JPH0637793A - Band limit system - Google Patents

Abstract

PURPOSE:To ensure band allocation to a traffic in which cell discard might be caused statistically when various sets of user information from a low speed till a high band in the asynchronous transfer mode (ATM) are sent through a network. CONSTITUTION:This system consists of CIN91-9N linking capacities of plural multiplex unit paths in the synchronous transfer mode(STM), a CNC7 allowing CLM81-8N multiplexing cells to the linked path to execute the linking for band limit and an STM 5 multiplexing the cell in the ST mode finally, and an ATM cell flow is subjected to band limit by using the linked path capacity as its upper limit. Thus, the upper limit of the band at the contract based on the information from the user is surely limited by the STM technology. Thus the cell discard including other information cells is avoided in the network.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a band limiting system, and particularly to a band for a user based on a user's declaration of various amounts of information in a multi-source digital information communication network that centrally handles low to high bands. The present invention relates to a band limiting method when performing allocation.

[0002]

2. Description of the Related Art In order to provide broadband services, B-
Research is being conducted for the construction of a network called ISDN. In particular, the asynchronous transfer mode (ATM) is considered to be suitable as the transfer mode of the transfer layer of this network, and international standardization is also in progress. This ATM-based multiplexed information transfer system is capable of transmitting a signal at a constant speed as in the conventional digital signal information or at a speed generated in a burst to the network side every time it is generated. Since it has a feature, if a large amount of information from multiple users occurs at the same time on the network side, it becomes impossible to transmit them. Further, there arises a problem of how the network handles the information generated when the amount of information generated by the user exceeds the declared value. Studies have been conducted to solve these problems by limiting the amount of generation, that is, the information bandwidth, by traffic control and policing control. At this time, as a conventional solution, a method of controlling the flow rate of information carried in the ATM cell unit, for example, a method of defining an average value in a certain time interval is adopted. However, since these conventional solutions are statistically multiplexed flow restrictions,
Under a certain probability, there is a problem that ATM cells are discarded. Further, even when the user information is declared as a fixed speed (bandwidth), it is common that the information can pass up to the maximum bandwidth value of the access transmission path from the user to the network.
If this is exploited and the user generates information that exceeds the declared value, the network side will adversely affect the cell flow of information of other users.

[0003]

SUMMARY OF THE INVENTION Such a conventional AT
In the bandwidth limitation method based on the flow rate of M cells, even if the user contracts at a declared speed (bandwidth) that is less than or equal to the transmission speed that can be transmitted by the user, in reality, it is the maximum that can be physically transmitted exceeding this declared speed. When a cell is transmitted near the speed, the method of notifying the source of this cell flow to limit it to the contracted declared speed or lower, and discarding the cells exceeding this limit are adopted. Even if it is not, there is a problem that cells may be discarded statistically.

In this conventional method, the bandwidth can be practically limited only up to the capacity of the access transmission line to the fine user.

FIG. 2 is a diagram showing a general model for transmitting user information to be multiplexed on an ATM basis in an access transmission line payload, and FIG. 3 is a diagram showing a state of cell multiplexing and an effective multiplexing capacity in FIG. is there.

As shown in FIG. 2, the user information cell-multiplexed within the capacity of the access transmission line (hereinafter referred to as the payload) has a contractual average speed (payload in the figure) as shown in FIG. 1/2 of the speed of
As described in (b), it is a method that allows physical loading to the maximum extent, so the above-mentioned problems occur.

[0007]

According to the band limiting method of the present invention, at least one synchronous transfer mode multiplexing unit has a path and the capacity of the multiplexing unit is expanded to an integral multiple capacity. Means, multiplexing means for multiplexing cells in the asynchronous transfer mode on the connected path, and control means for executing this multiplexing, and the cell flow rate of user information with the capacity of the connected multiplexing unit as an upper limit. It is characterized by limiting.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a band limiting system of the present invention, which shows a configuration for band limiting in the process of multiplexing a signal from an input terminal (hereinafter IN) 1 to an output terminal (hereinafter OUT) 2. It is shown that each component is not necessarily realized as a unit in the device or system,
Here, it is generalized.

ATM cell information for which band limitation is to be given is IN
The cell buffer (hereinafter referred to as BUF) 4 enters from 1. The actual bandwidth limitation depends on the synchronous transfer mode (STM) technology. A plurality of cell multiplexers (hereinafter, CLM) 81, 82 to 8N for performing STM multiplexing from the BUF4 are arranged in a multiplexing unit arranged at a position determined temporally. This multiplexing unit is an STM technology and is an international standard CCITT recommendation G.264. 708-G. 709 Management Unit (AU) or Tributary Unit (TU)
Etc. can be practically used. These multiplexing units have a fixed maximum multiplexing capacity on an STM basis, and by multiplexing cells therein, the upper limit can be limited by the capacity of this multiplexing unit. A plurality of the multiplexing units are arranged and the timings required by the multiplexing timing control unit (hereinafter TMC) 6 are assigned to the respective CLMs 81 to 8N according to an instruction from the limiting input terminal (hereinafter CT) 3 for band limitation. Distribute. At this time, for example, if two capacitors CLM81 and 82 are used to give a double capacity, the TMC6 gives timings to the CLMs 81 and 82, and the information from the BUF4 receives the information from the CLMs 81 and 8.
2 is multiplexed. At this time, a band control instruction is issued from the CT 3 to the concatenation control unit (hereinafter, CNC) 7 at the same time, and in this case, it is given to the concatenation display insertion unit (hereinafter, CIN) 91 and 92 that the two CLMs 81 and 82 should be coupled. . As a result, the two units are connected on the STM basis. Specifically, CCITT Recommendation G. 708-G. 709
The concatenation display mechanism is used. A combination of these two is multiplexed by an STM multiplexer (hereinafter referred to as STM) 5, and band-limited information is OUT.
It is output from 2.

[0010]

As described above, the band limitation method for the information of the ATM cell flow according to the present invention is realized by multiplexing the asynchronous (STM) -based multiplexing unit, which is connected to one or a plurality of units. It is possible to limit the bandwidth cap to the capacity of the combined multiplexing unit. As a result,
By using user information as a band at the time of contract with a value that can be taken by the combined capacity value, it becomes possible to physically limit, and in the case of statistically limiting by conventional ATM connection. This has the effect of preventing cell discard including other information cells in the network.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a band limiting method of the present invention.

FIG. 2 is a diagram showing a general model for transmitting user information multiplexed on an ATM basis in an access transmission line payload.

FIG. 3 is a diagram showing a state where cells are multiplexed in FIG. 2 and an effective multiplexing capacity.

[Explanation of symbols]

 1 Input Terminal (IN) 2 Output Terminal (OUT) 3 Control Input Terminal (CT) 4 Cell Buffer Unit (BUF) 5 STM Multiplexing Unit (STM) 6 Multiplexing Timing Control Unit (TMC) 7 Connection Control Unit (CNC) 81-8N Cell Multiplexing Unit (CLM) 91-9N Concatenated Display Inserting Unit (CIN)

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location H04Q 11/04

Claims (1)

[Claims] 1. A connection unit having a path by at least one multiplexing unit of a synchronous transfer mode and expanding the capacity of the multiplexing unit to an integral multiple capacity, and an asynchronous transfer mode for the connected path. A band limiting system characterized by comprising a multiplexing means for multiplexing cells and a control means for executing this multiplexing, and limiting the cell flow rate of user information with the capacity of the concatenated multiplexing unit as an upper limit.