JP3456406B2 - Traffic distribution method and traffic distribution value calculation device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traffic distribution method and a traffic distribution value calculating device, and particularly, in a communication network, call processing concentrates on a specific network device and the whole device is congested. In order to prevent performance degradation, based on the traffic data that is periodically measured, the outgoing call is regulated by another network device that is located before the congestion device, and the number of calls that arrive at the congestion device is reduced to reduce the congestion. The present invention relates to a traffic distribution method for reducing the load on the device and maintaining the processing capacity of the entire network, and a traffic distribution value calculation device suitable for use in this method.

[0002]

2. Description of the Related Art In the prior art, when congestion occurs in a device such as a switch or line of a communication network, the number of calls that can be processed by the congestion device is X out of the number of requests to the congestion device for processing. , the call to join to the congestion device classifies like call type and route, in a communication network that the number of outgoing calls class i belonging to the set G of that class was a _i,
Traffic measurement is performed periodically, and the number X of calls that can be processed by the congestion device is set to the next cycle k based on the measurement data of measurement cycle k-1.
By allocating to the number of calls x _{i, k} allocated to each congestion class for each class, and restricting the number of calls to be added to the congestion device of class i to be equal to or less than x _{i, k, the} total number of calls accepted by the congestion device is X _{i, k.} In the traffic control method that is limited to
The number of outgoing calls a _{i, k-1} for each class is measured as the measurement data of -1, and the number of allocated calls x of the class i of the cycle k is measured using this.
_{i, k}

[Equation 5] The traffic distribution method was adopted as follows. When this method is adopted, a call is regulated for each exchange on the calling side in order to regulate a call arriving at the congestion device, and a class is provided for each exchange.

As described above, in the conventional technology, the rate regulated for each call is equalized throughout the class.
That is, the number of distributed calls x _{i, k} is determined so that the fairness among users regarding communication opportunities is satisfied. According to this method, all of the allocated calls are regarded as completed calls, especially under the network conditions in which the number of calls that can be processed in each class is sufficiently large and they exceed the number of calls allocated to each class. Therefore, fairness among users is satisfied.
As for these technologies, for example, Shimogaki and Hasegawa "Can prevent congestion of telephones that are concentrated from all over the country" (NTT Technology Journal 1991.2), or Nakajima, Tokunaga, and Kawano "Absolute amount regulation is used. It is possible to refer to the description in "Proposal and performance evaluation of traffic congestion control method" (Journal of the Institute of Electronics, Information and Communication Engineers B-I Vol.J73-B-I No. 5, 1991).

[0004]

By the way, in addition to the congestion exchange, the network equipment includes a network equipment used for each class, for example, a line from the exchange serving as a regulation point to the congestion exchange. However, in the conventional technique as described above, since the network device for each class is not considered, there is a class in which the number of calls that can be processed by the network device used for each class is lower than the number of distributed calls. However, there is a problem that the number of completed calls in the entire network is low. For example, if the number of lines from the exchange that is the regulation point of class i to the congestion exchange is small with respect to the number of allocated calls x _{i, k,} the call may be lost without reaching the congestion exchange. Will be more likely. In other words, if the line capacity from the exchange to the congestion switch, which is the regulation point, is not taken into consideration, only the number of calls less than the number X of calls that can be processed by the congestion switch can be effectively processed, and the completed call of the entire network is completed. The number will be low.

In the above description, the line for each class is taken as an example, but as a network device used for each other class, the call processing processor of the exchange, which is the regulation point, has the same problem. . Further, in the above description, the class was divided for each exchange that is the regulation point,
The same problem also occurs when this class is set for each switch connected after the congestion switch, or for each network device connected after the congestion switch. An object of the present invention is to solve the above-mentioned problems in the prior art, and to control a call at the originating exchange based on periodic traffic measurement data at the time of congestion control in a communication network. Providing a traffic distribution method that maximizes the number of completed calls as a whole or maximizes the number of completed calls while maintaining fairness among classes as much as possible, and a traffic distribution value calculation device for realizing this To do.

[0006]

In order to achieve the above object, in the traffic distribution method according to the present invention, the number of calls that can be accepted by the congestion communication device is distributed for each class. In more detail, when congestion occurs in a device such as a switch or a line of a communication network, the number of calls that can be processed in the congestion device out of the calls requesting the congestion device is X, and the congestion Calls added to the device are classified by call type, route, etc., and traffic is periodically measured in a communication network in which the number of outgoing calls of class i belonging to the set G of the class is a _i , and a measurement cycle k
Based on the measurement data of -1, the congestion device processable call count X
Is allocated to the number of calls x _{i, k} allocated to each class in the next cycle k,
In the traffic control method of limiting the total number of calls accepted by the congestion device to X or less by limiting the number of calls to the congestion device of class i to be equal to or less than x _{i, k} , a measurement cycle k-1 completed call number b _i as the measurement data class _i, the call number x _'i for each actual class network accepts the _k-1, by measuring the _k-1, allocation completion ratio r _{i, k} for class i _-1

[Equation 6] Let f (z) be the non-decreasing function with respect to z _{, and the} number of distributed calls x _{i, k} of each class with period k

[Equation 7] It is characterized by

Further, the traffic distribution value calculating device 1 according to the present invention is capable of performing processing in a congestion device among calls requesting the congestion device to perform processing when congestion occurs in devices such as exchanges and lines of a communication network. A cycle in a communication network in which the number of calls is X, the calls added to the congestion device are classified into call types and routes, and the number of outgoing calls of class i belonging to the set G of the class is a _i Based on the measurement data of the measurement cycle k−1, the congestion device processable call count X is distributed to the number of calls x _{i, k} allocated to each class in the next cycle k, and By restricting the number of calls to the congestion device to be less than or equal to x _{i, k} ,
A traffic distribution value calculating device for realizing a traffic control method for limiting the total number of calls accepted by the congestion device to X or less, and receiving the traffic measurement data from a communication network device including the congestion device 2, A measurement data management unit 5 that accumulates and notifies the distribution value determination unit 4 below, and receives the traffic measurement data from the measurement data management unit 5, calculates a traffic distribution value based on this, and includes the congestion device 2 And a distribution value determination unit 4 for notifying the communication network device.

With respect to the first invention, firstly, f (r _{i, k-1} )
The operation when = 1 is described. In this case, the number of calls x _i allocated to each class in each cycle is simply determined by the number of completed calls. Since the number of completed calls is close to each other, the number of distributed calls proportional to the number of calls that can be processed by the network device for each class approaches each time the distribution update is repeated. The number of distributed calls that is proportional to the number of calls that can be processed means that the margin of the number of calls that can be processed is shared among the classes.
Only a certain class can be prevented from having an extremely large or extremely small number of allocated calls than the number of calls that can be processed, and the number of completed calls is maximized. In this invention, appropriate f
If (r _{i, k-1} ) is given, in addition to the number of completed calls approaching the maximum each time the distribution update is repeated, the number of completed calls can approach the maximum faster. F above
Other than (r _{i, k-1} ) = 1, for example, f (r _{i, k-1} ) = r _{i, k-1}
In the case of, the class having the low completion rate r _i, k-1 in the cycle k−1 is more allocated than the class having the high completion rate r _{i, k−1.} In the case of ( ₁₎ , a smaller allocation to the class having a low completion rate r _{i, k−1} accelerates the convergence of the number of completed calls to the maximum. For example,
This is satisfied when f (r _{i, k-1} ) = r _{i, k-1} .

The second aspect of the present invention is that the regulated rate for each call in the conventional method is equalized throughout the class, and the effective point of the first aspect is that the number of completed calls is maximized. Satisfy. Under the condition that the number of calls that can be processed in all classes is large enough to exceed the number of calls allocated to each class, all the allocated calls will be completed calls.

[Equation 8] The part of does not work in the direction of changing the distribution. On the contrary,

[Equation 9] In the part of (1), the number of allocated calls is updated so that the call origination ratio is met. Under the updated new number of allocated calls,

[Equation 10] Part does not work in the direction of changing the allocation,

[Equation 11] In the part of (1), the number of allocated calls is updated so that the call origination ratio is met. In this way, when the number of calls that can be processed in each class is sufficiently large, the number of distributed calls is updated so that the ratio of outgoing calls becomes equal to the ratio of outgoing calls.

Under the condition that the number of calls that can be processed in all classes is sufficiently small and is less than the number of calls allocated to each class, only some of the allocated calls are completed calls.

[Equation 12] Part of the function works so that the allocation becomes the number of calls that can be processed in each class. On the contrary,

[Equation 13] In the part (1), the number of allocated calls is updated so that the calling ratio is matched, and as a result, 100α% of the number X of calls that can be processed by the congestion exchange follows the allocation of the calling number ratio. Therefore, if α is set to a somewhat small value (for example, 0.05), the deviation becomes small, and the number of completed calls becomes almost maximum. As described above, the second aspect of the present invention has the advantage that the regulation rate after transmission in the conventional method is equalized among the classes, and that the number of completed calls in the first aspect is maximized. It can be used properly according to the traffic conditions.

The above situation is shown numerically. Here, consider the following model. FIG. 1 is a network diagram for showing the operation. Here, there are two types of classes as conditions of the model, the number of calls a _i of the class i and the number of processable calls d _i determined by the network device used only by the class i of the class i are constant during traffic control, k
The number of completed calls b _{i, k−1} of class i in −1 is determined by the following equation using the number of processable calls d _i , the number of distributed calls x _{i, k−1,} and the number of outgoing calls a _i. To do.

[Equation 14] In addition, the traffic conditions in Table 1 are given here.

[Table 1] The initial distribution ratio here is a ratio for allocating the number X of calls that can be processed by the congestion exchange to each exchange that is the regulation point immediately after the congestion in a certain exchange is detected. This value is a predetermined value irrespective of the traffic situation at the time of detection. Here, two cases in Table 2 are considered as the number of calls that can be processed by the congestion exchange.

[Table 2] In addition, here, in order to simplify the description, it is assumed that f (z) = 1 in the methods according to the first and second inventions. Furthermore, the second
The parameter α in the method according to the invention is set to 0.1.

2 to 4 show how the distribution ratio number to each class is periodically updated after congestion is detected. First, the calling ratio distribution used in the conventional technique will be described (see FIG. 2). In case 1, when the calling ratio distribution is performed, the number of calls allocated at that time is lower than the number of calls that can be processed in each class. That is, under this network condition, the conventional technique works effectively, the number of completed calls is maximized because all the distributed calls for the number of calls that can be processed by the congestion exchange are completed, and the regulation rate for outgoing calls is also high. Equalized and fair control. In case 2, when the calling ratio distribution is performed, the number of calls allocated to class # 1 at that time exceeds the number of calls that can be processed in class # 1, and the number of calls allocated to class # 2 is the number of calls that can be processed in class # 2. Fall below. That is, under this network condition, not all the number of calls that the congestion switch can handle can be completed. Under this network condition, as long as the number of completed calls is maximized, the restriction rate for outgoing calls is not equalized and fair control cannot be performed.

Next, the distribution in the first invention will be described (see FIG. 3). In case 1, when the first distribution is performed, the number of distributed calls at that time is less than the number of calls that can be processed in each class. That is, under this network condition, since all the distributed calls corresponding to the number of calls that can be processed by the congestion exchange are completed, the number of completed calls is maximized. In the case of Case 2, when the initial distribution is performed and the calling ratio distribution at that time is performed, the number of distributed calls of class # 1 at that time exceeds the number of calls that can be processed by class # 1, and the number of distributed calls of class # 2 is class#
2 is less than the number of calls that can be processed. According to this method, a large number of calls are allocated to a class having a large number of completed calls in the second and subsequent allocations. As the number of distributed calls is updated, the ratio of the number of completed calls among the distributed calls of each class is equalized. As a result, the number of completed calls is maximized.

Next, the distribution in the second invention will be described (see FIG. 4). In case 1, when the first distribution is performed, the number of distributed calls at that time is less than the number of calls that can be processed in each class. That is, under this network condition, since all the distributed calls corresponding to the number of calls that can be processed by the congestion exchange are completed, the number of completed calls is maximized. Further, as the number of distributed calls is updated, the call ratio distribution converges. In the case of Case 2, as in the case of the first invention, when the first distribution is performed, the number of distributed calls of class # 1 at that time exceeds the number of calls that can be processed by class # 1, and the number of distributed calls of class # 2. Is less than the number of calls that can be processed in class # 2. According to this method, a large number of calls are allocated to a class having a large number of completed calls in the second and subsequent allocations. As the number of allocated calls is updated,
If the constant α is set to be small, the ratio of the number of completed calls among the distributed calls of each class is almost equalized. As a result, the number of completed calls is maximized.

As described above, in the call ratio distribution used in the prior art, the number of completed calls is maximized in case 1 and fair regulation can be achieved, but the number of completed calls is not maximized in case 2. . On the other hand, in the method according to the first aspect of the present invention, the number of completed calls is maximized in both cases 1 and 2. In the method according to the second aspect of the invention, the number of completed calls can be maximized only in case 1, and fair regulation can be realized.
In case 2, the number of completed calls is almost maximized. Next, the distribution in the third invention will be described. Also in the first and second inventions, the number of distributed calls is periodically updated as described above. However, if the number of distributed calls for class i exceeds the actual number of calls for class i,
There is a possibility that the processing capacity of the congestion exchange will be surplus and the number of completed calls will decrease. Therefore, by redistributing the number of calls in each class,
It is possible to prevent the number of completed calls from decreasing.

[0016]

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. First Embodiment FIG. 5 shows a network device related to a traffic distribution value calculating device. The congestion switching system 2 is a switching system that requests the calling regulation switching system 3 to regulate the calling because the number of calls to be processed increases and the congestion state occurs. The outgoing call restriction exchange 3 is an exchange that restricts outgoing calls based on the number of calls allocated to the congestion exchange 2, and there are a plurality of switches in the network. The calling number regulation exchange 3 measures the number of calls for each class (calls not subject to regulation) accepted by the actual network and the number of completed calls for each class during congestion of the congestion exchange 2.

The traffic distribution value calculation device 1 is a device for calculating the number of calls distributed to the class i based on the traffic measurement data, and is composed of a measurement data management unit 5 and a distribution value determination unit 4. The measurement data management unit 5 receives the traffic data from the call number regulation exchange 3 and the congestion exchange 2, which are related network devices, and notifies them to the allocation value determination unit 4. Further, it notifies the distribution control unit 3 of the distribution value calculated by the distribution value determination unit 4. The distribution value determination unit 4
The traffic distribution value is determined based on the traffic measurement data received from the measurement data management unit 5.

FIG. 6 shows a flow for determining a traffic distribution value according to the first embodiment. The details of the procedure are shown below. Step 11: The calling number regulation exchange 3 instructs the measurement data management unit 5 to actually accept the number of calls x ′ _{i, k−1} for each class and the number of completed calls b _{i, k} for each class in the cycle k−1. _-1 is notified. Step 12: The congestion exchange 2 has the measurement data management unit 5
To the number X of calls that the congestion exchange 2 can process in the next cycle. Step 13: The measurement data management unit 5 uses the distribution value determination unit 4
To the number of calls that can be processed X and the traffic measurement value b of cycle k-1
_{i, k-1} and x _'i, to notify the _k-1.

Step 14: The distribution value determining unit 4 determines the distribution call number x _{i, k} for the cycle k for each class i which is an element of the class set G.

[Equation 15] However,

[Equation 16]

[Equation 17] The measurement data management unit 5 is notified of the result. Step 15: The measurement data managing unit 5 notifies the call regulation exchange 3 of the number of distributed calls x _{i, k} for the cycle k.

Embodiment 2 FIG. 5 shows a network device related to the traffic distribution value calculation device. This configuration
This is the same as in the first embodiment. FIG. 7 shows a flow of determining a traffic distribution value according to the second embodiment. The details of the procedure are shown below. Step 21: The number-of-calls regulation exchange 3 notifies the measurement data management unit 5 of the number of calls a for each class in the cycle k−1.
_i, the call number x _'i for each class actually received the _{k-1, k-1} and the number of completed calls per class b _i, and notifies the _k-1. Step 12: The congestion exchange 2 has the measurement data management unit 5
To the number X of calls that can be processed in the next cycle of the congestion exchange 2 (the same as in the first embodiment). Step 13: The measurement data management unit 5 uses the distribution value determination unit 4
To the number of calls that can be processed X and the traffic measurement value b of cycle k-1
_{i, k-1} and x _'i, and notifies the _k-1 (same as Example 1).

Step 24: The distribution value determination unit 4 determines the distribution call number x _{i, k} for the cycle k for each class i which is an element of the class set G.

[Equation 18] However,

[Formula 19]

[Equation 20] It is calculated by α = 0.05 and the measurement data management unit 5 is notified of the result. Step 25: The measurement data management unit 5 uses the call regulation exchange 3
Notify the number of allocated calls x _{i, k} for cycle k to.

Third Embodiment FIG. 5 shows a network device related to the traffic distribution value calculating device. This configuration
This is the same as in the first embodiment. FIG. 8 shows a flow of determining a traffic distribution value according to the third embodiment. The details of the procedure are shown below. Step 21: The number-of-calls regulation exchange 3 notifies the measurement data management unit 5 of the number of calls a for each class in the cycle k−1.
_i, the call number x of each class actually received the _{k-1 'i,} the number of completed calls per _k-1 and class b _i, and notifies the _k-1 (same as Example 2). Step 12: The congestion exchange 2 has the measurement data management unit 5
To the number X of calls that can be processed in the next cycle of the congestion exchange 2 (the same as in the first embodiment). Step 13: The measurement data management unit 5 uses the distribution value determination unit 4
To the number of calls that can be processed X and the traffic measurement value b of cycle k-1
_{i, k-1} and x _'i, and notifies the _k-1 (same as Example 1).

[0024] Step 34: distribution value determining unit 4, by the same procedure as in step 24, x _i, calculate the _k, calculated allocated call number x _i, for _k, x _{i, k>} a _{i, k} Let H be the set of classes that are _-1 and the elements of H

[Equation 21]

[Equation 22] And the elements not included in H

[Equation 23]

[Equation 24] And the number of allocated calls for all classes is x _{i, k} : = w
_The measurement data management unit 5 is notified as _{i, k} . Step 35: The measurement data management unit 5 uses the call regulation exchange 3
Notify new distribution call number x _{i, k} for cycle k.

Fourth Embodiment FIG. 5 shows a network device related to the traffic distribution value calculating device. This configuration
This is the same as in the first embodiment. FIG. 9 shows a flow of determining a traffic distribution value according to the fourth embodiment. The details of the procedure are shown below. Step 21: The number-of-calls regulation exchange 3 notifies the measurement data management unit 5 of the number of calls a for each class in the cycle k−1.
_i, the call number x of each class actually received the _{k-1 'i,} the number of completed calls per _k-1 and class b _i, and notifies the _k-1 (same as Example 2). Step 12: The congestion exchange 2 has the measurement data management unit 5
To the number X of calls that can be processed in the next cycle of the congestion exchange 2 (the same as in the first embodiment).

[0026] Step 13: the measurement data management unit 5 notifies the distribution value determining unit 4, processable number of calls X and cycle k-1 of the traffic measurements b _{i, k-1} and x _'i, the _k-1 (Same as Example 1). Step 44: The distribution value determining unit 4 calculates x _{i, k} by the same procedure as in Step 24, and the calculated distribution call number x
_{For i, k} ,

[Equation 25] Then, the measurement data management unit 5 is notified of the new x _{i, k} as the number of distributed calls. Step 45: The measurement data management unit 5 calls the call regulation exchange 3.
Notify new distribution call number x _{i, k} for cycle k.

It is needless to say that the above-mentioned embodiment shows an example of the present invention, and the present invention should not be limited to this. For example, in the above embodiment, the line for each class is considered, but the processor for call processing of the exchange, which is the regulation point as the network device used for each other class, is also considered. Further, in the above embodiment, the class was divided for each exchange as a regulation point, but this class is for each exchange connected to the latter stage than the congestion exchange, or a network connected to the latter stage than the congestion exchange. It is also considered as a target. Also, this example
In the traffic allocation method in
When the number of completed calls of class i becomes zero in k-1
If there is a class i call in the subsequent cycles,
Even so, the number of calls allocated to class i has become zero
There is a possibility that the
May be unfair. In addition, consider a class i call.
Unreasonably, determining the number of calls allocated in the next cycle is not complete.
The number of completed calls may not be maximized. So, to some extent
By giving at least a small number of distributed calls
Prevent the number of calls allocated to class i from becoming zero
be able to.

[0028]

As described above in detail, according to the present invention, a traffic distribution method capable of maximizing the number of completed calls in the entire network, and a traffic distribution value calculation device for realizing the method. It is possible to provide a remarkable effect.

[Brief description of drawings]

FIG. 1 is a diagram showing a model of a network.

FIG. 2 is a diagram showing an evaluation result (No. 1) for showing the action.

FIG. 3 is a diagram showing evaluation results (No. 2) for showing the action.

FIG. 4 is a diagram showing evaluation results (No. 3) for showing the action.

FIG. 5 is a configuration diagram of a traffic distribution value calculation device according to the first to fourth embodiments.

FIG. 6 is a flow chart for determining a traffic distribution value according to the first embodiment.

FIG. 7 is a flow chart for determining a traffic distribution value according to the second embodiment.

FIG. 8 is a flowchart of traffic distribution value determination according to the third embodiment.

FIG. 9 is a traffic distribution value determination flow chart according to the fourth embodiment.

[Explanation of symbols]

1 Traffic distribution value calculation device 2 Congestion switch 3 Call control exchange 4 Allocation value determination unit 5 Measurement data management section

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-4-119053 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04M 3/00

Claims (5)

(57) [Claims] 1. The number of calls that can be processed by the congestion device out of the calls requesting the congestion device to process at the time of congestion of a device such as a switch or a line of a communication network is X,
Calls added to the congestion device are classified by call type, route, etc., and traffic measurement is periodically performed in a communication network in which the number of outgoing calls of class i belonging to the set G of the class is ai, and a measurement cycle k Based on the measurement data of -1, the congestion device processable call number X is distributed to the distribution call number xi, k for each class in the next cycle k, and the number of calls added to the congestion device of the class i is xi, k. In the traffic control method in which the total number of calls accepted by the congestion device is limited to X or less by restricting the number of calls as follows, the number of completed calls of class i, bi, k-1, The number of calls x'i, k-1 actually accepted by the network is measured, and the distribution completion ratio r i,
k-1 is [Equation 1] Let f (z) be the non-decreasing function with respect to z, and the number of distributed calls xi, k of each class with cycle k to be Traffic distribution method. 2. In addition to the number of completed calls bi, k-1 for each class and the number of calls x'i, k-1 actually accepted by the network for each class as the measurement data of the measurement cycle k-1, The number of outgoing calls ai, k-1 is measured, α is a predetermined constant of 0 or more and 1 or less, and the distribution completion ratio ri, k-1 is expressed by And the non-decreasing function for z is f (z), and the number of distributed calls xi, k of each class with period k is given by The traffic control method according to claim 1, wherein 3. When the number of outgoing calls ai, k-1 for each class is measured and xi, k is calculated, if xi, k of class i exceeds ai, k-1, then xi, k Is set to ai, k-1, and the reduced number of calls is redistributed to another class j whose xj, k is lower than aj, k-1. 4. When xi, k of class i exceeds ai, k-1 after calculating xi, k based on the measurement result of the number of outgoing calls ai, k-1 for each class, xi , k is set to ai, k-1, and the reduced number of calls is reallocated to another class j in which xj, k is lower than aj, k-1. 5. The number of calls that can be processed by the congestion device out of the calls requesting the congestion device to process when the device such as a switch or line of a communication network is congested is X,
Calls added to the congestion device are classified by call type, route, etc., and traffic measurement is periodically performed in a communication network in which the number of outgoing calls of class i belonging to the set G of the class is ai, and a measurement cycle k Based on the measurement data of -1, the congestion device processable call number X is distributed to the number of calls xi, k allocated to each class in the next cycle k, and the number of calls added to the congestion device of class i is xi, k or less. A traffic distribution value calculating device for realizing a traffic control method for limiting the total number of calls accepted by the congestion device to X or less by restricting the congestion distribution device from the communication network device including the congestion device. A measurement data management unit that receives traffic measurement data, accumulates it, and notifies the distribution call number determination unit described below, and receives the traffic measurement data from the measurement data management unit. Ri, according to any one of claims 1 to 4 based on this
Traffic distribution value calculating apparatus for calculating the traffic distribution call number by the traffic distribution method and notifying it to a communication network apparatus including the congestion apparatus.