JPH10178430A - Communication channel band control method and packet transfer method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the service at a cost lower than that of a virtual private network using a private line. SOLUTION: This method is a control method for a communication channel band for an asynchronous transfer mode(ATM) communication channel where at least one virtual network for a closed user group on an asynchronous transfer mode(ATM) network is configured, a user group communication frequency band is assigned in advance to each user group and on the occurrence of communication relating to the user group, the communication frequency band for the user group is used with priority and communication bands among the user group communication band not used for the communication of the user group are used for communication for other users than the user group and the communication band other than the user group communication band among all the communication bands of the ATM communication channels is not used for the communication of the user group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication channel band control method and a packet transfer method, and more particularly to an ATM (Asyn
The present invention relates to a technology for providing a network over a wide area to a certain closed user group on a wide area networking service provided using a chronous Trabsfer Mode (asynchronous transfer mode) as a backbone.

[0002]

2. Description of the Related Art On a wide area networking service provided by using an ATM as a backbone, a virtual private network is a service for providing a network over a wide area to a certain closed user group. This virtual private network is broadly classified into the following two types in terms of the operation method of the band of the communication path. (1) A fixed band is allocated to a communication path constituting a virtual private network, and a user group occupies the fixed band. (2) The bandwidth of a communication path constituting a virtual private network is made variable, and a plurality of user groups share this variable bandwidth.

[0003] Specifically, the former band operation method is to allocate a dedicated line to a virtual private network as shown in FIG. 1 or to use one of ATM virtual paths (VP) having a fixed band as shown in FIG. A practical form in which the bandwidth of a part is allocated to a virtual private network is conceivable. In these bandwidth operation methods, since the bandwidth of the communication path is fixed,
There is an advantage that independent quality design can be performed for each user group without being affected by other users, and there is also an advantage that a plurality of quality classes can be operated within a user group.

[0004] On the other hand, the latter band operation method, as shown in FIG. 3, uses a function of packet multiplexing or statistical multiplexing of ATM to vary the communication path band of the virtual private network with respect to other communication bands. It is. In this method, the bandwidth is shared with users other than the user group of the virtual private network, so that the service provision cost can be reduced as compared with the case where the fixed bandwidth is occupied.

[0005]

In the former band operation method, a band is fixedly allocated to a user group, so that the band is occupied even when the band is not used. Is high.

Further, in the latter method of band operation, the communication quality of the virtual private network may be degraded due to the influence of a user other than the user group. Therefore, independent quality design cannot be performed for the user group. There is also a problem that quality classes in a plurality of user groups cannot be operated on the assumption of quality assurance due to the influence of other user groups.

The present invention has been made in view of the above-mentioned problems, and has the following objects. (1) A communication path band control method and a packet transfer method capable of providing services at a lower cost than a virtual private network using a dedicated line. (2) To provide a communication path band control method and a packet transfer method that enable independent quality design in a user group of a virtual private network without being affected by other users. (3) A communication channel band control method and a packet transfer method capable of operating a plurality of quality classes within a user group of a virtual private network.

[0008]

In order to solve the above-mentioned object, as a first means relating to a communication path band control method, A
A method for controlling a communication band of an ATM communication path in a case where at least one virtual network for a closed user group is configured on a TM network. Is assigned, and when communication relating to the user group occurs, the communication band for the user group is preferentially used, and a portion of the communication band for the user group which is not used for the communication of the user group is other than the user group. Is used for the communication of the user, and the communication band other than the communication band for the user group is not used for the communication of the user group in the entire communication band of the ATM communication path.

[0009] As a second means relating to a communication path band control method, in the first means, a plurality of quality classes are provided for communication in each user group, and communication priorities are set to the plurality of quality classes. Means is adopted.

The first means relating to the packet transfer method is a method for transferring fixed-length or variable-length packets from a packet transfer means to a link, and includes at least one priority class and at least one general class. The communication band of the link is divided into a priority class and a general class, respectively, and assigned.The weight of the packet transfer processing is weighted for each communication band assigned to the priority class and the general class. The transfer opportunity of the priority class and the general class packet is determined so that the transfer data amount of each priority class or general class packet within a certain time matches the above-mentioned weighting, and the packets to be transferred to the priority class are determined. If it does not exist, the transfer right of the packet is given to the general class, and the right to transmit the packet is given. If the packet to be transferred to the general class it does not exist, not that cede rights packet transmission priority class, means are employed not to perform packet forwarding.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS.
An embodiment of a communication path band control method and a packet transfer method according to the present invention will be described. In this embodiment, a communication path band control method and a packet transfer method for a virtual private network provided as a network service over a wide area for a certain closed user group on a wide area networking service provided using an ATM as a backbone. It is about the method.

This embodiment is characterized in that, as shown in FIG. 4, the bandwidth of a communication path provided to a virtual private network is separated by a semipermeable membrane boundary. This semipermeable membrane boundary prohibits the virtual private network from using the communication band beyond this, but conversely, if the communication band of the virtual private network is free, the band is changed to another user. Is defined as an asymmetric boundary that allows the use of Hereinafter, the present embodiment in which such a semipermeable membrane boundary is defined will be specifically described.

As shown in FIG. 5, the network model to which the present embodiment is applied is such that a network layer in which a router 1 (packet transfer means) is interconnected by a link 2 and an ATM switch 3 are interconnected by an ATM link 4. It is composed of connected ATM layers, and some of the routers 1 are connected to the ATM switch 3.

For such a network model,
The semipermeable membrane boundary is set for each link 2 connecting the router 1 in the network layer and for each ATM link 4 connecting the ATM switch 3 in the ATM layer. Then, the router 1 and the ATM switch 3 control the transfer of the packet or the cell based on the data transfer processing described below, whereby the communication path band control method and the packet transfer method of the present embodiment are realized.

Next, the data transfer process performed by the router 1 and the ATM switch 3 will be described with reference to the flowchart shown in FIG. [Step S1] First, for each link 2 and each ATM link 4 in the network layer, a communication band of a communication path provided to a virtual private network (generally a plurality of virtual networks exists) is preset. Then, each virtual private network i (i =
1,..., N), the cell (or packet) related to each virtual private network i (i = 1,..., N) and the virtual private network i (i =
Weights for transfer processing of cells (or packets) related to a plurality of users i (i = 0) other than 1,..., N) are set as follows. B1: B2: ...: Bn: B0 (1)

For example, in this case, the transfer processing relating to the communication band B1, ie, the virtual private network 1 (i = 1) is weighted the heaviest, and the communication band B0, ie, the user 0 (i)
= 0) is given the lightest weight.

Here, since the cells of the ATM layer are fixed length, the transfer processing is performed to the cells of each virtual private network i (i = 1,..., N) and the cells of the other users i (i = 0). The virtual private network i (i = 1,..., N) or the user i is set so that the rate of giving an opportunity always corresponds to the weight (1) in an appropriate time frame.
(I = 0) is given an opportunity for transfer processing. For example,
Such control is based on the virtual private network i (i = 1,
.., N) or user i (i = 0) is weighted (1) and is implemented by periodic cell transfer.

On the other hand, in the network layer, packets are of variable length. Therefore, considering the length of each packet for each virtual private network i (i = 1,..., N) and the other user i (i = 0), the ratio of the amount of transmitted data is The ratio corresponding to the above weighting (1) is set for each appropriate time frame,
A transfer opportunity is given to the virtual private network i (i = 1,..., N) or the user i (i = 0). For example, such control is performed for each virtual private network i (i = 1,
.., N) or by using a token packet for each user i (i = 0).

[Step S2] In this way, the value of i indicating either the virtual private network i (i = 1,..., N) or the user i (i = 0) that gives a transfer opportunity is determined. And the value is a virtual private network i (i = 1,...,
It is determined whether the value indicates n) or the value indicates user i (i = 0).

[Step S3] Then, this determination is made as "Y
In the case of "ES", it is determined whether or not there is data (cell or packet) to be transferred. [Step S4] If the result of this determination is "YES", that is, if there is data to be transferred by the virtual private network i (i = 1,..., N), the data is transferred as it is. Then, the processing of step S2 described above is repeated again, and the data of the virtual private network i (i = 1,..., N) corresponding to the sequentially determined value of i is transferred.

[Step S5] On the other hand, if the judgment in step S2 is "NO", that is, the value of i determined in step S1 is "0" indicating a user other than the virtual private network, and The judgment is "NO", that is, the virtual private network i (i = 1,
If there is no transfer data related to..., N), the user i
It is determined whether there is data to be transferred relating to (i = 0). If the determination is "YES", the data to be transferred relating to the user i (i = 0) is transferred as it is in step S4.

[Step S6] On the other hand, this judgment is "N
In the case of "O", the process of step S6 is repeated without sending any data.

Next, scheduling of data transfer processing for priority control in the communication band of each virtual private network having a semipermeable membrane boundary will be described. In order to realize this, for example, when a transfer opportunity is given to a certain virtual private network, a cell or a packet with a high priority may be transferred in that case. In this case, it is possible to directly apply the priority control technique in which a fixed band is allocated, for example, “Multi-class ATM call admission control method” (Japanese Patent Application No. 8-157269).
The techniques described in (1) can be applied. In order to realize a high communication quality service by using the priority control technology, it is necessary to perform a connection accepting process according to the usage status of the virtual private network, which generally has an effect of reducing the link usage rate of the virtual private network.

According to the above procedure, it is possible to prevent the communication quality of the virtual private network from being affected by other traffic, and to perform quality design and control of a plurality of classes closed in the virtual private network. In addition, since a user other than the virtual private network can temporarily use the communication band of the virtual private network, it is possible to provide a service at a lower cost as compared with exclusive bandwidth control using a dedicated line or the like. . In particular, by combining with technology that supports high communication services by priority control, the link utilization rate of the virtual private network can be kept low,
Link sharing by users other than the virtual private network is promoted, and the service of the virtual private network can be provided at lower cost.

[0025]

As described above, according to the communication channel band control method and the packet transfer method according to the present invention, the following effects can be obtained. (1) In connection with a virtual private network service provided in a wide area internetwork provided using an ATM as a backbone, it is possible to provide a service at a lower fee than a virtual private network using a dedicated line. (2) An independent quality design is possible for the user group without being affected by users other than the user group of the virtual private network. (3) A plurality of quality classes can be operated within the user group.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing operation of a communication band of a virtual private network service using a conventional dedicated line.

FIG. 2 is an explanatory diagram showing operation of a communication band of a virtual private network service using a conventional ATM virtual path having a fixed band.

FIG. 3 is an explanatory diagram showing a conventional operation of a communication band of a virtual private network service using a link having a variable band.

FIG. 4 is an explanatory diagram showing operation of a communication band in an embodiment of a communication path band control method and a packet transfer method according to the present invention.

FIG. 5 is a block diagram showing a configuration of a network model provided with an ATM as a backbone in an embodiment of a communication path band control method and a packet transfer method according to the present invention.

FIG. 6 is a diagram illustrating a router and an A in an embodiment of a communication band control method and a packet transfer method according to the present invention;
It is a flowchart which shows the data transfer process which a TM exchange performs.

[Explanation of Signs] 1 ... Router (packet transfer means), 2 ... Link, 3
…… ATM switch, 4 …… ATM link

Claims (3)

[Claims] 1. A method for controlling a communication path band of an ATM communication path in a case where at least one virtual network for a closed user group is configured on an ATM network, wherein: A communication band for the user group is allocated in advance, and when communication related to the user group occurs, the communication band for the user group is preferentially used. A portion not used is used for communication of users other than the user group, and a communication band other than the communication band for the user group among all communication bands of the ATM communication path is not used for communication of the user group. A communication channel band control method characterized by the above-mentioned. 2. The communication path bandwidth control method according to claim 1, wherein a plurality of quality classes are provided for communication within each user group, and communication priorities are set for the plurality of quality classes. Road band control method. 3. A method for transferring fixed-length or variable-length packets from a packet transfer means to a link, wherein the packets are classified into at least one priority class and at least one general class in advance, The communication band of the link is divided and assigned to each priority class and the general class, and the weight of the packet transfer process is weighted for each communication band assigned to the priority class and the general class. Alternatively, the transfer opportunity of the priority class and the general class packet is determined so that the transfer data amount of each packet of the general class matches the above weighting. If there is no packet to be transferred to the priority class, the general Give the transfer right of the packet to the class, and if there is a packet to be transferred to the general class to which If stomach, not that cede rights packet transmission priority class, does not transfer the packet, the packet transfer method, characterized in that.