physical interface between the LAN transmission line and this device
The data is transmitted to the LAN transmission path via the AN interface unit 5. At this time, the ID number of the test packet, the application type, and the packet transmission time are stored in the memory 1.
1 is stored.

At 405, the packet receiving unit 6 receives the packet from the LAN transmission path via the LAN interface unit 5 and transmits the packet to the packet analyzing unit 7. At 406, the packet analysis unit 7 analyzes whether or not the received packet received from the packet reception unit 5 includes data indicating a test packet, and if so, this packet is a test packet. Is transmitted to the packet check unit 8. If not included, the process returns to 405.
At 407, the packet check unit 8 checks the ID number included in the received test packet received from the packet analysis unit with the ID number stored in the memory 11, and determines that the test packet is the test packet transmitted by the own device. It is determined whether or not there is, and if the test packet is transmitted by the own device,
The reception time of this test packet is stored in the memory 11, and
Go to 09. If it is not a test packet transmitted by its own device, that is, if it is a test packet transmitted by another device,
The test packet is sent to the packet transmitting unit 4 and the process proceeds to 408. At 408, the packet transmitting unit 4 returns this test packet to the transmission source device, and returns to the processing at 405. 40
At 9, the CPU 10 calculates the time elapsed from the transmission time of the test packet stored in the memory 11 to the reception time, and outputs the result as a delay time of the application type via the output interface unit 9, For example,
The information is displayed on a display or the like, and the operation ends at 410.

FIG. 6 is a block diagram showing another embodiment of the network delay time measuring apparatus according to the present invention.
This intra-network delay time measuring device 1 'is almost the same as the device shown in FIG. 1, and the same components are denoted by the same reference numerals. The difference from the apparatus shown in FIG. 1 is that a packet filter unit 12, a packet counting unit 13, and a timer 14 are further provided. This intra-network delay time measuring device 1 'is connected to the network as shown in FIG. 2, similarly to the device 1 in FIG.

FIG. 7 is a flowchart for explaining the operation of the in-network delay time measuring apparatus 1 'of FIG. 7
01 starts the operation. At 702, the application type and the destination address of the test packet are input as in the device 1 of FIG. 1, and the transmission interval of the test packet is input. In 703, the packet setting unit 3 transmits the packet to the device 1 in FIG.
A test packet is set in the same manner as described above and sent to the packet transmission unit 4, and the transmission interval is set in the timer 14. 7
At 04, the timer 14 instructs the packet setting unit 3 at each test packet transmission interval to transfer the test packet to the packet transmission unit. The packet transmission unit 4 is a device that
As in the case of (1), the test packet is transmitted to the LAN transmission line, and the ID number, application type, and packet transmission time of the test packet are stored in the memory 11. At 705, if no more test packets are to be transmitted, the process proceeds to 713, and if transmission of the test packets is continued, the process returns to 704. The number of test packets to be transmitted or the transmission time zone may be set in the timer 14 together with the test packet transmission interval.

At 706, the packet receiving section 6 receives the packet from the LAN transmission path via the LAN interface section 5 and transmits the packet to the packet analyzing section 7. In step 707, the packet analysis unit 7 analyzes whether or not the received packet received from the packet reception unit 5 includes data indicating a test packet. If the data is included, the packet is a test packet. Is transmitted to the packet check unit 8 and proceeds to 709. If not included, the process proceeds to 708. At 708, a received packet matching the filter conditions such as the application type set in the packet filter unit 12 is sent to the packet count unit 13. The packet counting unit 13 counts, for example, the number of packets received at each test packet transmission interval set in the timer 14, stores the counted number in the memory 11 as traffic statistical information for each fixed time, and returns to the processing of 706. When the processing proceeds to step 709, the packet check unit 8 determines whether or not the test packet has been transmitted by the own apparatus by checking the ID number similarly to the apparatus 1 of FIG. In this case, the reception time of the test packet is stored in the memory 11 and 711
Proceed to. If the test packet is not a test packet transmitted by the own device, that is, a test packet transmitted by another device, the test packet is transmitted to the packet transmitting unit 4 and the process proceeds to 710. At 710, the packet transmitting unit 4 returns the test packet to the transmission source device, and returns to the processing of 706. 711
If the processing has proceeded to, the CPU 10 calculates the time elapsed from the transmission time of the test packet stored in the memory 11 to the reception time. At 712, the CPU 10 calculates the correlation between the delay time and the traffic statistical information, for example, at each test packet transmission interval, that is, at every fixed time.
The data is output via the output interface unit 9 and displayed on, for example, a display. At 713, if the operation is continued, 7
It returns to the process of 06, and if it ends, it progresses to 714 and ends.

FIG. 8 is a block diagram showing still another embodiment of the network delay time measuring apparatus according to the present invention. This intra-network delay time measuring apparatus 1 ″ is substantially the same as the apparatus 1 shown in FIG. 1, and the same components are denoted by the same reference numerals. The difference from the apparatus of FIG. This is further provided with a unit 15. The in-network delay time measuring device 1 ″ is also the device 1 in FIG.
In the same manner as described above, it is connected to the network as shown in FIG.

In the network delay time measuring apparatus 1 ″, a plurality of other similar network delay time measuring apparatuses connected to the network are measured before performing the same network delay time measurement as the apparatus 1 of FIG. The operation for confirming the position, that is, the address, is performed.
It is a flowchart for explaining the position confirmation operation of the in-network delay time measuring apparatus 1 ″.

At 801 the operation starts. In step 802, a command for performing a position confirmation operation is input to the packet setting input interface unit 2 using, for example, a keyboard. In step 803, the packet setting unit 3 sets a position confirmation test packet. At this time, data indicating a test packet for position confirmation and an ID number are set.
At 804, the packet transmission unit 4 broadcasts the packet to the network and stores the ID number of the test packet in the memory 11. At 805,
The packet receiving unit 6 receives a packet from a LAN transmission path via the LAN interface unit 5 and transmits the packet to the packet analyzing unit 7. In step 806, the packet analysis unit 7 analyzes whether or not the received packet received from the packet reception unit 5 includes data indicating that the packet is a position confirmation test packet. The packet is transmitted to the packet check unit 8 as a test packet for confirmation. If not included, the process returns to 805. 4
06, the packet check unit 8 stores the ID number included in the received test packet received from the packet analysis unit in the memory 1
1 to determine whether or not this position confirmation test packet is a position confirmation test packet transmitted by its own device. If there is, the packet is sent to the address resolution unit 15 and the process proceeds to 809;
And go to 808. At 808, the packet transmission unit 4
Returns this test packet to the transmission source device, and returns
Return to the processing of. If the process proceeds to 809, the address resolution unit 1
5 extracts the address of the device that has returned this packet from the returned packet, and passes this address to the packet setting unit 3 as destination information of another device. If at 810 the addresses of all other devices to be verified have been determined,
If not, the process returns to step 805.
After ending the position confirmation operation at 811, the same network delay time measurement as that of the device 1 of FIG. 1 is performed for each of the other devices.

10 shows an example of a sequence of a delay time measurement performed by the in-network delay time measurement device 1 ″ of FIG. 8 on a plurality of other similar devices. In this figure, device A is another device. It is assumed that delay time measurement is performed for the devices B, C, and D. The device A broadcasts a monitor position confirmation test packet to all the other devices B, C, and D, and confirms the address of each device. Thereafter, the delay time measurement for each device is individually performed.

A modification of the apparatus shown in FIG. 8 will be described. FIG.
The difference from this device is that the packet setting unit 3 includes a standard protocol for multicast such as IGMP and sets a packet for notifying a multicast ID to other similar devices arranged in the network. The packet analysis unit 7 analyzes whether the received packet is a multicast ID notification packet, and the packet check unit 8 enables packet transmission for joining the notified multicast ID group, and multicasts the test packet. Is to send.

FIG. 11 shows an example of a sequence of delay time measurement performed by such a modification of the apparatus shown in FIG. 8 on a plurality of other similar apparatuses. In this figure, it is assumed that device A performs delay time measurement for other devices B, C and D. The device A checks the addresses of the other devices B, C, and D as in FIG. Thereafter, the packet setting unit 3 of the device A sets the multicast ID in the multicast ID notification packet, and sends the packet to the packet transmitting unit 4. The packet transmitting unit 4 transmits this packet to the LAN
Broadcast transmission to the transmission unit. In each of the devices B, C, and D, the packet received by the packet receiving unit 6 is transferred to the packet analyzing unit 7, and the packet is analyzed. If the received packet is a multicast ID notification packet, the packet is sent to the packet check unit 8. The packet check unit 8 sends a packet for joining the group of the notified multicast ID to the packet transmission unit 4, and transmits the packet to a router of the local network. After forming the multicast group in this way, the device A multicast-transmits a test packet to another device.

FIG. 12 is a block diagram showing still another embodiment of the intra-network delay time measuring apparatus according to the present invention. This network delay time measuring device 1 '"
Is substantially similar to the device shown in FIG. 8, and similar components are indicated by the same reference numerals. The difference from the apparatus of FIG. 8 is that a map creation unit 16 that creates a network topology database from network configuration information and creates a network map based on this data is further provided.

13 is a flowchart for explaining the operation of the intra-network delay time measuring apparatus 1 '"shown in FIG. 12. The operation is started at 1301. At 1302, the packet receiving section 5 passes through the LAN interface section 4. LAN
The packet analyzer 6 captures packets flowing through the transmission path, and
Send to At 1303, the packet analysis unit 6 analyzes the received packet, checks whether network configuration information such as RIP is included, and determines that the packet is a routing packet if the network configuration information is included, This packet is sent to the map creation unit 16 and
Proceeding to 304, if the network configuration information is not included, the process returns to 1302. In 1304, the map creating unit 16 creates a topology database from the network configuration information included in the routing packet, and creates a network topology map based on the data. FIG. 14 schematically shows an example of such a network topology map. In 1305, if such a network topology map is completed, the process proceeds to 1307; otherwise, the process returns to 1302. In parallel with these operations of 1302 to 1305, 1306
Then, the delay time measurement is performed on each of the other devices similar to the in-network delay time measurement device 1 ″ in FIG.
In step 1307, the map creation unit 16 indicates the delay time of each device measured on the created network topology map by a numerical value, a color, or the like.
Output to FIG. 15 schematically shows an example of such a network topology map in which the measured delay times of the respective devices are indicated by numerical values. The operation ends at 1308.

[0027]

According to the first aspect of the present invention, it is possible to measure the delay time of each application in a LAN in which QoS is realized for each application, and it is possible to verify the QoS in the network. Becomes
According to the second aspect of the present invention, it is possible to associate the delay time measured periodically with the time and the traffic at the time of measurement. It is possible to grasp and to verify the effectiveness of QoS in the network in detail. According to the third aspect of the present invention, it is possible to easily measure the delay time between a plurality of devices, and to verify where in the network the bottleneck of the QoS implementation exists. According to the fourth aspect of the present invention, the amount of packets flowing in the network for measuring the delay time can be reduced, the network can be effectively used, and the delay time of the multicast packet can be reduced when the unicast packet is used. It can be verified by comparing with the result. According to the fifth aspect of the present invention, by displaying the measured delay time on the network map, it is possible to see at a glance where the delay amount is large in the network, thereby improving operability and improving the measurement route. By calculating the difference between them, the delay amount of the unmeasured route can be estimated. The same effect can be obtained by using the present invention together with another communication protocol such as IPX or Apple Talk.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an apparatus for measuring delay time in a network according to the present invention.

FIG. 2 is a diagram showing an example of a network in which a plurality of the devices shown in FIG. 1 are connected.

FIG. 3 is a diagram showing TCP and UDP packet headers.

4 is a flowchart illustrating an operation of the intra-network delay time measuring device of FIG. 1;

FIG. 5 is a diagram showing an example of a test packet.

FIG. 6 is a block diagram showing another embodiment of the network delay time measuring apparatus according to the present invention.

FIG. 7 is a flowchart for explaining the operation of the intra-network delay time measuring apparatus of FIG. 6;

FIG. 8 is a block diagram showing still another embodiment of the in-network delay time measuring apparatus according to the present invention.

FIG. 9 is a flowchart illustrating the operation of the intra-network delay time measuring device of FIG. 8;

FIG. 10 is a diagram showing an example of a sequence of delay time measurement performed by the delay time measuring device in the network of FIG. 8 on other similar devices.

FIG. 11 is a diagram showing an example of a sequence of delay time measurement performed by a modification of the device of FIG. 8 on other similar devices.

FIG. 12 is a block diagram showing still another embodiment of the in-network delay time measuring apparatus according to the present invention.

FIG. 13 is a flowchart illustrating an operation of the delay time measuring apparatus in a network of FIG. 12;

FIG. 14 is a diagram showing an example of a network topology map.

FIG. 15 is a diagram illustrating an example of a network topology map in which measured delay times of respective devices are indicated by numerical values.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 In-network delay time measuring device 2 Packet setting input interface unit 3 Packet setting unit 4 Packet transmitting unit 5 LAN interface unit 6 Packet receiving unit 7 Packet analyzing unit 8 Packet checking unit 9 Output interface unit 10 CPU 11 Memory 12 Packet filter unit 13 Packet counting unit 14 Timer 15 Address resolution unit 16 Map creation unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B045 AA03 BB02 BB50 5B089 GA01 GA11 GB02 HA06 JA40 JB11 JB19 KA13 KB06 KB11 KC30 LB14 MC06 MC12 MC16 5K030 HA08 KX28 MB06 MB09 MC02 MC03

Claims (5)

[Claims] 1. An in-network delay time measuring device for measuring an in-network delay time for each packet attribute such as an application type in a network interconnecting a plurality of computers, the test device having a specific packet attribute set on the network. Test packet transmitting means for transmitting a packet; receiving a test packet transmitted on the network; determining whether the test packet is transmitted by the own device or transmitted by another device; If it is determined that the test packet has been transmitted, the test packet receiving means for returning to the transmission source device and the test packet receiving means has passed from transmission to reception of the test packet determined to have been transmitted by the own device. And delay time measuring means for measuring time. Time measuring device. 2. The network delay time measuring apparatus according to claim 1, wherein said test packet is transmitted to said test packet transmitting means by a traffic measuring means for measuring a traffic volume of a packet other than said test packet at predetermined time intervals. And a timer means for transmitting at regular time intervals, and measuring the correlation between the delay time and the traffic amount at regular time intervals. 3. The in-network delay time measuring apparatus according to claim 1, further comprising address resolution means for automatically specifying addresses of a plurality of other similar devices arranged in the network, wherein said address is provided. A delay time measuring device in a network, characterized in that, after the address of each of these devices is specified, the delay time of each of these devices is individually measured. 4. The network delay time measuring apparatus according to claim 3, further comprising a standard protocol for multicast, wherein said apparatus for transmitting said test packet is a multicast server and said apparatus which is a destination of said test packet is An in-network delay time measuring device, wherein a multicast group is formed between each of the devices so as to serve as a multicast host, and the test packet is transmitted by multicast. 5. The network delay time measuring device according to claim 3, further comprising a map creation means for detecting a network topology using network configuration information included in the routing packet and creating a network topology map. Wherein the measured delay time is displayed on the network topology map.