JPH04200052A - Reception buffer control system - Google Patents

Abstract

PURPOSE:To prevent congestion restriction due to a burst overload by providing plural common buffers to be used by a subscriber who has fully used a reception buffer assigned to the user to the system and activating congestion restriction only when the entire margin is lost. CONSTITUTION:Reception buffers 21-1-12-60 implementing the basic service are assigned to all subscribers and the reception buffers are used normally to give the service to all the subscribers. However, the data quantity of the service is increased and the reception buffer assigned to a relevant user is used out, then a common buffer 12-0 is used to prevent congestion. Moreover, when the rate of use of the common buffer exceeds, e.g. 80%, congestion restriction is applied to the subscriber using the common buffer and the rate of use of the buffer assigned to each or the use of rate of the common buffer is less than 40%, the congestion restriction is released. Thus, only when the entire margin is lost, congestion restriction is activated and the congestion restriction due to a burst overload is prevented.

Description

[Detailed Description of the Invention] (Summary) Regarding a digital subscriber concentrator in a digital exchange, a reception buffer control method that prevents congestion regulation due to burst overload by operating congestion regulation only when there is no overall margin. The aim is to provide a digital subscriber concentrator (DLCC) with an allocated receiving buffer that should be able to provide basic services to all subscribers, and a common buffer used by subscribers who have used up their allocated receiving buffer. It is configured so that a plurality of are provided.

[Industrial application field]

The present invention relates to a digital switching device, and more particularly, the present invention relates to a digital subscriber concentrator in a digital switching device.

[Conventional technology]

A digital subscriber concentrator (DLCC) in a digital switching network, for example FETEX-150, requires a transmission/reception buffer for HDLC frame transmission/reception control.

Conventionally, in the above-described digital subscriber line concentrator, in order to accommodate a plurality of subscribers, for example 60 subscribers, each subscriber was independently controlled and a receiving buffer was quantitatively allocated to each subscriber. In other words, for example, in a DLCC device using the Prosensor MPU80186 having a memory space of 1M bytes, the use of the buffer is limited to the extent that the memory does not exceed the aforementioned 1M capacity even if all subscribers use the buffer. . However, as mentioned above, the reception buffer memory is limited, and if it is equally divided among 60 subscribers, the amount per subscriber will be small.

[Problem B to be solved by the invention] As mentioned above, as the capacity of the receiving buffer per subscriber decreases, even if the DLCC as a whole has a margin due to burst overload such as D channel packets of a particular subscriber. However, there was a problem in that congestion regulation was activated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a reception buffer control system in which congestion control is activated only when there is no overall margin, thereby preventing congestion control due to burst overload.

[Means for Solving the Problems and Their Effects] The present invention relates to a digital subscriber line concentrator.

Allocate a receiving buffer for basic services to all subscribers. In normal times, the reception buffer is used to provide services to all subscribers.

However, when the amount of data for this service increases further and the allocated reception buffer is used up, a common buffer is used to prevent congestion. Also, for example, when the usage rate of the common buffer exceeds 80%, congestion control is applied to the subscribers who are using the common buffer, and when the usage rate of the individually allocated buffer or the usage rate of the common buffer falls below 40%. To cancel.

As a result, congestion control does not immediately take effect even when bursts occur, and it is possible to provide a digital subscriber line concentrator that is resistant to burst-like overloads.

〔Example〕

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a diagram showing the configuration of the control system within the DLCC.

The subscriber terminal equipment ~TE60 is connected to the transaction management module 12 via RX/TX control modules 10-1~10-60. RX/TX! Ill? il
The modules lO1 to 1060 are further connected to congestion control modules 11-1 to 11-60. These are connected to an RX/TX control module 13 on the host side, that is, on the line concentration side, via a congestion control module (line concentration side) 14. These congestion control modules 11-1~
11-60 and the congestion control module 14 control bucket congestion in both directions.

In the transaction management module 12, each Rχ/T
Buffers 12-1 to 12-60 (P○OL I) are provided corresponding to the X control modules 10-1 to 10-60, and these reception buffers are used to provide service to service requests from each subscriber. It is carried out.

In the embodiment of the present invention, the buffer 12-
1 to 12-60 are used for service, but if the buffer POOLI is insufficient due to reception of burst data, etc., the common buffer POOLI is used for each line that is insufficient.
Start using I. (7) Interval buffer POOL I
The usage rate of the common buffer POOLI is monitored, and when the usage rate falls below, the use of the common buffer POOLI[ is discontinued.

On the other hand, congestion control of the common buffer POOLI[ is performed as follows.

■ When the usage rate of the common buffer P○OLI[ reaches 80%, it is assumed that congestion has occurred.

■ When the common buffer POOLII cannot be hunted even after hunting, the last buffer held is reused. Here, this reuse involves processing the previous information and then reusing it.

■ Buffer POOL I or common buffer P00
When the usage rate of any of the LHs falls below 40%, the convergence of the corresponding port is canceled.

By performing the above-described control, it is possible to prevent the occurrence of congestion restriction. In other words, in the past, congestion control was imposed due to burst overloads of specific subscribers on the D channel, even though the DLCC as a whole had sufficient margin. Common/N77APOOL] I4 allocation service is controlled and managed.

FIG. 2 is a flowchart of transmission RX/TX control. When control is started (START), that is, when the service is started, if it is signal reception, reception processing (Sl) is executed, and it is determined whether buffer POOL I is being regulated (
S2), and when the restriction is not in progress, a necessary area in the buffer POOL I is hunted (S3). And the usage rate of the hunted buffer POOLl is at a certain level Thresho
Determine whether ld is greater than l S4L, Thresho
When ld is greater than l (Y), buffer POOLI
is marked as being regulated (S5). That is, the flag that is under restriction is turned on and set to busy. Then, a signal reception notification is issued (S6). Further, if the threshold is not greater than Threshold l in determination S4 (N), a signal reception notification is immediately issued (S6).

-4, When it is determined in the determination (S2) that the buffer POOLI is being restricted (Y), that is, the usage rate is high before the specific Threshold L mentioned above, and the buffer P00LI is being restricted by the processing (S5). After that, buffer P00LI[ is used.

For this reason, first, it is determined whether the common buffer POOLII is being restricted (S7)L, and if it is not being restricted (N), a hunt process, that is, a process of hunting the usage rate area of the common buffer P00LII (S8) is executed. And the usage rate is Th
resh.

Determine whether it is greater than Idl or not, and if it is greater (Y)
The common buffer POOLII is marked as being restricted (SIO). In determination s9, the usage rate is Thr
When eshold is less than 1, or after completing the processing SIO, a signal reception notification (S6) is performed. Furthermore, when the common buffer POOLII is under regulation, a signal reception notification (311) is performed. Furthermore, at this time, this discand
The congestion control module that receives the marked signal reception notification performs only Layer 2 Header processing and releases the transaction.

On the other hand, when the start is by synchronous scanning, the buffer P
Determine whether OOL I, common buffer, and POOL II are under restriction (SI2) L. If they are not under restriction (N), the process ends, and when they are under restriction (Y), the usage rate is Th.
Determine whether reshold is 2 or less (S13) L,
When Threshold is not less than 2 (N), the process is terminated in the same way, and when Threshold is less than 2 (Y), the restriction of POOLn and ■ is canceled (314) L,
finish.

The specific value Threshold I mentioned above is 80%, and the specific value Threshold 2 is 40%. Note that this value is not limited to this, and the efficiency can be further improved by changing it depending on the channel to be concentrated.

〔Effect of the invention〕

Through the above-described operation, according to the present invention, instead of applying congestion standards equally to each subscriber as in the past, by providing a dynamic regulation logic, it is possible to realize services that meet the demands of subscribers. .

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of the control system within the DLCC, Figure 2 is the RX
/TXffA control flowchart.

Claims (1)

[Claims] 1) In a digital subscriber concentrator (DLCC), an allocated receiving buffer that should provide basic services to all subscribers, and a common buffer used by subscribers who have used up their allocated receiving buffers. A reception buffer control method characterized by providing a plurality of. 2) Congestion control in the digital subscriber line concentrator is performed for all subscribers using the common buffer when the usage rate of the common buffer exceeds the first usage rate, and Buffer usage is second
2. The reception buffer control method according to claim 1, wherein the reception buffer control method is canceled when the usage rate falls below a usage rate of . 3) The reception buffer control method according to claim 2, wherein the first usage rate is 80% and the second usage rate is 40%.