JP2014192584A - Setting device, terminal device, setting program, measuring system, and measuring method - Google Patents

Abstract

Kind Code: A1 A setting device or the like that can improve the efficiency of measurement related to a link in a network is provided.
A setting device (server device 1 as an example) calculates a route of a test packet corresponding to all links of a plurality of nodes (switches 12-1 to 12-N as an example) in an SDN and A route group acquisition unit (for example, a measurement route calculation unit 21) that acquires a group of routes, and a route that executes processing for setting the group of routes acquired by the route group acquisition unit to the plurality of nodes A setting unit (as an example, a communication path setting unit 22).
[Selection] Figure 1

Description

  The present invention relates to a setting device, a terminal device, a setting program, a measurement system, and a measurement method.

In recent years, an architecture called SDN (Software Defined Network) for centrally controlling network devices with software has been researched and developed (for example, see Non-Patent Document 1). In OpenFlow (see, for example, Non-Patent Document 2) that is a representative technique for realizing SDN, a MAC (Media Access Control) address, an IP (Internet Protocol) address, a port number, and the like are defined in combination. A communication path is set in units of “flow”, and therefore, a merit that flexible traffic control can be realized with respect to network configuration change, host addition, and the like is expected (for example, see Non-Patent Document 2). .
Here, OpenFlow (open flow) is a network control technology proposed by the OpenFlow switching consortium, and can be used as an example of SDN.

  However, the SDN management method has not been sufficiently studied. For example, in the OpenFlow switch, a method of remotely monitoring statistical information (MIB: Management Information Base) held by the network device itself can be used as in the case of a conventional network device. In order to increase the processing load on the switch, it is difficult to constantly monitor the communication quality. Another problem is that some quality metrics such as packet delay and available bandwidth are not defined in the MIB.

  On the other hand, in the conventional network, instead of directly monitoring the MIB, the measurement terminal transmits a test packet (for example, a set thereof) devised so that the switches at both ends of the link send back response packets, and is observed. Research and development of active measurement technology that estimates the communication quality (loss rate, average value of delay, etc.) of links on the communication path based on the number of response packets and the difference in reception time (for example, non-patent literature) 3 and 4).

An example of an active measurement technique is shown with reference to FIGS.
FIG. 8 is a diagram illustrating an example of an active measurement technique that performs link quality measurement.
The measurement terminal device 1001 transmits a plurality of (three in the example of FIG. 8) test packets 1021 to 1023 that are set to be returned by the routers 1011 to 1013. As this setting, the TTL (Time To Live) value of each test packet 1021 to 1023 is set to the number of hops. In the example of FIG. 8, test packets 1021 to 1023 are arranged in order from the smallest TTL value to the largest TTL value.
A response packet 1031 is transmitted (returned) from the router 1011 to the test packet 1021 having a TTL value of 1, a response packet 1032 is transmitted (returned) from the router 1012 to the test packet 1022 having a TTL value of 2, and A response packet 1033 is transmitted (returned) from the router 1013 to the test packet 1023 having a TTL value of 3. In the example of FIG. 8, response packets 1031 to 1033 of ICMP (Internet Control Message Protocol) are used. Response packets are lost in order from the transmitted test packet.
For these, the measurement terminal device 1001 measures the communication quality (loss rate, average value of delay, etc.) of each link between routers from the difference between the packet arrival rate and the packet round-trip delay.

FIG. 9 is a diagram illustrating an example of an active measurement technique for performing bottleneck estimation.
The measurement terminal device 1101 transmits these packets together by transmitting a packet train 1121 including the test packet and the load packet. In the example of FIG. 9, the packet train 1121 reverses a plurality of (three in the example of FIG. 9) test packets, the load packet 1131, and the plurality of test packets set so as to be folded back by the routers 1111 to 1113. It is made up of what was ordered in this order. Each test packet is set to be returned by each router 1111 to 1113. As this setting, the TTL value of each test packet is set to the number of hops. In the example of FIG. 9, in the packet train 1121, test packets are arranged in order from the smallest TTL value to the largest in the packet train 1121, and from the largest TTL value to the smallest in the tail (end). Test packets are arranged in order.
Response packets 1141 and 1142 are transmitted (returned) from the router 1111 to the first and last test packets having a TTL value of 1, and the first and last test packets having a TTL value of 2 are totaled. Response packets 1151 and 1152 are transmitted (returned) from the router 1112, and response packets 1161 and 1162 are transmitted (returned) from the router 1113 to the first and last two test packets having a TTL value of 3. Is done. In the example of FIG. 9, ICMP response packets 1141 to 1142, 1151 to 1152, and 1161 to 1162 are used. Response packets are lost in order from the transmitted test packet.
For these, the measurement terminal device 1101 identifies the bottleneck link from the observed response packet interval. In this case, a link with a small available bandwidth for a set of two response packets from each router 1111 to 1113 (a set of response packets 1141 to 1142, a set of response packets 1151 to 1152, and a set of response packets 1161 to 1162). Now, take advantage of the increased packet interval.

“Open Networking Foundation”, [online], [March 12, 2013 search], Internet <URL: http: // www. openflow. org /> "Openflow technology latest trend 2013 to realize next generation network", Impress R & D Internet Media Research Institute [Online], Internet <URL: http: // www. Microsoft. com / resources / documentation / windows / xp / all / productions / en-us / pathping. mspx? mfr = true> Ninging Hu, Li Erran Li, Zhuoqing Morley Mao, Peter Steenstein, Jia Wang, “Locating Internet Bottlenex: Algorithms, Measurements, and Implications.” of SIGCOMM 2004.

  In the active measurement technology in the conventional network, it is assumed that the test packet passes through a predetermined communication path (in many cases, the shortest path between the measurement terminal device and the router). In order to monitor the link, there is a problem that it is necessary to install a plurality of measurement terminal devices.

FIG. 10 is a diagram illustrating an example of an active measurement technique that performs link quality measurement in the network 1511.
Link quality measurement is performed for a plurality of routers v _{1 to} v ₅ provided in the network 1511 by the two measurement terminal devices 1501-1 to 1501-2. In this case, the first measurement terminal links that can not be measured from 1501 - for (a link between the router _{v 2} and the router _{v 5,} the link between the router _{v 3} and the router _{v 4)} includes a first It is necessary to measure from the second measurement terminal device 1501-2.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a setting device, a terminal device, a setting program, a measurement system, and a measurement method that can improve the efficiency of measurement related to a link in a network. To do.

(1) In order to solve the above-described problem, the setting device according to the present invention calculates a route group of a test packet corresponding to all links of a plurality of nodes in the SDN and acquires a group of the route. And a route setting unit that executes processing for setting the group of routes acquired by the route group acquisition unit to the plurality of nodes.
(2) In the setting device according to (1) described above, the route setting unit sets the group of routes in the controller of the SDN.

(3) In order to solve the above-described problem, the terminal device according to the present invention includes a storage unit that stores information on a group of test packet paths corresponding to all links of a plurality of nodes in the SDN, and the storage unit And a measurement execution unit that transmits a test packet and executes measurement based on the information stored in the storage.
(4) According to the present invention, in the terminal device according to (3) described above, the measurement execution unit transmits a test packet and deletes the redundant test packet, and then performs measurement.
(5) The present invention provides the terminal device according to (3) or (4) described above, wherein the measurement execution unit executes measurement relating to communication quality of the link, or a load packet together with the test packet. To measure the bottleneck of the link.

(6) In order to solve the above-described problem, in the setting program according to the present invention, the route group acquisition unit calculates the route of the test packet corresponding to all the links of the plurality of nodes in the SDN, and the group of the route. A program for causing a computer to execute a step of acquiring a path and a step of executing a process for setting the group of paths acquired by the path group acquiring unit to the plurality of nodes. is there.
(7) In order to solve the above problem, the measurement system according to the present invention calculates a route of a test packet corresponding to all links of a plurality of nodes in the SDN, and obtains a group of the routes. A route setting unit that executes processing for setting the group of routes acquired by the route group acquisition unit to the plurality of nodes, and the group of routes acquired by the route group acquisition unit. A measurement execution unit that transmits the test packet and performs measurement.
(8) In order to solve the above problem, in the measurement method according to the present invention, the route group acquisition unit calculates the route of the test packet corresponding to all the links of the plurality of nodes in the SDN, and the group of the route. The route setting unit executes a process for setting the group of routes acquired by the route group acquiring unit to the plurality of nodes, and the measurement executing unit is acquired by the route group acquiring unit. Based on the group of routes, a test packet is transmitted to perform measurement.

  According to the present invention, it is possible to improve the efficiency of measurement related to links in a network.

1 is a block diagram showing a schematic configuration of a network system according to an embodiment of the present invention. It is a figure for demonstrating the example of calculation of the communication path | route of the test packet which concerns on one Embodiment of this invention. It is a figure for demonstrating the example of calculation of the communication path | route of the test packet which concerns on one Embodiment of this invention. It is a figure for demonstrating the example of the deletion of the redundant test packet which concerns on one Embodiment of this invention. It is a figure for demonstrating an example of the procedure of the process (grouping process) which deletes the redundant test packet which concerns on one Embodiment of this invention. It is a figure for demonstrating transmission of the test packet in the case of performing the bottleneck estimation which concerns on one Embodiment of this invention. It is a figure which shows the example of the active measurement technique which performs link quality measurement in the network which concerns on one Embodiment of this invention. It is a figure which shows the example of the active measurement technique which performs link quality measurement. It is a figure which shows the example of the active measurement technique which performs bottleneck estimation. It is a figure which shows the example of the active measurement technique which performs the link quality measurement in a network.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<Configuration of network system according to this embodiment>
FIG. 1 is a block diagram showing a schematic configuration of a network system according to an embodiment of the present invention.
The network system according to the present embodiment includes a measurement system 61 according to an embodiment of the present invention, and a network 62 of SDN (OpenFlow as an example).

The measurement system 61 includes a server device 1 and a terminal device (measurement terminal device) 2.
The server device 1 includes a measurement path calculation unit 21, a communication path setting unit 22, and a storage unit 23.
The terminal device 2 includes a measurement execution unit 31 and a storage unit 32.
The network 62 includes an SDN controller 11, a plurality (N in the example of FIG. 1) of SDN switches (corresponding to routers) 12-1 to 12-N, and a plurality of hosts 13-1 to 13-. 2, 14-1 to 14-2.

The switches 12-1 to 12-N correspond to nodes (network nodes), and the controller 11 performs settings for the nodes (here, the switches 12-1 to 12-N).
A connection between nodes is called a link.

Here, the controller 11 and the switches 12-1 to 12-N are connected, and the switches 12-1 to 12-N and the hosts 13-1 to 13-2 and 14-1 to 14-14 under the switches 12-1 to 12-N are connected. -2 is connected.
Further, the server device 1 and the controller 11 are connected, the server device 1 and the terminal device 2 are connected, and the terminal device 2 and a switch (switch 12-1 in the example of FIG. 1) are connected. ing.
In the network system according to the present embodiment, various configurations may be used for the number of devices (devices), the location of the devices (devices), the connection of a plurality of devices (devices), and the like. Good.

In the server device 1, the measurement path calculation unit 21 calculates a communication path of the test packet and acquires a group of communication paths of the test packet. The communication path setting unit 22 communicates with the controller 11 and sets the calculated communication path of the test packet in the controller 11. The communication path setting unit 22 communicates with the terminal device 2 and sets the calculated communication path of the test packet in the terminal device 2. The storage unit 23 stores various types of information.
In the terminal device 2, the measurement execution unit 31 transmits and receives a test packet, and executes measurement processing such as estimating communication quality of each link from observation data.
Here, in this embodiment, topology information indicating the connection relationship between physical network devices (in this embodiment, switches 12-1 to 12-N), and management information of each switch 12-1 to 12-N. It is assumed that (for example, the MAC address) is known, and for example, these pieces of information are stored in the storage unit 23 of the server device 1.

The server device 1 and the terminal device 2 are each configured using a computer or the like. The function of the server device 1 and the function of the terminal device 2 may be integrated, for example.
The controller 11 and each of the hosts 13-1 to 13-2, 14-1 to 14-2 are each configured using a computer or the like.
The controller 11 and the switches 12-1 to 12-N are connected by a protocol (communication protocol) of SDN (OpenFlow as an example).
The plurality of switches 12-1 to 12-N are connected by SDN.
Data communication (in this embodiment, packet transfer) is performed between each of the switches 12-1 to 12-N and each of the hosts 13-1 to 13-2 and 14-1 to 14-2.
In addition, the network 62 may be arbitrary, for example, a general-purpose network such as the Internet may be used, or a closed network such as a corporate network may be used.

<Calculation of test packet communication path (measurement path)>
The measurement path calculation unit 21 of the server device 1 performs a test packet communication path (measurement path) for all links {e ₁ , e ₂ ,..., E _M } existing in the SDN to be monitored. ). A set of all links {e ₁ , e ₂ ,..., E _M } is defined as E. In the present embodiment, it is assumed that the number of links between the switches 12-1 to 12-N is M (M is an integer of 2 or more, for example).
Further, all the switches 12-1 to 12-N existing in the SDN to be monitored are represented by a set of {V ₁ , V ₂ ,..., V _N }. That is, in the description here, the switch 12-i corresponds to the switch V _i (i = 1, 2,..., N).
The measurement path calculation unit 21 of the server device 1 calculates the communication path for the test packet by the following (procedure 1-1) to (procedure 1-3).

(Procedure 1-1)
The shortest path (in this embodiment, a switch that passes through) starting from the terminal device 2 that executes the measurement to all the switches 12-1 to 12 -N (V _{1 to} V _N ) existing in the SDN to be monitored ), And R is a set of the shortest distances {r ₁ , r ₂ ,..., R _N }.
Here, in the calculation of the shortest path, as an example, a Dijkstra algorithm that can efficiently obtain the shortest path from the starting node to another node is used. In the Dijkstra algorithm, it is possible to calculate the shortest path based on the cost value of each link set based on the number of hops or the physical bandwidth. In this regard, in the present embodiment, there is no limitation on the index serving as a reference for the shortest path such as the number of hops and the cost value. However, the shortest path from the terminal device 2 that executes the measurement to each of the switches 12-1 to 12-N is always determined to be one. For this reason, for example, when there are a plurality of shortest paths by an equal cost multipath (ECMP), one communication path is selected as the shortest path.
A method other than the Dijkstra algorithm may be used.

FIG. 2 is a diagram for explaining an example of calculating a communication path of a test packet according to an embodiment of the present invention.
FIG. 2 shows an example of the terminal device 2 and a plurality of switches V _i and their shortest distances r _{i in} the network 62. In the example of FIG. 2, the case of N = 6 is shown.

(Procedure 1-2)
The shortest path r _i (i = 1, 2,..., N) calculated by the above (procedure 1-1) is used as the destination switch V _i and the switch V _j (j = 1) one hop ahead. 2,..., N and j ≠ i) is recorded (stored) as a communication path for measuring the link e _k (k is a value between 1 and M).
Here, the set of links e _k which communication path test packet is determined to F (⊆E).

(Procedure 1-3)
A set G (= E \ F) of links not included in the set F is extracted from the set E. Here, the set G is a set of links for which the communication path of the test packet has not yet been determined in the above (procedure 1-2).
For each link e _L (L is a value of 1 or more and M or less) (e _L εG) included in the set G, the switches V _p and V _q at both ends of the link e _L (p and q are each 1 or more and N Of the following values), the target link e _L and the other switch V _q at the end of the shortest path (in this example, r _p corresponding to V _p ) to one switch The added communication path r ′ _q is created, and this is used as the test packet communication path (additional test packet communication path) for the link e _L. A set of communication paths calculated here is R ′.

FIG. 3 is a diagram for explaining an example of calculation of a communication path of a test packet according to an embodiment of the present invention.
FIG. 3 shows an example of the terminal device 2, the plurality of switches V _i in the network 62, the plurality of links _ek, and the communication path r ′ _q of the additional test packet. In the example of FIG. 3, the case of N = 6 is shown. Further, the example of FIG. 3 shows a case where q = 2, 4, and 5 as the communication path r ′ _q of the additional test packet.
As a specific example, for the link e ₅ that is not measured, the communication path r ′ ₂ is calculated by adding the target link e ₅ and the remaining switch V ₂ to the shortest distance r ₆ to the switch V ₆ at one end.

<Setting the test packet communication path (measurement path)>
The communication path setting unit 22 of the server apparatus 1 sets the set R (the communication path shown in FIG. 2 in the present embodiment) and the set R ′ determined by the above (procedure 1-1) to (procedure 1-3). (In this embodiment, the additional communication path shown in FIG. 3) is set in the controller 11 (for example, its storage unit) as a test packet communication path together with the return path. Further, the communication path setting unit 22 of the server device 1 sets the same test packet communication path (bidirectional communication path) in the terminal device 2 (for example, the storage unit 32).
Here, the return path communication path is a communication path in the reverse direction of the communication path (outbound communication path) determined by the above (procedure 1-1) to (procedure 1-3). In this embodiment, communication paths in both directions are set in this way.

In the present embodiment, the following (setting i) and (setting ii) are performed as the setting of the communication path of the test packet.
In (Setting i), settings are made so that each of the switches 12-1 to 12-N identifies the test packet, based on a combination of the packet destination MAC address, communication port number, and the like.
In (Setting ii), after performing packet processing (such as rewriting of packet header) designated by each switch 12-1 to 12-N, a test packet is output to an output port (network interface) along the communication path. Set to
Here, for such (setting i) and (setting ii), it is conceivable to use various combinations of parameters. For example, the following (procedure 2-1) to (procedure 2-3) are used. Can be applied (used).

(Procedure 2-1)
A specific value is used for the destination port number of the test packet to identify the test packet (setting i).

(Procedure 2-2)
The MAC address of the destination switch 12-1 to 12-N (destination interface) is used as the destination MAC address of the test packet, and each of the switches 12-1 to 12-N is provided for each destination MAC address. Then, an output port along the communication path is set (1/2 of setting ii).

(Procedure 2-3)
In each of the switches 12-1 to 12-N, the destination MAC address is input by itself (each of the switches 12-1 to 12-N) so that the test packet is folded by the destination switches 12-1 to 12-N. When a test packet that is the same as the MAC address of the port is received, the MAC address of the destination of the test packet is rewritten to the MAC address of the terminal device (measurement terminal device) 2 and the MAC address of the transmission source is self (the relevant After rewriting to the MAC address of the input port of each switch 12-1 to 12-N), the test packet is set to be output (returned) to the input port (2/2 of setting ii).

<Preparation and transmission of test packet>
If a set of test packets is individually transmitted to a plurality of links sharing a communication path, measurement may become inefficient due to transmission of redundant test packets. For example, when measuring two consecutive links (two links in a configuration in which three switches are cascaded), if a set of test packets is transmitted to each of the two links, a total of 4 Although it is necessary to transmit the test packets, when the communication path from the terminal device (measurement terminal device) 2 to the link to be measured is common, by measuring these two links together, a total of 3 The link quality can be measured with a single packet.
In addition, in the method for measuring the available bandwidth described in Non-Patent Document 3, a load packet that gives a traffic load is transmitted in addition to the test packet (for example, see the example in FIG. 9), but the same as above. The number of load packets can be suppressed by using a common load packet for a plurality of links existing on the communication path.

FIG. 4 is a diagram for explaining an example of deleting redundant test packets according to an embodiment of the present invention.
4 shows, the terminal device 2, a plurality of switches V _i in the network 62 _is shown an example of a plurality of links e _k. In the example of FIG. 4, the case of N = 6 is shown.
As a specific example, in order to measure the link e ₁ between the switch V ₁ and the switch V ₂ , a set of a test packet 201 destined for the switch V ₁ and a test packet 202 destined for the switch V ₂ Is used. In order to measure the link e ₂ between the switch V ₂ and the switch V ₃ , a set of a test packet 211 destined for the switch V ₂ and a test packet 212 destined for the switch V ₃ is used. In this case, since the test packets 202 and 211 destined for the switch V ₂ are duplicated, redundant communication can be omitted by setting these two duplicate test packets 202 and 211 to only one test packet. Can do.

Referring to FIG. 5, as an example of a procedure for deleting a redundant test packet by the measurement execution unit 31 of the terminal device 2 when there is no load packet, (Procedure 3A-1) to (Procedure 3A-5) Indicates.
FIG. 5 is a diagram for explaining an example of a procedure of processing (grouping processing) for deleting redundant test packets according to an embodiment of the present invention.
In this example, test packets are grouped to create a test packet for measuring link communication quality.

(Procedure 3A-1)
The table 301 in FIG. 5A shows correspondences between the links e _{1 to} e ₈ to be measured, destination switches V _{1 to} V _{6 at} one end and the other end, and communication paths.
First, the communication paths (set R, set R ′) of test packets (sets) for the links e _{1 to} e ₈ are rearranged in ascending order of the number of hops.

(Procedure 3A-2)
In the table 302 of FIG. 5 (2), the links e _{1 to} e ₈ to be measured, the destination switches V _{1 to} V _{6 at} one end and the other end, the communication, Correspondence with a route is shown. In the example of FIG. 5, the case where the hop numbers are arranged in ascending order at the stage of the table 301 in FIG.
Next, in order from the test packet with the smallest number of hops, the communication path of the test packet is compared with the communication path of other test packets to check whether the communication path is included, and the communication path is included. Search for links.

(Procedure 3A-3)
In the table 303 in FIG. 5 (3), the links e _{1 to} e ₈ to be measured, the destination switches V _{1 to} V _{6 at} one end and the other end, the communication, Correspondence with a route is shown. A part of the search result of the link including the communication path is also shown. This is an example in the middle of searching for a link including a communication path.

(Procedure 3A-4: Continuation of 3A-3)
In the table 304 in FIG. 5 (4), the links e _{1 to} e ₈ to be measured, the destination switches V _{1 to} V _{6 at} one end and the other end, the communication, Correspondence with a route is shown. In addition, the result of repeated searches for the link including the communication path is shown.
A plurality of communication paths having a relationship including communication paths are classified into the same group. In this case, when communication paths are included in a plurality of test packets, a set of one test packet is selected and grouped. That is, each test packet (its set) is always classified into one group.

(Procedure 3A-5)
The table 305 in FIG. 5 (5) shows the correspondence between the measurement target links e _{1 to} e ₈ and the test packets (destination switches V _{1 to} V ₆ ) as a result of grouping.
Note that (Procedure 3A-2) to (Procedure 3A-4) described above are confirmed for all test packets (its set).
Then, redundant test packets are deleted. Specifically, after grouping is completed, the destination MAC address of each test packet is compared within the same group, and if there are multiple test packets with duplicate destination MAC addresses, the duplicate test Delete the packet.

(Procedure 3A-6)
The table 306 in FIG. 5 (6) shows the correspondence between the measurement target links e _{1 to} e ₈ and the test packets (destination switches V _{1 to} V ₆ ) as a result of grouping and deletion of redundant test packets. The attachment is shown.

The measurement execution unit 31 of the terminal device 2 transmits a set of test packets (for example, a plurality of consecutive test packet clusters) for each group, and performs measurement.
Here, when measuring the communication quality of the link, for example, it is composed of a plurality of test packet clusters arranged in ascending order of the number of hops from the terminal device 2 (for example, a plurality of test packets as shown in FIG. 8). Packet train).
As another configuration example, a configuration in which a plurality of test packet chunks arranged in descending order of the number of hops from the terminal device 2 may be used. Usually, a configuration in which the number of hops is arranged in ascending order. This is preferable because the test packet disappears from the tip and is not affected by other test packets.

Next, a case where bottleneck estimation is performed will be described.
When estimating a bottleneck, it is necessary to create a test packet and a load packet in consideration of the directionality of each link. For this reason, a round-trip route (bidirectional communication route) is set as the communication route of each test packet.
The measurement execution unit 31 of the terminal device 2 performs the same processing as the above (procedure 3A-1) to (procedure 3A-6) as an example of a procedure for creating a load packet when performing bottleneck estimation. (Procedure 3B-1) is further performed.

(Procedure 3B-1)
When performing bottleneck estimation, the MAC address of the same destination as the test packet having the communication path with the maximum number of hops is set as the destination of the load packet in each group obtained as a result of the grouping described above. Set to MAC address.
The measurement execution unit 31 of the terminal device 2 transmits a set of test packets (for example, a plurality of continuous test packets or a lump of load packets) for each group, and executes measurement. For example, a plurality of test packets are rearranged in the order in which the first and last test packets are returned each time the packet train passes through the measurement target link, and transmitted together with the load packet (group).

FIG. 6 is a diagram for explaining the transmission of a test packet when performing bottleneck estimation according to an embodiment of the present invention.
The terminal device 2 transmits these packets together by transmitting a packet train 501 including a test packet (shown as IF in the example of FIG. 6) and the load packet 511. In the example of FIG. 6, the packet train 501 includes a plurality of (seven in the example of FIG. 6) tests set so as to be folded back in each switch 601 to 604 (in this case, both directions except for the switch 604 having the longest distance). A packet, a load packet 511, and a plurality of test packets in the reverse order. Each test packet is set so as to be folded at each switch 601 to 604 (here, both directions except for the switch 604 having the longest distance). As this setting, the TTL value of each test packet is set to the number of hops. In the example of FIG. 6, in the packet train 501, the test packets are arranged in order from the smallest TTL value to the largest in the packet train 501, and the test packets are arranged in the order from the largest TTL value to the smallest in the tail. Are lined up.
Response packets 701 and 702 are transmitted (returned) from the switch 601 to a total of two test packets at the beginning and end with a TTL value of 1, and a total of two test packets at the beginning and end with a TTL value of 2. Response packets 711 and 712 are transmitted (returned) from the switch 602, and response packets 721 and 722 are transmitted (returned) from the switch 603 to the first and last two test packets having a TTL value of 3. Is done. Similarly, there are those with TTL values of 4 and 5 (not shown in FIG. 6), and the switch 602 responds to a total of two test packets at the beginning and end of the TTL value of 6. Packets 731 and 732 are transmitted (returned), and response packets 741 and 742 are transmitted (returned) from the switch 601 to the first and last two test packets having a TTL value of 7. In the example of FIG. 6, ICMP response packets 701 to 702, 711 to 712, 721 to 722, 731 to 732, and 741 to 742 are used. Response packets are lost in order from the transmitted test packet.
For these, the terminal device 2 can identify the bottleneck link from the observed response packet interval. In this case, it is possible to use a set of two response packets from each switch 601 to 604 (a set of response packets 701 to 702, a set of response packets 711 to 712, a set of response packets 721 to 722, and so on). For links with a small bandwidth, the fact that the packet interval is widened is used.

<Detection of link communication quality (estimation), detection of bottleneck (estimation)>
The measurement execution unit 31 of the terminal device 2 detects link communication quality (for example, detection of an estimated value) or bottleneck based on the reception status of the response packet obtained as a result of transmitting the test packet. Detection (for example, detection of an estimated value) is performed.
Specifically, the measurement execution unit 31 of the terminal device 2 receives the number of arrivals of test packets (response packets) returned by each node (in this embodiment, a switch) and the round-trip delay time (reception time and transmission). Based on the time difference, a packet loss rate and a packet delay (for example, an average value thereof) or a bottleneck bandwidth in a link between nodes is calculated. When performing statistical data processing by repeating a plurality of trials for highly accurate measurement, for example, a method similar to that described in Non-Patent Document 3 or Non-Patent Document 4 is applied. be able to.

  Here, in this embodiment, both the forward path and the return path are prepared and used for measurement for the communication path of the test packet.For example, when examining the loss rate and the delay, it is sufficient to use only the forward path, When examining the available bandwidth, it is necessary to use both the forward path and the return path.

  As described above, in the network system according to the present embodiment, the server device 1 of the measurement system 61 provides an algorithm for calculating the communication path of the test packet for measuring the communication quality of all the links in the SDN. Can do. In the network system according to the present embodiment, the server apparatus 1 of the measurement system 61 sets the destination MAC address and port number for the SDN controller 11 to realize a communication path for the test packet. Can do. As described above, in the network system according to the present embodiment, one (one) terminal device (measurement terminal) is set by setting a communication path for test packets corresponding to all links in the SDN to be monitored. (Device) 2 measures link communication quality (packet loss rate, packet delay, etc.) for all links in SDN (active measurement), and measures bottleneck links (links with small available bandwidth) ( Detection).

Further, in the network system according to the present embodiment, unnecessary test packets (for example, redundant test packets) are stored in the terminal device 2 of the measurement system 61 in advance or when measurement using a test packet is performed. It is possible to reduce the load on the network by the test packet. Specifically, for example, it is possible to perform measurement with a smaller number of test packets by grouping communication paths of test packets and deleting redundant test packets.
As described above, in the network system according to this embodiment, it is possible to improve the efficiency of measurement related to links in the network.

Here, in the present embodiment, the measurement path calculation unit 21 of the server device 1 has been configured to calculate the communication path of the test packet covering all the links. However, as another configuration example, such a calculation is performed. It is also possible to use a configuration that is executed by a person and sets information of the calculation result in the server device 1 or the like.
Moreover, as SDN, things other than OpenFlow may be used, for example.

<Specific examples of effects according to this embodiment>
FIG. 7 is a diagram illustrating an example of an active measurement technique that performs link quality measurement in the network 62 according to an embodiment of the present invention. The configuration example in FIG. 7 is an example corresponding to the configuration example in FIG.
One terminal device (measurement terminal device) 2 performs link quality measurement for a plurality of switches V _{1 to} V ₅ provided in the network 62. In this case, since the communication path of the test packet corresponding to all the links is set by the server apparatus 1, it is possible to measure all the links from one terminal apparatus 2.

[Configuration example according to the above embodiment]
As one configuration example, route group acquisition for calculating a route of a test packet corresponding to all links of a plurality of nodes in the SDN (in this embodiment, switches 12-1 to 12-N) and acquiring the group of the route. A unit (in this embodiment, the measurement route calculation unit 21) and a process for setting the group of routes acquired by the route group acquisition unit in the plurality of nodes (in the present embodiment, setting of the controller 11) A setting device (in this embodiment, the server device 1) including a route setting unit (in this embodiment, a communication route setting unit 22) that executes (processing).
As one configuration example, in the setting device, the route setting unit sets the group of routes in the controller of the SDN (controller 11 in the present embodiment).

As one configuration example, a storage unit (in this embodiment) that stores information related to a group of test packet paths corresponding to all links of a plurality of nodes (in this embodiment, switches 12-1 to 12-N) in the SDN. , A storage unit 32), and a measurement execution unit (in this embodiment, a measurement execution unit 31) that transmits a test packet and executes measurement based on the information stored in the storage unit. It is a device (terminal device 2 in this embodiment).
As a configuration example, in the terminal device, the measurement execution unit deletes redundant test packets and then transmits test packets to perform measurement.
As a configuration example, in the terminal device, the measurement execution unit executes measurement related to the communication quality of the link, or transmits a load packet together with the test packet to execute measurement related to the bottleneck of the link. Both of these measurements may be performed, and other measurements may be performed.

  As an example of the configuration, the route group acquisition unit (measured route calculation unit 21 in this embodiment) corresponds to all links of a plurality of nodes (switches 12-1 to 12-N in this embodiment) in the SDN. A step of calculating a route of the test packet to acquire the group of the route; and a route setting unit (in this embodiment, the communication route setting unit 22), the route group acquired by the route group acquiring unit This is a program (setting program) for causing a computer to execute a step of executing processing for setting a plurality of nodes (in this embodiment, setting processing for the controller 11).

  As one configuration example, route group acquisition for calculating a route of a test packet corresponding to all links of a plurality of nodes in the SDN (in this embodiment, switches 12-1 to 12-N) and acquiring the group of the route. A unit (in this embodiment, the measurement route calculation unit 21) and a process for setting the group of routes acquired by the route group acquisition unit in the plurality of nodes (in the present embodiment, setting of the controller 11) A route setting unit (communication route setting unit 22 in the present embodiment) that executes the processing) and a measurement is performed by transmitting a test packet based on the group of routes acquired by the route group acquiring unit. And a measurement execution unit (in this embodiment, a measurement execution unit 31), and a measurement system (in this embodiment, a measurement system 61). In addition, the function of each processing unit may be provided in various places in the system. For example, the functions of each processing unit may be integrated into one device or distributed to a plurality of devices. Further, the function of one processing unit may be provided in, for example, one apparatus, or may be distributed to a plurality of apparatuses.

  As an example of the configuration, the route group acquisition unit (measured route calculation unit 21 in this embodiment) corresponds to all links of a plurality of nodes (switches 12-1 to 12-N in this embodiment) in the SDN. The route of the test packet is calculated to obtain the group of the route, and the route setting unit (in this embodiment, the communication route setting unit 22) determines the route group obtained by the route group obtaining unit as the plurality of routes. A process for setting a node (in this embodiment, a process for setting the controller 11) is executed, and the measurement execution unit (in this embodiment, the measurement execution unit 31) is acquired by the route group acquisition unit. This is a measurement method (in this embodiment, a method performed in the measurement system 61) that transmits a test packet and performs measurement based on a group of routes.

[Summary of the above embodiments]
As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

  Further, a program for realizing the function of each device (for example, the server device 1 and the terminal device 2) according to the above-described embodiment is recorded on a computer-readable recording medium and recorded on the recording medium. Processing may be performed by causing the computer system to read and execute the program.

The “computer system” referred to here may include an operating system (OS) and hardware such as peripheral devices.
The “computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM (Read Only Memory), a writable nonvolatile memory such as a flash memory, a portable medium such as a DVD (Digital Versatile Disk), A storage device such as a hard disk built in a computer system.

Further, the “computer-readable recording medium” refers to a volatile memory (for example, DRAM (DRAM) inside a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. Dynamic Random Access Memory)) that holds a program for a certain period of time is also included.
The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting a program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
Further, the above program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

DESCRIPTION OF SYMBOLS 1 ... Server device, 2, 1001, 1101, 1501-1 to 1501-2 ... Terminal device (measurement terminal device), 11 ... Controller, 12-1 to 12-N, 601 to 604 ... Switch, 13-1 to 13 -2, 14-1 to 14-2 ... host, 21 ... measurement path calculation unit, 22 ... communication path setting unit, 23, 32 ... storage unit, 31 ... measurement execution unit, 61 ... measurement system, 62, 1511 ... network , 201-202, 211-212, 1021-1023 ... test packet, 301-306 ... table, 501, 1121 ... packet train, 511, 1131 ... load packet, 701-702, 711-712, 721-722, 731 732, 741 to 742, 1031 to 1033, 1141 to 1142, 1151 to 1152, 1161 to 1162,. Tsu door, 1011～1013,1111～1113 ... router

Claims (8)

A route group acquisition unit that calculates a route of a test packet corresponding to all links of a plurality of nodes in the SDN and acquires a group of the route;
A route setting unit that executes processing for setting the group of routes acquired by the route group acquisition unit to the plurality of nodes;
A setting device comprising: The path setting unit sets the group of paths in the controller of the SDN;
The setting device according to claim 1. A storage unit for storing information on a group of test packet paths corresponding to all links of a plurality of nodes in the SDN;
Based on the information stored in the storage unit, a measurement execution unit that transmits a test packet and performs measurement;
A terminal device comprising: The measurement execution unit transmits the test packet after deleting the redundant test packet, and executes the measurement.
The terminal device according to claim 3. The measurement execution unit executes measurement related to the communication quality of the link, or transmits a load packet together with the test packet, and executes measurement related to the bottleneck of the link.
The terminal device according to claim 3 or 4. A route group obtaining unit calculating a route of a test packet corresponding to all links of a plurality of nodes in the SDN and obtaining a group of the route;
A step of performing a process for setting a group of the routes acquired by the route group acquiring unit to the plurality of nodes, a route setting unit;
A setting program to make a computer execute. A route group acquisition unit that calculates a route of a test packet corresponding to all links of a plurality of nodes in the SDN and acquires a group of the route;
A route setting unit that executes processing for setting the group of routes acquired by the route group acquisition unit to the plurality of nodes;
Based on the route group acquired by the route group acquisition unit, a test execution unit that transmits a test packet and executes measurement;
Measuring system. A route group acquisition unit calculates a route of a test packet corresponding to all links of a plurality of nodes in the SDN, and acquires a group of the route.
A route setting unit executes a process for setting the group of routes acquired by the route group acquiring unit to the plurality of nodes,
A measurement execution unit transmits a test packet based on the group of routes acquired by the route group acquisition unit, and executes measurement.
Measurement method.

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