KR100336495B1 - System and method for simulating the packet transmission performance of Internet - Google Patents

Abstract

The present invention relates to a simulator that can mimic the end-to-end packet delivery performance of the Internet over a local area network (LAN).

In the present invention, by modifying the structure of a router, hub, bridge, or gateway system that connects two or more physically separated LANs, even when the terminals connected to the same small network communicate with each other, Experience the end-to-end packet delivery performance provided by the Internet.

Accordingly, the present invention can be used to construct a small scale network for simulation that can be used in the development and performance evaluation of Internet application programs, Internet services, protocols, transmission equipment and the like.

Description

Simulator for mimicking the packet transmission performance of the Internet over a local area network {System and method for simulating the packet transmission performance of Internet}

The present invention relates to a simulator that can mimic the end-to-end packet delivery performance of the global Internet over a local area network (LAN).

What is most important in the development and performance evaluation of applications, services, protocols, and equipment that will run on the Internet is the creation of a test environment that can provide delivery performance similar to the real Internet. In practice, however, configuring such an environment is not only physically simple, but it is also very difficult to tune the delivery performance in the created environment to be within the area of interest of the developer. Therefore, in general, the method widely adopted in the internet development / performance evaluation process is to use simulation.

Internet-related simulation programs have already been produced in various forms, but since these programs only provide a virtual Internet environment implemented in software, application or equipment developers can use it for simulation in addition to products that can actually be used in the network. There is a burden to develop the program separately.

On the other hand, there is a method of directly changing the packet transmission and reception module of the terminal in order to mimic the packet transfer performance of the Internet. Related prior art is US Patent US5862362 (patent: Microsoft, name: Network Failure Simulator).

This patent proposes a network fault simulator that can be used to evaluate the performance of a network application using software. It replaces a packet handler located on a computer's network input / output structure with an arbitrary program, which causes the application to drop packets. Misleading, it enables automated performance evaluation of network applications.

However, in this case, since the terminal having a different structure and function from the terminals actually used in the Internet is used for the simulation, it is a rather unsuitable method for evaluating the applicability in the actual internet network.

An object of the present invention is to change the structure and function of the terminal without any change in the structure and function of the terminal to configure a simulated environment on the LAN that can show the packet delivery performance similar to the Internet, and the burden of equipment to be introduced further It is to provide a simulator for mimicking the packet delivery performance of the Internet in a local area network that minimizes and does not affect packets irrelevant to the simulation.

1 is a block diagram of a new functional block required inside a router for implementing a simulator of the present invention.

2 is a configuration diagram of a router functional block and a router functional block according to an embodiment of the present invention;

3 is a configuration diagram of a router functional block and a router functional block according to another embodiment of the present invention;

In the embodiments of the present invention, a LAN in which the Internet Protocol (IP) is used is applied.

There are many parameters that can be used to describe the performance of delivering packets over the Internet, but the most important parameters for most applications and services are packet loss ratio, packet delay, There are four packet delay jitters and end-to-end throughput. Therefore, the embodiment of the present invention allows the simulator to control these four packet delivery performance factors.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In order to implement the present invention, a router, a hub, or a bridge is essential as a means for connecting two or more physically separated LANs. And, there is provided a functional block required for implementing the present invention inside or outside the connecting means or the connecting means.

In the following embodiments, only a case of using a router as a means for connecting two or more LANs, but this is only for convenience of practical implementation, embodiments according to the present invention is connected to two or more LANs The same may be applied to a hub or a bridge.

1 is a functional block diagram for implementing a simulator of the present invention.

As shown in the figure, the functional blocks required to implement the present invention are provided in the kernel of the router located at the connection point between two or more LANs physically separated, and the functional block provided in the router application area or outside the router It is divided into functional blocks.

The functional block provided in the kernel of the router includes two or more packet classifiers 11 present in the packet processing module, a packet buffer 12, a delay generator 13 present in the control module, and a packet dropper 14. , A traffic regulator (15), and a delivery performance meter (16) present in the measurement module.

In addition, a function modeler 17 and an Internet performance meter 18 are provided in a functional block provided in an application area of the router or outside the router.

2 is a block diagram of a simulator according to an embodiment of the present invention.

As shown in the figure, the simulator according to the present embodiment is composed of two LAN 1, 2 physically separated and the router providing a connection of the LAN 1, 2 and the Internet connection in a router provided separately from the LAN and If the packet belongs to a flow that needs to experience a random transmission performance after determining whether all packets transmitted from the LAN 1 and 2 to the router are simulated within the kernel of the router, Two or more packet classifiers 11 for inserting into the buffer 12; A plurality of packet buffers 12 for storing packets to apply any delay, delay variation, loss rate, end-to-end bandwidth, etc. to the packets related to the performance test classified by the packet classifier 11; Based on the delay and delay transition descriptors delivered by the performance modeler 17, the latency to be applied to each packet waiting in the packet buffer 12 is calculated, measured and monitored, Delay generator 13 for immediately passing the packet in excess of the packet transmission module; A packet dropper 14 for discarding packets in the packet buffer 12 at a constant rate based on the packet loss rate descriptor passed in the performance modeler 17; A traffic regulator 15 that measures, monitors and adjusts the number and size of packets actually transmitted per unit time among packets belonging to each packet flow to limit the end-to-end bandwidth; And a transmission performance meter (meter: 16) that continuously measures and monitors the loss rate, delay, delay variation, and bandwidth provided by the simulator to inform the user of its status and results.

The delay generator 13, the packet remover 14, and the traffic conditioner 15 are generated by generating actual values for each performance descriptor according to a probabilistic model of a performance descriptor that is arbitrarily designated by a user in an application area of the router. The performance modeler 17 and the simulator communicate with hosts on the Internet to measure the end-to-end packet delivery performance of the real Internet that the simulator attempts to imitate, and the delay, delay variation, loss rate and end-to-end bandwidth It characterized in that it comprises an Internet performance meter 18 for recording.

In general, a set of consecutive packets generated due to communication between terminals belonging to separate LANs (for example, communication between terminal A and terminal B in FIG. 2) is referred to as 'flow'. The simulated packet delivery performance provided by this simulator is classified by each 'flow'.

Referring to the functional blocks required in the router to implement the simulator according to the present embodiment are as follows.

The packet classifier 11 checks the relationship with the simulation for all the packets delivered to the router, and then, in the flow to experience random transmission performance (packet loss rate, packet delay and delay variation, end-to-end bandwidth). If the packet belongs to it is inserted into the corresponding packet buffer (12). Packets that do not have any guarantee of delivery performance, that is, all packets irrelevant to the simulation, are stored separately in a dedicated packet buffer, which contains resources (memory, output bandwidth) after processing all packets related to the simulation. Etc.), so as not to cause damage to packets involved in the simulation.

The packet buffer 12 provides a waiting place for a packet to apply any delay, delay variation, loss rate, end-to-end bandwidth, etc. to the packets classified by the packet classifier 11. Since each packet flow has different transfer performances, there are also several packet buffers 12, and the packets stored in each buffer can be dynamically sorted according to their priority. However, buffers for packets irrelevant to the simulation do not have to be equipped with priority-based dynamic sorting.

The delay generator 13 calculates, measures, and monitors the waiting time to be applied to each packet waiting in the packet buffer 12 based on the delay and the delay transition descriptor. In case of the packet exceeding the waiting time, the packet is immediately transmitted to a packet transmission module not shown. This function is possible by dynamically managing the transmission priority of packets stored in the packet buffer 12. And, since the value of the calculated delay variation is allowed to be larger than the time interval between packets, it is possible to mimic the generation of out of order packets which are very frequent on the real Internet.

The packet remover 14 discards the packets in the packet buffer 12 at a constant rate based on the packet loss rate descriptor. In order to limit the end-to-end bandwidth, the traffic conditioner 15 measures and monitors and adjusts the number and size of the packets actually transmitted per unit time among the packets belonging to each packet flow. Therefore, the functional block described above includes a scheduling function based on the transmission priority of the packet in a general sense.

The packet forwarding performance meter 16 continuously measures and monitors the loss rate, delay, delay variation and bandwidth provided by the simulator to inform the user of the status and result.

In addition, the performance modeler 17 existing in the application area of the router generates an actual value for each performance descriptor according to a probabilistic model of a performance descriptor that is arbitrarily designated by a user to generate the delay generator 13 and the packet. To the eliminator 14 and the traffic conditioner 15.

The Internet Performance Meter 18 also exists in the router's application area and communicates with hosts on the Internet to measure the end-to-end packet delivery performance of the real Internet that the simulator attempts to imitate. And end-to-end bandwidth. The user can determine whether or not to use the simulation based on the location where the host to be contacted is located, the date and time the record was obtained, and the like.

Hereinafter, a process for allowing a packet flow to experience any transfer performance required by a user will be described with reference to the functional blocks described above.

When the packet generated at the LAN terminal is delivered to the router via the transmission medium, each packet is determined by the packet classifier 11 to determine whether the packet is related to the simulation. If it is related to the simulation, the packet classification key 11 stores the received packet in the packet buffer 11 corresponding to the flow to which the packet belongs.

The packet buffers 11 corresponding to each flow are managed by three functional blocks belonging to the control module of the kernel region of the router, that is, the delay generator 13, the packet remover 14, and the traffic conditioner 15. Each block controls delay and delay variation, packet loss rate, and end-to-end bandwidth according to the functions described above.

The delivery performance that packets actually experience is monitored and recorded by the performance meter 16 per packet or flow and known to the user. If the user wishes to be notified immediately if the delivery performance provided for a flow exceeds a certain range, this function may also be implemented by the performance meter 16.

The delay generator 13, the packet remover 14, and the traffic conditioner 15, which directly control the packet forwarding performance, are controlled by the performance modeler 16 or the Internet performance meter present in the router's application area. In practice, whether to use the performance modeler or the Internet performance meter to control the delivery control blocks can be applied for each flow by the user.

The performance modeler 17 has a variety of probability distribution functions that can describe the change in the value of each parameter, and may add a user-produced probability distribution function. It is up to the user to decide what probability distribution to apply to each factor, and what values the initial values and parameters of the variables used in the distribution are.

When using the Internet performance meter 18, the user can specify a specific host or subnet on the actual Internet, measurement date and time, measurement tools, etc., the Internet performance meter 18 according to the method specified by the user, specific host or specific subnet Attempt communication with any host in the network for active measurement.

The internet performance meter 18 records the delay, delay variation, loss rate and end-to-end bandwidth measured by such a method and provides the user with the delay generator 13, the packet remover 14 and the traffic conditioner (based on this). 15).

3 is a block diagram of a simulator according to another embodiment of the present invention.

As shown in the figure, it is implemented with the same functional block as the above-described embodiment, except that the performance modeler 17 and the internet performance meter 18 are not present in the router's application area, but are independent control means (remote controller) outside the router. Present in the network, and control the delay generator 13, packet remover 14 and traffic conditioner 15 via the Internet.

That is, the present embodiment is a kernel of the router through two LANs 1 and 2 that are physically separated, a router providing a connection of the LANs 1 and 2, an Internet connection in a router configured separately from the LAN, and the Internet. It is composed of a remote controller that controls a functional block within the kernel of the router, to determine whether the relationship between the simulation and all the packets transmitted from the LAN 1, 2 to the router, to experience any transfer performance. Two packet classifiers 11 to be inserted into corresponding packet buffers 12 in case of packets belonging to a flow to be performed; A plurality of packet buffers 12 for applying any delay, delay variation, loss rate, end-to-end bandwidth, etc. to the packets filtered by the packet classifier 11; Based on the delay and delay transition descriptors transmitted by the performance modeler 17, the latency to be applied to each packet waiting in the packet buffer 12 is calculated, measured and monitored, and the latency exceeded. A delay generator 13 which directly transfers the packet to the packet transmission module; A packet eliminator (14) for discarding packets in the packet buffer (12) at a constant rate, based on the packet loss rate descriptor passed from the performance modeler (17); A traffic conditioner 15 for measuring, monitoring and adjusting the number and size of packets actually transmitted per unit time among the packets belonging to each packet flow in order to limit the end-to-end bandwidth; And a transfer performance meter 16 that continuously measures and monitors the loss rate, delay, delay variation, and bandwidth provided by the simulator to inform the user of its status and results,

The remote controller generates a real value for each performance descriptor according to a probabilistic model of a performance descriptor that is arbitrarily designated by a user, and transmits the actual value to the delay generator 13, the packet remover 14, and the traffic conditioner 15. A modeler 17; In order to measure the end-to-end packet delivery performance of the real Internet that the simulator attempts to imitate, it is necessary to communicate with the hosts on the Internet. It is characterized by including.

The operation of the simulator according to the present embodiment having such a configuration is the same as the above-described embodiment. However, since the performance modeler 17 and the internet performance meter 18 exist in the external remote controller, the control of the delay generator 13, the packet remover 14, and the traffic conditioner 15 existing inside the router kernel is controlled through the Internet. What is done is different.

The present invention as described above establishes a simulation environment that can mimic the end-to-end packet delivery performance provided by the global Internet at the LAN scale without bringing any functional changes or additions to the packet transmission / reception terminals. Can be used to

In particular, when using the simulator of the present invention, it is possible to perform a more realistic simulation because it can be carried out on a real LAN (LAN) of the system under development or performance evaluation without the need to separately produce a dedicated program for simulation. can do. In addition, among the packets transmitted and received on the LAN configured for the simulation, the packets irrelevant to the simulation have no influence on the transmission performance, and thus the simulation network can coexist with the business network, which is very efficient.

The technical spirit of the present invention has been described above with reference to the accompanying drawings, but this is by way of example only and not intended to limit the present invention. In addition, it is obvious that any person skilled in the art can make various modifications and imitations without departing from the scope of the technical idea of the present invention.

Claims (4)

In a simulator that can mimic the end-to-end packet forwarding performance of the Internet over a local area network, Two or more physically separated LANs and a connection means for providing a connection between the LANs and the Internet; a user and the connection means existing within or outside the connection means for simulating packet transfer performance; It consists of a packet forwarding performance control interface that provides an interface for The connection means checks the relationship between the simulations for all the packets transmitted from the LANs in the kernel, and then, if the packet belongs to a flow that should experience any forwarding performance, the corresponding packet buffer 12 The same number of packet classifiers (11) as the LANs inserted into the network; A plurality of packet buffers 12 for applying any delay, delay variation, loss rate, end-to-end bandwidth, etc. to the packets classified by the packet classifier 11; Based on the delay and delay transition descriptors transmitted by the packet forwarding performance control interface, the waiting time to be applied to each packet waiting in the packet buffer 12 is calculated, measured and monitored, and the waiting time is exceeded. A delay generator 13 which immediately transfers a packet to a packet transmission module; A packet remover (14) for discarding packets waiting at the packet buffer (12) at a constant rate, based on a packet loss rate descriptor delivered at the packet forwarding performance control interface; To limit the end-to-end bandwidth based on the end-to-end bandwidth descriptor transmitted from the packet forwarding performance control interface, measure and monitor the number and size of packets actually transmitted per unit time among the packets belonging to each packet flow. Traffic regulator 15 to adjust; And a packet forwarding performance meter that continuously measures and monitors the loss rate, delay, delay variation, and bandwidth provided by the delay generator 13, the packet remover 14, and the traffic conditioner 15, and provides the status and results to the user. Including 16, The packet forwarding performance control interface generates actual values for each performance descriptor that the user arbitrarily specifies to simulate the packet forwarding performance, so that the delay generator 13, the packet canceler 14, and the traffic conditioner 15 are generated. By measuring the end-to-end packet delivery performance of the real Internet to be simulated by the simulator, it is possible to mimic the packet delivery performance of the Internet without making any changes to the function and structure of the terminals constituting the LAN. Simulator for mimicking Internet end-to-end packet forwarding performance in a local area network, which has no effect on the forwarding performance of irrelevant packets. The method of claim 1, And the connection means is one of a router, a hub, and a bridge. The method according to claim 1 or 2, The packet forwarding performance control interface, A performance modeler 17 which generates actual values for each performance descriptor according to a probabilistic model of a performance descriptor that is arbitrarily designated by a user, and delivers the actual values to the delay generator 13, the packet remover 14, and the traffic conditioner 15. Wow; In order to measure the end-to-end packet delivery performance of the real Internet that the simulator attempts to imitate, it is necessary to communicate with the hosts on the Internet. Simulator for mimicking Internet end-to-end packet forwarding performance on a local area network, including. The method according to claim 1 or 2, The delay generator 13, Simulator for imitation of Internet end-to-end packet transfer performance in a local area network, characterized in that the out of order packets can be generated by allowing the delay variation to be applied to the packet to be larger than the time interval between packets.