JPH0828706B2 - Packet switching system - Google Patents

Description

The present invention relates to a packet switching system for performing high speed switching connection of packet signals.

[Conventional technology]

Since the packet switching system can multiplex a plurality of packet signals on one line, the line can be effectively used.

In a packet switch used in such a packet switching system, a CPU (central processing unit) generally performs switching connection by determining a connection destination from label information of a packet signal. However, in such a packet switch, high-speed switching processing cannot be performed because the CPU determines the connection destination for every packet. Therefore, an ATM (asynchronous transfer mode) switch has been developed that enables high-speed packet switching by connecting and switching packet signals without using a CPU.

FIG. 3 is for explaining the concept of such an ATM exchange.

The ATM exchange 11 is provided with a conversion table 12 that adds a physical address to a packet signal corresponding to call identification information. The conversion table 12 is a memory circuit, and the call identification information 13
And a physical address 14 corresponding thereto are written by a CPU (not shown) each time a call is generated. The packet signal 16 including the user information and the call identification information 13 transmitted from the terminal device (not shown) is supplied to the conversion table 12. The packet signal 16 has a physical address 14 corresponding to the call identification information 13.
Is added in the conversion table 12. The packet signal 17 to which the physical address 14 is added is supplied to the switching connection device 18. The switching connection device 18 performs switching connection by a switch circuit with reference to only the added physical address 14, and outputs the supplied packet signal 17 to a predetermined outgoing line 19.

FIG. 4 is a diagram for explaining exchange connection by switching of a shuffle type switch circuit as an example of the switch circuit of the exchange connection device 18.

The switch circuit 21 of the exchange connection device 18 has unit switches 22 each having two inputs and outputs arranged and connected according to a predetermined rule. To simplify the description, a switch circuit 21 including unit switches 22 arranged in four rows and three columns will be described. The unit switch 22 in each column of the switch circuit 21 switches according to the value of the bit string of the physical address 14 added in the conversion table 12. For example, each switch 22-1 in the first column of the unit switch 22 switches according to the value of the first bit of the physical address. Each unit switch 22 switches to the lower output line when the corresponding bit of the physical address is "1", and switches to the upper output line when the corresponding bit is "0".

If the numbers of the outgoing lines O _{0 to} O ₇ of the switch circuit 22 operating in this manner are expressed in binary numbers and added to the head of the packet signal as the physical address 14, no matter what incoming line the packet signal is input from, Output from the desired outgoing line. For example,
Packet signal 2 with the same physical address 14 “010” added
It is assumed that ₃ and 24 are input from separate incoming lines I ₅ and I ₇ . Each of these packet signals 23 and 24 is a path indicated by a bold line and is switched upward by a unit switch in the first column, downward by a unit switch in the second column, and upward by a unit switch in the third column. and output the same to the output line O _2.

[Problems to be Solved by the Invention]

In the packet switching system performed in this way,
Different from the circuit switching system, a plurality of packet signals can be multiplexed on one line, so that the line can be effectively used. However, if one physical line is exclusively used, it can be confirmed that the signal is transmitted to a specific terminal device by checking the connection of the line. Since there is no line to be used and packets are separately transmitted in packet units, it is necessary to individually confirm whether or not packet signals are normally transmitted. In particular, in a packet switching system using an ATM switch, high-speed packet switching is performed, and therefore it is necessary to regularly confirm that the packet signal transmission path is normal.

Therefore, an object of the present invention is to provide a packet switching system capable of confirming that a packet signal is normally transmitted.

[Means for solving the problem]

The network usage information transfer system of the present invention comprises (i) a physical address adding means for adding a physical address designating an outgoing line of a packet signal according to call identification information, and a physical address added by the physical address adding means. Originating side switching connection means for switching and connecting a packet signal to a designated outgoing line,
A calling side provided with a network usage information packet signal insertion means for supplying a network usage information packet signal having the same call identification information as the packet signal and information for distinguishing from the packet signal to the physical address addition means together with the packet signal. A packet switch, (ii) a transmission line connected to the outgoing line of the originating exchange connection device of this originating packet switch, and (iii) a packet signal connected to this transmission line and exchange-connected from the originating packet switch. Destination switching connection means for switching and connecting to the output line designated by the physical address, and a network usage information packet signal for extracting a network usage information packet signal from the packet signal output from the outgoing line of this destination side switching connection means And a destination-side packet switch equipped with extracting means.

That is, the packet switching system of the present invention transmits a packet signal for network use information including the same call identification information as the packet signal for user information and information indicating that it is not a packet signal for user information together with the packet signal for user information. However, the packet switch on the receiving side extracts this.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to Examples.

FIG. 1 shows the configuration of a packet switching system according to an embodiment of the present invention.

The packet switching system includes a first packet switching device 31 and a second packet switching device 32. In this embodiment, the first packet switch 31 is the originating side and the second packet switch 32 is
Will be described as the receiving side.

The first packet switch 31 includes a switching connection device 33. The switching / connecting device 33 switches and connects the packet signals supplied from the plurality of incoming lines 34 according to the physical addresses added thereto, and outputs the packets to the plurality of outgoing lines 36. The exchange connection device 32 is composed of a plurality of switch circuits. The switch circuit may be a shuffle type switch circuit shown in FIG. 4 or a shared memory type switch circuit (not shown). That is,
The switch circuit used in the switching / connecting device 32 may be a switch circuit for switching / connecting according to the physical address added to the packet signal for determining the outgoing line.

The first packet switch 31 has a conversion table 37. The conversion table 37 is a memory circuit, and the call identification information 41 of the packet signal supplied from the input line 38 and the physical address 42 corresponding thereto are written by the CPU (not shown) each time a call is generated.

The first packet switch 31 includes an inserter 43. The inserter 43 is connected and arranged on the input line 38, and the network use information packet signal 44 is inserted into the input line 38.

The packet signal transmitted from the second packet switch 32 is supplied to the switching connection device 33 from the incoming line 46 and output to the outgoing line 47. A dropper 48 for extracting a network use information packet signal from a packet signal transmitted from another packet switch is connected and arranged on the outgoing line 47.

Similarly to the first packet switch 31, the second packet switch 32 has a conversion table 51, a switching connection device 52, a dropper 54 on the outgoing line 53 of the switching connection device 52, and an inserter 57 on the incoming line 56. ing.

First packet switch 31 and second packet switch 32
Are connected via transmission lines 58 and 59.

In FIG. 1, the conversion tables 37 and 51 are shown only for signals in the upward direction, but conversion tables (not shown) are connected and arranged on the incoming lines 56 and 46 in the downward direction.

Next, the operation of the packet switching system configured as described above will be described.

FIG. 2 shows a format of a packet signal used for transmission in the packet switching system.

The packet signal 61 is composed of an information area 62, a label area 63 and a physical address area 64. The label area 63 is composed of a call identification information area 66 and a network use display bit area 67. The packet signal for user created for the user to actually perform packet communication and the packet signal for network use information for confirming the normality of the connection route of the packet switching network are configured in the format of this packet signal 61. There is. The packet signal for network use information is a signal used only in the packet switching network connected by each packet switch. The network use display bit area 67 is composed of 1 bit, and a logical "1" is always set in the case of a user packet signal, and a logical "0" is always set in the case of a network use information packet signal. .

At the time of call setup, the packet switch and the call identification information are determined. The user writes the call identification information given from the originating first packet switch 31 in the call identification information area, and generates a user information packet signal in which a logical "1" is written in the network use indication bit area 66. Then, it is input to the input line 38. This user information packet signal is the first
When supplied to the packet switch 31, the conversion table 37 adds the physical address corresponding to the call identification information. The user information packet signal to which the physical address is added in the conversion table 37 is supplied from the incoming line 34 to the switching connection device 33, and is switched and connected to the outgoing line corresponding to the physical address. It is assumed that the user information packet signal is switched and connected and is output to the outgoing line 36, for example.

The user information packet signal output from the output line 36 is
It is input to the destination second packet switch 32 through the transmission line 58. In the second packet exchange 32, the supplied user information packet signal is exchange-connected by the exchange connection device 52 to, for example, the outgoing line 53 corresponding to the physical address. The packet signal for user information output from the output line 53 has the network use display bit set to logic "1", so the dropper
It is supplied to a terminal device (not shown) without being extracted at 54.

Next, a case of checking whether or not the user information packet signal is normally transmitted between the first packet switch 31 and the second packet switch 32 will be described.

In the first packet switch 31, the network use information packet signal 44 is inserted from the inserter 43. In the network use information packet signal 44, the network use indication bit is set to logical "0", and the same call identification information as the user information packet signal is set.

When the network use information packet signal 44 thus set is inserted from the inserter 43 into the input line 38, it is supplied to the conversion table 37. Since the network use information packet signal 44 supplied to the conversion table 37 has the same call identification information as the user information packet signal, the same physical address is added. Therefore, the network use information packet signal 44 is switched and connected to the outgoing line 36 by the switching connection device 33 similarly to the user information packet signal, and further switched to the outgoing line 53 by the switching connection device 52 of the second packet switch 32. Connected. That is, the network use information packet signal 44 is transmitted through the same route as the user information packet signal.

The network use information packet signal 44 output from the outgoing line 53 of the exchange connection device 52 is supplied to the dropper 54. In the dropper 54, since the logic of the network use display bit area of the supplied packet signal is "0", this is judged as the network use information packet signal 44 and is extracted from the output line 53. As a result, the network use information packet signal 44 is not supplied to the terminal device (not shown).

In the second packet switch, from the call identification information of the network use information packet signal 44 extracted from the dropper 54,
The user information packet signal supplied from the input line 38 to the first packet switch 31 is normally transmitted to the second packet switch 32.
It is possible to confirm that the signal has been transmitted up to the outgoing line.

Downward direction of the packet signal for user information, that is, the second
When confirming the normality of the transmission path from the packet switch 32 to the first packet switch 31, the packet signal for network use information is inserted from the inserter 57, and this is extracted by the dropper 48.

In the first packet switch 31, by inserting a packet signal for network use information in which specific test information is described in the information area from the inserter 43 into the input line 38, various tests other than the connection route can be performed. it can. For example, the transmission time between the first packet switch 31 and the second packet switch can be known by describing the time when the packet signal for network use information is inserted in the inserter 43 as the test information.

Generally, when the calling or called terminal displays the end of the call, the connection route is released, but depending on a specific terminal, the connection of the incoming call may be displayed as the end of the call from the calling terminal. There are cases where you want to suspend the connection route without depending on it. When there is an incoming call to such a specific terminal, the control device (not shown) of the destination packet switch 32 describes the connection route hold information in the information area and the same call as the user information packet signal in the call identification information area. A packet signal for network usage information in which the network usage information indicating bit is set to logic "0" is inserted into the inserter 57 while the identification information is described. The packet signal for network usage information in which the connection route reservation information is described is
The packet is extracted from the dropper 48 of the first packet switch 31 to which the calling terminal is connected. A control device (not shown) of the first packet switch reads the connection route reservation information described in the information area of the extracted network use information packet signal, and retains the connection route as it is without opening it.

As a result, the normality of the user information packet signal can be confirmed by using the method such as sending a special hold signal for holding the connection route from the called exchange to the calling exchange. The same circuit configuration can be used.

In the embodiment described above, the network use indication bit is set to logic "1" for the user information packet signal and set to logic "0" for the network use information packet signal. It may be done. Further, the network use display bit area is not limited to one bit and may be composed of a plurality of bits. In this case, the packet signal for network use information and the packet signal for user information may be distinguished from each other by using those designated in advance uniformly among all packet switches, and the contents thereof are not particularly limited.

〔The invention's effect〕

As described above, according to the present invention, means for inserting the network use information packet signal having the same call identification information as the user information packet signal and the information for distinguishing from the user information packet signal into the transmission line is provided. Since the packet switch for the originating side is provided with a means for extracting the packet signal for network use information inserted in the transmission path at the packet switch for the destination side, the normality of the connection route of the packet signal for user information is confirmed. It becomes possible.

[Brief description of drawings]

1 and 2 are for explaining one embodiment of the present invention. Of these, FIG. 1 is a system configuration diagram for explaining an outline of a packet switching system, and FIG. 2 is a packet signal format. The configuration diagram shown in FIG. 3, FIG. 3 is a schematic configuration diagram of the ATM switch, and FIG. 4 is a circuit diagram for explaining the concept of the switch circuit of the exchange connection device. 31 ... First packet switch, 32 ... Second packet switch, 33, 52 ... Switching connection device, 37, 51 ... Conversion table, 44, 57 ... Inserter, 49, 54 ... Dropper, 5
8, 59 …… Transmission path.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04L 12/56 9466-5K H04L 11/20 102 A

Claims (1)

[Claims] 1. A physical address adding means for adding a physical address designating an outgoing line of a packet signal according to call identification information, and the packet to an outgoing line designated by the physical address added by the physical address adding means. A packet signal for network use information having a calling side switching connection means for switching and connecting signals, call identification information same as the packet signal, and information for distinguishing from the packet signal, and the physical address addition means together with the packet signal. A calling-side packet switch equipped with a network-use information packet signal inserting means to be supplied, a transmission line connected to the outgoing line of the calling-side switching connection device of the calling-side packet switch, and connected to this transmission line, Destination switching connection means for switching connection of a packet signal exchange-connected from the originating packet switch to an output line designated by a physical address, And a destination-side packet switch equipped with network-use information packet signal extracting means for extracting a packet signal for network-use information from the packet signal output from the outgoing line of the destination-side switching connection means. Exchange system.