JP3132719B2 - Usage parameter control circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for information transfer in an asynchronous transfer mode (ATM). In particular, it monitors whether or not the user uses the network resources more than the declared connection, and monitors the quality (QOS: Quality) of other connections in the network.
technology that does not worsen the service of service).

[0002]

2. Description of the Related Art Conventionally, in an ATM network, it is monitored whether a user uses a network resource more than a declared connection for a set connection. If it is used more than declared, it is determined to be a violation, and at that point, the cell is discarded, or the cell is tagged and transferred to the network, and the tag is added according to the congestion situation in the network Control for discarding the assigned cell. As a result, the QO of other connections in the network
S can be prevented from deteriorating, and transfer of a certain amount of cells can be guaranteed. Such a technique is called usage parameter control (UPC).

FIG. 43 is a view for explaining a conventional UPC, and FIGS. 44 and 45 show an algorithm thereof. Although the expression form is different between FIG. 44 and FIG.
The content is the same. Here, ITU-T Recommendation I. 37
The leaky bucket type UPC specified in No. 1 will be described.

In the leaky bucket type UPC, when a cell from a user arrives, it is monitored whether or not the network resource is used more than the user has declared, and if the cell is used more than the declared, the cell is violated. Judge. The determination as to whether or not a violation is made is based on the time when the k-th cell arrives at t.
_a (k), t _a when the most recent bucket depth in arrival time LCT of normal cells from (k) and X, immediately after the bucket has output t _a (k) bucket depth in X 'is X − (T _a (k) −LCT). here,
X ′> τ, that is, the kth cell is “arrival time determined by the value declared by the user” − “delay variation allowable value τ”
If it arrives earlier, it is using more network resources than declared and the cell is violated. X '<[tau], that is, if the k-th cell arrives later than "arrival time determined by the value declared by the user"-"delay variation allowable value [tau]", use network resources beyond the declared value. And that cell is normal. Since the cells that are determined to be normal is input to the bucket, to update the bucket depth in t _a (k) to X = max (0, X ' ) + T.

[0005]

However, when judging a violation on a cell-by-cell basis, there is a possibility that the violating cells may be distributed among a plurality of packets at the packet level including a plurality of cells. FIG. 46 shows such a state. In such a case, if TCP or other control is used in the upper layer, when the offending cell is discarded, all packets including the offending cell are retransmitted. For this reason,
There is a problem that the packet transfer efficiency is reduced.

The present invention solves such a problem, and provides a UPC circuit capable of preventing a decrease in packet transfer efficiency due to a situation in which a violating cell is dispersed in a plurality of packets and all of them are retransmitted. It is another object of the present invention to provide an ATM communication device capable of efficiently transferring a user's packet.

[0007]

The UPC circuit of the present invention comprises:
Monitoring means for monitoring cells transferred from the user terminal into the asynchronous transfer mode network, and judging the cell as a violation if the user terminal uses more network resources than declared;
A UPC circuit comprising: a discard processing unit for performing a process for discarding a cell determined to be in violation; and a head cell identification unit for identifying a head cell of the packet for each packet including a plurality of cells, The monitoring means includes a judgment means for judging a violation or a normality of the identified first cell, and the discard processing means includes a cell processing means for performing a cell discarding process for each packet in which the first cell is violated. It is characterized by.

[0008] The cell processing means is a means for assigning a tag from the head of the packet in which the first cell is determined to be a violation to the cell immediately before the last cell, which permits the cells to be discarded in the network. And a means for discarding the last cell from the beginning of the packet when the first cell is determined to be in violation.

The monitoring means includes a tag identifying means for identifying whether or not the input cell is provided with a tag indicating that the cell is permitted to be discarded in the network. The means discards the cells in the network from the cell determined to be in violation by either the tag identification means or the determination means to the cell immediately before the last cell of the packet including the cell. Means for providing a tag that allows the

The monitoring means may determine the violation of the cell by monitoring only the average cell speed, or may monitor the average cell speed and the peak cell speed to determine the violation of the cell.

The monitoring means includes second determining means for determining whether the cells are normal or violated for all cells except the first cell and the last cell of the packet. The second cell processing means may perform the cell discarding process from the cell violated by the means for performing the above to the cell immediately before the last cell. In this case, the parameter for judging whether the cell is normal or violated in the second judgment means can be set differently from the judgment means for the head cell.

[0012]

FIG. 1 is a block diagram showing an embodiment of the present invention, showing a connection configuration between a user terminal and an ATM network.

Each of the plurality of user terminals 1 is connected to the ATM line via the subscriber transmission line 2 (i is the input terminal position of the subscriber transmission line) and the UPC circuit 3 at the physical speed L _i [cell / sec].
It is housed in the switch 4. The ATM connection sent from the user terminal 1 is logically connected from the ATM switch 4 to the destination via some relay transmission lines and the ATM switch. FIG. 1 shows ATM switches 4 and 5
And shows a state in which an ATM connection 6 from one user terminal 1 is set via the ATM switch 4, the relay transmission line 7, the ATM switch 5, and the relay transmission line 8. In the relay transmission lines 7 and 8 through which the ATM connection passes, it is assumed that a band of S _i [cells / second] is allocated to the ATM connection.

Each of the UPC circuits 3 monitors a cell of the ATM connection from the corresponding node terminal 1, and if the user terminal 1 uses more network resources than declared, determines that the cell is a violation, A process for discarding the cell determined to be is performed. At this time, for each packet including a plurality of cells, the first cell of the packet is identified,
The identified top cell is determined to be in violation or normal, and cell discard processing is performed for each packet in which the top cell is violated.

That is, the cell of the ATM connection is monitored at S _i [cells / second], and when the user terminal 1 transmits a cell to the ATM connection at a speed of S _i [cells / second] or less, the user terminal 1 transmits the cell. Transfer the cell as it is. When the user terminal 1 sends a cell at a rate exceeding S _i [cells / second], the discard processing is performed on the cell exceeding the rate in packet units.

In this discarding process, when the first cell is determined to be in violation, the UPC circuit 3 may discard the first to last cells of the packet, and the first cell is determined to be in violation. From the beginning of the packet to the cell immediately before the last cell, a tag may be added to allow those cells to be discarded in the network.

When a tag is added, since the relay transmission lines 7 and 8 secure a band of S _i [cells / second] for the ATM connection, the cells to which no tag is added by the UPC circuit 3 are: It passes through the ATM switches 4 and 5 without congestion. If a cell with a tag is congested with other connection traffic when there is much traffic, the AT
It is discarded in the M switches 4 and 5 and passes without being discarded when there is little other traffic. Therefore, the user terminal 1 is guaranteed to transfer cells at a rate of at least S _i [cells / second], and can transfer cells at a higher speed when there is little other traffic and there is no congestion in the network.

When the user terminal 1 transmits a cell at a rate of S _i [cells / second] or more, the user side distinguishes between a high-priority cell and a low-priority cell in advance, The terminal 1 can also send a tag. At this time, in the UPC circuit 3, the cell to which the tag is added is regarded as a violation, and the cells from that cell to immediately before the last cell of the packet are regarded as violation cells. If no tag has been assigned, the above processing is performed. In this way, a high-priority packet from the user terminal 1 is reliably transferred,
It is possible to realize a best-effort service in which low-priority packets can be transferred without congestion in the network.

When the packet length is extremely long, it is preferable to determine whether the packet is normal or not only at the beginning of the packet but also in the middle. That is, for all cells except the first cell and the last cell of the packet, it is determined whether the cell is normal or violated, and tags are assigned from the offending cell to the cell immediately before the last cell. Or discard on the spot.

It is desirable that the ATM switches 4 and 5 have means for notifying the user terminal 1 of the ATM connection of the congestion state when detecting congestion of the cell to which the tag is added. The method of notification is as follows:
In the ATM switch 4 or 5 in which congestion has occurred or another ATM switch, there is a method of writing a congestion notification bit in a PTI field of a user cell and notifying the user terminal 1 through a connection in the reverse direction of the ATM connection. The user terminal 1 that has received the notification of the congestion can reduce the speed of cells transmitted to the ATM connection to S _i [cells / second] or less in order to avoid cell loss. This prevents the user terminal 1 from losing cells,
It is possible to avoid retransmission of the packet.

FIG. 2 is a diagram for explaining the operation of the UPC circuit 3. According to the present invention, this UPC circuit 3
In addition to the violating cell determination function of the PC circuit,
The packet is identified at the cell level using the M and AAL (ATM Adaptation Layer) header, and violation and normality are determined for each identified packet.

FIGS. 3 and 4 are diagrams for explaining a method of identifying a packet from a cell. FIG. 3 shows the AUU parameters of an ATM cell, and FIG. 4 shows the relationship between the AUU parameters and the packet. Here, AAL type 5 which is often used when performing data communication by ATM will be described as an example. In the AAL type 5, as shown in FIG. 3, the AUU (ATM Layer User) of the last cell constituting the same packet is used.
to User) parameter is set to “1”, and others are set to “0”. Therefore, as shown in FIG. 4, the AUU parameter is set to “1”.
Cells up to the cell where the U parameter is “1” can be identified as cells constituting the same packet. Since the AUU parameter is in the PTI field in the ATM layer header, it can be easily identified as "0" or "1". In addition to the AAL type 5, if the bit for identifying the head or tail of the packet is present in the ATM and AAL layer header,
Similarly, a packet can be identified.

[0023]

FIG. 5 is a block diagram showing the details of the UPC circuit. The UPC circuit includes a cell identification unit 11, a violation determination unit 12, a violation processing unit 13, a parameter memory 14,
Operation memory 15, cell counting unit 16, counting memory 1
7. Control interface 18 and alarm collection unit 19
Is provided. The cell identification unit 11 identifies a VPI and identifies a cell to be discarded. The violation determining unit 12 identifies a user or non-user cell, and determines violations of a user cell and a non-user cell. The violation processing unit 13 discards the cell determined to be in violation by the violation determination unit 12. The parameter memory 14 holds the input cell monitoring parameter value of each VP used in the violation determination unit 12. The calculation memory 15 stores control parameters for determining a violation of each VP used by the violation determination unit 12 and parameters related to the UPC. The cell counting unit 16 counts passing and violating cells. The counting memory 17 holds a counted value of the number of passed and discarded cells. The control interface 18 is U
Performs various settings control of the PC. The alarm collection unit 19
An alarm is notified for a PC failure or user abnormality.

Regarding an embodiment of the operation of the UPC circuit,
This will be described in more detail below.

FIGS. 6 to 8 are diagrams for explaining the first embodiment. FIG. 6 shows the operation of the leaky bucket type UPC, and FIG. 7 shows the process of judging whether the first cell constituting a packet is normal or not. Flow, FIG. 8 shows the flow of processing for individual cells. Here, the user transmits only untagged cells, and in the UPC circuit, the average cell rate SCR
An example will be described in which only the SCR is monitored and a tag is attached to the offending cell when there is a violation in the SCR.

In this case, when a cell arrives from the user, the UPC circuit determines whether the cell is the first cell constituting a packet. If the cell is the first cell, it is monitored whether or not the network resource is used more than the user has declared. If the cell is used more than the report, the cell is determined to be in violation. Then, a packet including a cell determined to be in violation is regarded as a violation cell from the first cell to immediately before the last cell. The last cell is a cell indicating the end of the packet and is not considered a violation. The cell determined to be in violation is attached with a tag, transferred to the network, and allowed to be discarded according to the congestion situation in the network.

The determination as to whether the first cell of the packet is normal or illegal is made as follows. First, assuming that the time at which the first cell constituting the packet arrives is t _a (k) and the depth of the bucket at the arrival time LCT of the nearest normal cell from t _a (k) is X, immediately after the bucket is output Of the bucket at t _a (k) is X- (t _a (k) -LC
T). Here, if X ′> TH, that is, the first cell constituting the packet arrives earlier than “arrival time determined by the value declared by the user” − “delay variation allowable value TH”, it is more than declared. Assuming that network resources are used, the parameter V indicating the normal or violating state of the packet is V = 1, that is, violated. X '<TH,
That is, if the first cell constituting the packet arrives later than "arrival time determined by the value declared by the user"-"delay variation allowable value TH", the network resources are not used any more than declared. It is determined that V indicating a normal or violating state of the packet is V = 0, that is, normal. The cells that are determined to be normal type in a bucket, to update the bucket depth in t _a (k) to X = max (0, X ' ) + T.

FIG. 8 shows the processing for each cell to be inputted.
This will be described with reference to FIG. First, as an initial value, t _a (1) the time at which the first cell arrives, bucket depth X = 0, sets the most arrival of the last normal cell time LCT = t _a (1). Then, the time t _a (k) at which the k-th cell arrives
Next, it is determined whether the cell is the first cell constituting the packet. If the cell is the first cell, a violation or normal judgment is made as described above. If the cell is judged normal, V = 0 is set and all cells constituting the same packet as the cell are regarded as normal cells. I do. V = in case of violation
The tag is set to 1, and a tag indicating that the cell is permitted to be discarded in the network is added. When the input cell is neither the first cell nor the last cell of the packet, the first cell is normal if V = 0 is set, and if V = 1, the cell is also violated. The tag is similarly assigned to the offending cell.
It is not necessary to determine whether the last cell is normal or violated. In this manner, in the packet in which the first cell is determined to be in violation, the cells from the beginning to the cell immediately before the last cell are determined to be in violation, and a tag is attached to each cell.

FIG. 9 shows an example in which the processing shown in FIG. 8 is modified. In this example, a virtual scheduling algorithm is used, and the normality or violation of the first cell constituting a packet is determined based on the ideal arrival time TAT of the cell. That is, when the time t _a (k) at which the first cell constituting the packet arrives is too early in consideration of the delay variation allowable value TH (TAT> t _a (k) + TH).
Then, the cell is determined to be in violation. The following processing is equivalent to the processing shown in FIG.

FIGS. 10 and 11 are views for explaining the second embodiment. FIG. 10 shows the operation of a leaky bucket type UPC.
FIG. 11 shows a processing flow for each cell. This embodiment is different from the first embodiment in that when the first cell is determined to be in violation, the packet from the beginning to the last cell of the packet is discarded on the spot. That is, at the time t _a (k) at which the k-th cell arrives, it is determined whether or not the cell is the first cell constituting the packet. If the cell is the first cell, a violation or normal judgment is made as described above. If the cell is judged normal, V = 0 is set and all cells constituting the same packet as the cell are regarded as normal cells. I do. In the case of a violation, V = 1 is set and the cell is discarded. When the input cell is not the first cell constituting the packet, V = 0 in the first cell.
Is set as normal, and if V = 1, the cell is discarded as a violation. In this case, the last cell of the packet is also discarded if V = 1.

FIG. 12 shows a modification of the processing shown in FIG. This processing is a modification of the processing shown in FIG. 11 into a virtual scheduling algorithm, and the normal or violation of the first cell constituting a packet is determined based on the ideal arrival time TAT of the cell. different.

FIGS. 13 and 14 are diagrams for explaining the third embodiment. FIG. 13 shows the operation of a leaky bucket type UPC.
FIG. 14 shows the flow of the processing. Here, the user
When transmitting a cell violating the above, a tag to that effect is added, and in the UPC circuit, the average cell rate SCR
An example will be described in which only the SCR is monitored and a tag is attached to the offending cell when there is a violation in the SCR.

[0033] In this case, as an initial value, t _a (1) the time at which the first cell arrives, bucket depth X = 0, sets the most arrival of the last normal cell time LCT = t _a (1) . Then, the time t _a (k) at which the k-th cell arrives
Next, it is determined whether or not the cell is tagged. If a tag has been assigned, the cell is determined to be in violation, and the cells from the cell determined to be in violation to the cell immediately before the last cell are determined to be in violation. If the tag is not attached, it is determined whether the cell is the first cell constituting the packet. This determination can be made in the same manner as in the first embodiment.
If it is the first cell, it is determined whether the cell is normal or violated. If this cell is determined to be normal, V = 0 is set, and all cells forming the same packet as the cell are regarded as normal cells. If the first cell of the packet is a violating cell, V = 1 is set, and the cell from that cell to the cell immediately before the last cell is regarded as a violating cell, and the last cell is regarded as a normal cell. The value of X is updated for a cell determined to be normal. X is not updated for the cell determined to be in violation. The cell determined to be in violation is attached with a tag and transferred to the network. In the network, the cell is discarded according to the congestion state.

FIG. 15 shows a modification of the processing shown in FIG. This processing is a modification of the processing shown in FIG. 14 into a virtual scheduling algorithm, and the normality or violation of the first cell constituting a packet is determined based on the ideal arrival time TAT of the cell. different.

FIGS. 16 and 17 are views for explaining the fourth embodiment. FIG. 16 shows the operation of a leaky bucket type UPC.
FIG. 17 shows a processing flow. Here, the user transmits only the cell without the tag, and the UPC circuit
Average cell rate SCR as well as peak cell rate PC
An example will be described in which R is also monitored and a tag is added to a violating cell when an SCR is violated. In this case, two buckets are provided for PCR monitoring and SCR monitoring.

As in the above example, as the initial values, the time at which the first cell arrived is t _a (1), the depth of the SCR monitoring bucket X _SCR = 0, and the depth of the PCR monitoring bucket X X
_PCR = 0, arrival time LCT _SCR of the nearest normal cell to each bucket for SCR monitoring and PCR monitoring
= LCT _PCR = t _a (1) Then, at the time t _a (k) at which the k-th cell arrives, it is determined whether or not the cell is the first cell constituting the packet. This determination can be made in the same manner as in the first embodiment. If it is the first cell, it is determined whether the cell is normal or violated. If this cell is determined to be normal, V = 0 is set; if it is determined to be in violation, V = 1 is set, and the cells from that cell to the last cell are set as violating cells. I do.

Next, the PCR is monitored in the same manner as in the conventional UPC. If the violation is determined, the PCR is discarded. If it is determined that the cell is normal, the _XPCR is updated. Update X _SCR .

The cell determined to be in violation is attached with a tag, transferred to the network, and discarded according to the congestion state in the network.

FIG. 18 shows a modification of the processing shown in FIG. This processing is a modification of the processing shown in FIG. 17 into a virtual scheduling algorithm. The normal or violation of the first cell constituting a packet is determined by the ideal arrival time TAT _SCR of the cell for the SCR, and the PCR is performed. Is the ideal arrival time TAT _PCR
Is different from the processing in FIG.

FIGS. 19 and 20 are views for explaining the fifth embodiment. FIG. 19 shows the operation of a leaky bucket type UPC.
FIG. 20 shows a processing flow for each cell. This embodiment is different from the fourth embodiment in that the cell is discarded when the SCR is violated. That is, when the cell arriving at the time t _a (k) is the first cell constituting the packet, and when it is determined that the cell is in violation, V = 1 is set and the cell from the cell to the last cell is set. Discard as a violating cell. Then PCR was monitored as in the conventional UPC, discarded if it is determined that the violation, if it is determined that the normal update the X _PCR, and updates the V = 0 if X _SCR.

FIG. 21 shows a modification of the processing shown in FIG. This processing is a modification of the processing shown in FIG. 20 into a virtual scheduling algorithm. The normal or violation of the first cell constituting the packet is determined by the ideal arrival time TAT _SCR of the cell for SCR, and the PCR is performed. Is the ideal arrival time TAT _PCR
20 is different from the processing in FIG.

FIGS. 22 and 23 are views for explaining a sixth embodiment of the UPC circuit. FIG.
FIG. 23 shows the operation of the PC, and the flow of processing for each cell. Here, when the user sends out a cell violating the SCR, a tag to that effect is added, and the UPC
In the circuit, an example will be described in which the peak cell rate PCR and the average cell rate SCR are monitored, and a tag is assigned to a violating cell when the SCR is violated.

In this case, as initial values, the time at which the first cell arrives is t _a (1), the bucket depth for monitoring _SCR X _SCR = 0, the bucket depth for PCR monitoring X _PCR = 0,
Arrival time of the nearest normal cell to each bucket for SCR monitoring and PCR monitoring LCT _SCR = LCT
Set _PCR = t _a (1). Then, at time t _a (k) at which the k-th cell arrives, it is determined whether or not the cell is tagged. If the tag is attached, the cell is determined to be in violation, and the cells from the cell determined to be in violation to the cell immediately before the last cell are determined to be in violation. If the tag is not attached, it is determined whether the cell is the first cell constituting the packet. This determination can be made in the same manner as in the first embodiment. If it is the first cell, it is determined whether the cell is normal or violated. If this cell is determined to be normal, V = 0 is set, and if it is determined to be in violation, V = 1 is set. When V = 1 is set, all the cells and the cells constituting the same packet except the last cell are regarded as violating cells.

Next, the PCR is monitored in the same manner as the conventional UPC. If the violation is determined, the PCR is discarded. If it is determined that the cell is normal, the _XPCR is updated. Update X _SCR .

The cell determined to be in violation is attached with a tag, transferred to the network, and discarded according to the congestion state in the network.

FIG. 24 shows a modification of the processing shown in FIG. This processing is a modification of the processing shown in FIG. 23 into a virtual scheduling algorithm. The normal or violation of the first cell constituting a packet is determined by the ideal arrival time TAT _SCR of the cell for the SCR, and the PCR is performed. Is the ideal arrival time TAT _{PC R}
Is different from the processing in FIG.

In the above embodiment, when it is determined that the packet is normal at the head of the packet, all subsequent cells are also determined to be normal. In this case, when the packet length is extremely long and the cells constituting the packet arrive continuously, a large number of cells may pass through the UPC circuit without adding a tag, and the QOS of another connection may be deteriorated. There is. Therefore, when cells constituting a long packet are successively input, by determining a violation even in the middle of the packet, it is possible to prevent quality deterioration of other connections. Such an embodiment will be described below.

FIGS. 25 and 26 are views for explaining the seventh embodiment. FIG. 25 shows the operation of a leaky bucket type UPC.
FIG. 26 shows the flow of processing for each cell. Here, an example will be described in which the user transmits only cells to which no tag has been added, and the UPC circuit monitors only the average cell rate SCR, and adds a tag to the offending cell when there is a violation in the SCR.

In this case, the delay variation allowable value TH used in the first embodiment is represented as TH1, and it is determined as a new parameter whether the packet other than the first cell and the last cell constituting the packet is normal or violated. Fluctuation tolerance TH for
2 is introduced. As an initial value, t _a (1) the time at which the first cell arrives, bucket depth X = 0, sets the most arrival of the last normal cell time LCT = t _a (1). Then, at the time t _a (k) at which the k-th cell arrives, it is determined whether or not the cell is the first cell constituting the packet. This determination can be made in the same manner as in the first embodiment.
If the cell is the first cell, it is determined whether the cell is normal or not by using TH1. If this cell is determined to be normal, V = 0, and if it is determined to be in violation, V = 1. Further, for cells other than the first cell and the last cell, if V = 1, the cell is determined to be a violation cell, and if V = 0, the cell is determined to be normal or violated using TH2. V if determined to be in violation
= 1. X is updated for the cell determined to be normal and the last cell. X is not updated for the cell determined to be in violation. The cell determined to be in violation is attached with a tag, transferred to the network, and discarded according to the congestion state in the network.

FIG. 27 shows a modification of the process shown in FIG. This processing is a modification of the processing shown in FIG. 26 into a virtual scheduling algorithm, and differs from the processing in FIG. 26 in that normality or violation of a cell is determined based on the ideal arrival time TAT of the cell.

FIGS. 28 and 29 are views for explaining an eighth embodiment of the UPC circuit. FIG.
FIG. 29 shows the operation of the PC, and the flow of processing for each cell. This embodiment is different from the seventh embodiment in that a cell determined to be in violation is discarded. That is, whether the first cell of the packet is normal or violated is determined using TH1, and if this cell is determined to be normal, V = 0, and if it is determined to be violated, V = 1. In the subsequent cells, if V = 1, the cells up to the last cell are regarded as violating cells.
If = 0, it is determined whether the cell is normal or violated using TH2, and if it is determined to be violated, V = 2. X is updated for the cell determined to be normal and the last cell where V = 2. For cells determined to be in violation,
Discard at that point.

FIG. 30 shows a modification of the processing shown in FIG. This processing is a modification of the processing shown in FIG. 29 into a virtual scheduling algorithm. The normal or violation of the first cell constituting a packet is determined based on the ideal arrival time TAT of the cell. different.

FIGS. 31 and 32 are views for explaining the ninth embodiment. FIG. 31 shows the operation of a leaky bucket type UPC.
FIG. 32 shows the flow of processing for each cell. Here, when the user sends a cell that violates the SCR, a tag indicating that fact is given. The UPC circuit monitors only the average cell rate SCR, and adds a tag to the violating cell when the SCR is violated. An example of the assignment will be described.

[0054] In this case, as an initial value, t _a (1) the time at which the first cell arrives, bucket depth X = 0, sets the most arrival of the last normal cell time LCT = t _a (1) . Then, the time t _a (k) at which the k-th cell arrives
Next, it is determined whether or not the cell is tagged. If the tag is attached, the cell is determined to be in violation, and the cells from the cell determined to be in violation to the cell immediately before the last cell are determined to be in violation. If the tag is not attached, it is determined whether the cell is the first cell constituting the packet.
This determination can be made in the same manner as in the first embodiment. If it is the first cell, T determines whether the cell is normal or not.
This is performed using H1. If this cell is determined to be normal, V =
It is set to 0, and if it is determined to be a violation, V = 1. For cells other than the first cell and the last cell, if V = 0, it is determined whether the cell is normal or not using TH2. If it is determined to be a violation, V = 1. X is updated for the cell determined to be normal and the last cell. X is not updated for the cell determined to be in violation. The cell determined to be in violation is attached with a tag, transferred to the network, and discarded according to the congestion state in the network.

FIG. 33 shows a modification of the processing shown in FIG. This processing is a modification of the processing shown in FIG. 32 into a virtual scheduling algorithm, and differs from the processing in FIG. 32 in that normality or violation of a cell is determined based on the ideal arrival time TAT of the cell.

FIGS. 34 and 35 are views for explaining the tenth embodiment. FIG. 34 shows the operation of a leaky bucket type UPC.
FIG. 35 shows the flow of processing for each cell. Here, an example will be described in which the user transmits only cells to which no tag has been added, and the UPC circuit monitors the average cell rate SCR and the peak cell rate PCR, and adds a tag to the violating cell when the SCR is violated. I do.

In this embodiment, similarly to the seventh embodiment, a delay variation allowable value TH1 for judging whether the first cell of a packet is normal or violated, and a normal or violating value other than the first cell and the last cell. And a delay variation allowable value TH2 for judging. Also, as initial values, the time when the first cell arrived is t _a (1), the depth of the SCR monitoring bucket X _SCR = 0, and the depth of the PCR monitoring bucket X
_PCR = 0, arrival time LCT _SCR of the nearest normal cell to each bucket for SCR monitoring and PCR monitoring
= LCT _PCR = t _a (1) Then, at the time t _a (k) at which the k-th cell arrives, it is determined whether or not the cell is the first cell constituting the packet. This determination can be made in the same manner as in the first embodiment. If the cell is the first cell, it is determined whether the cell is normal or not by using TH1. If this cell is determined to be normal, V = 0,
If it is determined to be a violation, V = 1. With respect to cells other than the first cell and the last cell, if V = 1, the cell is regarded as a violation cell, and if V = 0, it is determined whether the cell is normal or violation by TH.
2 is performed. If it is determined to be a violation, V = 1.

Next, the PCR is monitored in the same manner as in the conventional UPC. If the violation is determined, the PCR is discarded. If it is determined that the cell is normal, the _XPCR is updated. Update X _SCR .

The cell determined to be in violation is attached with a tag, transferred to the network, and discarded according to the congestion state in the network.

FIG. 36 shows a modification of the process shown in FIG. This processing is a modification of the processing shown in FIG. 35 into a virtual scheduling algorithm, and is different from the processing in FIG. 35 in that normality or violation of a cell is determined based on the ideal arrival time TAT of the cell.

FIGS. 37 and 38 are views for explaining the eleventh embodiment. FIG. 37 shows the operation of the leaky bucket type UPC, and FIG. 38 shows the flow of processing for each cell. This embodiment is different from the tenth embodiment in that a violating cell is discarded when an SCR is violated.

That is, whether the first cell of the packet is normal or violated is determined using TH1, and if this cell is judged to be normal, V = 0, and if it is judged to be violated, V = 1. Then, with respect to the cells thereafter, if V = 1, the last cell is regarded as a violating cell, and if V = 0, it is determined using TH2 whether the cell is normal or violating. If it is determined that there is a violation, V = 2. Next, the PCR is monitored in the same manner as in the conventional UPC, and discarded if it is determined to be a violation, _XPCR is updated if it is determined to be normal, and V = 0 or V = 2
If it is the last cell, the X _SCR is updated. The cell determined to be in violation is discarded at that time.

FIG. 39 shows a modification of the process shown in FIG. This processing is a modification of the processing shown in FIG. 38 into a virtual scheduling algorithm, and differs from the processing in FIG. 38 in that normality or violation of a cell is determined based on the ideal arrival time TAT of the cell.

FIGS. 40 and 41 are views for explaining the twelfth embodiment. FIG. 40 shows the operation of the leaky bucket type UPC, and FIG. 41 shows the flow of processing for each cell. Here, the user shall attach a tag to that effect when transmitting a cell violating the average cell rate SCR,
In UPC circuits, SCR and peak cell rate PCR
An example will be described in which the SCR is monitored and a tag is attached to the offending cell when the SCR is violated.

In this embodiment, similarly to the seventh embodiment, the delay variation allowable value TH1 for judging whether the first cell of the packet is normal or violated, and the normal or violated value other than the first cell and the last cell. And a delay variation allowable value TH2 for judging. Also, as initial values, the time when the first cell arrived is t _a (1), the depth of the SCR monitoring bucket X _SCR = 0, and the depth of the PCR monitoring bucket X
_PCR = 0, arrival time LCT _SCR of the nearest normal cell to each bucket for SCR monitoring and PCR monitoring
= LCT _PCR = t _a (1) Then, at time t _a (k) at which the k-th cell arrives, it is determined whether or not the cell is tagged. If a tag is attached, the cell is regarded as a violating cell, and the cells from the cell determined to be violated to the cell immediately before the last are regarded as violating cells. If the tag is not attached, it is determined whether the cell is the first cell constituting the packet. This determination can be made in the same manner as in the first embodiment. If the cell is the first cell, it is determined whether the cell is normal or not by using TH1. If this cell is determined to be normal, V = 0, and if it is determined to be in violation, V = 1. For cells other than the first cell and the last cell, if V = 1, it is determined to be a violating cell, and if V = 0, it is determined using TH2 whether the cell is normal or violating. If it is determined to be a violation, V = 1. Next, the conventional U
Monitors the PCR similar to the PC, discarded if it is determined that the violation, if it is determined that the normal update the X _PCR, for the cell or the last cell of V = 0 and updates the X _SCR.
If V = 1, X _SCR is not updated. The cell determined to be in violation is attached with a tag, transferred to the network, and discarded according to the congestion state in the network.

FIG. 42 shows a modification of the process shown in FIG. This processing is a modification of the processing shown in FIG. 41 into a virtual scheduling algorithm, and is different from the processing in FIG. 41 in that normality or violation of a cell is determined based on an ideal arrival time TAT of the cell.

[0067]

As described above, the UPC circuit of the present invention determines whether cells constituting the same packet are normal or violated on a packet basis, so that violating cells are concentrated on the same packet. . Therefore, there is an effect that a reduction in packet transfer efficiency due to retransmission of a large number of packets can be prevented.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating an operation of a UPC circuit 3.

FIG. 3 is a diagram for explaining a method of identifying a packet from cells, and a diagram for explaining AUU parameters of an ATM cell;

FIG. 4 is a diagram illustrating a method of identifying a packet from a cell, and is a diagram illustrating a relationship between an AUU parameter and a packet.

FIG. 5 is a block diagram showing details of a UPC circuit.

FIG. 6 is a diagram illustrating a first embodiment of the operation of the UPC circuit, and illustrates the operation of the leaky bucket type UPC.

FIG. 7 is a diagram showing the flow of processing for determining whether the first cell constituting a packet is normal or in violation.

FIG. 8 is a diagram showing a flow of processing for each cell.

FIG. 9 is a view showing a modification of the processing shown in FIG. 8;

FIG. 10 is a diagram illustrating a second embodiment of the operation of the UPC circuit, and is a diagram illustrating the operation of the leaky bucket type UPC.

FIG. 11 is a diagram showing a flow of processing on cells constituting a packet.

FIG. 12 is a view showing a modification of the processing shown in FIG. 11;

FIG. 13 is a diagram illustrating a third embodiment of the operation of the UPC circuit, and illustrates the operation of the leaky bucket type UPC.

FIG. 14 is a diagram showing a flow of processing on cells constituting a packet.

FIG. 15 is a diagram showing a modification example of the processing shown in FIG. 14;

FIG. 16 is a diagram illustrating a fourth embodiment of the operation of the UPC circuit, and illustrates the operation of the leaky bucket type UPC.

FIG. 17 is a diagram showing a flow of processing for cells constituting a packet.

FIG. 18 is a view showing a modification of the processing shown in FIG. 17;

FIG. 19 is a diagram illustrating a fifth embodiment of the operation of the UPC circuit, and illustrates the operation of the leaky bucket type UPC.

FIG. 20 is a diagram showing a flow of processing for cells constituting a packet.

FIG. 21 is a diagram showing a modification example of the processing shown in FIG. 20;

FIG. 22 is a diagram illustrating a sixth embodiment of the operation of the UPC circuit, and illustrates the operation of the leaky bucket type UPC.

FIG. 23 is a diagram showing a flow of processing on cells constituting a packet.

FIG. 24 is a view showing a modification of the processing shown in FIG. 23;

FIG. 25 is a diagram illustrating a seventh embodiment of the operation of the UPC circuit, and is a diagram illustrating the operation of the leaky bucket type UPC.

FIG. 26 is a diagram showing a flow of processing for cells constituting a packet.

FIG. 27 is a view showing a modification of the processing shown in FIG. 26;

FIG. 28 is a diagram illustrating an eighth embodiment of the operation of the UPC circuit, and is a diagram illustrating the operation of the leaky bucket type UPC.

FIG. 29 is a diagram showing a flow of processing for cells constituting a packet.

FIG. 30 is a view showing a modification of the processing shown in FIG. 29;

FIG. 31 is a diagram illustrating a ninth embodiment of the operation of the UPC circuit, and is a diagram illustrating the operation of the leaky bucket type UPC.

FIG. 32 is a diagram showing the flow of processing for cells constituting a packet.

FIG. 33 is a view showing a modification of the processing shown in FIG. 32;

FIG. 34 is a diagram illustrating a tenth embodiment of the operation of the UPC circuit, and is a diagram illustrating the operation of the leaky bucket type UPC.

FIG. 35 is a diagram showing a flow of processing for cells constituting a packet.

FIG. 36 is a view showing a modification of the processing shown in FIG. 35;

FIG. 37 is a diagram illustrating an eleventh embodiment of the operation of the UPC circuit, and illustrates the operation of the leaky bucket type UPC;

FIG. 38 is a diagram showing the flow of processing for cells constituting a packet.

FIG. 39 is a view showing a modification of the processing shown in FIG. 38;

FIG. 40 is a diagram illustrating a twelfth embodiment of the operation of the UPC circuit, and is a diagram illustrating the operation of the leaky bucket type UPC.

FIG. 41 is a diagram showing a flow of processing on cells constituting a packet.

FIG. 42 is a view showing a modification of the processing shown in FIG. 41;

FIG. 43 is a view for explaining a conventional UPC.

FIG. 44 is a diagram showing an algorithm.

FIG. 45 is a diagram showing the algorithm shown in FIG. 44 in a different expression form.

FIG. 46 is a diagram showing a state in which a violating cell is distributed among a plurality of packets.

[Explanation of symbols]

 Reference Signs List 1 user terminal 2 subscriber transmission path 3 UPC circuit 4, 5 ATM switch 6 ATM connection 7, 8 relay transmission path 11 cell identification unit 12 violation determination unit 13 violation processing unit 14 parameter memory 15 arithmetic memory 16 cell counting unit 17 Counting memory 18 Control interface 19 Alarm collection unit

Continuation of the front page (56) References JP-A-4-372245 (JP, A) JP-A-6-268866 (JP, A) JP-A-8-274786 (JP, A) JP-A-9-168012 (JP, A) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H04L 12/28 H04L 12/56

Claims (4)

(57) [Claims] 1. A monitoring means for monitoring cells transferred from a user terminal into an asynchronous transfer mode network, and judging the cell as a violation when the user terminal uses more network resources than declared. A usage parameter control circuit comprising: a discard processing unit for performing a process for discarding a cell determined to have been determined to be. A head cell identification unit for identifying a head cell of a packet for each packet including a plurality of cells. The monitoring means includes a head cell determining means for determining whether the identified head cell is violated or normal, and the discarding means includes a packet whose head cell is determined to be violated.
From the beginning of the cell to the cell immediately before the last cell.
Allow cells to be discarded in the network according to congestion conditions
A usage parameter control circuit, comprising: a tag assigning unit that assigns a tag indicating that the tag is a usage tag . (2)The cell from the user terminal contains the cell
Use more network resources than declared by the user terminal
The cell is allowed to be discarded in the network if
Tag indicating that the The monitoring means determines that the input cell is abandoned in the network.
Tag indicating that it is permitted to be discarded.
Tag identification means for identifying whether or not The tag assigning means determines that a violation has occurred by the tag identifying means.
The last cell of the packet containing the cell
Includes means to attach the tag to the cell immediately before Claim
Item 2. A usage parameter control circuit according to item 1. (3)The monitoring means comprises a first cell of the packet.
And all cells except the last cell
Intermediate cell judgment means for judging whether the cell is normal or not
See The tag assigning means violates this intermediate cell determining means.
From the specified cell to the cell immediately before the last cell.
Includes means to add a tag The usage param according to claim 1.
Meter control circuit. 4. The system according to claim 1, wherein said intermediate cell determining means determines that the cell is normal.
Alternatively, the parameter for judging a violation is
4. The usage parameter control circuit according to claim 3, wherein the control circuit is set differently from the controller.