JP3434921B2 - Congestion control device and method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a congestion control device and method used for controlling transmission data in a frame relay terminal, a frame relay switch and the like.

[0002]

2. Description of the Related Art As a conventional example showing a conventional congestion control apparatus and method, there is one as shown in FIG. FIG. 2 is a block diagram showing the configuration of a congestion control device that implements a conventional congestion control method.

In FIG. 2, reference numeral 21 is a reception time registration unit, 22 is a calculation unit for calculating transmission intervals and data lengths of transmission data, and 23 is a transmission determination for guaranteeing access speed and controlling congestion for each connection. Reference numeral 24 is a receiving buffer memory for storing received data.

Next, with reference to FIG. 2 as well, the operation of the congestion control device according to the conventional example will be described. First, when data is received, the received data is stored in the reception buffer memory 24, and the reception time is registered in the reception time registration unit 21. Therefore, the receiving buffer memory 2 is externally supplied.
The arrow for 4 indicates the storage of received data, and the arrow from the reception buffer memory 24 to the transmission determination unit 23 indicates the position on the buffer of the reception buffer memory 24.

Further, the arrow that goes out from the transmission determination unit 23 indicates the transmission of data, and the arrow from the reception time registration unit 21 to the calculation unit 22 indicates the timing of the reception time and the data length thereof. The calculation unit 22 calculates the data transmission interval and the data length, and the transmission determination unit 23 guarantees the access speed for each connection and controls the congestion . The arrow from the calculation unit 22 to the transmission determination unit 23 indicates the calculation result of the data transmission interval and the data length.

That is, also in the congestion control device according to the above-mentioned conventional example, the reception timing and its data length are calculated based on the reception time registered in the reception time registration unit 21.
Sent to 2. In the calculation unit 22, the transmission interval of transmission data, each data length, etc. are calculated and sent to the transmission determination unit 23, where the access speed guarantee and congestion control for each connection are effectively performed.

[0007]

However, in the conventional congestion control method as shown in FIG. 2, the judgment of the discard of the transmission data is made mainly by the transmission interval in the same connection, so that it is guaranteed instantaneously. However, there is a problem that the amount of calculation increases or cannot cope with the burst data of the connection that exceeds the access speed, and as a result, the transmission line cannot be used up effectively.

The present invention has been made in order to solve the problems in the conventional congestion control method as described above, and is capable of handling burst data and guaranteeing the access speed set for each connection. An object of the present invention is to provide a congestion control device and method capable of maximally utilizing a transmission path.

[0009]

In order to achieve the above-mentioned object, a congestion control device according to the present invention is provided with a common buffer memory for holding received transmission data on the receiving side of the congestion control device, and transmits the transmission data. Before transmission to the road, hold it temporarily to smooth the variations in the data arrival rate, set a timer to set the unit time, and a communication management unit to control the amount of transmission data, and to set the data for each connection (or link). It is characterized in that a transmission amount and a threshold value are set so that a fixed amount of data is transmitted in a fixed unit time on all connections.

Further, the congestion control system according to the present invention, for achieving the above object, a terminal communicating simultaneously via a plurality of connections, congestion controller for congestion <br/> control of the transmission data in the exchange, etc. Therefore, the common buffer memory that temporarily holds the received transmission data and the transmission data amount and threshold value of each connection are determined based on the transmission request from the common buffer memory, and whether the transmission data is transmitted or discarded based on the congestion control. And a protocol processing unit that is connected to the communication management unit and that sets a certain unit time required for transmission, and a protocol processing unit that performs protocol processing to transmit the transmission data. It is a thing.

In the congestion control device according to the present invention, in order to achieve the above-mentioned object, the communication management unit is [rule] V: interface access speed (physical speed) T _c × V: the access speed V At, unit time Tc
Amount of data that can be transmitted between I _i : arbitrary connections B _I1 , B _I2 , ..., B _Im : each connection (I1,
I2, ..., Im) threshold value (allowable transmission data amount during unit time Tc) B _Ii : threshold value (allowable transmission data amount) of each connection (I _i ) ΣB _Ii : total threshold value of all connections At this time, ΣB _Ii is in accordance with ΣB _Ii ≦ T _c × V (1 ≦ i ≦ m) (Rule-1), and b _Ii : t = 0 to t = T (of each connection I _i ) 0 ≦ T
≦ T _c ) The amount of transmitted data that can be transmitted, t: an arbitrary time between time variables T: 0 to T _c, Lt: the data length of the current transmission data, and when t = 0, b _Ii = 0 (1 ≦ i ≦ m), when t = T> 0, the received transmission data belongs to the connection I _i , and when b _Ii + L _T ≦ B _Ii , the data is transmitted as it is. , ... (rule -2) when b _Ii + L _T> B _Ii performs congestion control, based on ... (rule -3), determines a threshold value and the transmission data amount of all connections, send data Is transmitted or congestion control is performed.

Further, in order to achieve the above object, the congestion control device according to the present invention is such that when the communication management unit [rule] b _Ii + L _T > B _Ii ( congestion control),

[0013]

[Equation 3]

Based on the above, it is characterized in that it includes means for deciding whether to transmit the transmission data or discard it.

Further, in the congestion control device according to the present invention, in order to achieve the above object, the communication management unit cooperates with a timer to set a unit time, a maximum data unit length (L _max ) and a minimum allowable access. [Rule] showing the relationship with the velocity (V _In ), where c: c >> 1 and a sufficiently large constant value, T _c > c × L _max / V _In (rule) _Where L _max : maximum data unit length V _In : minimum allowable access speed (V _I1, V _I2,
······················ _{, Vmin} ) based on the minimum speed).

Further, in the congestion control device according to the present invention, in order to achieve the above object, the communication management unit cooperates with a timer to secure (allow) the connection and the communication for the connection (V _Ii ). = B _Ii /
T _c ) and set the access speed of the connection (V _I1 ,
Of the V _I2 , ..., V _Im , the minimum access speed (V
_min ) and the unit time, [Rule] The minimum access speed V _min is determined, and the unit time of each connection is fixed as T _c = c × L _max / V _min (c is c >> 1). Value) and the threshold value of each connection is B _Ii = T _c × V _Ii (1 ≦ i ≦ m)
It is characterized by including means for determining the unit time of each connection and the threshold value of the transmission data based on the above.

The congestion control method according to the invention, for achieving the above object, a terminal communicating simultaneously via a plurality of connections, a congestion control method for performing congestion control of the transmission data in the exchange or the like, the transmission data In the transmission side interface, the transmission data amount of all the connections (I1, I2, ..., Im) is measured at the same time for each unit time (Tc), and a threshold value is set in advance for each connection, and the transmission for each connection is performed. [Rule] V: Interface access speed (physical speed) _Tc x V: Unit time Tc at the access speed V
Amount of data that can be transmitted between I _i : arbitrary connections B _I1 , B _I2 , ..., B _Im : each connection (I1,
I2, ..., Im) threshold value (allowable transmission data amount during unit time Tc) B _Ii : threshold value (allowable transmission data amount) of each connection (I _i ) ΣB _Ii : total threshold value of all connections At this time, ΣB _Ii is in accordance with ΣB _Ii ≦ T _c × V (1 ≦ i ≦ m) (Rule-1), and b _Ii : t = 0 to t = T (of each connection I _i ) 0 ≦ T
≦ T _c ) The amount of transmitted data that can be transmitted, t: an arbitrary time between time variables T: 0 to T _c, Lt: the data length of the current transmission data, and when t = 0, b _Ii = 0 (1 ≦ i ≦ m), when t = T> 0, the received transmission data belongs to the connection I _i , and when b _Ii + L _T ≦ B _Ii , the data is transmitted as it is. , ... (rule -2) when b _Ii + L _T> B _Ii performs congestion control, determined by ... (rule -3), to determine whether congestion control whether to transmit the transmission data It is characterized by comprising each step.

Further, in order to achieve the above-mentioned object, the congestion control method according to the present invention uses the transmission data amount and the threshold value for each connection when the connection has transmission data that must be transmitted exceeding the threshold value. Rule] When b _Ii + L _T > B _Ii ( congestion control),

[0019]

[Equation 4]

On the basis of the above, the method further comprises the step of determining whether to transmit the transmission data or discard it.

Further, in order to achieve the above-mentioned object, the congestion control method according to the present invention has a unit time (T _c ) of the unit time, the maximum data unit length (L _max ) and the minimum allowable access speed. [Rule] showing the relationship with (V _In ), where c: c >> 1 and a sufficiently large constant value, T _c > c × L _max / V _In (rule) where , L _max : maximum data unit length V _In : minimum allowable access speed (V _I1, V _I2,
...., characterized in that so as to ensure the communication in the V _Im comprising determining, based on the minimum rate of), to a threshold of the connection with the lowest threshold (B _In) (I _n) It is what

In order to achieve the above-mentioned object, the congestion control method according to the present invention sets a connection and an access speed (V _Ii = B _Ii / T _c ) at which communication for the connection should be guaranteed (allowed). , The relation between the minimum access speed (V _min ) of the connection access speeds (V _I1 , V _I2 , ..., V _Im ) and the unit time. [Rule] The minimum access speed V _min is determined. Then, the unit time of each connection is determined by T _c = c × L _max / V _min (c is a constant value of c >> 1), and the threshold value of each connection is B _Ii = T _c × V _Ii (1 ≦ i ≦ m)
Based on the rule, and, including each step to determine the threshold value of the unit time of each connection and the amount of transmission data, based on the rules, and, automatically guarantee the set speed of all connections, transmission, discard, etc. It is characterized in that processing is performed.

[0023]

The congestion control apparatus and method according to the present invention is configured as described above, and by providing the common buffer memory on the data receiving side, the data reception with uneven arrival rate is smoothed and each connection is connected. By setting the data transmission amount and the threshold value and transmitting a fixed amount of data in a fixed unit time for all connections, the transmission processing against bursty occurrence of transmission data and the access speed guarantee for each connection are performed more finely. It was done like this.

Further, the congestion control device and method according to the present invention are configured as described above, and the minimum access speed of each connection is guaranteed by [rule] based on the threshold value set for each connection. Is.

Further, the congestion control device and method according to the present invention are configured as described above, and further, based on the (rule),
It can be effectively transmitted even in the access speed area other than the guaranteed access speed of each connection.

Further, the congestion control device and method according to the present invention are configured as described above, and the unit time is set by the timer, so that regardless of the size of the data unit to be transmitted based on the [rule]. , The transmission is guaranteed up to the connection threshold having the minimum threshold, and the congestion control can be performed.

Further, the congestion control device and method according to the present invention are configured as described above, and based on the [rule], for each connection, determine the unit time at which the maximum transmission data unit can be transmitted at the minimum access speed. However, by setting the threshold of the amount of transmission data, the set access speed of each connection is guaranteed, and it is possible to effectively transmit the other access speed areas.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings and FIG. FIG. 1 is a block diagram showing a configuration of a congestion control device that implements a congestion control method according to an embodiment of the present invention with respect to a transmission section of a data terminal or a transmission section of a data repeater.

In FIG. 1, reference numeral 13 denotes a common buffer memory for storing transmission data when a transmission data transmission request is made.
4 shows a transmission data transmission request to the congestion control device and the transmission data. 11 is a communication management unit for evaluating the common buffer connection belongs the received data stored in the memory 13 of the received data _{I 1, I 2, ····,} I m and the data length, from the shared buffer memory 13 The arrow for the communication management unit 11 indicates the acquisition of transmission data requested to be transmitted, and includes actual data, data length, connection information to which the data belongs, and the like.

Further, 12 is a timer for starting and expiring a unit time for transmission time control and notifying the unit time to the communication management unit 11. From the timer 12 to the communication management unit 11
An arrow for indicates a notification that a unit time has elapsed. Reference numeral 14 denotes a protocol processing unit that performs a process such as a protocol on the transmission data under the control of the common buffer memory 13 and transmits the data. The arrow from the communication management unit 11 to the protocol processing unit 14 indicates the transmission permitted by the communication management unit 11. The arrow indicating the possible transmission of data indicates the transmission data transmitted from the congestion control device to the external transmission path.

Similar to the above, the operation of the congestion control apparatus according to this embodiment and the congestion control method thereof will be described below with reference to FIG. First, when a data transmission request is issued to this congestion control device, the received transmission data is stored in the common buffer memory 13. Then, the transmission request is sent to the communication management unit 11 together with the transmission data stored in the common buffer memory 13, and the transmission data is sent there.
The connection (or link) to which the transmission data belongs and the data length are evaluated and calculated. When the amount of received transmission data exceeds the capacity of the transmission path, the received data is temporarily stored in the common buffer memory 13 and waits for processing.

In one embodiment of the present invention, the amount of data that can be transmitted within a predetermined unit time (which can be calculated according to one embodiment of the present invention below) is limited or controlled for each connection according to the following [rule]. Therefore, even if only the transmission data amount of a certain connection is projected, the transmission allowable data amount of another connection is not transmitted. In that sense, it can be said that the present congestion control device controls the congestion of each connection.

[Rule] V: Interface access speed (physical speed) T _c × V: Unit time Tc at the access speed V
Amount of data that can be transmitted between I _i : arbitrary connections B _I1 , B _I2 , ..., B _Im : each connection (I1,
I2, ..., Im) threshold value (allowable transmission data amount during unit time Tc) B _Ii : threshold value (allowable transmission data amount) of each connection (I _i ) ΣB _Ii : total threshold value of all connections Then, ΣB _Ii is in accordance with ΣB _Ii ≦ T _c × V (1 ≦ i ≦ m) (Rule-1),

B _Ii : t = 0 to t = T (0 ≦ T of each connection I _i )
≦ T _c ) The amount of transmitted data that can be transmitted, t: an arbitrary time between time variables T: 0 to T _c, Lt: the data length of the current transmission data, and when t = 0, b _Ii = 0 (1 ≦ i ≦ m), when t = T> 0, the received transmission data belongs to the connection I _i , and when b _Ii + L _T ≦ B _Ii , the data is transmitted as it is. , ... (rule -2) when b _Ii + L _T> B _Ii performs congestion control, which shall be determined by ... (rule -3).

As can be seen from the above [Rule], when the transmitted data amount (b _Ii ) of each connection has not reached the respective threshold (Rule-2), the communication management unit 11
Sends the transmission data as it is to the protocol processing unit 14.
In addition, when each threshold is reached (Rule-3)
In this case, the data transmission rate for each connection is guaranteed by sending data to the protocol processing unit 14.
In addition to this [rule], the protocol processing unit 1
In 4, it is possible to perform finer control.

When the unit time expires by the timer 12,
Amount of transmitted data of each connection of the communication management unit 11 (b
_Ii ) and the amount of transmitted data of all connections (Σb _Ii or Σb _Ij : _i and _j are arbitrary) are cleared to zero, and transmission of the next unit time is started. The unit time by the timer 12 may be triggered continuously as long as there is transmission data to be transmitted to the common buffer memory 13.

However, in the case where more than the permissible data amount (B _Ii ) of all connections can be transmitted in the corresponding interface (when rule-1 is an inequality sign), in order to use the transmission line more sufficiently Is not enough with [rules] alone. Therefore, in this embodiment,
Data that exceeds the transmittable data amount of each connection (hereinafter referred to as T _c × V−ΣBI _i , hereinafter referred to as surplus data) should be transmitted as much as possible based on the following [rules], and the transmission line should be used efficiently. ing.

[Rule] When b _Ii + L _T > B _Ii ( congestion control),

[0039]

[Equation 5]

Based on the above, it is determined whether the transmission data is transmitted or discarded.

Since data transmission requests are made in a fixed order, it is considered that there are many data transmission requests for a certain connection instantaneously. The transmission path can be effectively used by transmitting by using the surplus data area in the order in which the transmission requests are generated without providing the transmission upper limit value for each connection. Even if the data of the connection (I _i ) reaches the allowable data amount (B _Ii ) before the expiration of the timer 12, as long as the condition based on the [rule] is satisfied, the protocol processing unit 14
It can be sent by sending data to. As a result, the amount of data discarded in the communication management unit 11 is suppressed.

Further, considering the effect of the common buffer memory 13, it is considered that the congestion control device of the present embodiment can further cope with burst data.
That is, if too much data is generated that cannot be sent,
It is retained in the common buffer memory 13 so that it is not immediately sent to the communication management unit 11. Since there are variations in the reception of data, the communication management unit 11 can process all the requested data in the common buffer memory 13 after the expiration of the timer 12 several times. During this time, this congestion control device [rule]
Therefore, I try to send data as much as possible.
Therefore, the burst data of a certain connection that occurs in a short period of time is smoothed, and it is possible to transmit more data than the allowable data amount.

[Rule] and [Rule] are used above.
The congestion control method does not mention how to determine the unit time T _c . The longer the unit time, the more accurate the results of the simulation by sampling the data amount due to the statistically large amount effect. Further, the longer the length, the more the buffer area of the common buffer memory 13 is required. In other words, the device to be realized becomes expensive. The length of the unit time is
It is considered that there is a trade-off relationship between congestion control accuracy and device cost.

Therefore, in the congestion control according to this embodiment, the problem is solved by using the following [rule]. That is, the [rule] is used to determine the minimum required unit time T _c according to the access speed and data amount of each connection.

[Rule] If c: c >> 1 and a sufficiently large constant value, T _c > c × L _max / V _In (rule) Here, L _max : maximum data Unit length V _In : Minimum allowable access speed (V _I1, V _I2,
·················· _{, Vim} , the unit time T _c is determined. The connection (I) having the minimum threshold value or the guaranteed data amount (B _In = MIN (B _Ii ): MIN means the minimum)
The communication up to the threshold of _n ) is guaranteed.

The unit data length is determined in a certain range (by frame, packet, etc.), paying attention to the maximum unit data length that will arrive here, and the maximum data unit length (L _max ) for any connection. If the data is requested to be sent at a rate that is acceptable, it must be sent.

In the congestion control device according to the present embodiment, the minimum guaranteed data amount (B _In ) of the connections exceeds the maximum data unit length (L _max ), so this connection is large or small in data units. No transmission is guaranteed. (For example, if the unit time is small and the guaranteed data amount is less than the maximum frame length, the maximum frame cannot be transmitted forever.)

That is, before the timer 12 times out, it is guaranteed that a plurality of data of the connection given the minimum access speed will be transmitted, so that the given speed is guaranteed for all the connections. Will be. Further, in the congestion control method according to the present embodiment, the minimum access speed (V _min ) is calculated from the authorized speed given to each connection based on the [rule], and the access speed and the protocol of data transmission are calculated. Depending on the maximum data unit length (L _max ), the unit time for congestion control and the amount of data that can be transmitted by each connection (B
_Ii ) can be determined.

[Rule] The minimum access speed V _min is determined, the unit time of each connection is determined by T _c = c × L _max / V _min (c is a constant value of c >> 1), and The connection threshold is B _Ii = T _c × V _Ii (1 ≦ i ≦ m)
Determined by

Further, in the congestion control method according to the present embodiment, the unit time calculated based on [Rule] is used to guarantee the data transmission to the connection having the lowest access speed. On the other hand, when the transmission to each connection occurs, if it is equal to or less than the data amount calculated according to (Rule-2), it is transmitted by the protocol processing unit 14. As shown in (Rule-3), in the case of more than that, according to [Rule], if possible, the data is transmitted. If it cannot be sent, discard it. In this way, the present congestion control method can provide effective congestion control that can reliably guarantee the authorized speed of each connection and can effectively use the transmission path.

In this embodiment, the data is fetched from the common buffer memory 13 in the order in which the transmission request is made and sent to the communication management section 11. At that time, priority is given to each connection or each data. You may change and take out. In that case, the effect of more detailed congestion control according to the present embodiment can be exhibited.

[0052]

The congestion control device and method according to the present invention are
By setting the data transmission amount and threshold value for each connection and sending a fixed amount of data in a fixed unit time for all connections, the access speed is guaranteed,
At the same time, by providing a common buffer memory on the data receiving side, data reception with uneven arrival rates is smoothed, and transmission processing against bursty generation of transmission data and access speed guarantee for each connection are more finely tuned. You can do it.

Further, the congestion control device and method according to the present invention determines the minimum access speed of each connection and determines the unit time and the threshold value of each connection based on the minimum access speed, thereby guaranteeing the minimum transmission speed. In addition, congestion control can be performed regardless of the size of the transmission data unit, and the unit time and threshold of each connection for each transmission data can be dynamically determined and changed. Therefore, the setting can be performed in real time according to the transmission status or the congestion.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a congestion control device that implements a congestion control method according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a congestion control device implementing a conventional congestion control method.

[Explanation of symbols]

11 Communication Management Department 12 timers 13 Common buffer memory 14 Protocol processing unit 21 Reception time registration section 22 Calculation Department 23 Transmission determination unit 24 Receive buffer memory

Claims (4)

(57) [Claims] 1. A congestion control device for controlling congestion of transmission data in a terminal, an exchange, etc., which simultaneously communicates via a plurality of connections, the common buffer memory temporarily holding received transmission data, and the common buffer memory. A communication management unit that determines the transmission data amount and threshold value of each connection based on the transmission request from the communication unit, and determines whether to transmit or discard the transmission data based on congestion control, and is connected to the communication management unit and is required for transmission. It has a timer for setting a fixed unit time and a protocol processing unit for performing a protocol process to transmit the transmission data, and the communication management unit is [rule] V: interface access speed (physical speed) T _c × V: unit time Tc at the access speed V
Amount of data that can be transmitted between I _i : arbitrary connections B _I1 , B _I2 , ..., B _Im : each connection (I1,
I2, ..., Im) threshold value (allowable transmission data amount during unit time Tc) B _Ii : threshold value (allowable transmission data amount) of each connection (I _i ) ΣB _Ii : total threshold value of all connections Then, ΣB _Ii is in accordance with ΣB _Ii ≦ T _c × V (1 ≦ i ≦ m) (Rule-1), and b _Ii : t = 0 to t = T (of each connection I _i. 0 ≦ T
≦ T _c ) The amount of transmitted data that can be transmitted, t: an arbitrary time between time variables T: 0 to T _c, Lt: the data length of the current transmission data, and when t = 0, b _Ii = 0 (1 ≦ i ≦ m), when t = T> 0, the received transmission data belongs to the connection I _i , and when b _Ii + L _T ≦ B _Ii , the data is transmitted as it is. , ... (rule -2) when b _Ii + L _T> B _Ii performs congestion control, based on ... (rule -3), determines a threshold value and the transmission data amount of all connections, send data Is transmitted or congestion control is performed, and the communication management unit is configured to: [Rule] When b _Ii + L _T > B _Ii (congestion control), The communication management unit, in cooperation with the timer, determines the unit time, the maximum data unit length (L _max ) and the minimum allowable value. shows such a relationship between the access speed (V _{an in),} [rule] c: c> a _{1, T c> c × L} max / V in ··· ( rule) where, L _max: maximum data Unit length V _In : Minimum allowable access speed (V _I1, V _I2,
... _, Congestion control apparatus characterized by including means for determining a unit time based on the minimum speed of V _Im ). 2. The communication management unit cooperates with the timer,
Access speed (V _Ii = B _Ii /) at which the connection and communication for the connection should be guaranteed (allowed)
T _c ) and set the access speed (V
_{Of the I1} , V _I2 , ..., V _Im ), it represents the relationship between the minimum access speed (V _min ) and the unit time. [Rule] The minimum access speed V _min is determined and the unit of each connection is determined. The time is determined by T _c = c × L _max / V _min (c is a constant value of c> 1), and the threshold of each connection is B _Ii = T _c × V _Ii (1 ≦ i ≦ m)
The congestion control device according to claim 1, further comprising means for determining a unit time of each connection and a threshold value of transmission data based on the following. 3. A congestion control method for controlling congestion of transmission data in a terminal, an exchange, etc., which simultaneously communicates via a plurality of connections, wherein the transmission-side interface of the transmission data is controlled at every unit time (Tc). Connection (I1, I2,
.., Im), the transmission data amount is measured at the same time, a threshold is set in advance for each of the connections, and the transmission data threshold for each of the connections and the propriety of transmission are [Rules] V: interface access speed (Physical speed) T _c × V: Unit time Tc at the access speed V
Amount of data that can be transmitted between I _i : arbitrary connections B _I1 , B _I2 , ..., B _Im : each connection (I1,
I2, ..., Im) threshold value (allowable transmission data amount during unit time Tc) B _Ii : threshold value (allowable transmission data amount) of each connection (I _i ) ΣB _Ii : total threshold value of all connections Then, ΣB _Ii is in accordance with ΣB _Ii ≦ T _c × V (1 ≦ i ≦ m) (Rule-1), and b _Ii : t = 0 to t = T (of each connection I _i. 0 ≦ T
≦ T _c ) The amount of transmitted data that can be transmitted, t: an arbitrary time between time variables T: 0 to T _c, Lt: the data length of the current transmission data, and when t = 0, b _Ii = 0 (1 ≦ i ≦ m), when t = T> 0, the received transmission data belongs to the connection I _i , and when b _Ii + L _T ≦ B _Ii , the data is transmitted as it is. , ... (rule -2) when b _Ii + L _T> B _Ii performs congestion control, determined by ... (rule -3), to determine whether congestion control whether to transmit the transmission data has the steps, when the connection is transmission data must be transmitted beyond the threshold, the transmission data amount and the threshold of each of the connection [rule] the _{b Ii + L T> B Ii} ( congestion control ), When And determining whether to transmit the transmission data or discard the transmission data, the unit time (T _c ) is the unit time, the maximum data unit length (L _max ) and the minimum allowable access speed. (V
_In ), [rule] c: c> 1, T _c > c × L _max / V _In (rule) where, L _max : maximum data unit length V _In : Minimum acceptable access speed (V _I1, V _I2,
... _, Congestion characterized by guaranteeing communication up to the threshold value of the connection (I _n ) having the minimum threshold value (B _In ) including a step of determining based on (the minimum speed of V _Im ) Control method. 4. An access speed (V _Ii ) for guaranteeing (permitting) the connection and communication for the connection.
= B _Ii / T _c ), and represents the relationship between the minimum access speed (V _min ) of the access speeds (V _I1 , V _I2 , ..., V _Im ) of the connection and the unit time. [Rule] The minimum access speed V _min is determined, the unit time of each connection is determined by T _c = c × L _max / V _min (c is a constant value of c> 1), and the threshold of each connection is set. , B _Ii = T _c × V _Ii (1 ≦ i ≦ m)
Based on the above, it includes each step of determining the unit time of each connection and the threshold of the amount of transmission data, and automatically guarantees the set speed of all connections based on the above rules and, and transmission, discard, etc. The congestion control method according to claim 3, wherein processing is performed.