JPH04309038A - Congestion control system in packet exchange network - Google Patents

Abstract

PURPOSE:To implement communication restriction in response to the degree of congestion at the detection of congestion of a packet exchange network. CONSTITUTION:A logic communication line congestion detection section 2 of a packet exchange 1 detects congestion by using control information from other packet exchange inputted through a relay line 3. A restriction inhibiting new call connection is informed to a call control section 4 before a stage that an input restriction is noticed to the call control section 4 to restrict input of a packet to a terminal equipment 5 and sets a stage of rejection when a call connection request comes from the terminal equipment as the congestion detection. Communication is implemented by avoiding a rejected logic communication line. Thus, congestion control is executed in details to the terminal equipment and the service through the communication line with high reliability is offered to the terminal equipment.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a congestion control method in a packet switching network.

0002

2. Description of the Related Art FIG. 3 shows, for example, "IEE TRANSA
CTIONS ON COMMUNICATIONS,
VOL. COM-27, No. 8, AU-GUST 1
979, P1153 to 1160” with the paper name “Comp
Arative Discussion of Cir
cuit-VS, Packet-Switched
FIG. 3 is a diagram illustrating congestion detection in a conventional packet-switched network of this type shown in "Voice", and shows how one congestion detection level is set.

Next, the operation will be explained with reference to the packet switching device shown in FIG. Figure 3 in the logical communication path congestion detection unit 2
When it is detected that the congestion detection level shown in is exceeded, the call control unit 4 is notified to restrict the input of packets from the terminal 5. The call control unit 4 that received the notification sends the terminal 5
The input of packets from is regulated for a certain period of time by RNR packets.

0004

[Problem to be Solved by the Invention] Conventional congestion control methods in packet-switched networks are methods that limit input packets from terminals based on only one congestion level, so call connection is not completed. However, as soon as data actually begins to flow, input restrictions are imposed on the network, which occurs more frequently as the traffic within the network increases.

[0005] This invention was made to solve the above-mentioned problems, and it is possible to prevent input restrictions immediately after a call connection is completed, and also to spread the load within the network by using an alternative communication path when a call is connected. The purpose of this invention is to provide a congestion control method in a packet-switched network that can be effectively implemented.

[0006]

[Means for Solving the Problems] The congestion control method in a packet switching network according to the present invention uses packets that fixedly connect logical communication paths between terminals via the packet switching network at the start of packet communication. The congestion detection level of the packet switching network is set to multiple levels, low and high, on the switching equipment,
The device is equipped with a communication restriction means that restricts packet communication to be performed through an alternative logical communication path when a low-order congestion detection level is detected, and restricts input to terminals currently communicating when a high-order congestion detection level is detected.

[0007]

[Operation] The congestion control method in a packet-switched network according to the present invention prevents the use of the currently connected logical communication path and uses an alternative logical communication path when a set low-order congestion detection level is detected. When a high-level congestion detection level is detected, input restrictions are applied to terminals currently communicating.

[0008]

[Embodiment] FIG. 1 is a functional block diagram of a packet switching device to which an embodiment of the present invention is applied, in which 1 is a packet switching device, 2 is a logical communication path congestion detection unit, and 3 is a functional block diagram of a packet switching device in a packet network. 4 is a relay circuit for collecting information on other stations; 4 is a call control unit that performs communication with terminal 5; and 5 is a user terminal.

In the packet switching device configured as described above, when the logical channel congestion detection unit 2 detects that the congestion detection level 1 in FIG. That is, when there is a new call connection request, the system avoids using the corresponding logical communication path and uses another logical communication path. Furthermore, when the logical communication path congestion detection unit 2 detects that the congestion detection level 2 has been exceeded, the call control unit 4 is restricted to the restriction level 2, that is,
As a restriction on the call currently being communicated, a restriction is implemented in which an RNR packet is sent in order to impose input restriction on the terminal 5.

[0010] In the above embodiment, regulation level 2 is limited to restricting packet input to the terminal, but even if it is combined with regulation level 1, which prohibits new call connections,
The same effects as in the above embodiment are achieved.

Furthermore, in the above embodiment, the logical communication path congestion detection unit 2 is divided into two parts: a congestion detection unit in the own packet switching device and a congestion detection unit in another packet switching device, and the congestion detection unit 2 is separately notified to the call control. It may be controlled by

0012

[Effects of the Invention] As described above, according to the present invention, the congestion detection level is divided into two levels, and different restrictions are applied to each level, so that it is possible to prevent input restrictions immediately after a call connection is completed, and This has the effect of effectively distributing the load.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram within a packet switching device for explaining a first embodiment of the present invention.

FIG. 2 is a graph diagram showing a congestion control method for explaining Embodiment 1 of the present invention.

FIG. 3 is a graph diagram for explaining a conventional congestion control method.

[Explanation of symbols] 1 Packet switching device 2 Logical communication path congestion detection unit 3 Relay line 4 Call control unit 5 Terminal

Claims (1)

[Claims] Claim 1: At the start of packet communication, the packet switching device that permanently connects the logical communication path between each terminal via the packet switching network is configured to set the congestion detection level of the packet switching network to low and high levels. A communication regulation means that sets multiple levels to perform packet communication through an alternative logical communication path when a low congestion detection level is detected, and imposes input restrictions on terminals currently communicating when a high congestion detection level is detected. A congestion control method in a packet-switched network characterized by the following features: