JPH0766837A - Variable capacity control method for packet network - Google Patents

Abstract

PURPOSE:To prevent congestion with simple control by allowing a sender side node to reduce a packet communication speed when a congestion prediction notice is received or disregarding the prediction notice depending whether the communication speed is increased or not within a predetermined period up to now. CONSTITUTION:A transmission reception packet of a variable speed terminal equipment 30 and a relay node equipment 20 is stored tentatively by buffer memories 32, 33 and 21, 33 and sends the packet to a transmission line 11 and a path selection circuit 23 or the like. Furthermore, the equipments 30, 20 have congestion prediction notice display insert circuits 24, 25 and the circuits 24, 25 of the equipment 20 predict congestion after a predetermined time based on the communication speed of a passing packet and an upper limit of a degree of increase and display it as a notice. A congestion prediction notice display reception circuit 36 of the equipment 30 receives the prediction notice and a transmission control circuit 35 reduces the communication speed by the presence of the increase in the packet communication speed within a predetermined time up to now or disregards the prediction notice. Thus, the packet is efficiently sent under simple protocol control and congestion is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable capacity control method in a packet network having variable speed. The present invention relates to variable capacity control of packets in data communication in which packets containing cells are used and the packet communication speed changes.

[0002]

2. Description of the Related Art (Variable Speed Service in Packet Network) A conventional variable speed service in a packet network will be described. When the terminal increases the packet transmission rate, it transmits a rate increase request signal to the network according to the transmission rate increase request procedure from the terminal side. This speed increase request signal usually takes the form of a packet. When the network judges from the contents of the speed increase request signal that congestion does not occur even if the increased capacity is allocated to the resource in the network, when the speed increase request signal is received, the speed increase request signal is transmitted. On the other hand, if it is determined that congestion will occur when the increased capacity is allocated to the resources in the network, a speed increase request acceptance refusal signal is sent to the request terminal side. Upon receiving the speed increase request acceptance refusal signal, the terminal side gives up the speed increase request. In this way, congestion is not generated in the network by sequentially allocating resources in the network on the network side. FIG. 2 shows a sequence diagram for explaining the procedure of the variable speed service in this conventional packet network.

(Variable speed service of congestion avoidance variable speed network) The inventors have introduced the concept of acceleration or acceleration ratio of the packet communication speed as a congestion avoidance method in the packet network, by which the congestion of the packet network is predicted and the congestion is predicted. A packet congestion avoidance method in a variable speed packet network for prevention has been proposed in Japanese Patent Application No. 5-99746.

A variable speed service of this packet network will be described. The transmitting node sends the packet to the network based on the upper limit of the packet communication speed acceleration or the acceleration ratio allowed for the transmitting node. On the other hand, when the relay node or the receiving node determines that congestion occurs after time t seconds, the network sends a congestion prediction notification signal to the terminal side which is the transmitting node. When the terminal side itself is performing the variable speed service, the packet transmission amount or the packet communication speed is reduced to a predetermined value regardless of whether the packet transmission state is constant transmission or increase transmission. In this way, the network side sequentially determines the remaining amount of resources in the network and reduces the speed at all variable speed terminals, so that congestion in the network can be avoided. FIG. 3 shows a sequence for explaining the above procedure.

[0005]

As described above, in the conventional packet variable speed control in the packet network, the communication procedure between the network and the terminal is complicated, and when packets are used, it is necessary to ensure reliable information transfer. Since protocol processing is added, high-speed reception processing is difficult. Also, when there is a request for increasing the packet communication speed from a large number of terminals, the network side normally performs reception processing on a first-come-first-served basis.
Furthermore, there was a problem that the response from the network was delayed.

Further, in the congestion avoidance variable speed network, all variable speed terminals that have received the congestion prediction notification signal decrease the packet transmission speed all at once, so that the packet communication speed is decreased even to terminals having a small burst property. , There was also a problem that sufficient communication capacity could not be secured.

The present invention solves the above-mentioned problems.
It is an object of the present invention to provide a method for easily performing congestion avoidance control without reducing the packet communication speed to a constant speed terminal in a variable speed service.

[0008]

According to the present invention, a packet is transmitted and received between a transmitting node and a receiving node via a relay node, and the degree of increase in packet communication speed allowed for these transmitting nodes is determined. In the packet network in which an upper limit is set to the time change rate or the time change ratio shown, the relay node or the receiving node in the packet network is the packet communication speed of the passing packet or the packet communication speed of the arriving packet. , Based on the upper limit of the value representing the degree of increase in the packet communication speed, predict the packet communication speed after a predetermined time set in the packet network, if congestion is predicted, congestion is predicted To the sending node, the sending node receives the notification that the congestion is predicted, and sends a packet communication within a predetermined time until now. If there is an increase in speed, the packet communication speed at that point is reduced, and if there is no increase in the packet communication speed within a predetermined time up to the present time, the notification that the congestion is predicted is ignored. And

The receiving node transmits a packet to the transmitting node side at least within a certain time interval, and when congestion is predicted at the relay node or the receiving node, the receiving node indicates that congestion is predicted. Notification can be performed using the packet to be transmitted.

[0010]

According to the present invention, when the transmitting side node receives the congestion prediction notification and does not increase the number of transmission packets in a predetermined period until then, it means that the cause of the congestion prediction is not in its own node. , It ignores the congestion prediction notification and does not reduce the packet communication speed during transmission. This allows
A constant speed terminal that holds the packet communication speed can also transmit packets with a required capacity on the network.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of the configuration of a packet network according to an embodiment of the present invention, which represents a variable speed terminal device 30 corresponding to a transmitting node and a relay node device 20 in the network as a representative. ing.

The variable speed terminal device 30 includes a packet assembling circuit 31 for assembling a packet to be transmitted, a buffer memory 32 for temporarily accumulating a packet to be transmitted and transmitting it to the transmission line 11, and a buffer memory for temporarily accumulating a received packet. 33 and a packet disassembly circuit 3 for disassembling this packet
4, a congestion prediction notification display receiving circuit 36 that receives a congestion prediction notification display that is a notification that the congestion transmitted from the relay node 20 is predicted from the received packet, and packet transmission based on this congestion prediction notification display And a transmission control circuit 35 for controlling the packet communication speed, which is the speed. It should be noted that, in the case where the variable speed terminal device 30 operates as a receiving node, the congestion prediction circuit 24 for predicting congestion
And a congestion prediction notification display insertion circuit 25 for the transmission side variable speed terminal device based on this congestion prediction.

The relay node device 20 receives a bidirectional packet from the transmission line 11 and relays it.
1, 22 and a route selection circuit 23 for selecting a route of a transmission line
And a congestion prediction circuit 24 and a congestion prediction notification display insertion circuit 25 bidirectionally as means for performing the congestion prediction and the congestion prediction notification.

Here, the feature of this embodiment is that an upper limit is set for the time change rate or the time change ratio indicating the degree of increase in the packet communication speed allowed for the variable speed terminal device 30 serving as the transmission node. Relay node device 20
Is a packet communication speed of passing packets, and based on the upper limit of a value representing the degree of increase in the packet communication speed, predicts the packet communication speed after a predetermined time set in the packet network, and congestion When it is predicted, the variable speed terminal device 30 serving as the transmitting node is notified of the notification that congestion is predicted, and the variable speed terminal device 3 serving as the transmitting node is notified.
0 receives the notification that congestion is predicted, and if there is an increase in the packet communication speed within the predetermined time up to the present time, the packet communication speed at that time is reduced and within the current predetermined time When the packet communication speed does not increase, the notification that the congestion is predicted is ignored.

Next, the operation of the present invention in the packet network shown in FIG. 1 will be described.

(When a new capacity increase request is made from the information source to the network) The information input to the variable speed terminal device 30 is packetized by the packet assembling circuit 31 and stored in the buffer memory 32. The sending control circuit 35 controls the buffer memory 32 to send packets to the transmission line 11 at a predetermined packet communication speed.

When a new capacity increase request is made from the information source to the network, it is not a special signal such as a speed increase request signal, but within the range of increase conditions predetermined by the network,
Packets with increased transmission information capacity (information packets)
From the variable speed terminal device 30 to the network. Within a certain time after that, when receiving a congestion prediction notification signal from the network,
If the capacity increase request is rejected, at least the increase is reduced. On the other hand, if the congestion prediction notification signal is not received, the transmission is continued assuming that the capacity increase request has been accepted.

(When a capacity reduction instruction is issued from the network to the information source) (Operation of the relay node device 20)
A packet from each terminal device is input to and accumulated in the buffer memories 21 and 22 through the transmission path 11. The congestion prediction circuit 24 on the variable speed terminal device 30 side detects the total packet communication speed or the packet amount input to the buffer memory 21, or the output packet amount of the buffer memory 21, and the packet communication after the time t determined by the network. If the speed is predicted and congestion is predicted, the congestion prediction notification display insertion circuit 25 is activated. As the congestion prediction circuit 24,
The congestion prediction circuit proposed in Japanese Patent Application No. 5-99746 can be used. The congestion prediction notification display insertion circuit 25
By the activation control of the congestion prediction circuit 24, a notification that congestion is predicted is sent to the corresponding path or transmission line 11. If there is a notification destination packet on the corresponding path or transmission line, congestion prediction is notified using that packet.

(Operation of the variable speed terminal device 30 (reception side)) In the variable speed terminal device 30 serving as a receiving node, the packet from the relay node device 20 is input to the buffer memory 33 through the transmission path 11 and accumulated. It Congestion prediction circuit 2
4 is the total packet communication speed or packet amount input to the buffer memory 33, or the buffer memory 3
When the output packet amount of 3 is detected and congestion is predicted, the congestion prediction notification display insertion circuit 25 is activated. The congestion prediction notification display insertion circuit 25 causes the corresponding transmitting device to send a signal notifying the congestion prediction under the activation control of the congestion prediction circuit 24. If the corresponding transmission device has a notification destination packet, a congestion prediction notification display is inserted in the packet to notify.

(Operation of Variable Speed Terminal Device 30 (Transmitting Side)) The variable speed terminal device 30 serving as a transmission node displays the congestion prediction notification display generated in the relay node device 20 or the variable speed terminal device 30 of the receiving node. When received,
If the packet transmission has been increased by the predetermined time t until then, the packet communication speed or the packet amount is reduced at least for the increase.

On the other hand, when the congestion prediction notification display is received from the network but the own information source is not the cause of the suppression signal, that is, when the packet transmission is not increased for a certain period of time, the congestion prediction notification is ignored. Then, the packet is transmitted at the same speed as before. This corresponds to a fixed rate terminal (CBR) that sends packets at a constant rate.

As described above, when securing the capacity of the packet to be transmitted from the variable speed terminal device 30, it is not necessary to define a new procedure or packet, and the information cell is simply transmitted in accordance with the regulation. On the other hand, if the relay node device 20 predicts congestion and receives the congestion prediction notification, but the own terminal is not the cause of the congestion, it is not necessary to reduce the transmission capacity. A sequence showing the above operation is shown in FIGS. 4 and 5 are sequences when the relay node device makes congestion prediction, and FIGS. 6 and 7 are sequences when the receiving terminal makes congestion prediction.

Although the variable capacity control between the transmission side terminal device and the relay node has been described in the above description of the embodiment, the same applies to the case where the reception terminal device is provided with a congestion prediction circuit and a congestion prediction notification display insertion circuit. The effect of can be obtained.

[0025]

According to the present invention, with this configuration, (1) there is no need to define a new packet or notification signal for performing variable capacity control, and (2) for performing variable capacity control. No new sequence required (3)
There is no new load for performing variable capacity control, (4) the capacity of only the service that causes congestion is reduced, and efficient transmission is possible. (5) The bandwidth of the CBR service is
After reaching a certain speed and the capacity is established, it is guaranteed reliably, and there is an effect that the required capacity cannot be secured by the congestion prediction notification.

[Brief description of drawings]

FIG. 1 is a diagram showing configurations of a variable speed terminal device and a relay node device used in an embodiment of the present invention.

FIG. 2 is a sequence diagram illustrating conventional capacity control.

FIG. 3 is a sequence diagram illustrating conventional variable capacity control.

FIG. 4 is a sequence diagram illustrating variable capacity control based on congestion prediction notification by a relay node according to an embodiment of the present invention.

FIG. 5 is a sequence diagram illustrating variable capacity control based on congestion prediction notification by a relay node according to the embodiment of this invention.

FIG. 6 is a sequence diagram illustrating variable capacity control based on congestion prediction by a receiving terminal in the congestion avoidance variable speed network according to the embodiment of this invention.

FIG. 7 is a sequence diagram illustrating variable capacity control based on congestion prediction by a receiving terminal in the congestion avoiding variable speed network according to the embodiment of this invention.

[Explanation of symbols]

 11 transmission line 20 relay node device 21, 22 buffer memory 23 route selection circuit 24 congestion prediction circuit 25 congestion prediction notification display insertion circuit 30 variable speed terminal device 31 packet assembly circuit 32, 33 buffer memory 34 packet disassembly circuit 35 transmission control circuit 36 Congestion prediction notification display receiving circuit

Claims (2)

[Claims] 1. A time change rate or a time change ratio indicating a degree of increase in packet communication speed allowed between these transmitting nodes when packets are transmitted and received between a transmitting node and a receiving node via a relay node. In the packet network with an upper limit set in the above, the relay node or the receiving node in the packet network is configured to increase the packet communication speed of the passing packet or the packet communication speed of the arriving packet and the increase of the packet communication speed. Based on the upper limit value of the value indicating the degree, predict the packet communication speed after a predetermined time determined in the packet network, if congestion is predicted, the notification that congestion is predicted the transmission node When the transmission node receives the notification that the congestion is predicted, and if there is an increase in the packet communication speed within a predetermined time until now, Variable capacity control of a packet network characterized by reducing the packet communication speed at that time and ignoring the notification that the congestion is predicted if the packet communication speed does not increase within a predetermined time until now Method. 2. The receiving node transmits a packet to the transmitting node side at least at a fixed time interval or less, and when congestion is predicted at the relay node or the receiving node, the receiving node indicates that congestion is predicted. The variable capacity control method for a packet network according to claim 1, wherein notification is performed using the packet to be transmitted.