JP2002261796A - Packet-switching equipment and packet-switching method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of the high-speed packet-switching and large capacity being unable to be realized even though by preparing an output connec tion number of buffers 4-1 to 4-n which operate faster than the transmission speed of output connection 5-1 to 5-n, a circuit scale will be increased, when the number of output connections becomes large, because the output connection number of the buffers 4-1 to 4-n which operate at a high speed must be pre pared. SOLUTION: The transfer speed of transfer circuits is made higher than the total sum of output speeds of a plurality of output connections, corresponding to the transfer circuits.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packet switching device and a packet switching method for exchanging large-capacity packets at high speed.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing a conventional packet switching apparatus. In the figure, 1-1 to 1-n indicate input connections, and 2 indicates data input from input connections 1-1 to 1-n. Output packets 5-1 to 5-
n, a multiplexer 3 for multiplexing data packets input from the input connections 1-1 to 1-n, and 4-1 to 4-n for an output connection 5-1.
5-1 to 5-n are buffers for temporarily storing data packets, and 5-1 to 5-n are output connections.

Next, the operation will be described. Upon input of an ATM cell which is a data packet from the input connection 1-1 to 1-n, the packet switching unit 2 refers to the destination address of the ATM cell and outputs the ATM cell to the output connection 5-1 to 5-n Perform the process of sorting to

That is, the MUX 3 of the packet switching unit 2 multiplexes the ATM cells input from the input connections 1-1 to 1-n, and the buffers 4-1 to 4-n correspond to the corresponding output connections 5-1 to 5-n. n, and stores only the ATM cells to be output to the output connections 5-1 to 5-1.
5-n.

Thus, the input connections 1-1 to 1-1
-N is multiplexed by the MUX3 once, and the buffer 4-1 for each direct output connection
Output connection 5-1 to -5
Packet switching becomes possible without causing interference between -n.

However, from the viewpoint of reducing the capacity of the buffers 4-1 to 4-n, the read speed of the ATM cells stored in the buffers 4-1 to 4-n is controlled by the output connection 5-1.
５−5-n faster than the transmission speed. As a result, the throughput is improved as compared with the case where ATM cells are read at the same read speed as the transmission speed of the output connections 5-1 to 5-n, so that the capacity of the buffers 4-1 to 4-n can be reduced.

[0007]

Since the conventional packet switching apparatus is constructed as described above, the buffers 4-1 to 4-n which operate faster than the transmission speed of the output connections 5-1 to 5-n. Are prepared for the number of output connections,
High-speed and large-capacity packet exchange can be realized.
However, since buffers 4-1 to 4-n that operate at high speed must be prepared for the number of output connections, there is a problem that the circuit scale increases when the number of output connections increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a packet switching apparatus and a packet switching method capable of suppressing an increase in circuit scale even when the number of output connections increases. With the goal.

[0009]

A packet switching apparatus according to the present invention determines an output connection for outputting a data packet by referring to a destination address of the data packet input from a plurality of input connections, and determines the output connection. And a first packet switching unit for outputting the data packet to a transfer line corresponding to the data line, and an output connection for outputting the data packet by referring to the destination address of the data packet when the data packet is input from the transfer line. And a second packet switching unit that outputs the data packet to the output connection, constitutes a packet switching unit, and determines the transfer rate based on the sum of the output speeds of the plurality of output connections corresponding to the transfer line. The transfer speed of the line is increased.

[0010] The packet switching device according to the present invention comprises:
When the packet switching unit detects the congestion of an output connection and outputs a congestion notification to the first packet switching unit, the first packet switching unit outputs a data packet to be output to the congested output connection. It is intended to be discarded.

[0011] The packet switching apparatus according to the present invention has a first
Has a buffer for temporarily storing data packets for each transfer line.

[0012] The packet switching apparatus according to the present invention comprises:
Is provided with a buffer for temporarily storing data packets for each output connection corresponding to a transfer line.

[0013] In the packet switching device according to the present invention, a buffer of the first packet switching unit is configured using a plurality of queuing units corresponding to call types.

[0014] In the packet switching apparatus according to the present invention, a buffer of the second packet switching unit is configured by using a plurality of queuing units corresponding to call types.

[0015] The packet switching apparatus according to the present invention comprises:
When the packet switching unit detects congestion of a certain call type and outputs the congestion notification to the first packet switching unit, the first packet switching unit discards the data packet related to the congested call type. It is something to do.

The packet switching device according to the present invention has a first
The number of levels of the call type handled by the queuing unit in the packet switching unit is smaller than the number of levels of the call type handled by the queuing unit in the second packet switching unit.

The packet switching device according to the present invention has a second
In this case, the number of levels of the call type handled by the queuing unit in the packet switching unit is smaller than the number of levels of the call type handled by the queuing unit in the first packet switching unit.

The packet switching device according to the present invention has a first
And the second packet switching unit is an input buffer type ATM.
The switch is an ATM switch of an output buffer type or an ATM switch of a common buffer type.

The packet switching apparatus according to the present invention determines the output connection group that outputs the data packet by referring to the destination address of the data packet input from the plurality of input connection groups, and corresponds to the output connection group. A first packet switching unit that outputs the data packet to the transfer line, and when a data packet is input from the transfer line, an output connection group that outputs the data packet is determined by referring to a destination address of the data packet And a second packet switching unit that outputs the data packet to the output connection group, and constitutes a packet switching unit, and determines the transfer rate based on the sum of the output speeds of the plurality of output connection groups corresponding to the transfer line. Increase the line transfer speed Those were Unishi.

The packet switching device according to the present invention has a second
When the packet switching unit detects congestion of an output connection group and outputs a notification of the congestion to the first packet switching unit, the data output from the first packet switching unit to the congested output connection group This is to discard the packet.

The packet switching device according to the present invention determines the output port for outputting the data packet by referring to the destination address of the data packet input from the plurality of input ports, and sets the output port corresponding to the output port to the transfer line. A first packet switching unit for outputting the data packet, and when a data packet is input from the transfer line, an output port for outputting the data packet is determined by referring to a destination address of the data packet. And a second packet switching unit that outputs the data packet to the port, and constitutes a packet switching unit. From a sum of output speeds of a plurality of output ports corresponding to the transfer line,
In addition to increasing the transfer speed of the transfer line,
Detects the congestion of the output port where the packet switching unit of
When the congestion notification is output to the first packet switching unit, the first packet switching unit discards the data packet output to the congested output port.

According to the packet switching method of the present invention, the output connection for outputting the data packet is determined by referring to the destination address of the data packet input from the plurality of input connections, and the output connection is transmitted to the transfer line corresponding to the output connection. When the data packet is output from the transfer line while the data packet is output, the output connection for outputting the data packet is determined by referring to the destination address of the data packet, and the output connection is determined for the output connection. Output the packet,
The transfer speed of the transfer line is made higher than the sum of the output speeds of the plurality of output connections corresponding to the transfer line.

In the packet switching method according to the present invention, when congestion of a certain output connection is detected, a data packet to be output to the congested output connection is discarded.

In the packet switching method according to the present invention, the output connection group that outputs the data packet is determined by referring to the destination address of the data packet input from the plurality of input connection groups, and the output connection group is corresponded to the output connection group. While outputting the data packet to the transfer line and inputting the data packet from the transfer line, the output connection group that outputs the data packet is determined by referring to the destination address of the data packet, and the output connection group is determined. The data packet is output to the transfer line, and the transfer speed of the transfer line is made higher than the sum of the output speeds of the plurality of output connection groups corresponding to the transfer line.

In the packet switching method according to the present invention, when congestion of a certain output connection group is detected, data packets output to the congested output connection group are discarded.

In the packet switching method according to the present invention, the output port for outputting the data packet is determined by referring to the destination address of the data packet input from the plurality of input ports, and the output port is connected to the transfer line corresponding to the output port. When the data packet is output from the transfer line while the data packet is output, the output port that outputs the data packet is determined by referring to the destination address of the data packet, and the data port is output to the output port. When a packet is output, the transfer speed of the transfer line is increased from the sum of the output speeds of the plurality of output ports corresponding to the transfer line, and when congestion of a certain output port is detected, the output in which the congestion occurs is output. The data packet output to the port is discarded.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a configuration diagram showing a packet switching apparatus according to Embodiment 1 of the present invention.
Reference numerals -1 to 11-n denote input connections, and reference numeral 12 denotes a reference to the destination address of an ATM cell which is a data packet input from the input connections 11-1 to 11-n.
A first-stage packet switching unit (first packet switching unit) that outputs the TM cell to the transfer lines 15-1 to 15-i corresponding to the output connections 18-1 to 18-n; Are input connections 11-1 to 11-n
MUX for multiplexing ATM cells input from
1 to 14-i exist for each transfer line 15-1 to 15-i, and a buffer for temporarily storing ATM cells;
15-i are transfer lines whose transfer speed is faster than the sum V of the output speeds of the output connection group.

16-1 and 16-2 are transfer lines 15-1 and
When an ATM cell is input from 15-2, an output connection for outputting the ATM cell is determined by referring to the destination address of the ATM cell, and a second-stage packet switching for outputting the ATM cell to the output connection is performed. Units (second packet switching units) 17-1 to 17-m are buffers that exist for each output connection, temporarily store ATM cells, and detect congestion of the corresponding output connection.

18-1 to 18-n are output connections,
Reference numeral 19 denotes a discard control unit that discards ATM cells to be output to the congested output connection upon receiving congestion notification from the buffers 17-1 to 17-m. The first-stage packet switching unit 12 and the second-stage packet switching unit 16
-1, 16-2 constitute packet switching means. FIG. 2 is a flowchart showing a packet switching method according to the first embodiment of the present invention.

Next, the operation will be described. The first-stage packet switching unit 12 has input connections 11-1 to 11-.
When an ATM cell, which is a data packet, is inputted from step n (step ST1), the ATM cell is referred to the transfer addresses 15-1 to 15- with reference to the destination address of the ATM cell.
i (steps ST2 and ST2).
4).

That is, the MU of the first-stage packet switching unit 12
X13 multiplexes the ATM cells input from the input connections 11-1 to 11-n, and buffers 14-1 to 14
-I stores only the ATM cells to be output to the corresponding transfer lines 15-1 to 15-i, and outputs the ATM cells to the transfer lines 15-1 to 15-i. However, the buffer 14
From the viewpoint of reducing the capacity of -1 to 14-i, the transfer line 1
The transfer speed of 5-1 to 15-i is set to be higher than the sum V of the output speeds of the output connection group.

Second-stage packet switching units 16-1 and 16-
2 receives the ATM cells from the transfer lines 15-1 and 15-2 (steps ST5a and 5b), refers to the destination address of the ATM cell, and transfers the ATM cell to the output connections 18-1 to 18-k, 18-k + 1 to 18-k
+ L is performed (step ST6a,
6b, ST7a, 7b, ST10a, 10b).

That is, the second-stage packet switching units 16-1 and 16-1
Output connections 18-1 to 18-k and 18-k + 1 to 18 corresponding to buffers 17-1 to 17-m of 16-2.
-K + L, store only ATM cells to be output to
Outputs TM cells to output connections 18-1 to 18-k, 18
-K + 1 to 18-k + L.

As described above, the buffers 14-1 to 14 which operate faster than the sum V of the output speeds of the output connection group.
By preparing -i for the number of transfer lines, high-speed and large-capacity packet exchange can be realized without causing interference between connections. (In the conventional example, it is necessary to prepare buffers for high-speed operation for the number of output connections. ), It is possible to suppress an increase in circuit scale.

In the first embodiment, the buffers 17-1 to 17-1 of the second-stage packet switching units 16-1 and 16-2 are used.
When 17-m detects the congestion of the corresponding output connection (steps ST8a and 8b), it outputs a congestion notification to the discard control unit 19 (steps ST9a and 9b). Upon receiving the congestion notification from the buffers 17-1 to 17-m, the discarding control unit 19 discards the ATM cell to be output to the congested output connection (step ST3). As a result, there is an effect that the occurrence of interference between output connections can be suppressed.

Embodiment 2 In the first embodiment, 1
Buffers 14-1 to 14- of the packet switching unit 12 at the stage
i, the second-stage packet switching units 16-1, 16-
Although the configuration of the second buffers 17-1 to 17-m is not particularly described, the configuration may be as shown in FIG.

That is, for the buffers 14-1 to 14-i of the first-stage packet switching unit 12, the queuing unit 21 for storing ATM cells and writing and reading of ATM cells to and from the queuing unit 21 are controlled. And the second-stage packet switching unit 16-
The buffers 17-1 to 17-m 1 and 16-2 include a queuing unit 23 for storing ATM cells and a queue control unit 24 for controlling writing and reading of ATM cells to and from the queuing unit 23. .

Then, the queue control units 22 and 24 compare the accumulated amount of the ATM cells stored in the queuing units 21 and 23 with a threshold value. The control unit 19 discards the ATM cell for the queuing unit exceeding the threshold value.

Embodiment 3 In the second embodiment, 1
Buffers 14-1 to 14- of the packet switching unit 12 at the stage
For i, a queuing unit 2 for storing ATM cells
1 and a queue control unit 22 that controls writing and reading of ATM cells to and from the queuing unit 21, the configuration may be as shown in FIGS. 4 and 6.

That is, for the buffers 14-1 to 14-i of the first-stage packet switching unit 12, a plurality of queuing units 21a corresponding to call types (for example, service type: data, voice, image, etc.) , 21b,
A distributing unit 31 for distributing ATM cells for each call type, and the ATM cells distributed by the distributing unit 31 are written into the queuing units 21a and 21b.
A queue control unit 32 for reading cells, and a queue control unit 32
Outputs the ATM cell read out by the transfer line to the transfer line.
EL33.

The queue control unit 32 compares the stored amount of ATM cells stored in the queuing units 21a and 21b with a threshold value. When the stored amount of ATM cells exceeds the threshold value, the queue control unit 32 performs discard control. The unit 19 discards the ATM cell for the queuing unit that exceeds the threshold. As a result, there is an effect that occurrence of interference between call types can be suppressed.

Embodiment 4 In the second embodiment, 2
Buffer 1 of the packet switching units 16-1 and 16-2 at the stage
For 7-1 to 17-m, a queuing unit 23 for storing ATM cells and an AT for the queuing unit 23
Queue control unit 2 for controlling writing and reading of M cells
4 and FIGS. 5 and 6
It may be configured as follows.

That is, the second-stage packet switching units 16-1 and 16-1
The buffers 17-1 to 17-m of the 16-2 include a plurality of queuing units 23a and 23b corresponding to call types (for example, service types: data, voice, image, etc.), and each call type A sorting unit 41 for sorting ATM cells, and A assigned by the sorting unit 41
The TM cell is written into the queuing units 23a and 23b, and the queuing units 23a and 23b are
A queue control unit 42 for reading an ATM cell from 23b;
And an SEL 43 for outputting the ATM cell read by the queue control unit 42 to the transfer line.

The queue control unit 42 compares the accumulated amount of ATM cells stored in the queuing units 23a and 23b with a threshold value. If the accumulated amount of ATM cells exceeds the threshold value, the queue control unit 42 performs discard control. The unit 19 discards the ATM cell for the queuing unit that exceeds the threshold. As a result, there is an effect that occurrence of interference between call types can be suppressed.

Embodiment 5 FIG. In FIG. 6, the number of levels of call types handled by the queuing units 21a and 21b in the first-stage packet switching unit 12 is two, and the queuing units in the second-stage packet switching units 16-1 and 16-2. 23
Although the case where the number of levels of the call types handled by a and 23b is 2 is shown, the number of levels of the call types handled by the queuing unit in the first-stage packet switching unit 12 is equal to the second-stage packet switching unit 16- The number of levels of call types handled by the queuing unit in 1, 16-2 may be smaller.
As a result, there is an effect that the circuit scale of the first-stage packet switching unit 12 can be reduced.

Conversely, the second-stage packet switching units 16-1 and 16-1
The number of levels of call types handled by the queuing unit in 16-2 may be smaller than the number of levels of call types handled by the queuing unit in the first-stage packet switching unit 12. As a result, the second-stage packet switching units 16-1,
The effect that the circuit scale of 16-2 can be reduced can be obtained.

Embodiment 6 FIG. In the first to fifth embodiments, although not particularly mentioned, the first-stage packet switching unit 1
The second and second stage packet switching units 16-1 and 16-2
Input buffer type ATM switch, output buffer type A
You may comprise so that it may be a TM switch or a common buffer type ATM switch. As a result, there is an effect that the present invention can be applied to the ATM exchange which is a fixed-length packet exchange.

Embodiment 7 FIG. In the first to sixth embodiments, an ATM cell is input from an input connection,
Although the output of TM cells to an output connection has been described, an ATM cell is input from an input connection group (an input connection group is composed of a plurality of input connections), and the ATM cell is output to an output connection group (output connection group). Is composed of a plurality of output connections).

Similarly, an ATM cell is inputted from an input port (an input port is one physical line and is composed of a plurality of input connections), and the ATM cell is inputted.
The cell may be output to an output port (an output port is one physical line and is composed of a plurality of output connections).

[0050]

As described above, according to the present invention, the output connection for outputting the data packet is determined by referring to the destination address of the data packet input from the plurality of input connections, and the output connection is determined. A first packet switching unit that outputs the data packet to the transfer line to be connected, and when a data packet is input from the transfer line, determines the output connection that outputs the data packet by referring to the destination address of the data packet. And a second packet switching unit that outputs the data packet to the output connection, and constitutes a packet switching unit. Since the transfer rate is set to be high, the number of output connections increases. Also, there is an effect that it is possible to suppress an increase in circuit scale.

According to the present invention, when the second packet switching unit detects congestion of an output connection and outputs a notification of the congestion to the first packet switching unit, the first packet switching unit causes the occurrence of congestion. Since the configuration is such that the data packet output to the output connection is discarded, it is possible to suppress the occurrence of interference between the output connections.

According to the present invention, the first packet switching unit is configured to have a buffer for temporarily storing data packets for each transfer line. There is an effect that occurrence of interference can be suppressed.

According to the present invention, the second packet switching unit is configured to temporarily have a buffer for storing data packets for each output connection corresponding to the transfer line, so that the configuration is not complicated. This has the effect of suppressing the occurrence of interference between output connections.

According to the present invention, the buffer of the first packet switching unit is constituted by using a plurality of queuing units corresponding to the call types. There is an effect that the occurrence of interference between output connections can be suppressed without causing complication.

According to the present invention, the buffer of the second packet switching unit is constituted by using a plurality of queuing units corresponding to the call types. There is an effect that the occurrence of interference between output connections can be suppressed without causing complication.

According to the present invention, when the second packet switching unit detects congestion of a certain call type and outputs the congestion notification to the first packet switching unit, the first packet switching unit generates congestion. Since the data packet related to the call type is discarded, it is possible to suppress the occurrence of interference between call types.

According to the present invention, the number of levels of the call type handled by the queuing unit in the first packet switching unit is equal to the second number.
Since the number of call types handled by the queuing unit in the packet switching unit is smaller than the number of call types, the circuit size of the first packet switching unit can be reduced.

According to the present invention, the number of levels of the call type handled by the queuing unit in the second packet switching unit is equal to the first number.
Is configured to be smaller than the number of levels of call types handled by the queuing unit in the packet switching unit of (1), so that the circuit scale of the second packet switching unit can be reduced.

According to the present invention, the first and second packet switching units are provided with an input buffer type ATM switch, an output buffer type ATM switch or a common buffer type ATM switch.
Since the switch is configured as a switch, there is an effect that the switch can be applied to an ATM exchange which is a fixed length packet exchange.

According to the present invention, the output connection group that outputs the data packet is determined by referring to the destination address of the data packet input from the plurality of input connection groups, and the output connection group corresponding to the output connection group is determined. When a data packet is input from the first packet switching unit for outputting the data packet and the transfer line, the output connection group for outputting the data packet is determined by referring to the destination address of the data packet. And a second packet switching unit that outputs the data packet to the output connection group. The packet switching means comprises a packet switching unit, and transfers the transfer line based on the sum of the output speeds of the plurality of output connection groups corresponding to the transfer line. I configured it to be faster , Even when many number of output connections group, there is an effect that it is possible to suppress an increase in circuit scale.

According to the present invention, when the second packet switching unit detects congestion in an output connection group and outputs a congestion notification to the first packet switching unit, the first packet switching unit
Is configured to discard data packets output to an output connection group in which congestion has occurred, so that it is possible to suppress the occurrence of interference between output connection groups.

According to the present invention, the output port for outputting the data packet is determined by referring to the destination address of the data packet input from the plurality of input ports, and the output port corresponding to the output port is determined. When a data packet is input from a first packet switching unit for outputting a data packet and the transfer line, an output port for outputting the data packet is determined by referring to a destination address of the data packet. And a second packet switching unit that outputs the data packet to form a packet switching unit, and increase the transfer speed of the transfer line from the sum of the output speeds of the plurality of output ports corresponding to the transfer line, The second packet switching unit detects congestion at an output port, and notifies the congestion notification to the first packet switching unit. When output, since it is configured to discard the data packet to be output to the output port a first packet switching unit is congestion, there is an effect that it is possible to suppress occurrence of interference between the output ports.

According to the present invention, the output connection for outputting the data packet is determined with reference to the destination address of the data packet input from the plurality of input connections, and the output connection corresponding to the output connection is determined. While outputting a data packet, when a data packet is input from the transfer line, an output connection for outputting the data packet is determined with reference to a destination address of the data packet, and the data packet is output to the output connection. Then, from the sum of the output speeds of the plurality of output connections corresponding to the transfer line,
Since the transfer speed of the transfer line is configured to be high, there is an effect that even if the number of output connections increases, an increase in the circuit scale can be suppressed.

According to the present invention, when the congestion of a certain output connection is detected, the data packet output to the congested output connection is discarded. There is an effect that can be suppressed.

According to the present invention, the output connection group that outputs the data packet is determined by referring to the destination address of the data packet input from the plurality of input connection groups, and the output connection group corresponding to the output connection group is determined. When the data packet is output from the transfer line while the data packet is output, the output connection group that outputs the data packet is determined with reference to the destination address of the data packet. Since the data packet is output and the transfer speed of the transfer line is configured to be higher than the sum of the output speeds of the plurality of output connection groups corresponding to the transfer line,
Even if the number of output connection groups increases, there is an effect that an increase in circuit scale can be suppressed.

According to the present invention, when the congestion of a certain output connection group is detected, the data packet output to the congested output connection group is discarded. There is an effect that generation can be suppressed.

According to the present invention, the output port for outputting the data packet is determined with reference to the destination addresses of the data packets input from the plurality of input ports, and the output port corresponding to the output port is determined. When a data packet is input from the transfer line while the data packet is output, the output port that outputs the data packet is determined by referring to the destination address of the data packet, and the data packet is output to the output port. Then, the transfer speed of the transfer line is increased from the sum of the output speeds of the plurality of output ports corresponding to the transfer line, and when congestion of a certain output port is detected, the output is output to the output port where the congestion occurs. Is configured to discard the data packets to be transmitted, so that the occurrence of interference between output ports can be suppressed. There is a kill effect.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a packet switching device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a packet switching method according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram showing the inside of a buffer of a packet switching unit.

FIG. 4 is a configuration diagram showing the inside of a buffer of a packet switching unit.

FIG. 5 is a configuration diagram showing the inside of a buffer of a packet switching unit.

FIG. 6 is a configuration diagram showing the inside of a buffer of a packet switching unit.

FIG. 7 is a configuration diagram illustrating a conventional packet switching device.

[Explanation of symbols]

11-1 to 11-n input connection, 12 first stage packet switching unit (first packet switching unit, packet switching unit), 13 MUX, 14-1 to 14-i buffer, 15-1 to 15-i Transfer line, 16-1, 16-
2 Second-stage packet switching unit (second packet switching unit,
Packet switching means), 17-1 to 17-m buffers,
18-1 to 18-n output connection, 19 discard control unit, 21a, 21b queuing unit, 22
Queue control unit, 23, 23a, 23b Queuing unit, 24 Queue control unit, 31 Distributing distribution unit, 32 Queue control unit, 33 SEL, 41 Distributing distribution unit, 42 Queue control unit, 43 SEL.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasutaka Saito 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Hiroshi Hayakawa 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F term in Ryo Denki Co., Ltd. (reference) 5K030 GA06 HA08 KA03 KX02 KX12 KX13 KX17 LC11 LC14 LC15 LE03 MA13 MB02 MB15

Claims (18)

[Claims] 1. A packet switching device comprising packet switching means for distributing a data packet input from a plurality of input connections to a plurality of output connections.
A first connection for referring to a destination address of the data packet input from the plurality of input connections, determining an output connection for outputting the data packet, and outputting the data packet to a transfer line corresponding to the output connection; When a data packet is input from the packet switching unit and the transfer line, an output connection for outputting the data packet is determined with reference to a destination address of the data packet, and a data connection for outputting the data packet to the output connection is determined. A packet switching apparatus comprising the packet switching unit and the packet switching unit, wherein the transfer rate of the transfer line is higher than the sum of output speeds of a plurality of output connections corresponding to the transfer line. 2. When the second packet switching unit detects congestion of an output connection and outputs a notification of the congestion to the first packet switching unit, the first packet switching unit is congested. 2. The packet switching device according to claim 1, wherein the data packet output to the output connection is discarded. 3. The packet switching device according to claim 1, wherein the first packet switching unit has a buffer for temporarily storing data packets for each transfer line. 4. The packet switching device according to claim 1, wherein the second packet switching unit has a buffer for temporarily storing data packets for each output connection corresponding to a transfer line. . 5. The packet switching device according to claim 3, wherein a buffer of the first packet switching unit is configured using a plurality of queuing units corresponding to call types. 6. The packet switching device according to claim 4, wherein a buffer of the second packet switching unit is configured using a plurality of queuing units corresponding to call types. 7. When the second packet switching unit detects congestion of a certain call type and outputs a congestion notification to the first packet switching unit, the first packet switching unit is congested. 7. The packet switching device according to claim 6, wherein the data packet related to the call type is discarded. 8. The method according to claim 1, wherein the number of levels of call types handled by the queuing unit in the first packet switching unit is smaller than the number of levels of call types handled by the queuing unit in the second packet switching unit. Item 7. The packet switching device according to Item 6. 9. The method according to claim 1, wherein the number of levels of call types handled by the queuing unit in the second packet switching unit is smaller than the number of levels of call types handled by the queuing unit in the first packet switching unit. Item 7. The packet switching device according to Item 6. 10. The first and second packet switching units are an input buffer type ATM switch and an output buffer type AT switch.
10. The packet switching device according to claim 1, wherein the packet switching device is an M switch or a common buffer type ATM switch. 11. A packet switching device having packet switching means for distributing data packets input from a plurality of input connection groups to a plurality of output connection groups, wherein a destination address of the data packet input from the plurality of input connection groups is provided. And a first packet switching unit that outputs the data packet to a transfer line corresponding to the output connection group, and outputs the data packet from the transfer line. When input, the output connection group that outputs the data packet is determined by referring to the destination address of the data packet, and the packet is output from the second packet switching unit that outputs the data packet to the output connection group. A packet switching device comprising packet switching means, wherein the transfer speed of the transfer line is made higher than the sum of the output speeds of a plurality of output connection groups corresponding to the transfer line. 12. When the second packet switching unit detects congestion of an output connection group and outputs a congestion notification to the first packet switching unit, the first packet switching unit generates congestion. 12. The packet switching device according to claim 11, wherein a data packet output to an output connection group is discarded. 13. A packet switching apparatus having packet switching means for distributing data packets input from a plurality of input ports to a plurality of output ports, referring to destination addresses of the data packets input from the plurality of input ports. A first packet switching unit that outputs the data packet to a transfer line corresponding to the output port, and a data packet that is input from the transfer line. A packet switching unit configured to determine an output port for outputting the data packet with reference to a destination address of the packet, and to output the data packet to the output port; From the sum of the output speeds of the multiple output ports corresponding to the line, When the transmission speed is increased and the second packet switching unit detects congestion at an output port where the second packet switching unit is located and outputs the congestion notification to the first packet switching unit, the first packet switching unit detects the congestion. A packet switching device for discarding a data packet output to a generated output port. 14. A packet switching method for distributing a data packet input from a plurality of input connections to a plurality of output connections, wherein the data packet is output by referring to a destination address of the data packet input from the plurality of input connections. The output connection is determined, and the data packet is output to the transfer line corresponding to the output connection. On the other hand, when the data packet is input from the transfer line, the data packet is referred to by referring to the destination address of the data packet. The output connection to be output is determined, the data packet is output to the output connection, and the transfer speed of the transfer line is made higher than the sum of the output speeds of the plurality of output connections corresponding to the transfer line. Packet switching method. 15. The packet switching method according to claim 14, wherein when a congestion of a certain output connection is detected, a data packet output to the congested output connection is discarded. 16. A packet switching method for distributing data packets input from a plurality of input connection groups to a plurality of output connection groups, said data packet being referred to a destination address of the data packets input from the plurality of input connection groups. The output connection group that outputs the packet is determined, and while the data packet is output to the transfer line corresponding to the output connection group and the data packet is input from the transfer line, the destination address of the data packet is referred to. The output connection group that outputs the data packet is determined, the data packet is output to the output connection group, and the output connection group is output from the sum of the output speeds of the plurality of output connection groups corresponding to the transfer line. A packet switching method characterized by increasing the transfer speed of the transfer line. 17. The packet switching method according to claim 16, wherein upon detecting congestion of a certain output connection group, data packets output to the congested output connection group are discarded. 18. A packet switching method for distributing a data packet input from a plurality of input ports to a plurality of output ports, wherein the data packet is output by referring to a destination address of the data packet input from the plurality of input ports. The output port to be output, and outputs the data packet to the transfer line corresponding to the output port. When a data packet is input from the transfer line, the data packet is referred to by referring to the destination address of the data packet. The output port to be output is determined, the data packet is output to the output port, and the transfer speed of the transfer line is set higher than the sum of the output speeds of the plurality of output ports corresponding to the transfer line. When the congestion of the output port is detected, the output is output to the congested output port. A packet switching method comprising: discarding a data packet to be exchanged.