JPH118633A - User-oriented input type network design device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a network design apparatus which does not require a designer to individually set traffic parameters and can reduce the amount of calculation (time). A network design apparatus for designing a network connecting nodes based on given node arrangement information and inter-node traffic information, comprising: a node arrangement information and an inter-node traffic information input from an input unit. A design unit 400 that determines the link configuration and link speed of the network connecting the nodes based on the link configuration 220 and transfers the link configuration and link speed to the calculation unit 500; and a network cost based on the link configuration and link speed and the input inter-node traffic information. An apparatus having a calculation unit 500 for performing calculation and quality calculation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network design device, and more particularly to a user-oriented input type network design device capable of reducing the burden on a designer who is a user of the network design device.

[0002]

2. Description of the Related Art In a conventional network design, a peak rate, an average rate, a peak average ratio, a peak duration, and the like are input as detailed data of traffic generated between nodes, and the design is performed. quality
(Delay time, cell loss rate, etc.). FIG. 1 shows a network design module of a conventional network design apparatus. The network design device includes a control unit 1
In response to the instruction of 00, detailed traffic data such as the peak rate, average rate, peak average ratio, and peak duration input from the input unit 300 is stored in the design data storage unit 220. When the traffic input is completed, the network design device reads the office (node position) information from the design data storage unit 220 and transmits the information to the quality calculation unit 520.
The quality calculation unit 520 performs quality calculation such as a delay time and a cell loss rate. When the quality is required, the quality calculation unit 520
Sends the result to the design unit 400 and the design work storage unit 240. The design unit 400 generates a network skeleton based on the quality calculation result, and determines the bandwidth of each link.
When each link band of the network is determined, the design unit 400 stores the result in the design result storage unit 280.

[0003]

However, detailed traffic data such as the peak rate, average rate, peak average ratio, and peak continuation time in the above-mentioned prior art cannot be grasped without careful traffic observation. Also,
For designers who are users of network design equipment,
It was very difficult to understand the meaning of these parameter values and the effect on the design results. The conventional network design apparatus has a drawback that the designer must input all of these traffic detail data. In the quality calculation, MM is used for delay time calculation.
Various models and methods such as a lightweight cell estimation method and a non-parametric method exist for calculating a cell loss rate such as a PP model and a POISON model. For example, the MMPP has only an approximate solution based on a simulation that requires a matrix operation.
The amount of calculation increases in the square order. As described above, each method has a drawback that the amount of calculation is large and the calculation time is long. The present invention has been made in view of the above circumstances, and aims at solving the above-described problems in the conventional technology, so that a designer who is a user does not need to individually set traffic parameters. Another object of the present invention is to provide a network design device capable of reducing the amount of calculation (time).

[0004]

An object of the present invention is to provide a network designing apparatus for designing a network connecting nodes based on given node arrangement information and inter-node traffic information. Input section 300 for inputting information and traffic information between nodes
Means for determining the link configuration and link speed of the network connecting the nodes based on the node arrangement information and the inter-node traffic information input from the input unit 300, and transferring the link configuration and the calculation result to the calculation unit; When the quality does not satisfy the predetermined required value, the design unit 500 includes means for changing the link speed and transferring the changed link configuration and link speed to the calculation unit; The present invention is attained by a network design device having a calculation unit 200 that performs network cost calculation and quality calculation based on inter-node traffic information input from an input unit 300.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a network design apparatus according to the present invention, a function of setting and storing standard values of traffic parameters for each application and a standard value of customized traffic parameters are set in a conventional network design apparatus. By adding the function of storing and storing the data and the function of selecting the traffic parameters corresponding to the input application, the designer can simply select the position of the transmitting / receiving node of the traffic and the application used between them, and the designer can individually Even without setting
The detailed traffic data corresponding to the application can be transmitted to the quality calculator. Further, by adding a simple calculation function for calculating the delay time and the cell loss rate from only the peak rate to the quality calculation unit, the amount of calculation can be reduced and the number of designers can be shortened.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. FIG. 2 shows a network design module of the network design apparatus according to one embodiment of the present invention. Also,
FIG. 3 shows an example of user-oriented traffic input in the network design apparatus according to the embodiment, FIG. 4 shows an example of an application parameter standard value customizing function in the network design apparatus according to the embodiment, and FIG. FIG. 6 shows a specific example of a simple quality calculation formula in the network design device according to the embodiment. First, the network design module of the network design device shown in FIG. 2 will be described with reference to FIGS.

The network design device transmits the application name input from the input unit 300 (see FIG. 3A) to the design data storage unit 220 according to an instruction from the control unit 100. When the design data storage unit 220 receives the application name, the application parameter standard value storage unit 225 stores the peak rate, average rate, peak average ratio, and peak rate corresponding to the received application name.
Search for detailed traffic data such as peak duration
(See FIGS. 3 (2) and (3)). When the search for the traffic detail data is completed, the network design device transmits the searched traffic detail data from the design data storage unit 220 to the quality design unit 520 (see FIGS. 3 (4) and (5)). The quality design unit 520 performs quality calculations such as a delay time and a cell loss rate. When the quality is required, the quality design unit 520 sends the result to the design unit 400 and the design work storage unit 240.

The design section 400 generates a network skeleton based on the quality calculation result, determines the bandwidth of each link, and stores the result in the design result storage section 280. Also,
When the user wants to change the application parameter standard value to a customized value, the network design device is input from the application parameter customization input unit 310 according to the instruction of the control unit 100 (FIGS. 4A to 4C).
Reference) The application name and the parameter value to be changed are transmitted to the application parameter customization standard value storage unit 226 in the design data storage unit 220,
Remember. When the application parameter customization standard value is stored, the following operation is performed.

[0009] The network design device transmits the application name input from the application parameter customization input unit 310 to the design data storage unit 220 according to an instruction from the control unit 100. Design data storage unit 2
At 20, when the application name is received, the application parameter standard value storage unit 225 and the application parameter customization standard value storage unit 226 store traffic such as the peak rate, average rate, peak average ratio, and peak duration corresponding to the received application name. Explore detailed data. When the search is completed, the network design device
Transmits the searched traffic detail data to the application parameter selection unit 540. In the application parameter selection unit 540, when received from the application parameter customization standard value storage unit 226, the value is selected and passed to the quality design unit 520.
Performs quality calculations such as delay time and cell loss rate.

When there is no reception from the application parameter customization standard value storage unit 226 and only reception from the application parameter standard value storage unit 225, this parameter value is passed to the quality design unit 520,
Similar to the above, the quality calculation such as the delay time and the cell loss rate is performed. When the quality is required, the quality design unit 520 sends the result to the design unit 400 and the design work storage unit 240. The design unit 400 generates a network skeleton based on the quality calculation result, determines the bandwidth of each link, and stores the result in the design result storage unit 280. In the network design apparatus according to the present embodiment, it is assumed that the user can easily grasp only the peak rate, and the peak rate, the allowable delay time, and the allowable cell loss rate are used as the standard values of the traffic parameters for each application. Set. In setting the standard values, various experimental data and the following literature were referred to.

(1) "New Generation Communication Network Experiment / Application / Charge Review Report" New Generation Communication Network, 1995, published. In the network design apparatus according to this embodiment, calculation of delay time for CBR traffic is performed. Is calculated for the VBR traffic, and the bandwidth is determined so as to satisfy the allowable delay time (and cell loss rate) set for each application.

The following equation is used as the equation for calculating the delay time. CBR delay time = cell transmission time + average waiting time + PBX
Encoding / decoding time + celling / deceleration delay + transmission path delay VBR delay time = cell transmission time + average waiting time + cellization / decellation delay + transmission path delay The average waiting time W in the switch is calculated by the equation of FIG. 6A, which is a simplified version of the population arrival model described in the following reference (2) using only PCR.

(2) Tsuji, Kubota: "Performance evaluation of enterprise network design support system-Design of multimedia network integrating packet, voice and data-" IEICE Technical Report, SSE97-3,1997 Is easy to calculate, the M / M / 1 / (K + 1) model where the result is on the safe side, the CAC method that can be calculated in a short time regardless of the number of call sources, and the accuracy is small when the number of call sources is small. By adopting a good nonparametric method and combining the advantages of these three methods, a highly accurate value is calculated with a small amount of calculation. However, as in the calculation of the delay time, the equation of FIG. 6B simplified so that the cell loss rate Ploss can be obtained only from the PCR is used.

In the following, an existing design system in which a plurality of network integrators have already designed a corporate network for an actual user, and a network design apparatus according to the present embodiment (hereinafter, referred to as “apparatus of the embodiment”) For, evaluation and comparison of cost and processing time obtained by design are performed. The above-mentioned existing design system and the apparatus of the embodiment are installed on the same workstation,
Comparisons are made in the same working environment. In the device of the embodiment,
By selecting an application to be used, only PCR and required quality (permissible delay time, permissible cell loss rate) are set as input parameters used in the design, whereas in the existing design system, packet traffic is designed. It is necessary to set the packet size, average packet traffic, peak / average ratio, and allowable delay time.

Therefore, when comparing the two, the design parameters of the existing design system are set so as to correspond to the PCR selected by the apparatus of the embodiment. A. Design result (cost): Using the set parameter values in FIG. 10, the design results of the apparatus of the embodiment and the existing system are compared under the following evaluation conditions. <Evaluation conditions> * When increasing the number of offices, the offices are selected at random * The number of offices is 10, 20, 30, 40, 50 offices * The input traffic is the equipment of the embodiment: Only the ATM traffic (VBR), PCR
Is 128 kbit / s Existing system: Packet traffic only * In each case, two traffics in Fig. 10 are star-shaped from Tokyo to all other locations.

FIG. 7 shows the design result (cost). However,
The graph of FIG. 7 shows that the cost calculated by the existing system is 10%.
This is a value obtained by normalizing the calculation cost by the apparatus of the embodiment as 0. From FIG. 7, the cost calculated by the device of the embodiment is a difference of up to about 6% compared to the cost calculated by the existing system, and the design result by the device of the embodiment is almost appropriate. Recognize. In addition, in order to confirm the effect of using the simple formula using only the PCR in the quality calculation by the apparatus of the embodiment, in the case of 10 bases in FIG. 7, the PCR is constant, and the average rate of the existing system (=
FIG. 8 shows the effect on the design result when (packet size × average packet traffic) is changed. However, similarly to FIG. 7, the cost calculated by the existing system is 10%.
This is a value obtained by normalizing the calculation cost by the apparatus of the embodiment as 0.

In the apparatus of the embodiment, as described above, the average arrival time W is calculated using the collective arrival model, and the cell loss rate is calculated using the M / M / 1 / (K + 1) model. Are simplified so that they can be obtained only by PCR. However, as shown in FIG. 8, when compared with the calculation cost of the existing system, it can be seen that even if the average rate changes in the conventional system, the difference in cost from the apparatus of the embodiment is very small. Also, from the above-mentioned document (1) (see page 7) and the like, even in the case of an application having a high burst property, the burst rate (= PCR / SCR) is about 10, so that the peak rate is 128 kbit / s. , The average rate is considered to be at least 10 kbit / s or more. Therefore, it can be said from FIG. 8 that the cost difference between the apparatus of the embodiment and the conventional system is sufficiently small.

From the above results, it is possible to design a simple formula in which the quality calculation (delay time, cell loss rate) is not performed from the average rate and the peak rate as in the conventional system, but the calculation is performed only using the peak rate. It was confirmed that the results were satisfactory. B. Design Result (Processing Time): Next, the result of comparing the processing time of the apparatus of the embodiment with the conventional system under the same evaluation conditions as the previous section will be described with reference to FIG. According to FIG. 9, it can be seen that the processing time is about 1/6 at 50 locations as compared with the conventional system. Further, in the device of the embodiment,
It can be seen that the larger the number of bases, the faster the processing time.

The reason why the speed can be increased is that the calculation formula is simplified so that the quality calculation (delay time, cell loss rate) can be calculated only from the PCR.
In addition, the above-mentioned embodiment shows an example of the present invention,
It goes without saying that the present invention is not limited to this.

[0020]

As described above in detail, according to the present invention, it is not necessary for a designer who is a user to individually set traffic parameters, and a network design capable of reducing the amount of calculation (time). This has a remarkable effect that the device can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a network design module of a network design apparatus according to the related art.

FIG. 2 is a diagram showing a network design module of the network design device according to one embodiment of the present invention.

FIG. 3 is a diagram illustrating an example of a user-directed traffic input in the network design apparatus according to the embodiment;

FIG. 4 is a diagram illustrating an example of an application parameter standard value customizing function in the network design apparatus according to the embodiment.

FIG. 5 is a diagram illustrating a design example by a simple quality calculation in the network design apparatus according to the embodiment;

FIG. 6 is a diagram illustrating a specific example of a simplified quality calculation formula in the network design apparatus according to the embodiment.

FIG. 7 is a diagram (part 1) illustrating an example of a design result by a simple quality calculation in the network design apparatus according to the embodiment;

FIG. 8 is a diagram (part 2) illustrating an example of a design result by a simple quality calculation in the network design apparatus according to the embodiment.

FIG. 9 is a diagram (part 3) illustrating an example of a design result by a simple quality calculation in the network design apparatus according to the embodiment.

FIG. 10 is a diagram illustrating an example of setting parameter values in the network design apparatus according to the embodiment.

[Explanation of symbols]

Reference Signs List 100 control unit 200 storage unit 220 design data storage unit 225 application parameter standard value storage unit 226 application parameter customization standard value storage unit 240 design work storage unit 280 design result storage unit 300 input unit 310 application parameter customization input unit 400 design unit 500 calculation Section 520 quality calculation section 540 application parameter selection section

Claims (5)

[Claims] 1. A network design apparatus for designing a network connecting nodes based on given node arrangement information and inter-node traffic information, wherein the input unit inputs the node arrangement information and inter-node traffic information. Means for determining a link configuration and a link speed of a network connecting the nodes based on the node arrangement information and the inter-node traffic information input from the input unit, and transferring the link configuration and the quality to the calculation unit; If does not meet the predetermined requirement, change the link speed,
A design unit having means for transferring the changed link configuration and link speed to the calculation unit; and a network cost calculation and quality calculation based on the link configuration and link speed and the inter-node traffic information input from the input unit. A network design device comprising: a calculation unit for performing the calculation. 2. The system according to claim 1, further comprising: means for holding a standard value of a traffic parameter for each application used for communication between nodes, in addition to said constituent elements, wherein said input unit is configured to input said application information when inputting traffic information. 2. The network design apparatus according to claim 1, wherein a traffic parameter corresponding to the application name is retrieved from a unit that holds the traffic parameter standard value using the application name as a key. 3. The system according to claim 1, further comprising: a unit for storing a standard value list of application parameters specific to the network to be designed, in addition to each of the constituent elements, wherein the input unit supports the application when inputting traffic information. A traffic parameter to be searched is retrieved from the application parameter standard value list, and if it exists, its value is obtained. If it does not exist, the means for holding the traffic parameter standard value is retrieved using the application name as a key. The network design apparatus according to claim 2, wherein: 4. A delay time and a cell loss rate are calculated from a traffic peak rate, a calculation result is transmitted to the designing unit, and the designing unit determines a line band satisfying a required quality based on the calculated result. The network design apparatus according to claim 1, wherein 5. When calculating a delay time and a cell loss rate from the peak rate of the traffic, (1) the following equation is used as a calculation equation of the delay time: CBR delay time = cell transmission time + average wait time Time + PBX
Encoding / decoding time + celling / deceleration delay + transmission line delay VBR delay time = cell transmission time + average waiting time + celling / deceleration delay + transmission line delay average waiting time W = a / 2 (1− a) · h where h = 53 × 8 / v (v is the line speed: bit / sec) a = λ ^* · h (2) The following formula is used as a formula for calculating the cell loss rate. Cell loss rate Ploss = (1−ρ) / (1−ρ ^{K + 2} ) · ρ ^{K + 1} where (C is a coefficient) μ ⁻¹ = 53 × 8 / v (v is the line speed: bit / sec) ρ = λ / μ K is the buffer length in the exchange