JPH0458644A - Packet switch and its connection controller - Google Patents

Abstract

PURPOSE:To exchange packets without an overflow of buffer on an input line by providing r-lines of intermediate output lines for each output line. CONSTITUTION:A pseudo connection control section 3i analyzing inputted reservation information and detecting it that only one intermediate output line is reserved in the circulation of the reserved information reserves intermediate output lines 1311-13mr by a number of operation inhibit intermediate output lines for each output line inputted from a congestion control section 5. Since r-lines of intermediate output liens for each line are provided, even when a packet addressed to plural same output lines are inputted at once, up to r-sets of packets addressed to a same output line are exchanged and packets are exchanged so as not to overflow a buffer on the input line for wait of exchange.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a packet switch used in a packet switch or the like and a connection control device thereof.

Conventional technology FIG. 6 shows the configuration of a conventional packet switch.

In FIG. 6, input lines 601 to 60n are connected to packet destination information separation units 621 to 62n via packet receiving units 611 to 61n, respectively.

The packet destination information separation units 621 to 62n have two output systems, one of which is a packet output terminal 62i1 (
i=l−n) is the packet input terminal 6 of the switch network 63
311 to 631n. The other output destination information output terminal 62i2 (i=+1 to n) is connected to the output destination information input terminals 6411 to 641n of the switch network control section 64. Switch network control output terminals 6421 to 642m of the switch network control section 64 are connected to control input terminals 6321 to 632m of the switch network 63, respectively. Packet output terminal 63 of the switch network 63
31 to 633m are connected to switch network monitoring input terminals 6431 to 643m and output buffer units 651 to 65m of the switch network control unit 64, respectively. The outputs of the buffer sections 651 to 65m are sent to the packet transmitting sections 661 to 65m.
It is connected to output lines 671 to 67m via 66I11.

FIG. 7 shows the configuration of the switch network 63 portion. In FIG. 7, 6341 to 634m are multiplexers, and packet input terminals 6311 to 634m are used as signal input terminals.
631n is connected, the control input terminals 6321 to 632m are connected to the connection selection terminal, and the packet output terminals 6331 to 633ffl are connected to the output terminal.

Next, the operation of the above conventional example will be explained. Input line 60
When a packet is input to i, it is received by the packet receiving section 61i, and is input to the packet destination information separation section 62i. The packet input to the packet output destination information separation section 62i is buffered, and at the same time, the output destination information is separated and input to the switch network control section 64. The switch network control unit 64 determines the output line 67j to which the packet should be output based on the input output destination information, and monitors whether the packet output terminal 633j of the switch network 63 is outputting the packet. When the output is not in progress, a selection signal is output to the selection connection terminal of the multiplexer 634j, and the packet input terminal 631i and the packet output terminal 633j are connected. After being connected, the packet destination information separation unit 62
The packet buffered at i is input to the packet input terminal 631i, and is sent to the packet transmitter 6 via the packet output terminal 633j and the output buffer 65j.
6j to the output line 67j.

In this way, even in the conventional packet switch described above, when a packet is input, it is possible to output the packet to an output line according to the output destination information in the packet.

Problems to be Solved by the Invention However, in the conventional packet switch described above, since the switch network can connect only one input line to one output buffer at the same time, packets destined for the same output line are simultaneously input through multiple input lines. In this case, it takes time to complete exchanging all the packets, and the buffer in the bucket output destination information separation unit overflows, resulting in the problem that all the packets cannot be exchanged.

The present invention solves these conventional problems, and aims to provide an excellent packet switch and its connection control device that can exchange all input packets.

Means for Solving the Problems The bow switch of the present invention connects n input lines and m output lines, and particularly connects n input lines and (m,×r) intermediate output lines. Concentrate the connecting switch network and the above intermediate output lines into r pieces for each output line,
an output means connected to an output line via an output buffer;
A connection control unit is provided for each input line to control the connection between the input line and the intermediate output line in the switch network, and the connection control unit of each input line is ring-connected to the connection control unit of other input lines, and the ring The upper connection control unit outputs the reservation information of the intermediate output line described in 2 to the ring lower connection control unit, and the ring lower connection control unit refers to the reservation information input from the ring upper connection control unit. Then, reserve an unreserved intermediate output line from among the intermediate output lines that can be connected to the output line indicated by the packet input from the input line,
Thereafter, the reservation information is updated and output to a connection control section at a lower level of the ring, and after the reservation information has circulated on the ring, connection control means is provided for controlling the connection between the reserved intermediate output line and the input line. It is characterized by

Further, the packet switch connection control device of the present invention controls a switch network in a packet switch, and the switch network has n input lines and (m×r) intermediate output lines, and has n input lines. It controls the connection between the line and (m×r) intermediate output lines, and is provided for each input line.
It consists of a connection control unit that controls the connection between input lines and intermediate output lines in the arrangement switch network, and the connection control unit of each input line is connected in a ring with the connection control unit of other human-powered lines, and the connection control unit of the upper layer of the ring outputs the reservation information of the intermediate output line to the connection control unit at the lower level of the ring, and the connection control unit at the lower level of the ring refers to the reservation information input from the connection control unit at the upper level of the ring, and determines the reservation information input from the human-powered line. Reserves an unreserved intermediate output line from among the intermediate output lines that can be connected to the output line indicated by the packet, then updates the reservation information and outputs it to the connection control unit below the ring, and After the reservation information has passed through the network once, the connection between the reserved intermediate output line and the input line is controlled.

Effects The present invention has the following effects due to the above structure. In other words, since r intermediate output lines and output buffers are provided for each output line, up to r packets addressed to the same output line 11il that arrive at the same time can be written to the output buffer, and up to r packets can be written at the same time. Same-
Packets addressed to the output line can be exchanged.

Embodiment FIG. 1 shows the configuration of an embodiment of the present invention. In FIG. 1, 101 to 101] are input lines;
Each of them is connected to packet destination information separation units 121 to 12n via packet reception units 111 to lln. The packet destination information separation units 121 to 12n include:
There are two output systems, one bucket output terminal 12j, l
(C1-n) is the packet input terminal 2 of the switch network 2
11 to 21n.

The other output destination information output terminals 12i2 (i.1 to n) are the output destination information input terminals 3i of the connection control units 31 to 3n, respectively.
1 (i=l−n). The connection control units 31 to 3o have three output terminals and J input terminals. Switch control output terminals 3i2 (i=1-n), which are output terminals of the connection control sections 31 to 3n, are connected to switch control input terminals 221 to 22n of the switch network 2. Output permission terminal 3i3 which is another output terminal
(i=l=n) is the packet output destination information separation unit 121
~12n output control input terminal 12i3 (CI-n)
connected to. Reservation information output terminal 3 which is another output terminal
14 to 3n4 are reservation information input terminals 315 of the connection control units 31 to 3n via the pseudo connection control units 41 to 4n, respectively.
~3n5 as shown in FIG.

5 is a congestion control unit, and the reservation control output 5 of the congestion control unit 5 is
1 is connected to the pseudo connection control sections 41 to 4n.

Intermediate output buffer units 1411 to 141r, 1421 to
Waiting cell number outputs of 142r, . Intermediate output lines 1311 to 131r, 1 are connected to the input terminals of the intermediate output buffer units 1411 to 14mr.
321-132r, -, 13m1~! 3■r (hereinafter,
packet outputs 2311 to 231r, 23 of the switch network 2
21~232r,..., 23IIll~23ffir
(hereinafter simply referred to as 2311-23mr). The intermediate output buffer section 1411"14mr
The other terminal is input to multiplexers 151 to 15m. The outputs of the multiplexers 151 to 15m are sent to the output line 1 via packet transmitters 161 to 16m.
Connected to 71-17m.

Figure 2 shows the switch network 2 (i=l-n) shown in Figure 1.
It is a figure showing a specific example. In Figure 2, 24111~
24 is a multiplexer connected as shown in FIG.

FIG. 3 is a diagram showing a specific example of the connection control section 3i (i=ln) shown in FIG. 1. In FIG. 3, 3i6 is an unreserved detection unit, 3i7 is a reservation unit, 3t8 is a switch control signal generation unit, 3i9 is a firstborn detection unit, 3i10 is an unreservation information generation unit, 3111 is a two-man power one-output multiplexer, 3i12 is a timing generator, 3113 is an intermediate output line number signal line, and 3i14 is a reservation permission signal line, which are connected as shown in the figure.

FIG. 4 shows the configuration of the pseudo connection control section 41 (i=
l-n). In FIG. 4, 4i1 is a prohibited intermediate line input terminal, 4i2 is a reservation information input terminal, 4i4 is a reservation detection section, 4i5 is a pseudo reservation section, and 4i6 is a two-man power one-output multiplexer, which are connected as shown in the figure. ing.

FIG. 5 shows the configuration of the congestion control section 5. In FIG. 5, 52 is a convergence detection input, and a convergence determination unit 53i
(i=l−n). Congestion determination unit 53
The output of i (i=l-n) is input to the intermediate output line restriction section 54. The reservation control output terminal 51 of the intermediate output line restriction section 54 is connected to the pseudo connection control section 4i (iJ-n).
Prohibited use of intermediate line input terminal 4i1 (i・1~n)
is input.

Next, the packet output destination information separation unit 1 in the above embodiment
2i, the operation of the switch network 2, the congestion control section 5, and the pseudo connection control section 41 will be explained.

First, the operation of the packet output destination information separation unit 12i will be explained (i=l−n). The packet input to the input line 10i is received by the packet receiving section 11i, and is input to the packet output destination information separation section 12i. When the packet output destination information separating section 12i receives a packet from the packet receiving section 11i, it writes it into an internal buffer, and at the same time analyzes the header of the packet to obtain the output line number of the output light. Then, the output line number of the output light of the first packet in the internal buffer is outputted from the output destination information output terminal 1212 and inputted to the output destination information input terminal 3i1 of the connection control section 31. When the output permission signal is input to the output control input terminal 12i3, the first packet in the buffer is read out, outputted from the packet output terminal 12i1, and inputted to the packet input terminal 21i of the switch network 2.

Next, the operation of the switch network 2 will be explained. The internal multiplexers 24111-24nmr connect the upper input terminal and output terminal shown in FIG. 2 in the default state. When a switch control signal is input to the switch control input terminal 22i, the multiplexers 24i11 to 24imr
The specified multiplexer in the multiplexer is switched to connect the lower input and output terminals.

Next, the operation of the comparison control section 5 will be explained. The main body control unit 5 monitors the number of packets waiting to be output for each output line, and performs control to keep the number of packets waiting to be output always equal to or less than a set value.
The number of packets waiting to be output from the 14mr is received at the congestion detection input terminal 52, and the received number of packets waiting to be output is input to the congestion determining section 53i. Congestion determination unit 5
3i, the input number of packets waiting to be output is added to calculate the total number of packets waiting to be output to the output line 17i. The congestion determining unit 53i determines that the output line 17 is a wheel axle when the total number of output waiting packets exceeds a set value.
Depending on the size of the total number of packets waiting to be output to i, the number of packets that are permitted to be written to the intermediate output buffers 14i1 to 14ir at one time (the number of write-permitted packets) is determined,
It is output to the intermediate output line restriction section 54. The intermediate output line restriction unit 54 subtracts the number of write permission packets from the number r of intermediate output lines for each output line to obtain the number of prohibited intermediate lines for each output line, and outputs it to the pseudo connection control units 41 to 4.

Next, the operation of the pseudo connection control unit 41 will be explained (CI-n
). The reservation detection unit 4i4 analyzes the reservation information input to the reservation information input terminal 4i2, and outputs the intermediate output lines 1311 to 1311.
Only if only one of the 13mr is reserved,
The multiplexer 4i6 is notified of switching permission. On the other hand, the pseudo reservation unit 4i5 analyzes the input reservation information and reserves intermediate lines for each output line inputted from the congestion control unit 5 to the prohibited intermediate line input terminal 4i1. and update the reservation information and connect multiplexer 4.
Enter into i6. The multiplexer 4i6 outputs the reservation information input to the reservation information input terminal 4i2 from the reservation information output terminal 4i3 in the default state. Only when permission to switch has been notified, the reservation information updated in the pseudo reservation section 4i5 is outputted from the reservation information output terminal 4i3.

Next, the overall operation of the above embodiment will be explained. First, the overall operation when the output ports 11171-17 are not in contrast will be described.

Since there is no convergence, the pseudo connection control unit 41:
Since the intermediate line is not reserved, the pseudo connection control unit 41
The reservation information entered in is not updated and is output as is. The connection control unit 31 detects in the first born reservation detection unit 3i9 that a reservation was made for the first time in the previous packet exchange, switches the multiplexer 3i11, and connects the intermediate output lines 1311 to 13a+r from the unreserved information generation unit 3i10.
Reservation information indicating that all are unreserved is output to the reservation information output terminal 3i4.

The connection control unit 3p (p=i+i) is located at the lower level of the ring.

The reservation information input to the reservation information input 3p5 is analyzed by the non-reservation detecting section 396, and if all the intermediate output lines 1311-13mr are unreserved, the first-born reservation detecting section 3p9 is notified. On the other hand, if the output line number is input to the output destination information input terminal 3pl, the reservation unit 3p7
analyzes the reservation information and selects the desired output line 171~
Intermediate output line 1311” that can be connected to 17m
13mr, the number of the unreserved one is obtained, a reservation permission signal is output from the reservation permission signal line 3114, and the switch control signal generation unit 3p8 is output from the intermediate output line number signal line 3p13.
Output to. At the same time, the reservation information is updated and output from the reservation information output terminal 3p4. However, if all intermediate output lines 1311 to 13mr that can be connected to the desired output line 171 = 17+a have been reserved,
A reservation disapproval signal is output from the reservation permit signal line 3114,
The reservation information is output as is from the reservation information output terminal 3p4.

By each connection control unit 3p performing the above operations, the intermediate output lines 1311 to 13+or are reserved, and the reservation information circulates around the ring. In each connection control section 3p, a timing generation section 3p12 operates in synchronization with the timing generation sections of other connection control sections, and generates the timing at which the reservation information completes one round on the ring. At this timing, a control signal for connecting to the intermediate output line number outputted from the switch control signal generation section 3p8 is outputted via the switch control output terminal 3p2, and a desired one of the multiplexers 24111 to 24nmr in the switch network 2 is output. Multiplexers corresponding to intermediate output lines are switched, and connections within the switch network 2 are established. At the same time, an output permission signal is input from the output permission terminal 393 to the packet destination information separation unit 12p, and the buffered packet is transferred to the multiplexer 2 in the switch network 2.
Intermediate output line 1311 via 411-24nrnr
~l Sent to 3~n. Also, at the above timing, the firstborn detection unit 3p9 detects that the unreserved detection unit 3p
Since the non-reservation information is detected in step 6 and the reservation is permitted in the reservation section 3p7, it is detected that the reservation has been made for the first time. Thereafter, the above operation is repeated.

On the other hand, packets sent onto intermediate output lines 1311-13-n are buffered in intermediate output buffers 1411-14mr, and sent to output line 171 via multiplexer 151-15m and packet transmitters 161-16m.
~17m.

Next, the overall operation in the case where the output ports 49171 to 17m are wheeled in the above embodiment will be described.

The operation of starting the reservation information when the output line 171-17m is congested and the operation of sending the packet onto the intermediate output line after the reservation information has completed one cycle are the same as when the output line is not connected. .

However, in one round of the reservation information, the pseudo connection control section 31 analyzes the input reservation information and detects that only one intermediate output line is reserved, and the pseudo connection control section 31 detects that only one intermediate output line is reserved. Intermediate output lines 1311 to 13 to n are reserved as many as the number of intermediate output lines prohibited for each use. The intermediate output lines 1311-l3-n reserved here are not used for outputting packets.

That is, on the ring, when the connection control unit 31 first reserves an intermediate output line, the pseudo connection control unit 41 immediately reserves the intermediate output lines 1311 to 13mr that are not actually used.
Intermediate output port 411311-13m
The use of r can be restricted.

As shown in the above embodiment, since r intermediate output lines are provided for each output line, even if a plurality of packets addressed to the same output line are input at a time, up to r intermediate output lines can be processed at a time. Packets addressed to the output line can be exchanged without overflowing the buffer on the input line due to waiting for exchange.

In addition, since a means is provided for making the reservation for the input line that made the first reservation for the intermediate output line last in the reservation for the next intermediate output line, the input line and the output line can be connected without biasing towards a particular input line.

Further, since a means is provided to variably limit the number of intermediate output lines that can be reserved depending on the number of packets waiting to be output to the output line, it is possible to control the restriction of packet exchange according to the axle status of the output line.

Effects of the Invention As described above, according to the above embodiment, since r intermediate output lines are provided for each output line, even if a plurality of packets addressed to the same line are input at a time, up to r pieces of the same packet can be processed at once. - Packets addressed to the output line can be exchanged without overflowing the buffer on the input line due to waiting for exchange.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram of a packet switch according to an embodiment of the present invention, FIG. 2 is a block diagram showing a specific example of the switch network shown in FIG. 1, and FIG. 3 is a block diagram showing a specific example of the switch network shown in FIG. 4 is a block diagram showing a specific example of the pseudo connection control section shown in FIG. 1, FIG. 5 is a block diagram showing a specific example of the congestion control section shown in FIG. 1, and FIG. 6 is a block diagram showing a specific example of the congestion control section shown in FIG. FIG. 7 is a block diagram showing a specific example of the switch network shown in FIG. 6. 2... Switch network, 5... Trunk control section, 31-30
... Connection control section, 41 to 4n... Pseudo connection control section,
54...Intermediate output line restriction section, 101~Ion...
Input line, 111-lln...Packet receiving unit, 12
1~12n...Packet destination information separation unit, 151~1
5I11...Multiplexer, 161 N16m...
・Packet transmitter, 171-17+r-output line, 3i
6 (i=l-n) --- unreserved detection section, 3i7 (i=
l=n) - reservation section, 3i8 (i=1-n) -... switch control signal generation section, 3i9 (i=1-n)...
Firstborn detection unit, 3i10 (C1-n)...Unreserved information generation unit, 3111 (i=1 to n)...Multiplexer, 3i12 (i:1 to n)...Timing generation unit,
4i4 (i=1 to n)...Reservation detection unit, 4j5
(i=l-n)-pseudo reservation part, 4i6(i:1-n)・
... Multiplexer, 531-53m... Convergence judgment section, 1311-13mr-intermediate output line, 1411-14
mr...Middle output buffer, 24111~24nmr
...Multiplexer. Agent Patent attorney Shigetaka Awano (1 person) Figure 3 (5i4) Diagram (from connection drawing section (4i-1)) To connection control section (,) (41+1)

Claims (5)

[Claims] (1) In a packet switch that connects n input lines and m output lines, there is a switch network that connects n input lines and (m×r) intermediate output lines, and outputs the above intermediate output lines. An output means for concentrating r lines for each line and connecting them to the output line via an output buffer, and a connection control unit for each input line for controlling the connection between the input line and the intermediate output line in the switch network, The connection control unit of each input line is connected in a ring with the connection control unit of other input lines, and the connection control unit at the upper level of the ring outputs reservation information for the intermediate output line to the connection control unit at the lower level of the ring. The connection control unit refers to the reservation information input from the connection control unit on the upper side of the ring, and selects an unreserved intermediate output line from among the intermediate output lines that can be connected to the output line indicated by the packet input from the input line. A connection that reserves an intermediate output line, then updates the reservation information and outputs it to the lower connection control unit of the ring, and after the reservation information has circulated on the ring, controls the connection between the reserved intermediate output line and the input line. A packet switch comprising a control means. (2) When the reservation information goes around the ring, the ring-connected connection control unit recognizes that the intermediate output line has been reserved first, and recognizes that the intermediate output line has been reserved first. The connection control unit below the ring of the connection control unit that was
2. The packet switch according to claim 1, wherein the packet switch starts a cycle of the next reservation information. (3) Count the number of packets waiting to be output stored in the output buffer in the output means, and disable use of a part of the intermediate output lines according to the number of packets waiting to be output for each output line. , is provided with a means for rewriting the reservation information transmitted on the ring between the connection control devices, and when the output line is congested, the connection to the intermediate output line connected to the congested output line is restricted. 2. The packet switch according to claim 1, wherein the packet switch is configured to avoid congestion on an output line. (4) Control the switch network in the packet switch,
And in a connection control device in which the switch network includes n input lines and (m x r) intermediate output lines, and controls the connection of the n input lines and (m x r) intermediate output lines, the input line The connection control unit for each input line is connected to the connection control unit for other input lines in a ring, and the connection control unit for each input line is ring-connected to the connection control unit for other input lines. The upper connection control unit outputs the reservation information of the intermediate output line to the ring lower connection control unit, and the ring lower connection control unit refers to the reservation information input from the ring upper connection control unit. Reserves an unreserved intermediate output line from among r intermediate output lines that can be connected to the output line indicated by the packet input from the input line, and then updates the reservation information and sends it to the connection control unit at the lower level of the ring. 1. A connection control device for a packet switch, which controls connection between a reserved intermediate output line and the input line after the reservation information has been output and made one circuit on a ring. (5) When the reservation information goes around the ring, the ring-connected connection control unit recognizes that the intermediate output line has been reserved first, and recognizes that the intermediate output line has been reserved first. The connection control unit below the ring of the connection control unit that was
5. The packet switch connection control device according to claim 4, wherein the device starts a cycle of the next reservation information.