JP5750175B1 - Network simulator and network simulation method - Google Patents

Abstract

An object of the present invention is to accurately simulate traffic transfer and setting processing in a network including a forwarding node and a transmission node, and to simulate a network having a scale of 10,000 nodes. A network simulator (1) refers to network topology information of a simulation target network, determines the number of soft switches that are a combination of a transfer node and a transmission node, and determines a predetermined number provided on one or more servers. A topology configuration unit 112 that configures a topology by activating a VM and a soft gateway, and a soft switch configuration unit that configures a network in the VM by activating a soft switch and connecting a plurality of soft switches 113, for each soft switch, refer to the optical path information of the simulation target network, set the transfer destination of the transmission node, refer to the transfer path information of the simulation target network, and transfer paths between the transfer nodes And a soft switch setting management unit 115 for setting. [Selection] Figure 3

Description

  The present invention relates to a network simulator and a network simulation method for simulating (simulating) a communication network.

  It is important for network operators to effectively use the resources of the entire network to maintain transfer quality and reduce network costs. In the carrier network, an optical path is set on the physical optical infrastructure network, and a transfer device on an upper layer network (for example, an IP (Internet Protocol) network or an MPLS (Multi Protocol Label Switching) network) is connected by the optical path. Provide a logical link to Transfer of user traffic is realized by setting a transfer path such as MPLS in an upper layer network including a transfer device and a logical link.

  At this time, a technique for flexibly responding to a change in the state of the network by dynamically reconfiguring an optical path and a packet transfer path using a centralized control device has been studied (see Non-Patent Document 1). On the other hand, in order to realize the technique described in Non-Patent Document 1, it is necessary to verify that not only algorithm performance but also traffic collection and control to each node operate stably and at high speed. It is not easy to build a test environment with a real machine of a large-scale multi-layer network composed of 1 to 10,000 nodes.

  To solve the above problem, a simulator configuration method has been proposed that realizes simulation of a network composed of a maximum of 1000 nodes (IP router and OXC (Optical Cross Connect)) (non-simulation) Patent Document 2). In the simulator configuration method described in Non-Patent Document 2, for example, in the optical network configuration shown in FIG. 10A, an open source software switch (hereinafter referred to as “soft switch”. As shown in FIG. 10B, a soft switch serving as a traffic input / output point is transferred to a forwarding node (for example, an IP router) and a transmission node (for example, OXC). A multi-layer network is simulated by considering it as a set of Note that a soft switch serving as a traffic input / output point is connected to a traffic generator (start / end point of traffic demand assuming an IP router).

T. Miyamura, et al., “Experimental Demonstration of Adaptive Virtual Network Topology Control Mechanism based on SDTN Architecture”, in proc. Of ECOC 2013, September 2013 Seihei Kamamura, 5 others, “Study on configuration method of 1000-node optical network emulator”, The Institute of Electronics, Information and Communication Engineers, Spring Conference, B-6-63, March 2012

  However, in the technique described in Non-Patent Document 2, as shown in FIG. 11, a packet transfer action (such as an output destination port number) is defined by one setting for each soft switch. For this reason, there is a problem that the setting to the apparatus configured by the multilayer cannot be simulated, and the measurement of the apparatus setting time becomes inaccurate. For example, this has a great effect when the device setting time differs greatly between the IP router and the OXC.

  As a simple solution to the above problem, a method of simulating each of the forwarding node (IP router) and the transmission node (OXC) as one soft switch can be considered. As a result, individual setting for each device (IP router, OXC) is realized, but this configuration causes another problem that a transfer loop occurs. This problem will be described with reference to FIG.

FIG. 12 shows an example in which traffic is transferred through an MPLS path via a plurality of optical paths. Here, FIG. 12A shows an example in which the IP router and the OXC are configured by individual soft switches. That is, each of the IP router “A ₂ ”, OXC “a ₂ ”, IP router “B ₂ ”, OXC “b ₂ ”, IP router “C ₂ ”, and OXC “c ₂ ” has one soft switch (“A”). , “A”, “B”, “b”, “C”, “c”).

  At this time, the soft switch “b” transfers the packet received from the soft switch “a” to the soft switch “B”. Next, the soft switch “b” wants to send the packet received from the soft switch “B” to the soft switch “c”, but the setting to transfer to the soft switch “B” (setting of the transfer table) becomes effective. If so, since the data is transmitted again to the soft switch “B” (symbol α), this process is repeated, and a transfer loop occurs between the soft switches “b” and “B”.

The problem of this forwarding loop is that, as shown in FIG. 12B, a pair of IP router and OXC is simulated by one soft switch (for example, a pair of IP router “A ₁ ” and OXC “a ₁ ”). In this case, as described above, for one soft switch, a setting corresponding to OXC and a setting corresponding to IP router are set. It is necessary to accurately simulate the two-stage setting.

  The present invention has been made in view of such a background, and the present invention can accurately simulate traffic transfer and setting processing in a network including a transfer node and a transfer node. It is an object of the present invention to provide a network simulator and a network simulation method capable of simulating the network.

In order to solve the above-described problem, the invention according to claim 1 is directed to network topology information that is a topology indicating a connection relationship between a plurality of forwarding nodes and a plurality of transmission nodes in the simulation target network, and the simulation target. The optical path information set in the network and the storage unit storing the information of the transfer path set in the simulation target network, the network topology information is referred to, the transfer node and the transfer node The number of soft switches in a set is determined, a predetermined number of VMs provided on one or more servers that accommodate the soft switches are started, and the one or more servers and the predetermined number of VMs are connected to each other. By starting the soft gateway, the topology that configures the topology corresponding to the simulation target network Each of the soft switch configuration unit, a soft switch configuration unit that configures a network in the VM by activating the soft switch and connecting a plurality of the soft switches, and for each of the soft switches, Refers to the information on the optical path, generates a preset setting delay to set the transfer destination of the transmission node, and refers to the information on the transfer path of the simulation target network to generate a preset setting delay And a soft switch setting management unit configured to set a transfer path between the transfer nodes.

The invention according to claim 2 is set in the network to be simulated, network topology information that is a topology indicating a connection relationship between each of a plurality of transfer nodes and a plurality of transmission nodes of the network to be simulated. A network simulator including a storage unit that stores information on optical paths and information on transfer paths set in the simulation target network refers to the network topology information, and sets a combination of the transfer node and the transfer node. Software that determines the number of certain soft switches, starts a predetermined number of VMs provided on one or more servers that accommodate the soft switches, and connects the one or more servers and the predetermined number of VMs respectively. By starting the gateway, the topology corresponding to the simulation target network is configured. Configuring the network in the VM by activating the soft switch and connecting a plurality of the soft switches, and for each of the soft switches, the optical path of the simulation target network Referring to information, and setting the transfer destination of the transmission node by generating a previously provided setting delay, for each said soft switch, the information in the transfer path of the simulated target network, provided in advance And a step of setting a transfer path between the transfer nodes by generating a set delay .

  In this way, the network simulator can accurately simulate the transfer and setting process in two stages of the transmission node and the transfer node. In addition, by appropriately deploying the software gateway to a server or a predetermined number of VMs, a 10,000-node simulation that has been difficult to construct can be realized using a general-purpose server device.

  According to the present invention, it is possible to provide a network simulator and a network simulation method for accurately simulating traffic forwarding and setting processing in a network including a forwarding node and a transmission node, and simultaneously simulating a network having a scale of 10,000 nodes. Can do.

It is a figure for demonstrating the setting process of the two steps of the network simulator which concerns on this embodiment. It is a figure for demonstrating the network which the network simulator which concerns on this embodiment simulates. It is a functional block diagram which shows the structural example of the network simulator which concerns on this embodiment. It is a figure which shows the network model used as simulation object. It is a figure for demonstrating the setting process of the optical path to the soft switch which concerns on this embodiment. It is a figure for demonstrating the setting process of the MPLS path to the soft switch which concerns on this embodiment. It is a figure for demonstrating the advantage which introduces a soft gateway. It is a figure which shows the structural example of the network of 10,000 nodes scale which concerns on this embodiment. It is a flowchart which shows the flow of the whole process of the network simulator which concerns on this embodiment. It is a figure for demonstrating the simulator structure method in a prior art. It is a figure for demonstrating the transfer setting process to the soft switch in a prior art. It is a figure for demonstrating the problem at the time of comprising each of an IP router and OXC as a soft switch.

  Next, a network simulator and a network simulation method in a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described.

<Overview>
First, an outline of processing executed by the network simulator 1 (see FIG. 3) according to the present embodiment will be described.

The network simulator 1 according to the present embodiment utilizes a feature of a software switch (soft switch) that can refer to a multilayer (L3) (L3 to L4) header, and performs two stages (transmission node (OXC, etc.) for a multilayer network. ) And forwarding nodes (IP routers, etc.)) and transfer processing are accurately simulated. In other words, a packet transfer action (output destination port number, etc.) that has been defined once (one step) for each soft switch (see FIG. 11), as shown in FIG. In the network simulator 1 according to the embodiment, the transfer destination (optical path) of the hop-by-hop is set with reference to the information of the layer 4 (start / end TCP port number) (step S100). 3 (IP start / end address) information is used to set an end-to-end transfer path (MPLS path) (step S101).
Specifically, the network simulator 1 sets the optical path transmission for each transmission node (OXC) toward the soft switches “A”, “B”, “C”, and “D”. Subsequently, the network simulator 1 makes the start and end point IP addresses (in this case, the start point IP address “10.0.0.0/8” and the end point IP address “20.0.0.0/” toward the soft switches “A”, “C”, and “D”. 8)), set the transfer path. Details will be described later with reference to FIGS.

  Further, the network simulator 1 according to the present embodiment constructs a system using a soft gateway in order to construct a system with a scale of 10,000 nodes. Then, by appropriately arranging the soft gateway function in a plurality of VMs (Virtual Machines) and servers, a 10,000-node simulation is realized using a general-purpose server device. Details will be described later with reference to FIGS.

<Network to be simulated>
Next, a network simulated by the network simulator 1 (see FIG. 3) according to the present embodiment will be described with reference to FIG.
FIG. 2 is a diagram for explaining a network simulated by the network simulator 1 according to the present embodiment.

  As shown in FIG. 2A, the network simulator 1 simulates (sets on the network simulator 1) a network 50 that includes a forwarding node (such as an IP router) and a transmission node (such as OXC). In the following description of the present embodiment, the forwarding node is an IP router and the transmission node is an OXC. The IP router and OXC are connected by a physical link (such as an optical fiber). The total number of IP routers and OXCs is 10,000 at maximum. On the network simulator 1, as shown in FIG. 2 (b), an optical path having an IP router as a start / end point is set on the physical network, and the optical path is a logical link in an upper layer (IP layer). Configure. Furthermore, a transfer path for user traffic is generated by setting a transfer path (for example, an MPLS path) on the logical network. In the present embodiment, an example in which an optical path is set on a physical network and an MPLS path is set on a logical network will be described below. A network simulator 1 (see FIG. 3) that simulates the network 50 is connected to the network control device 5. The network control device 5 transmits the information on the optical path and the MPLS path for each node (IP router, OXC) on the network simulator 1 to the network simulator 1, and at the same time the traffic in the network constructed on the network simulator 1. Receive status notifications such as information and malfunctions.

<Configuration of network simulator>
Subsequently, the network simulator 1 according to the present embodiment will be specifically described.
FIG. 3 is a functional block diagram illustrating a configuration example of the network simulator 1 according to the present embodiment. The network simulator 1 is composed of one or more physical servers (general-purpose servers), and is connected to a network control device 5, a traffic generator 6, a controller corresponding to a soft switch (not shown), and the like. Here, the network control device 5 gives the network simulator 1 topology information (network topology information) of the network to be simulated, specifically information indicating the connection relationship between the OXC and the IP router or between the OXC, etc. The optical path information set on the physical network, the MPLS path information set on the logical network, and the like are stored and transmitted to the network simulator 1. Further, the traffic generator 6 has a function of generating traffic and transmitting it to the network set on the network simulator 1. The controller for soft switches will be described later.
The network simulator 1 includes a control unit 11, an input / output unit 12, and a storage unit 13.

  The input / output unit 12 includes a communication interface for transmitting / receiving information to / from the network control device 5, the traffic generator 6, a soft switch compatible controller (not shown), and the like via a communication line, It comprises an input / output interface for inputting / outputting information to / from an input means such as a keyboard and an output means such as a monitor.

  The control unit 11 controls the entire network simulator 1, and includes an input information processing unit 111, a topology configuration unit 112, a soft switch configuration unit 113, a traffic transmission / reception unit 114, a soft switch setting management unit 115, and output information. And a processing unit 116. In addition, this control part 11 is implement | achieved when CPU (Central Processing Unit) expand | deploys and executes the program stored in the memory | storage part 13, for example in RAM (Random Access Memory).

The input information processing unit 111 acquires network topology information from the network control device 5 via the input / output unit 12 and stores it in a network topology DB (DataBase) 131 in the storage unit 13. The network topology information is topology information of the network to be simulated, and stores, for example, a connection configuration between the IP router and the OXC and OXC. The network topology information designates a soft switch (a combination of an IP router and an OXC) that is a traffic input / output point.
Similarly, the input information processing unit 111 is set via the input / output unit 12 from the network control device 5 to information on a transmission path (here, an optical path) to be set on the physical network, on the logical network. Information on transfer paths (here, MPLS paths) is acquired and stored in the optical path DB 132 and the MPLS path DB 133 in the storage unit 13.

  Based on the network topology information stored in the network topology DB 131 stored in the storage unit 13, the topology configuration unit 112 determines the number of soft switches to be activated and the hardware that accommodates them, and activates the soft gateway. Do. Note that the hardware of the network simulator 1 is assumed to be one or more physical servers (general-purpose servers), and a predetermined number of VMs (Virtual) are included in the physical servers (hereinafter sometimes simply referred to as “servers”). Machine) is started (details will be described later). And the topology structure part 112 implement | achieves the link over the same server and VM through a soft gateway. That is, the topology configuration unit 112 starts up the physical interfaces and virtual interfaces that connect physical servers and VMs by the number of connections to the soft gateway.

  The soft switch configuration unit 113 activates a soft switch on the VM of each physical server, connects a plurality of the activated soft switches, and configures a network. This function can be realized using, for example, mininet (http://mininet.org/). The soft switch configuration unit 113 connects physical links according to the network topology information in the VM of the same server.

  The traffic transmission / reception unit 114 is connected to the traffic generator 6 via the input / output unit 12 and inputs / outputs traffic to / from the soft switch.

  The soft switch setting management unit 115 receives the optical path information and the MPLS path information received from the network control device 5 and stored in the optical path DB 132 and the MPLS path DB 133 in the storage unit 13 for simulator setting. Convert to contents and input settings to each soft switch. Note that the setting information of the transmission path (optical path) and transfer path (MPLS path) to each soft switch by the soft switch setting management unit 115 receives an instruction from a controller corresponding to the soft switch (not shown). However, it may be executed. The controller corresponding to the soft switch is realized as an OpenFlow controller, for example. In this case, the software switch setting management unit 115 of the network simulator 1 converts control information from the OpenFlow controller into information for setting by the network simulator 1 and inputs the information to each soft switch (OpenFlow switch). Further, the soft switch setting management unit 115 receives control result information and status information from each soft switch of the network, and transmits them to the controller.

  The soft switch setting management unit 115 refers to the information of the layer 4 (start / end TCP port number) based on the optical path information stored in the optical path DB 132 in the storage unit 13, and sets each soft switch (transmission node). (OXC)) sets a hop-by-hop transfer destination. Then, the soft switch setting management unit 115 refers to the information of the layer 3 (start / end point IP address) based on the information of the MPLS path stored in the MPLS path DB 133 in the storage unit 13, and the soft switch (forwarding node (forwarding node ( An end-to-end transfer path is set in the IP router)). Details of the soft switch setting process by the soft switch setting management unit 115 will be described later with reference to FIGS.

  In addition, the soft switch setting management unit 115 provides, for example, several hundred msec for the OXC table setting and 1 sec for the IP router table setting as an accurate setting delay when the setting is input, thereby controlling the network device. Realize accurate simulation. Further, the soft switch setting management unit 115 performs accurate prior verification of the control time and stability of the network by receiving failure information and status information from each soft switch on the simulator.

  The output information processing unit 116 transmits the result of setting input executed by the soft switch setting management unit 115 to each soft switch, network failure information, status information, and the like via the input / output unit 12. Or output to output means such as a controller corresponding to a soft switch (not shown) or a monitor (not shown).

  The storage unit 13 includes storage means such as a hard disk, a flash memory, and a RAM, and stores information including the network topology DB 131, the optical path DB 132, and the MPLS path DB 133 described above.

  The soft switch (SS) is activated by the soft switch configuration unit 113, and in this embodiment, a combination of an IP router and an OXC is configured as one soft switch. This soft switch is realized, for example, as a soft switch (OpenFlow switch) having an OpenFlow interface, and is set on each server.

  The software gateway (SG) is activated by the topology configuration unit 112 and has a function of consolidating links connecting a plurality of nodes into one when setting a network across a plurality of hardware (servers) and VMs. Prepare.

<Traffic transfer and device setting process simulating a multi-layer device>
Next, a device setting process for traffic transfer simulating a multilayer device, which is executed by the soft switch setting management unit 115 of the network simulator 1, will be described. The soft switch setting management unit 115 of the network simulator 1 executes a two-stage setting for the transmission node (OXC) side and the forwarding node (IP router) side with respect to the soft switch composed of the IP router and the OXC.

Here, as a network model to be simulated, as shown in FIG. 4, an IP router “A ₁ ” → OXC “a ₁ ” → OXC “b ₁ ” → OXC “c ₁ ” → IP on a physical network. Two optical paths, an optical path passing through the router “C ₁ ” and an optical path passing through the IP router “C ₁ ” → OXC “c ₁ ” → OXC “d ₁ ” → IP router “D ₁ ” The MPLS path of the route of IP router “A ₁ ” → IP router “C ₁ ” → IP router “D ₁ ” is set on the logical network using these two optical paths. To do.

  In order to simulate the network shown in FIG. 4, the soft switch setting management unit 115 refers to layer 4 (start / end TCP port number) information based on the optical path information, and hop-bys each soft switch (OXC). Sets the hop-by-hop destination. Then, the soft switch setting management unit 115 refers to layer 3 (start / end IP address) information based on the information of the MPLS path, and sends end-to-end to each soft switch (IP router). Set the transfer path.

Here, as shown in FIG. 5 to be described later, the soft switch configuration unit 113 configures a set of the IP router “A ₁ ” and the OXC “a ₁ ” as the soft switch “A”. A set of the IP router “B ₁ ” and the OXC “b ₁ ” is configured as a soft switch “B”. A set of the IP router “C ₁ ” and the OXC “c ₁ ” is configured as a soft switch “C”. Further, a set of the IP router “D ₁ ” and the OXC “d ₁ ” is configured as a soft switch “D”.

  Then, the soft switch setting management unit 115 executes optical path setting for each soft switch. FIG. 5 is a diagram for explaining optical path setting processing by the soft switch setting management unit 115. The soft switch setting management unit 115 registers, for each soft switch, a match condition based on the start / end TCP port number and transfer destination information (for each OXC) when the match condition is satisfied in the table entry as an action condition.

For example, as shown in FIG. 5, an optical path set between soft switches “A”-“B”-“C” has a Match condition with a start point (source) TCP port number “1”, an end point ( Destination) TCP port number is set as “2” (Match condition “src port = 1, dst port = 2”). Then, as the transfer destination information when this Match condition is satisfied, the output from IF “1” is set in the soft switch “A” (OXC “a ₁ ”) (Action condition “Action output IF1”), and the software The output from the IF “2” is set to the switch “B” (OXC “b ₁ ”) (Action condition “Action output IF2”), and the IF to the soft switch “C” (OXC “c ₁ ”) The output from “3” is set (Action condition “Action output IF3”).
Also, the optical path set between the soft switches “C” and “D” sets the Match condition as “3” for the start TCP port number and “4” for the end TCP port number (Match condition “src port”). = 3, dst port = 4 "). Then, as the transfer destination information when this Match condition is satisfied, the output from IF “4” is set to the soft switch “C” (OXC “c ₁ ”) (Action condition “Action output IF4”), and the software The output from the IF “5” is set to the switch “D” (OXC “d ₁ ”) (Action condition “Action output IF5”).
In this way, in each OXC, whether or not the Match condition is satisfied is determined by identifying layer 4 (start / end TCP port number) information, and the transfer process is performed to an appropriate transfer destination. .

  Next, the soft switch setting management unit 115 executes transfer path (MPLS path) setting for each soft switch. FIG. 6 is a diagram for explaining MPLS path setting processing by the soft switch setting management unit 115. The soft switch setting management unit 115 registers, for each soft switch, the match condition based on the start / end IP address and the TCP port number rewriting process (for each IP router) when the match condition is satisfied in the table entry as the action condition. To do.

For example, as shown in FIG. 6, for the MPLS path set between the soft switches “A” and “D”, the soft switch “A” is set between the soft switches “A”, “B” and “C”. As a setting to use the optical path to be used, the Match condition is set so that the start point (source) IP address is "10.0.0.0/8" and the end point (destination) IP address is "20.0.0.0/8" (Match condition “src = 10.0.0.0 / 8”, “dst = 20.0.0.0 / 8”). Then, as the rewrite process (Action condition) when the Match condition is satisfied, the start TCP port number is set to “1” and the end TCP port number is set to “2” (Action condition “Mod src port = 1, dst port = 2 ").
Also, the soft switch “C” has a Match condition as a setting for using the optical path set between the soft switches “C” and “D”, the start point IP address is “10.0.0.0/8”, The end point IP address is set as “20.0.0.0/8” (Match condition “src = 10.0.0.0 / 8”, “dst = 20.0.0.0 / 8”). Then, as the rewrite processing (Action condition) when the Match condition is satisfied, the start TCP port number is set to “3” and the end TCP port number is set to “4” (Action condition “Mod src port = 3, dst port = Four").
By doing so, each IP router determines whether or not the Match condition is satisfied by identifying the information of layer 3 (start / end IP address), and the forwarding process is performed to an appropriate visiting route. .

Here, the soft switch setting management unit 115 determines the hop-by-hop transfer destination by referring to the information of the start and end point TCP port numbers of layer 4 regarding the setting of the optical path. Although described as being set, the transfer destination may be set using other information of the layer 4 TCP header or information of the layer 3 IP header.
Further, regarding the setting of the MPLS path, the soft switch setting management unit 115 refers to the information of the start / end point IP address of the layer 3 and determines and sets an end-to-end transfer path. As described above, the transfer path may be set using other information of the layer 3 IP header and information of the layer 4 TCP header.

  Since the two-stage setting for the soft switch described above is the same processing as that for an actual network in which OXC and IP routers are mixed, an accurate setting delay (for example, OXC table setting is several hundred msec when each setting is input) By providing the IP router table setting of 1 sec), an accurate simulation of the entire network control can be realized.

<10,000 node scale network configuration>
Next, a configuration example of a network with a scale of 10,000 nodes using a soft gateway executed by the topology configuration unit 112 will be described with reference to FIGS.

FIG. 7 is a diagram for explaining the advantages of introducing a soft gateway. As shown in FIG. 7A, when a soft gateway is not used, soft switches arranged in different servers (server “A”, server “B”) or different VMs (VM “A”, VM “B”), respectively. If a plurality of links are set between them, the number of physical interfaces (physical NICs (Network Interface Cards)) or virtual interfaces (virtual NICs) is required by the number of the set links. In particular, the number of virtual interfaces connecting VMs is limited to about 10 even when a commercial VM is used.
On the other hand, as shown in FIG. 7B, by using a soft gateway (denoted as “SG” in the figure), a plurality of links between the soft switches across the servers and VMs are combined into one. Can do.

Next, a configuration example of a network having a scale of 10,000 nodes will be described.
FIG. 8A shows a system configuration example <1> for configuring a 10,000 node network.
In this system configuration example <1>, five VMs are started on one physical server, and a total of 250 soft switches (IP routers and OXCs) are placed on each VM (VM “1” to “5”). 500 units). Since each VM is connected through a soft gateway, the number of virtual interfaces (virtual NICs) on each VM is five. One of the five is connected to a soft gateway on the physical server. Four physical servers having the same configuration are activated, and the physical servers and the physical server and the traffic generator 6 are connected through the soft gateway. With this configuration, a simulator environment of 10,000 scales is constructed by four servers equipped with four physical interfaces (physical NICs).

FIG. 8B shows a system configuration example <2> for configuring a 10,000 node network.
In this system configuration example <2>, six VMs are started on one physical server, and only one of the soft gateways is set on one VM (VM “6” in FIG. 8B). Is done. The other five VMs (VM “1” to “5”) have 250 soft switches (500 IP routers and OXC in total) on each VM as in the system configuration example <1>. to start. The soft gateway on the physical server is connected to only the VM (VM “6”) in which only the soft gateway is set, and the soft gateway (VM “6”) and each VM (VM “1” to “5”). )) Soft gateway.

  In the system configuration example <1>, each of the VMs “1” to “5” on the physical server starts 250 soft switches and its own soft gateway connected to five soft gateways other than itself. As a result, the usage amount of the CPU and the memory may become high. On the other hand, in the system configuration example <2>, by starting the VM dedicated to the software gateway (VM “6”), the software gateway on the VMs “1” to “5” transmits the packet to the VM “6”. It is only necessary to transfer to “1”, so that the load on one VM can be reduced.

<Process flow>
Next, the overall processing flow of the network simulator 1 according to the present embodiment will be described.
FIG. 9 is a flowchart showing an overall processing flow of the network simulator 1 according to the present embodiment.

  As shown in FIG. 9, first, the input information processing unit 111 of the network simulator 1 acquires network topology information from the network control device 5 via the input / output unit 12, and stores it in the network topology DB 131 (step S1). ).

Next, based on the network topology information stored in the network topology DB 131, the topology configuration unit 112 determines the number of activated soft switches, the number of physical servers (number of physical servers) that accommodate them, the number of VMs on the physical server, and the like. At the same time, the software gateway is activated (step S2).
For example, the topology configuration unit 112 determines physical servers (number of physical servers) so that the system configuration <1> illustrated in FIG. 8A and the system configuration <2> illustrated in FIG. Then, a predetermined number of VMs are activated, and a soft gateway is activated between the VMs and physical servers.
The number of soft switches activated by the topology configuration unit 112, the number of physical servers that accommodate the topology, the number of VMs, and the like are determined in advance by a network administrator or the like depending on the scale of the network to be simulated (number of devices, etc.) The topology configuration unit 112 may be set, or the topology configuration unit 112 may have logic for calculating the number of units according to the scale of the network to be simulated (number of devices, etc.).

  Subsequently, based on the network topology information stored in the network topology DB 131, the soft switch configuration unit 113 activates a soft switch on the VM of each server, connects the activated soft switches, and configures a network. (Step S3).

  Next, the input information processing unit 111, via the input / output unit 12, from the network control device 5, information on the optical path set on the physical network and information on the transfer path (MPLS path) set on the logical network. Are stored in the optical path DB 132 and the MPLS path DB 133 (step S4).

Then, the soft switch setting management unit 115 executes soft switch setting based on the optical path information stored in the optical path DB 132 and the MPLS path information stored in the MPLS path DB 133 of the network to be simulated. (Step S5).
Specifically, as described above, the soft switch setting management unit 115 performs two steps for the transmission node (OXC) side and the forwarding node (IP router) side with respect to the soft switch composed of the IP router and the OXC. Perform configuration. For example, based on the optical path information, the soft switch setting management unit 115 refers to layer 4 (start / end TCP port number) information, determines a hop-by-hop transfer destination, Set each soft switch. Subsequently, the soft switch setting management unit 115 determines the end-to-end transfer path by referring to the information of the layer 3 (IP start / end address) based on the information of the MPLS path, Set each soft switch. At this time, the soft switch setting management unit 115 simulates the setting process of the entire network by measuring the time when the setting information is transmitted to each soft switch and the time when the setting completion is received.

  Next, the traffic transmission / reception unit 114 applies the traffic from the traffic generator 6 to each soft switch via the input / output unit 12 (step S6). Thereby, the simulation of the network is started. At this time, the soft switch setting management unit 115 monitors the traffic to acquire failure information and error information of each device, verify stability, and the like.

  As described above, according to the network simulator 1 and the network simulation method according to the present embodiment, it is possible to accurately simulate the setting process for each transmission node (such as OXC) and forwarding node (such as an IP router). In addition, the software gateway can be appropriately deployed on a server or a predetermined number of VMs. As a result, it is possible to execute accurate prior verification of control time and stability of a large-scale network such as 10,000 nodes, which has been difficult to construct conventionally. That is, it is possible to perform risk hedging for the network operator by confirming in advance the effects of the path calculation algorithm and the network control without performing the network construction using the actual machine.

DESCRIPTION OF SYMBOLS 1 Network simulator 5 Network control apparatus 6 Traffic generator 11 Control part 12 Input / output part 13 Storage part 111 Input information processing part 112 Topology composition part 113 Soft switch composition part 114 Traffic transmission / reception part 115 Soft switch setting management part 116 Output information processing part 131 Network topology DB
132 Optical path DB
133 MPLS path DB
SS soft switch SG soft gateway

Claims (2)

Network topology information that is a topology indicating a connection relationship between each of a plurality of forwarding nodes and a plurality of transmission nodes of the simulation target network, information on optical paths set in the simulation target network, and the simulation target A storage unit for storing information on transfer paths set in the network;
Referring to the network topology information, the number of soft switches that are a combination of the forwarding node and the transmission node is determined, and a predetermined number of VMs (Virtual Machines) provided on one or more servers that accommodate the soft switches ) And starting a soft gateway that connects each of the one or more servers and the predetermined number of VMs, thereby configuring a topology configuration unit that configures a topology corresponding to the simulation target network;
A soft switch configuration unit that configures a network in the VM by activating the soft switch and connecting a plurality of the soft switches;
For each of the soft switches, the information on the optical path of the simulation target network is referred to, a preset delay is generated to set a transfer destination of the transmission node, and the transfer path of the simulation target network is set. A soft switch setting management unit that sets a transfer path between the transfer nodes by generating a set delay in advance ,
A network simulator comprising: Network topology information that is a topology indicating a connection relationship between each of a plurality of forwarding nodes and a plurality of transmission nodes of the simulation target network, information on optical paths set in the simulation target network, and the simulation target A network simulator including a storage unit that stores information on a transfer path set in a network,
Referring to the network topology information, determine the number of soft switches that are a combination of the forwarding node and the transmission node, and activate a predetermined number of VMs provided on one or more servers that accommodate the soft switches Configuring a topology corresponding to the simulation target network by activating a soft gateway connecting each of the one or more servers and the predetermined number of VMs;
Configuring the network in the VM by activating the soft switch and connecting a plurality of the soft switches;
For each of the soft switches, referring to the information of the optical path of the simulation target network, setting a transfer destination of the transmission node by generating a preset delay, and
For each of the soft switches, referring to the transfer path information of the simulation target network, setting a transfer path between the transfer nodes by generating a preset delay, and
The network simulation method characterized by performing.

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