JP2000354042A - Band allocation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smooth band usage of every circuit by setting the band allocation for 'each service category that is supplied via an ATM layer'. SOLUTION: A band management control part 21 manages the band allocation, in response to the decision results of a time deciding part 22 and a band deciding part 23. The part 22 calculates an allocatable area from the requested service category defined in a calling mode and the relevant time, and the part 23 compares the allocatable band calculated at the part 22 with the current working area to calculate a remaining band of every service category. A band management DB part 3 sets a band area of every service category in advance. A time band data part 31 integrates the request bands in each service category at a fixed time interval and decides an allocation band in each service category of a time τ, in response to the integration value. Then band allocation data part 32 records the band securing and releasing situations of every service category and holds the remaining band data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a band allocation system, and more particularly to a band allocation (or reservation) system in an ATM (Asynchronous Transfer Mode) exchange.

[0002]

2. Description of the Related Art In the prior art relating to a band allocation system of an ATM exchange, a user declares parameters relating to a newly used band by communication. On the other hand, the ATM exchange judges whether or not a bandwidth can be allocated based on the amount of available bandwidth for each line based on these report parameters.

[0003]

However, in the conventional bandwidth allocation method, the bandwidth is allocated from the exchange only when the user declares the bandwidth to be used when actually calling.
At this time, if it is simply determined whether or not a band can be allocated for each line based on the amount of available bandwidth, there may be a case in which the band usage rate for each service category is biased depending on the line. For example, CB
In a line where a large band of the R (Constant Bit Rate) category is obtained, communication is performed at a variable rate such as UBR (Unspecified Bit Rate). The communication efficiency is reduced in communication of other categories (that is, other than CBR). On the other hand, it is conceivable that the bandwidth usage rate for each service category greatly changes depending on the time zone.

[0004] Here, in particular, PCR, SCR, MC
Attention is paid to three parameters of R. Here, the “service category” represents a service category in the ATM layer, and the following five types are assumed. That is, CBR
(Fixed bit rate service category), rt-VBR
(Real time variable bit rate service category), nrt
-VBR (non-real time variable bit rate service category), URR (unspecified bit rate service category)
And ABR (available bit rate service category).

[0005] An object of the present invention relates to a band allocation method in an ATM exchange, and makes it possible to set a band allocation for each "service category provided by the ATM layer" to thereby smooth the band use rate per line. That is. It is another object of the present invention to provide a bandwidth allocation method for dynamically allocating a bandwidth for each service category in order to cope with a change in connection demand for each service category that changes every moment.

[0006]

In order to solve the above-mentioned problems, the band allocation system according to the present invention employs the following characteristic configuration.

(1) In a bandwidth allocation method in an ATM exchange, a bandwidth management database unit for dynamically setting a bandwidth allocation for each service category in response to a connection request from a user, and actually according to the settings of the bandwidth management database unit. A bandwidth management control unit that performs allocation.

(2) In the bandwidth management database section,
A time zone data section that integrates the required bandwidth for each service category at a fixed time interval and determines an allocated bandwidth for each service category at the next fixed time interval in accordance with the integrated value, and a bandwidth securing and releasing status for each service category. And (b) a bandwidth allocation data unit that stores and retains remaining bandwidth data.

(3) The bandwidth management control unit cooperates with the bandwidth management database unit to calculate an allocatable bandwidth based on the requested service category and the time required for the invention. The bandwidth allocation method according to the above (1) or (2), wherein the bandwidth allocation management is performed based on a determination made by a bandwidth determination unit that calculates a remaining bandwidth for each service category by comparing the bandwidth in use with the bandwidth.

[0010] (4) In a bandwidth allocation method for an ATM exchange connected to one or more terminals, a minimum usable bandwidth is set in advance for each service category, and the remaining bandwidth is allocated according to a connection request bandwidth in order to allocate the remaining bandwidth. A bandwidth management database unit for setting an allocated bandwidth for each dynamic service category, and a bandwidth management control unit for actually setting a bandwidth allocation, wherein the bandwidth management database unit includes a traffic volume for each service category at fixed time intervals. Set the allocation of the remaining bandwidth for each service category in the next fixed time interval, the bandwidth management control unit, in response to a connection request from the terminal,
A bandwidth allocation method in which the time at that time and the requested service category are inquired to the bandwidth management database unit, and if there is an available bandwidth, it is determined that allocation is possible.

(5) The bandwidth allocation method according to the above (4), wherein the bandwidth management database unit also records the bandwidth usage status for each line and each service category.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a preferred embodiment of a band allocating system according to the present invention; FIG.

First, FIG. 1 is a configuration diagram showing the principle of the band allocation system according to the present invention. The ATM switch 1 of FIG. 1 includes a control unit 2 and a bandwidth management DB (database) unit 3. The control unit 2 includes a bandwidth management control unit 21 that receives a bandwidth request from a user, a time determination unit 22, and a bandwidth determination unit 23. The bandwidth management DB unit 3 stores the time zone data unit 3
1 and a band allocation data section 32.

The band management control unit 21 performs band allocation management based on the judgment by the time judgment unit 22 and the band judgment unit 23. The time determination unit 22 calculates a bandwidth that can be allocated based on the requested service category at the time of calling and the time at that time. The band determining unit 23 compares the assignable band obtained by the time determining unit 22 with the currently used band to calculate the remaining band for each service category.

The bandwidth management DB unit 3 sets an allocated bandwidth for each service category. The time zone data unit 31 integrates the required bandwidth for each service category at regular time intervals,
The allocated bandwidth for each service category for the next τ time is determined according to the amount. Further, the bandwidth allocation data unit 32 records the status of securing and releasing the bandwidth for each service category, and retains the remaining bandwidth data.

The ATM switch 1 shown in FIG. 1 dynamically changes the bandwidth allocation amount for each service category provided in the dynamically changing ATM layer, thereby smoothing the bandwidth usage rate for each line. enable. FIG. 2 shows a parameter list for each service category used at the time of bandwidth calculation. Here, PCR indicates a peak cell rate, SCR indicates an average cell rate, and MCR indicates a minimum cell rate.

Next, FIG. 3 shows a conceptual diagram of a band allocation system according to the present invention. Between the ATM exchanges SWj and SWk
There are n lines. It is assumed that terminals X and Y are connected to the ATM exchanges SWj and SWk, respectively. In FIG. 2, at time t from terminal X, band C in service category S2
This shows a case where a request for s2 (t) has been made. In this case, AT
The M switch SWj determines the current band usage status for each service category, and determines the band Bl1s2 (ti) of the line l1.
Indicates that it has been assigned to At the same time, the ATM switch SWk responds to the request from the terminal Y by using the band B12s1 of the line l2.
(Ti) is assigned.

The bandwidth management DB unit (see 3 in FIG. 1) of each ATM exchange SW manages data used in the bandwidth allocation determination unit. First, the time zone data unit 31 integrates the required bandwidth for each service category at a fixed time interval τ, and determines an allocated bandwidth for each service category in the next τ time according to the amount.

On the other hand, in the band allocation data section 32, the time τ
Of the bandwidth usage for each line and service category,
Used for bandwidth allocation.

At a certain time, when a terminal of a user making a communication makes a call request, the time determining unit 22 calculates a band that can be allocated based on the requested service category and the time at that time. This is compared with the currently used bandwidth, and the bandwidth determination unit 23 calculates the remaining bandwidth for each service category. Finally, the bandwidth management control unit 21 compares the remaining bandwidth with the required bandwidth, and when the remaining bandwidth is larger than the required bandwidth, determines to accept this request.

The following is a calculation formula for calculating the allocated bandwidth. First, i) indicates that the bandwidth allocation is not changed when the connection required bandwidth Cs (t) in the service category s is 0 in the category between the time and the second time. Next, ii) shows that, when a connection request is made in any of the service categories, the allocated bandwidth at the next time τ is determined by the ratio of the sum of the required bandwidths. At this time, it is assumed that a minimum bandwidth Ms is allocated to all service categories in consideration of a case where a connection request is made during the next time τ for a service category for which no connection request has been made.

(Equation 1)

Next, the time interval τ and the detailed bandwidth allocation will be described with reference to FIG. FIG. 4 is an example of band allocation when a line of band T (l) is used in two service categories S1 and S2.

In the specific example of FIG. 4, a connection request is issued twice to S1 during the time τ1 (total required bandwidth = 5),
(Total required bandwidth = 2). Thus, the bandwidth allocation amount for each service category at time τ2 is as follows.

S1 is 5 / (5 + 2) * T (l) = T
(L) * 5/7. Also, S2 is 2 / (5 + 2) * T
(L) = T (l) * 2/7. The example of the next time τ2 is an example in the case where there is no bandwidth request. If there is no request in S1 and there are two requests in S2 (total required bandwidth = 4), in the next next time τ3, the minimum bandwidth reservation capacity (Ms1) is stored in S1, and the rest is stored in S2. Will be assigned.

FIG. 5 shows an example of band allocation management when the line capacity is 1.5 Mbps. In the case of the request time t0 to t1 and the service category CBR, the maximum bandwidth use capacity is 0.6 Mb.
In ps, the current bandwidth use capacity is 0.45 Mbps, so the remaining bandwidth is 0.15 Mbps. In such a case, when a call comes in with a connection request bandwidth capacity of 0.1 Mbps, the bandwidth management control unit 21 can accept the call (the remaining bandwidth is 0.15 Mbps).
s> requested bandwidth 0.1 Mbps), and at the same time, secures the bandwidth and registers it in the bandwidth allocation data unit 32.

It is to be noted that, for a terminal determined to be unassignable due to lack of available bandwidth, a request is made to change the required service category or reduce or cancel the required bandwidth. FIG. 6 shows a processing flowchart for that.

At step S1, a time zone determination process is performed. Next, a service category determination process is performed in step S2. After that, in step S3, the assignable band is determined under the condition of (used band + required band) ≦ applicable condition. In the case of Yes, the process proceeds to step S4, and the request is accepted by adding the required bandwidth to the used bandwidth in the corresponding condition. If No, step S5
Go to and reject the bandwidth request.

The preferred embodiment of the bandwidth allocating method according to the present invention has been described above in detail. However, the present invention should not be limited to only such specific examples, and various modifications and changes are possible.

[0029]

According to the bandwidth allocation method of the present invention, the ATM
By setting the bandwidth allocation for each service category provided by the layer, it is possible to smooth the bandwidth usage rate per line. Further, in order to cope with a change in connection demand for each service category that changes every moment, dynamic bandwidth allocation for each service category becomes possible, and the practical effect is remarkable.

[Brief description of the drawings]

FIG. 1 is a principle configuration diagram of a band allocation system according to the present invention.

FIG. 2 is a diagram showing a parameter list for each service category used at the time of bandwidth calculation in the embodiment of the present invention.

FIG. 3 is a conceptual diagram of a bandwidth allocation method according to the embodiment of the present invention.

FIG. 4 is an example of band allocation by a band allocation method according to the embodiment of the present invention.

FIG. 5 shows a circuit capacity of 1.5 M according to the embodiment of the present invention.
It is a figure which shows the example of band allocation management in the case of bps.

FIG. 6 is a processing flowchart of a connection request reception in the embodiment of the present invention.

[Explanation of symbols]

1, SWj, SWk ATM switch 2 Control unit 3 Bandwidth management database (D
B) unit 21 bandwidth management control unit 22 time determination unit 23 bandwidth determination unit 31 time zone data unit 32 bandwidth allocation data unit

Claims (5)

[Claims] In a bandwidth allocation method in an ATM exchange, a bandwidth management database unit dynamically sets bandwidth allocation for each service category in response to a connection request from a user, and an actual allocation according to the settings of the bandwidth management database unit. And a band management control unit that performs the following. 2. The bandwidth management database unit integrates a required bandwidth for each service category at fixed time intervals and determines time zone data for determining an allocated bandwidth for each service category at the next fixed time interval according to the integrated value. The bandwidth allocation method according to claim 1, further comprising: a bandwidth allocation unit configured to store a status of securing and releasing a bandwidth for each service category and retain remaining bandwidth data. 3. The bandwidth management control unit cooperates with the bandwidth management database unit to calculate an allocatable bandwidth based on the requested service category and its time according to the present invention. The bandwidth allocation system according to claim 1, wherein the bandwidth allocation management is performed based on a determination by a bandwidth determination unit that calculates a remaining bandwidth for each service category by comparing the bandwidth with a middle bandwidth. 4. A bandwidth allocation method in an ATM exchange connected to one or more terminals, wherein a minimum usable bandwidth is set in advance for each service category, and the remaining bandwidth is allocated according to a connection request bandwidth in order to allocate the remaining bandwidth. A bandwidth management database unit for setting an allocated bandwidth for each dynamic service category and a bandwidth management control unit for actually setting a bandwidth allocation are provided, and the bandwidth management database unit reduces the traffic volume for each service category at regular time intervals. The bandwidth management control unit sets the allocation of the remaining bandwidth for each service category at the next fixed time interval in response to the connection request from the terminal, and stores the time at that time and the requested service category in the bandwidth management database. A band allocation method characterized by inquiring a part and determining that allocation is possible when there is an empty band. 5. The bandwidth allocating method according to claim 4, wherein said bandwidth management database unit also records a bandwidth usage status for each line and each service category.