JPH1013425A - Band variation control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase an efficiency of band utilization by a user by passing a band reduction request to a decision process preferentially to an increase request if band variation requests which wait for the possible/impossible decision process overlap with each other. SOLUTION: When a protocol processing process 3 become vacant at a point (a) and becomes usable, a band decrease request arrives from a user terminal device 22 later than a band increase request which arrives first from a user terminal device 27 and is queued in a PDU(protocol data unit) processing process is selectively accepted by the protocol processing process 3 preferentially to the band increase request. Consequently, in-use band is speedily released.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ATM communication system,
In particular, the present invention relates to a variable control method of a VP band in an ATM communication system.

[0002]

2. Description of the Related Art In an ATM communication system, a VP (Virt) which is a virtual transmission line is used by using a transmission line actually connected.
ual Path). The VP divides the band within a range not exceeding the maximum bit rate of the transmission path, and
Can share one transmission line.

In the conventional band variable control method, a band change request from a plurality of users made in a standby state of a band change request determination process is determined in the order of arrival without distinguishing between a band increase request and a band decrease request. Judgment processing had been performed.

[0004] For example, in an ATM communication network including a plurality of user terminal devices, a subscriber terminating device, and a variable bandwidth control device, it is determined whether or not a bandwidth change can be performed by a request from a user terminal device, and bandwidth management in the network is performed. When a bandwidth change request from a user terminal subscribed to the bandwidth variable service arrives, the bandwidth variable control device accepts the bandwidth change request from the user terminal device and transmits the change request to a protocol processing process in a PDU (Protocol Data Un).
It) has a protocol processing unit that performs processing of encoding / decoding a message with a processing process unit, refers to a band database, and determines whether or not the transmission path can be accommodated, and waits for processing because there is no free space in the protocol processing process The bandwidth change request becomes vacant,
They are sent to the vacant process in the order in which they arrived to perform the judgment process, and control the subscriber network terminating device.

[0005] For each bandwidth change request, the protocol processing process performed while referring to the bandwidth database and communicating with the subscriber network terminator is occupied for a long time.
It has a plurality of processes and is used sequentially. However, when the bandwidth change request is congested, there is no idle process waiting, and the determination process for the bandwidth change request cannot be started, that is, the process is in a waiting state. If a vacant process occurs in such a case, conventionally, a first-come-first-served bandwidth change request is sent to the protocol processing process related to the determination process without distinguishing between a bandwidth increase request and a bandwidth decrease request.

[0006]

In a conventional bandwidth variable control method in an ATM communication network, a bandwidth change request arriving without a standby protocol processing process is processed in the order of arrival while a standby process is generated. If there is a bandwidth reduction request arriving after the increase request,
Bandwidth reduction request determination processing is performed after bandwidth increase request determination processing, which not only delays the bandwidth release service to the user who transmitted the bandwidth reduction request, but also determines the bandwidth release request without releasing the bandwidth. The determination of whether or not the request for increasing the bandwidth is made “No”, and the possibility that the increase request is rejected increases, so that the quality of the bandwidth variable service is reduced from the user's side. To release the used bandwidth after rejection of the increase request, despite the fact that there was available bandwidth,
There is a problem that band resources are not effectively used.

An object of the present invention is to reexamine the band variable control method in ATM communication, and to provide a more effective band variable control method from both the user side and the network side.

[0008]

According to the bandwidth variable control method of the present invention, when there is a second bandwidth change request before the process of determining whether or not to allow the preceding first bandwidth change request is started. When the first bandwidth change request is a bandwidth increase request and the second bandwidth change request is a bandwidth decrease request, the determination process for the second bandwidth change request is performed based on the determination process for the first bandwidth change request. Priority.

[0009] Information indicating whether the change request is a band increase request or a band decrease request may be added to the band change request.

[0010]

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

FIG. 2 is a block diagram showing a basic configuration of an ATM communication network to which the band variable control method of the present invention is applied.

In FIG. 2, a plurality of user terminal devices 22 and 27, all of which have contracted for a variable bandwidth service, are connected to the VPs in the ATM communication network by subscriber network terminating devices 23 and 26.
Of the main signal transmitted via the network, are housed in cross-connect devices 24 and 25 for performing an exchange connection process.

The user terminal devices 22 and 27 and the subscriber network terminating devices 23 and 26 are connected to the cross-connect device 2.
The VP band change request from the user terminal devices 22 and 27 is processed by the band variable control device 21 via the control lines for transferring control signals via the control lines 4 and 25.

FIG. 1 shows the band variable control device 2 shown in FIG.
1 is a block diagram showing a configuration of FIG. In FIG. 1, the bandwidth variable control device 1 receives a bandwidth change request including a destination and a transmission path bandwidth value from the user terminal device, a communication interface unit 4 for exchanging messages with the user terminal device and the subscriber network terminating device, PDU processing unit 2 that performs message encoding / decoding processing, searches the usage state of a protocol processing process, and transmits a bandwidth change request from a user terminal device to an idle protocol processing process.
Manages a series of control procedures of the user terminal device, the subscriber network terminating device, and the band variable control device, analyzes a message received from the PDU processing process unit, and indicates the message in the band change request while referring to the database 5. After determining whether or not the bandwidth can be accommodated, and passing a message of information on parameters such as the peak rate of the cell indicating the bandwidth used for each VP to and from the subscriber network terminating device, the user terminal device is sent to the PDU processing unit 2. It has a protocol processing process unit 4 composed of a plurality of protocol processing processes for sending a message notifying the accommodation availability determination result addressed to the destination.

Here, when a message from the user terminal is received by the band variable control device, the encoding / decoding processing conventionally performed by the protocol processing unit is separated from the main processing for managing a series of control procedures, and the PDU is processed. It should be noted that the process has been moved to the processing section.

FIG. 3 and FIG. 4 are sequence diagrams showing the flow of messages associated with the band variable control processing. In any case, in a state where there is no waiting protocol processing process, a bandwidth increase request from the user terminal device 27 arrives first at the PDU processing process unit 2 of the bandwidth variable control device 1, and then a bandwidth reduction request from the user terminal device 22. Shows the progress when one processing process becomes empty while both are waiting for the determination process in the PDU processing process unit 2.

FIG. 4 is an example of a sequence diagram according to a conventional control method in which determination processing is performed in the order of arrival of a bandwidth change request. For convenience of comparison, this is an example of a sequence diagram when priority control according to the present invention is performed. This will be described with reference to FIG.

As shown in FIGS. 3 and 4, bandwidth change requests from the user terminal devices 22 and 27 subscribed to the bandwidth variable service are received by the communication interface unit 4 of the bandwidth variable control device 1, and are processed by the PDU. Delivered to the process unit 2. The message received by the PDU processing unit 2 is further passed to the protocol processing unit that has returned to the standby state (empty state) of the protocol processing unit 3. Transmits a parameter update request to the subscriber terminating devices 23 and 26 via the communication interface unit 4. Next, as a response, an update completion notification is transmitted from the subscriber network terminating devices 23 and 26 to the protocol processing process unit 3 via the communication interface unit 4. Recognizing that the parameters have been updated in the subscriber terminating device, the bandwidth variable control device 1 sends a determination result notification indicating “acceptance permitted” or “rejection rejection” to the user terminal device in response to the bandwidth change request, in the protocol processing process unit. 3 to the PDU processing unit 2 and return it to the user terminal device via the communication interface unit 4.

The reason for transferring a message between the variable bandwidth control device and the subscriber terminating device without passing through the PDU processing process unit 2 and directly transferring the message from the protocol processing process unit 3 to the communication interface unit 4 is as follows. When a communication error or a protocol error occurs, the protocol processing process is performed until the transfer to the subscriber network terminating device is completed in order to return the database 5 that manages the used bandwidth value to the original value. Because it is occupied.
Since this protocol processing process has a long occupation time, a plurality of processes are started, and the PDU processing process unit 2
, The waiting protocol processing processes are sequentially used.

As described above, FIGS. 3 and 4 show that when the protocol processing process in use returns to the standby state, which one of the two bandwidth requests waiting in the PDU processing process is processed first. In the conventional selection shown in FIG. 4, the determination process is performed in the order of arrival at the band variable control device, whereas the determination process according to the present invention shown in FIG. 3 is performed. The selection prioritizes the bandwidth decrease request over the bandwidth increase request, and performs the process of determining the bandwidth decrease request that arrives late while the bandwidth increase request is waiting while the bandwidth increase request arrives first. . That is, in FIG. 4, after the determination processing of the bandwidth increase request indicated by the solid line is completed, the determination processing of the bandwidth reduction request indicated by the dotted line is advanced. In FIG. The process of determining the increased bandwidth request is proceeding.

That is, when the protocol processing process becomes available at the point (a) in FIG. 3 and the protocol processing process becomes available, the user terminal device 27 which has arrived earlier and is in a waiting state in the PDU processing process. The bandwidth used is released immediately by giving priority to the selection process of passing the bandwidth reduction request from the user terminal device 22 arriving later to the protocol processing process, rather than the bandwidth increase request from. The band release point (b1) shown in FIG. 4 and FIG.
Comparing the band release point (b2) shown in (1), it can be seen that the band is released earlier when the priority control is performed.

Next, the band variable control device needs to identify whether the band change request is a band increase request or a band decrease request. As a method for easily performing this, the user terminal devices 22 and 27 are required. A field for discriminating between a band increase request and a band decrease request is provided in the message of the band change request from, and the PDU processing unit 2 that performs the encoding / decoding processing identifies the band increase request or the band decrease request.

[0023]

As described above, according to the present invention, when the bandwidth change requests awaiting the processing of the availability determination are duplicated, the bandwidth reduction request is given priority over the bandwidth increase request and is sent to the determination processing. There is an effect that the available band in the transmission path is released more reliably and quickly, resources in the network are effectively used, and the efficiency of band use by the user is improved.

[Brief description of the drawings]

FIG. 1 is an example of a process configuration diagram of a band variable control device in the ATM communication network shown in FIG. 2;

FIG. 2 is an ATM to which the band variable control method of the present invention is applied;
FIG. 2 is an example of a block diagram illustrating a basic configuration of a communication network.

FIG. 3 is an example of a sequence diagram showing a flow of a telegram accompanying the band variable control processing of the present invention.

FIG. 4 is an example of a sequence diagram showing a flow of a message accompanying the conventional band variable control process.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 band variable control device 2 PDU processing unit 3 protocol processing unit 4 communication interface unit 5 database 21 band variable control unit 22, 27 user terminal unit 23, 26 subscriber network terminal unit 24, 25 cross-connect unit

Claims (2)

[Claims] 1. A band variable control method in an ATM communication system for increasing or decreasing a VP band used by a user terminal in response to a request from at least a part of the user terminal sharing a transmission line. If there is a second bandwidth change request before the process of determining whether to allow the change request, the first bandwidth change request is a bandwidth increase request and the second bandwidth change request Is a bandwidth reduction request, the determination process for the second bandwidth change request is performed prior to the determination process for the first bandwidth change request. 2. The variable bandwidth control method according to claim 1, wherein information indicating whether the change request is a bandwidth increase request or a bandwidth decrease request is added to the bandwidth change request.