JP3439639B2 - ATM device and cell transmission interval correction method in the device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises an ATM (Asynchronous Transfer Mode) network,
Involved in an ATM device having a shaping function,
The present invention relates to an ATM device in which the shaping function is made efficient and a cell transmission interval correction method in the device.

[0002]

2. Description of the Related Art Broadband integrated service digital network (B
-ISDN: Broadband-Integrated Services Digital
ATM is used as a network transmission technology. This ATM is, for example, edited by Hiroshi Ishikawa and edited by Isao Miyake
As described in "M Network Bible" (issued by Ohmsha Co., Ltd. in 1995) and the like, this is a technique for transferring information in units of fixed-length packets called cells.

An ATM-PDS (Passive Double Star) system is an example of a subscriber accommodation network which causes cell delay fluctuation. The ATM-PDS is described in, for example, Tetsuya Kaneda / Noriyuki Terada, "High Speed Optical (ATM-PDS) Access System" (NTT R & D, Vol.44, Dec, 1995). When using the ATM-PDS system, cell delay fluctuation (CDV: Cell Delay Varia), which is a variation in cell interval, is used.
tion) occurs.

The ATM device has a shaping function for correcting the cell transmission interval in order to absorb the influence of the CDV on the line utilization rate. FIG. 11 shows a conventional ATM network.

The ATM network shown in FIG. 11 is a terminal 105 and an ATM device 101 which are respectively connected to a subscriber premises network 201 and a subscriber accommodation network 202 which are connected via a UNI (user network interface), and an ATM. ATM device 106 connected to device 101 via NNI (Network Node Interface)
It is composed by. Further, the ATM device 101 includes a transfer system processing unit 102 that performs a cell transfer process and a control system processing unit 103 that controls the operation thereof. The transfer system processing unit 102 includes a shaping unit 104 that executes a shaping function that corrects the cell transmission interval.

However, depending on the traffic characteristics, the CD
Since the effect of V is small in some cases, CDV in a wide range
It is not economical to use a shaping function that can tolerate the number of connections and to prepare a shaping function for the number of connections.

[0007]

The problem to be solved is that in the prior art, the shaping function must always be used even when the shaping is not necessary.

An object of the present invention is to solve the above-mentioned problems of the prior art and to reduce the shaping function without using the shaping function when the influence of CDV is not so great.
An M device and a cell transmission interval correction method using the device.

[0009]

In order to solve the above-mentioned problems, an ATM device according to the present invention provides a peak bit rate of a connection, a maximum burst length, and a cell delay fluctuation generated in a subscriber premises network and a subscriber. A means for determining the necessity of the shaping function in consideration of the degree of influence of the cell delay fluctuation on the network from the cell delay fluctuation occurring in the structure of the accommodation network, and shaping for compensating the cell delay fluctuation according to the judgment result. And a means for performing. Further, the cell transmission interval correction method according to the present invention uses the peak bit rate of the connection, the maximum burst length, the cell delay fluctuation occurring in the subscriber premises network, and the cell delay fluctuation occurring due to the configuration of the subscriber accommodation network. In consideration of the degree of influence of cell delay fluctuation on the network, the necessity of the shaping function is determined, and shaping is performed to compensate for the cell delay fluctuation according to the determination result.

More specifically, the ATM device according to the present invention, as a circuit for controlling shaping, for example, has a peak bit rate and maximum burst length of a connection, cell delay fluctuations occurring in a subscriber premises network, and A determination circuit is newly provided to determine whether or not to perform shaping using the cell delay fluctuation generated in the subscriber accommodation network,
The feature is that the shaping is performed only when it is determined that the shaping function should be used.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of a configuration relating to an ATM device of the present invention.
In the figure, reference numeral 1 is an ATM device of the present embodiment, which includes a transfer system processing unit 2 for performing a cell transfer process, a determination circuit 7 for determining the necessity of a shaping function, a transfer system processing unit 2 and a determination circuit 7. It is composed of a control system processing unit 3 for controlling the operation of the above. The transfer system processing unit 2 is connected to a selector 21 that switches between supplying the input cell connected to the subscriber accommodation network 202 to the shaping unit 22 or bypassing the shaping unit 22, and one output of the selector 21. The shaping unit 22 corrects the traffic cell interval.

Regarding parameters such as the bit rate and burst length of incoming cells and CDV, the information set at the time of contract of the line is specified in PVC (fixed connection type virtual circuit), and is specified in SVC (switched type virtual circuit). VPI
The communication is started when the terminal calls by the user / line signal distinguished by the (virtual path identifier) and the VCI (virtual channel identifier), the line sets the connection, and the network notifies the terminal of the connection establishment. Information based on the negotiation performed between the terminal and the ATM device at the start of the communication is sent to the determination circuit 7 through the control system processing unit 3, respectively.
Entered in. The determination circuit 7 switches the output of the selector 21 on the basis of the input information to select whether to output each cell after passing the shaping unit 22 or output it by bypassing.

Here, the setting of parameters such as the bit rate and burst length of the inflowing cell and CDV will be described in detail. As mentioned above, in PVC, it is contractually determined. On the other hand, in the SVC, based on the declared values such as the peak bit rate and the maximum burst length described in the user / network signal, the network side considers the current network usage status and determines whether or not to permit the reception. Connection control is performed. The current usage status is understood by the part that controls network resources. If the acceptance is permitted, a vacant VCI number is given to this connection and communication is started. In other words, negotiation means that the user only declares the parameter and the network only makes a decision as to whether or not to permit. In the present invention, the information such as the peak bit rate and the maximum burst length obtained here is sent to the determination circuit 7.

In FIG. 1, 5 is a terminal, and 6 is an ATM device in the latter stage. In FIG. 1, the same components as those in FIG. 11 are designated by the same reference numerals and description thereof will be omitted.

The judgment circuit 7 is a part related to the present invention, and is the peak bit rate and maximum burst length of the connection, the cell delay fluctuation generated in the subscriber premises network, and the cell generated in the subscriber accommodation network. From the delay fluctuation, the degree of influence of the cell delay fluctuation on the network is evaluated, and the necessity of the shaping function is determined. Therefore, the determination circuit 7
Connection peak bit rate, maximum burst length, and cell delay fluctuations that occur in the subscriber premises network,
And from the cell delay fluctuations that occur in the subscriber accommodation network,
It has a function of determining whether or not shaping should be performed and a function of switching the state of the selector 21.

The operation of the ATM device 1 having such a configuration will be described below.
As an example, a process for a connection in which the terminal 5 and the ATM device 6 are connected as shown in this figure will be described. First,
The terminal 5 negotiates with the ATM device 1 about the peak bit rate, the maximum burst length, and the cell delay fluctuation. In the judgment circuit 7, the peak bit rate of the connection, the maximum burst length, and the subscriber premises network are generated based on the information supplied at the time of contract or through the negotiation, which is supplied through the control system processing unit 3. The effect of the cell delay fluctuation on the network is evaluated based on the cell delay fluctuation and the cell delay fluctuation generated due to the construction of the subscriber accommodation network.

As a method of evaluating the degree of influence of cell delay fluctuation on the network, for example, considering CDV, only the peak speed is changed to evaluate the multiplexing effect, and the CDV reduces the line utilization rate. A method can be considered. Here, the multiplexing effect or the statistical multiplexing effect is generally a characteristic peculiar to a communication method using label multiplexing, and in variable speed traffic where there is a peak speed and an average speed, cells always flow at the peak speed. Since it does not exist, it is an effect that a band larger than the total value of each peak speed can be used when multiplexing. At the call level, it is similar to the lumping effect of circuit switching. Here, it is specifically used to mean the output side line utilization rate when the cell discard rate is constant in the ATM device. Evaluation means comparing the multiplexing effects with and without the addition of cell delay fluctuations and investigating to what extent there is a difference. Specifically, the term “impact” refers to a decrease in the line usage rate.

As an evaluation method of the multiplexing effect in this case,
For example, the upper limit formula (Hiroshi Saito, “Call Admission Contro
l in an ATM Network Using Upper Bound of Cell Loss
Probability ”, IEEE Trans. Comm., Sep., 1992.). In general, the burstiness of traffic increases as the CDV occurs, and the multiplexing effect decreases. Although the cell interval may become narrower or wider due to the above, changing only the peak speed means that the traffic received by CDV is always sent out at the minimum cell interval, considering only the minimum cell interval. It means that it is regarded as the traffic of the above, that is, in this case, it is simply considered that the peak speed of the traffic has increased, and the line usage rate is calculated and evaluated, but this is only an example of the evaluation.

When the decision circuit 7 evaluates the traffic having the characteristics obtained by the negotiation or the like, and when it decides that the influence of the cell delay fluctuation is not so much, the decision circuit 7 switches the selector 21 to the bypass circuit side to perform the shaping. However, if it is determined that the degree of influence is large, the output of the selector 21 is connected to the shaping unit 22. An example of the evaluation method using the upper limit formula will be described. First, the line utilization rate is calculated from the peak bit rate and the maximum burst length input to the determination circuit 7 using the upper limit formula. Next, in the traffic pattern obtained from the peak bit rate and the maximum burst length, the CDV
In consideration of the above, only the peak speed is changed and the line usage rate is calculated by the upper limit formula. The determination circuit 7 compares the line usage rates in these two cases, and switches the selector 21 to the bypass circuit side when shaping is not performed, that is, when the latter line usage rate is better or does not change so much.
On the contrary, when shaping is performed, that is, when the former line utilization is considerably better, the output of the selector is connected to the shaping unit 22. It should be noted that many methods have been proposed, including this upper limit expression, for obtaining the line usage rate for the traffic characteristics in order to evaluate the multiplexing effect, and the present invention does not limit the evaluation method.

FIG. 2 shows a specific example of data when passing through the shaving unit 22 and when making a detour. In the cell flow input from the subscriber expropriation network, cell delay fluctuation occurs due to, for example, insertion of control time ((a)). When bypassing the shaping unit 22,
The input cells are input to the ATM switch 23 (not shown in FIG. 1) at the same time intervals ((b)). On the other hand, when passing through the shaping unit 22, after the cell interval is corrected, the ATM switch 2
3 is input ((c)). The ATM switch 23 routes each cell to a predetermined output terminal according to the information in the cell header. The multiplexer 24 (not shown in FIG. 1) multiplexes the cells output from the ATM switch 23 and outputs the multiplexed cells to a predetermined line ((d)).

As described above, the ATM device 1 of this embodiment
Then, the determination circuit 7 is provided and the selector 21 is switched to control the presence or absence of the shaping function to use a shaping function that allows a wide range of cell delay fluctuations, that is, a buffer of the shaping unit corresponding to a large cell delay fluctuation. It is possible to reduce the shaping function because it is not necessary to increase the amount and use the shaping function to prevent cell loss even for large cell delay fluctuations, and to prepare the shaping function for the number of connections. is there. The determination circuit 7
The information that is input to and evaluated for switching the output of the selector 21 is obtained by negotiation. However, a monitor is provided in front of the selector 21, and the bit rate, burst length, CDV, etc. of the cell obtained by monitoring are provided. It is also possible to adopt a configuration in which the parameter information of 1 is input to the determination circuit 7 and the output of the selector 21 is switched. That is, the present invention can be applied to the peak bit rate and the maximum burst length, both declared and observed.

In FIG. 3, the monitor 20 is provided in front of the selector 21.
It is a block diagram which shows the structure which provided. In FIG. 3, the same components as those shown in FIG. 1 are designated by the same reference numerals, and the components having the same functions are designated by the same reference numerals with a dash. The ATM device 1'shown in FIG.
Transmission system processing unit 2 ′, determination circuit 7, and transmission system processing unit 2 ′
And a control system processing unit 3 ′ that controls the operation of the determination circuit 7. The monitor 20 is a subscriber acquisition network 202.
Incoming cell bit rate, burst length and CD
A parameter such as V is monitored, and the information obtained there is input to the determination circuit 7 via the control system processing unit 3 '.

In the ATM device 1'shown in FIG.
Parameter information such as the cell bit rate, burst length, and CDV obtained by monitoring the state of the inflowing cell by 0 is input to the determination circuit 7. Then, in the decision circuit 7, the peak bit rate of the connection, the maximum burst length, and the cell delay fluctuation occurring in the subscriber premises network are based on the information supplied from the monitor 20 via the control system processing unit 3 '. Then, the degree of influence of the cell delay fluctuation on the network is evaluated based on the cell delay fluctuation caused by the configuration of the subscriber accommodation network.

FIG. 4 is a block diagram showing a second embodiment of the structure relating to the ATM device of the present invention. The present embodiment shows a detailed configuration example of the ATM device in FIGS. 1 and 3. FIG. 4 shows, as an example, a configuration in which parameter information such as the bit rate, burst length, and CDV of the cell shown in FIG. 3 is obtained by the monitor 20, but as shown in FIG. 1, the monitor 20 is not used. Only parameter information obtained at the time of contract or negotiation
It is also possible to use a configuration that uses as a basic configuration. The determination circuit 7a in the ATM device 1a of the present embodiment uses the cell traffic pattern obtained from the peak bit rate of the connection and the maximum burst length to determine the cell delay fluctuation generated in the subscriber premises network and the subscriber. The functions of the means 1 for obtaining the multiplexing effect and the means 2 for obtaining the multiplexing effect with and without the cell delay fluctuation generated in the accommodation network are compared with the statistical multiplexing effect in each network. Have the function to

Next, the operation of the ATM device 1a of the present embodiment will be described by taking as an example the processing for the connection to which the terminal 5a and the subsequent ATM device 6a are connected, as in FIG. Similar to the first embodiment described above, the terminal 5a
Negotiates with the ATM device 1a regarding the peak bit rate, the maximum burst length, and the cell delay fluctuation. Then, in the decision circuit 7a, the statistical multiplexing effect is first obtained by the means 1 for obtaining the multiplexing effect from the peak bit rate of the connection and the maximum burst length. Similarly, in the means 2 for obtaining the multiplexing effect, the cell traffic pattern obtained from the peak bit rate and the maximum burst length, the cell delay fluctuation occurring in the subscriber premises network, and the construction of the subscriber accommodation network The statistical multiplexing effect is calculated when the cell delay fluctuation generated above is added. Then, the statistical multiplexing effects in both networks are compared, and when it is determined that the characteristics are better without shaping, the shaping function is not used, and conversely, the characteristics are better with shaping. If determined, it is connected to the shaping unit 22a.

In the ATM device in the second embodiment described above, the form of the subscriber accommodating network 202a is not specified, but as shown in FIG. 5, FIG. 7 and FIG. The configurations may be different. In addition,
In FIG. 4, the structure of the reference numeral with the letter a is shown in FIGS.
It corresponds to the configuration of the code without the letters.

FIG. 5 is a block diagram showing a third embodiment of the configuration relating to the ATM device of the present invention. In the ATM device 1b of this embodiment, the subscriber accommodation network of the second embodiment shown in FIG. 4 is configured by STM-PDS (synchronous transfer mode PDS), and at least two or more subscribers are on the same line. It is configured to be accommodated separately at the time position of. In FIG. 5, the terminal 5b is connected to the ATM device 1b via an ONU (optical network terminating device) 8b and an SLI (subscriber line interface). Here, it is assumed that a plurality of ONUs corresponding to other terminals (not shown) are connected to the SLI. Note that the configuration indicated by the reference numeral with the letter b in FIG. 5 corresponds to the configuration of the reference numeral with the letter b removed or with the letter a added thereto in FIG. 1, FIG. 3, or FIG. 4, respectively.

In the structure of such a subscriber accommodation network, as shown in FIG.
As shown in (1), since the cell transmission rate transmitted from the terminal and the transmission rate of the accommodated line are different, the cell interval fluctuates and cell delay fluctuation occurs. Therefore, the determination circuit 7b
In the means 2a for obtaining the multiplexing effect in the above, the peak bit rate of the connection, the maximum burst length, and the cell delay fluctuation occurring in the subscriber premises network, and the peak bit rate of the connection are allocated as shown in FIG. The statistical multiplexing effect is obtained from the cell delay fluctuation that occurs due to the relationship with the time position, and the above determination processing is performed.

FIG. 7 is a block diagram showing a fourth embodiment of the configuration relating to the ATM device of the present invention. In the ATM device 1c of this embodiment, the subscriber accommodation network of the second embodiment shown in FIG. 4 is composed of ATM-PDS,
At least two or more subscribers are distinguished and accommodated at the time position on the same line, and there is a time position on this line which is periodically allocated for control in the network and in which cell transfer cannot be performed. ing. Further, the configuration indicated by the reference numeral with the letter c in FIG. 7 corresponds to the configuration of the reference numeral with the letter c removed or with the letter a added thereto in FIGS. 1, 3 or 4.

The configuration of such a subscriber accommodation network is shown in FIG.
As shown in (1), since there is a time position where the cells are allocated for control and cell transfer cannot be performed, the cell interval fluctuates and cell delay fluctuation occurs. Also, when the lines are transferred to different speed accommodation lines, cell delay fluctuations occur as shown in FIG. Therefore, in the means 2b for obtaining the multiplexing effect in the decision circuit 7c, the peak bit rate of the connection, the maximum burst length, and the cell delay fluctuation occurring in the subscriber premises network and the peak bit of the connection as shown in FIG. • Cell delay fluctuations caused by the relationship between the rate and the time position where cell transfer cannot be performed, which are periodically allocated for control within the network, and the peak bit rate of the connection is allocated as shown in FIG. The statistical multiplexing effect is obtained from the cell delay fluctuation that occurs due to the relationship with the time position, and the above determination processing is performed.

FIG. 9 is a block diagram showing a fifth embodiment of the configuration relating to the ATM device of the present invention. In the ATM device 1d of this embodiment, the configuration of the subscriber accommodation network of the second embodiment shown in FIG. 4 performs label multiplexing of signals from at least two or more ATM multiplexers in the preceding stage on the same line. It is in the form of housing. Label multiplexing here means that the transmission line is multiplexed by the information (for example, the destination) written in the header of the packet or cell, and is different from the multiplexing form in the synchronous time division transmission system. is there.

In FIG. 9, the terminal 5d is connected to the ATM device 1d via the UNI and ATM multiplexer 9d. However, in FIG. 9, illustration of a plurality of other ATM multiplexers is omitted. Further, the configuration indicated by the reference numeral with the letter d in FIG. 9 corresponds to the configuration of the reference numeral with the letter d removed or with the letter a added thereto in FIGS. 1 and 3 or 4, respectively.

In the construction of such a subscriber accommodation network, as shown in FIG.
As shown in 0, cell delay fluctuation occurs in the ATM multiplexer 9d and the transmission line in the preceding stage. Therefore, in the means 2c for obtaining the multiplexing effect in the decision circuit 7d, the peak bit rate of the connection, the maximum burst length, and the cell delay fluctuation occurring in the subscriber premises network, and FIG.
As described above, the statistical multiplexing effect is calculated from the cell delay fluctuation generated in the ATM device and the transmission line in the preceding stage, and the above-mentioned determination processing is performed.

In the first to fifth embodiments described above, the maximum burst length is considered to be infinite for traffic for which the maximum burst length is not defined.

As described above with reference to FIGS. 1 to 10, in the ATM devices 1, 1 ', to 1d of this embodiment,
The shaping circuits 22 to 22d are determined by the determination circuits 7 to 7d.
Control whether or not to work. With such a configuration, it is possible to reduce the scale of the shaping function in the ATM device.

[0036]

According to the present invention, the shaping function of the ATM device can be reduced depending on the presence or absence of the influence of cell delay fluctuation in the network, and the economy can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a modification of the first embodiment of the configuration of an ATM device of the present invention.

FIG. 2 is a schematic diagram showing a specific example of data in the ATM device shown in FIG.

FIG. 3 is a block diagram showing a modification of the first embodiment of the configuration of the ATM device of the present invention.

FIG. 4 is a block diagram showing a second embodiment of the configuration of the ATM device of the present invention.

FIG. 5 is a block diagram showing a third embodiment of the configuration of the ATM device of the present invention.

FIG. 6 is an explanatory diagram showing an example of cell delay fluctuations occurring in a subscriber accommodation network in the third embodiment.

FIG. 7 is a block diagram showing a fourth embodiment of the configuration of the ATM device of the present invention.

FIG. 8 is an explanatory diagram showing an example of cell delay fluctuations that occur in a subscriber accommodation network in the fourth embodiment.

FIG. 9 is a block diagram showing a fifth embodiment of the configuration of the ATM device of the present invention.

FIG. 10 is an explanatory diagram showing an example of cell delay fluctuation that occurs in a subscriber accommodation network in the fifth embodiment.

FIG. 11 is a block diagram showing a configuration example of a conventional ATM device.

[Explanation of symbols]

1, 1 ', 1a-1d: ATM device, 2, 2', 2a-
2d: transfer system processing unit, 3, 3 ', 3a to 3d: control system processing unit, 20, 20a to 20d: monitor 21, 21a to
21d: selector, 22, 22a to 22d: shaping unit, 5, 5a to 5d: terminal, 6, 6a to 6d: ATM
Device, 7, 7a to 7d: determination circuit, 8b to 8c: ON
U, 9d: ATM multiplexer, 101: ATM device, 10
2: Transfer system processing unit, 103: Control system processing unit, 104: Shaping unit, 105: Terminal, 106: ATM device

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiromi Ueda 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nihon Telegraph and Telephone Corporation (56) Reference Japanese Patent Laid-Open No. 6-338904 (JP, A) Kaihei 4-108239 (JP, A) JP-A-11-55291 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 12/28 H04Q 3/00

Claims (5)

(57) [Claims] 1. An ATM device for accommodating subscribers using a subscriber accommodating network which causes cell delay fluctuation due to a configuration, which performs communication in units of fixed length packets called cells , based on information obtained by negotiation. , connection of the peak bit rate, maximum burst length, and from the cell delay variation which occurs at the subscriber premises network, a cell delay variation caused the configuration of the subscriber accommodating network, principal of shea Epin <br/> grayed function means for determining whether, and means for performing shaping to compensate for cell delay variation in accordance with the determination result provided, the means for determining the necessity of the shaping function, connector
Peak bit rate and maximum burst
In addition to the means to obtain the statistical multiplexing effect from the length,
Cell delay fluctuations that occur in the subscriber premises network, and subscribers
Statistics in consideration of cell delay fluctuations occurring in the storage network
Means for obtaining the multiplexing effect and the statistical multiplexing effect of each
Whether or not the shaping function is necessary is determined by means of comparing
An ATM device characterized by: 2. The ATM device according to claim 1 ,
The configuration of the subscriber accommodation network is such that at least two or more subscribers are separately accommodated at the time positions on the same line, and cell delay fluctuations occurring in the subscriber premises network and the subscriber accommodation network are taken into consideration. The means to obtain the statistical multiplexing effect is
Peak bit of connection in subscriber accommodation network
An ATM device comprising means for obtaining a statistical multiplexing effect in consideration of cell delay fluctuations caused by being assigned to a time position different from the rate. 3. The ATM device according to claim 1 ,
The time during which cell transfer cannot be performed, in which the configuration of the subscriber accommodation network accommodates at least two or more subscribers by distinguishing them at time positions on the same line, and is periodically allocated on this line for control in the network. The means for obtaining the statistical multiplexing effect in the case where the position is present and the cell delay fluctuation occurring in the subscriber premises network and the subscriber accommodation network is taken into consideration is
Peak bit of connection in subscriber accommodation network
ATM comprising means for obtaining a statistical multiplexing effect in consideration of cell delay fluctuations caused by the relationship between the rate and the time position where cell transfer cannot be performed, which is periodically allocated for control within the network. apparatus. 4. The ATM device according to claim 1 ,
The subscriber accommodation network has a configuration in which signals from at least two or more ATM devices at the preceding stage are label-multiplexed and accommodated on the same line, and the necessity of the shaping function is determined. apparatus. 5. An ATM device for accommodating subscribers using a subscriber accommodating network which causes cell delay fluctuation due to the configuration, which performs communication in units of fixed length packets called cells , based on information obtained by negotiation. , connection of the peak bit rate, maximum burst length, and from the cell delay variation which occurs at the subscriber premises network, a cell delay variation caused the configuration of the subscriber accommodating network, principal of shea Epin <br/> grayed function This is a method for determining whether or not there is a decision, and performing shaping for compensating the cell delay fluctuation according to the determination result. The peak bit rate of the connection and the maximum bandwidth are determined.
The statistical multiplexing effect is calculated from the
Cell delay fluctuations that occur in the customer premises network, and subscriber revenue
A large number of statistics in consideration of cell delay fluctuations generated in the distribution network
Duplicate effect and compare each statistical multiplexing effect
Accordingly, the necessity of the shaping function is determined, and the cell transmission interval correction method in the ATM device is characterized.