JP3492466B2 - Band variable control method - Google Patents

Description

Detailed Description of the Invention

[0001]

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

[0002]

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

In the conventional variable bandwidth control method, the bandwidth change requests from a plurality of users made in the waiting state for the bandwidth change request determination processing are sorted in the order of arrival without distinguishing between the bandwidth increase request and the bandwidth decrease request. Judgment processing was being performed.

For example, in an ATM communication network including a plurality of user terminal devices, a subscriber terminal device, and a variable bandwidth control device, it is judged whether or not the band can be changed according to a request from the user terminal device, and the band in the network is managed. When a band change request from a user terminal that has a contract for the band variable service arrives, the band variable control device accepts the band change request from the user terminal device and notifies the protocol processing process of the change request to a PDU (Protocol Data Un).
It) Has a protocol processing unit that performs a message encoding / decoding process and refers to the bandwidth database to determine whether or not the transmission path can be accommodated, and waits for processing because there is no space in the protocol processing process The bandwidth change request that has become
In the order of arrival, they were sent to the vacant process to perform a determination process and control the subscriber network termination device.

For each bandwidth change request, the bandwidth database is referred to, and the protocol processing process performed while communicating with the subscriber network termination device is occupied for a long time.
It is equipped with multiple processes and is used in sequence, but when the bandwidth change request is congested, there are no idle processes waiting, and it becomes a situation where the determination processing for the bandwidth change request cannot be started, that is, a processing waiting state. When an empty process occurs at such a time, conventionally, the first-arrival bandwidth change request is sent to the protocol processing process related to the determination processing without distinction between the bandwidth increase request and the bandwidth reduction request.

[0006]

In the conventional variable bandwidth control method in the ATM communication network, the bandwidth change requests that arrive without a waiting protocol processing process are processed in the order of arrival as the waiting process occurs. If there is a bandwidth reduction request that arrives after the increase request,
The bandwidth reduction request is determined after the bandwidth increase request determination processing, and the bandwidth release service is delayed for the user who sent the bandwidth reduction request, and the determination processing is performed without releasing the bandwidth due to the bandwidth reduction request. The decision as to whether or not the bandwidth increase request made is "No", and the increase request is more likely to be rejected, resulting in a decrease in the quality of the variable bandwidth service from the user's point of view. Since the used bandwidth is released after the acceptance request for the increase request is rejected, although there may be available bandwidth,
There is a problem that the bandwidth resources are not effectively used.

An object of the present invention is to review the bandwidth variable control method in ATM communication and to provide a more effective bandwidth variable control method from the viewpoint of 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 start of the processing for determining whether or not the preceding first bandwidth change request is permitted. When the first bandwidth change request is a bandwidth increase request and the second bandwidth change request is a bandwidth reduction request, the determination processing for the second bandwidth change request is performed for the first bandwidth change request. Prioritize.

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]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

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

In FIG. 2, a plurality of user terminal devices 22 and 27, each of which has a contract for a variable bandwidth service, are connected to the VP in the ATM communication network by the subscriber network termination devices 23 and 26.
It is housed in the cross-connect devices 24 and 25 that perform exchange connection processing of the main signal transmitted via the.

The user terminal devices 22 and 27 and the subscriber network termination devices 23 and 26 are the cross-connect device 2.
It is connected to the band variable control device 21 by a control line for transferring a control signal via 4, 25, and a request for changing the VP band by the user terminal devices 22, 27 is processed by the band variable control device 21.

FIG. 1 shows a variable bandwidth controller 2 in FIG.
2 is a block diagram showing a configuration of No. 1. In FIG. 1, the bandwidth variable control device 1 receives a communication interface unit 4 for exchanging electronic messages with a user terminal device and a subscriber network termination device, and a band change request including a destination and a transmission line band value from the user terminal device, A PDU processing unit 2 that performs a message encoding / decoding process, retrieves a usage state of a protocol processing process, and notifies a bandwidth changing request from a user terminal device to an idle protocol processing process.
Managing a series of control procedures of the user terminal device, the subscriber network terminating device, and the bandwidth variable control device, analyzing the telegram received from the PDU processing unit, and referring to the database 5 to indicate the bandwidth change request. After determining whether or not the band can be accommodated and passing a telegram of information about parameters such as the peak rate of the cell indicating the band used for each VP to the subscriber network termination device, the user terminal device is transmitted to the PDU processing unit 2. It has a protocol processing unit 4 composed of a plurality of protocol processing processes for sending a telegraphic message notifying the accommodability determination result for the destination.

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

FIG. 3 and FIG. 4 are sequence diagrams showing the flow of electronic messages accompanying the bandwidth variable control processing. In either case, in a state where there is no protocol processing process on standby, a bandwidth increase request from the user terminal device 27 comes first to the PDU processing process unit 2 of the bandwidth variable control device 1, and then a bandwidth decrease request from the user terminal device 22. Has arrived and both of them have waited for determination processing in the PDU processing process unit 2 and one processing process has become idle.

FIG. 4 is an example of a sequence diagram according to a conventional control method for performing determination processing in the order of arrival of band change requests, but for convenience of comparison, it is an example of a sequence diagram when priority control according to the present invention is performed. A description will be given together with FIG.

As shown in FIG. 3 and FIG. 4, the bandwidth change request from the user terminal devices 22 and 27 contracting for the bandwidth variable service is received by the communication interface unit 4 of the bandwidth variable control device 1, and the PDU processing is performed. It is delivered to the process unit 2. The electronic message received by the PDU processing process unit 2 is further passed to the protocol processing process which has returned to the standby state (empty state) of the protocol processing process unit 3 and, after the availability determination and the update of the database 5, the protocol processing process unit 3 Sends a parameter update request to the subscriber terminating devices 23, 26 via the communication interface unit 4. Next, as a response, the update termination notice is transmitted from the subscriber network termination devices 23 and 26 to the protocol processing unit 3 via the communication interface unit 4. Recognizing that the parameters have been updated in the subscriber terminal device, the bandwidth variable control device 1 sends a determination result notification indicating "acceptance permitted" or "rejection denied" to the bandwidth change request to the user terminal device to the protocol processing unit. 3 to the PDU processing unit 2 and then to the user terminal device via the communication interface unit 4.

When passing a message between the variable bandwidth controller and the subscriber terminating device, the reason why the message is directly passed from the protocol processing unit 3 to the communication interface unit 4 without passing through the PDU processing unit 2 is as follows. When a communication error or a protocol error occurs, the database 5 that manages the used bandwidth value is returned to the original value. Therefore, the protocol processing process is performed until the transfer with the subscriber network termination device is completed. Because it is occupied.
Since this protocol processing process has a long occupation time, a plurality of processes are activated, and the PDU processing process unit 2
By selecting, the waiting protocol processing processes are sequentially used.

As described above, in FIGS. 3 and 4, when the protocol processing process in use returns to the waiting state, which of the two bandwidth requests waiting for processing in the PDU processing process is processed first. 4 shows the difference in selection as to whether or not to advance the determination process. In the conventional selection shown in FIG. 4, the determination process is advanced in the order of arrival at the variable bandwidth control device, while according to the present invention shown in FIG. In the selection, the bandwidth reduction request is prioritized over the bandwidth increase request, and even if the bandwidth increase request comes first, the determination processing is first performed for the bandwidth reduction request that arrived late while waiting for the bandwidth increase request. . That is, in FIG. 4, the determination process for the bandwidth increase request shown by the solid line is completed, and then the determination process for the bandwidth reduction request shown by the dotted line is advanced. In FIG. The determination process of the request for increasing the bandwidth is in progress.

That is, at the point (a) in FIG. 3, when the protocol processing process becomes available and the protocol processing process becomes available, the user terminal device 27 that arrives first and is in the waiting state in the PDU processing process 27. The bandwidth used is promptly released by preferentially performing the selection processing of passing the bandwidth reduction request from the user terminal device 22 that arrives 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 points (b2) shown in (1), it can be seen that the band is released earlier when the priority control is performed.

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

[0023]

As described above, according to the present invention, when the bandwidth change requests waiting for the availability determination overlap, the bandwidth reduction request is prioritized over the bandwidth increase request and sent to the determination processing. This has the effects of releasing the usable band in the transmission path more reliably and quickly, effectively utilizing the resources in the network, and improving the efficiency of the band utilization by the user.

[Brief description of drawings]

FIG. 1 is an example of a process configuration diagram of a bandwidth variable control device in an ATM communication network shown in FIG.

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

FIG. 3 is an example of a sequence diagram showing a flow of a message according to the bandwidth variable control processing of the present invention.

FIG. 4 is an example of a sequence diagram showing a flow of a telegram associated with a conventional bandwidth variable control process.

[Explanation of symbols]

1 Bandwidth control device 2 PDU processing section 3 Protocol processing part 4 Communication interface section 5 database 21 Bandwidth control device 22, 27 User terminal device 23, 26 Subscriber network terminating device 24,25 Cross-connect equipment

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-28273 (JP, A) Matsunaga et al., Proposal of function-distributed virtual path variable bandwidth control method for ATM networks, IEICE technical report, Japan, The Institute of Electronics, Information and Communication Engineers, November 25, 1994, IN94-125, CS94-153, p21-27 (58) Fields investigated (Int.Cl. ⁷ , DB name) H04L 12/28 H04Q 3/00

Claims (2)

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