JPH0451106B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a packet transmission system that is composed of a plurality of conversion devices and a switching management device connected to a trunk line, and a plurality of terminal devices connected to the switching device. It relates to an improved system in an exchange system.

[Conventional technology]

Regarding the improvement of the exchange system as mentioned above,
The applicant of this invention previously applied for patent application No. 58-173534.
No. (filed on September 20, 1982). FIG. 8 is a block diagram showing an example of a conventional exchange system. In the figure, 1a and 1b are terminal devices 2a and 2b, respectively, switching devices, 3 is a switching management device, and 4 is a ring-shaped trunk line. Further, FIG. 9 is a diagram showing an example of a sequence of signals and packets between the terminal device, the switching device, and the switching management device in the switching system of FIG. 8. This example shows a sequence of signals and packets when the terminal device 1a connected to the switching device 2a requests connection to the terminal device 1b connected to the switching device 2b. In the figure, 27 is a connection request signal, 28 and 29 are connection request packets, 30 is an incoming call signal, 31 is an incoming call response signal, 32 is a connection response packet, and 33 is a connection response signal.

Next, details of the sequence example shown in FIG. 9 will be explained. First, upon receiving the connection request signal 27 from the terminal device 1a, the switching device 2a checks a table within the local station to determine whether the terminal device to which the connection request is made is accommodated within the local station. As a result, if it is found that the call is not accommodated within its own station, the switching device 2a sends a connection request packet 28 containing the called subscriber number to the switching management device 3.
Send. The switching management device 3 that receives this connection request packet 28 converts the called subscriber number into a terminal physical address by referring to a table within the switching management device 3, and converts the called subscriber number into a terminal physical address, and then converts the called subscriber number into a terminal physical address. The connection request packet 29 is transferred to the device 2b. The switching device 2b that received this connection request packet 29 knows from the terminal physical address shown in the packet that the connection request is addressed to the terminal device 1b, and sends an incoming call signal 30 to the terminal device 1b. . Thereafter, first, the terminal device 1b sends an incoming call response signal 31 to the switching device 2b, then the switching device 2b sends a connection response packet 32 to the switching device 2a, and finally, the switching device 1a sends a call response signal 31 to the switching device 2a.
Each response signal or packet is transmitted to the connection response signal 33 in the order of the connection response signal 33, and communication between the terminal device 1a and the terminal device 1b becomes possible.

[Problem that the invention seeks to solve]

The conventional switching system described above is configured as described above, so that the packet sequence from when a connection request packet is sent from the calling side switching equipment to when a response packet is returned is the same as the calling side. Communication is between three parties: the side switching device, the switching management device, and the called side switching device. In such communication between three parties, it is difficult to synchronize with the communicating parties, especially between toll exchange devices that require relaying by the exchange management device. Therefore, there was a problem in that it became very difficult to control the switching system when it was congested.

The present invention was made to solve these problems, and it is possible to use a subscriber number that does not depend on the physical location of the terminal device, and it is possible to easily control the switching system even in times of congestion. The purpose is to obtain a packet switching system that can

[Means for solving problems]

In the packet switching system according to the present invention, the switching device includes means for inquiring the switching management device about the terminal physical address corresponding to the called subscriber number designated by the terminal device, and the switching management device has An all-subscriber number table that shows the correspondence between subscriber numbers and terminal physical addresses for all terminal devices accommodated, and an incoming subscriber number by referring to the all-subscriber number table in response to inquiries from switching equipment. It is provided with means for converting the address into a terminal physical address and responding to the switching device.

[Effect]

In the packet switching system of this invention,
The terminal physical address inquiry and response mechanism between the switching equipment and the switching management equipment allows the calling switching equipment to know the terminal physical address corresponding to the called subscriber number before sending the connection request packet; Therefore, the connection request packet can be directly transmitted to the called switching device. Therefore, the communication between the calling switching equipment, the switching management equipment, and the called switching equipment is, in part, a communication between two parties in which the requests or inquiries and corresponding responses are reversed. As a result, it is easier to synchronize the communication partners with each other.

〔Example〕

FIG. 1 is a block diagram showing a packet switching system which is an embodiment of the present invention. In the figure, 1a, 1b, 1c are terminal devices, 2
Reference numerals a and 2b are switching devices, 3 is a switching management device, and 4 is a link type trunk line. Each exchange device 2
a, 2b and the exchange management device 3 are configured using a processing device exclusively for exchange, as well as a microcomputer, a minicomputer, or the like. Further, the ring-shaped trunk line 4 is, for example, a coaxial cable, an optical fiber, or the like.

FIG. 2 is a block diagram showing a switching device in the packet conversion system of FIG. 1. In the figure, 2 represents each exchange device 2a, 2 shown in FIG.
Exchange device similar to b, 5 is CPU (central processing unit),
6 is a storage device, and 7 is a communication device. Storage device 6
Various programs and data that are read and processed by the CPU 5 are stored therein, and the communication device 7 performs transmission control for transmitting signals between the terminal device 1 and the switching device 2 (not shown). This is hardware including devices, etc. In the storage device 6, there are an in-office subscriber number table address, an exchange processing section 9, and the like.

FIG. 3 is a block diagram showing the switching management device in the packet switching system of FIG. 1.
In the figure, 3 is equivalent to the exchange management device shown in FIG. 1, 10 is a CPU, 11 is a storage device, and 12 is a communication device. The storage device 11 includes an all-subscriber number table 13 and an exchange management processing unit 1.
4th grade exists.

FIG. 4 is a format diagram showing the format of packets transmitted through trunk lines in the packet switching system of FIG. 1. In the figure, 15 is a destination physical address field, 16 is a source physical address field, 17 is a packet header field, and 18 is an additional data field. The packet header field 17 contains information such as the type of the packet, such as a code indicating whether it is a connection request packet or an inquiry packet, and the number of the called subscriber.

FIG. 5 is a diagram showing the stored contents of the intra-office subscriber number table in the switching device of FIG. 2. In the figure, 81 is the physical address of the switching device, 8
2 is the number of terminal devices connected to the relevant exchange device,
Reference numeral 83 represents a subscriber number, and 84 represents a physical address of the terminal equipment housing location indicating the housing location of the terminal equipment 1 within the exchange equipment, and each exists in the intra-office subscriber number table 8. In the example shown in FIG. 5, for [1] to [m] of the subscriber numbers 83 of the terminal devices connected to the exchange device 2, [1] to [m] of the corresponding terminal device accommodation location physical addresses 84 are used. ] to [m].

FIG. 6 is a diagram showing the stored contents of the all subscriber number table in the exchange management device of FIG. 3. In the figure, 131 is the physical address of the switching management device, 132 is the total number of terminal devices in the packet switching system shown in FIG. 1, 133 is the physical address of the switching device to which terminal device 1 is connected, and 134 is the switching device. This is a physical address of the terminal device accommodation location indicating the accommodation location of the terminal device 1 within the device, and each exists in the all subscriber number table 13. In the example shown in FIG. 6, subscriber meal boxes [1] to [n]
, the physical addresses [1] to [n] of the switching device to which the terminal device is connected are shown as corresponding terminal physical addresses, and the housing position of the terminal device in the switching device. Terminal device housing location physical addresses 134 [1] to [n] are provided.

FIG. 7 is a diagram showing an example of a sequence of signals and packets among the terminal device, switching device, and switching management device in the packet switching system of FIG. 1. In this example, when the terminal device 1a connected to the switching device 2a requests connection to the terminal device 1b connected to the switching device 2b, each terminal device 1a and 1b, the switching device 2a and 2b , the sequence of signals and packets between the switching management device 3. In the figure, 19 is a connection request signal, 20 is an inquiry packet, 21 is an inquiry response packet, 22 is a connection request packet, and 23 is an inquiry packet.
is an incoming call signal, 24 is an incoming call response signal, 25 is a connection response packet, and 26 is a connection response signal.

Next, the operation of the above-mentioned packet switching system of the present invention will be explained with reference to FIGS. 1 to 7. Now, when the switching device 2a receives the connection request signal 19 from the terminal device 1a, the switching device 2a refers to the in-office subscriber number table 8 in its own switching device, and selects the incoming call indicated in the connection request signal 19. It is checked whether a subscriber signal 83 in the intra-office subscriber number table 8 exists that matches the subscriber number. In this case, since there is no matching subscriber number in the in-office subscriber number table 8,
The exchange device 2a transmits a terminal device address inquiry packet 20 to the exchange management device 3.
The switching management device 3 that receives this inquiry packet 20 refers to the all subscriber number table 13 and assigns the called subscriber number shown in the inquiry packet 20 to the switching device to which the terminal device is connected. It is converted into a terminal physical address consisting of a physical address and a physical address indicating the housing position of the terminal device within the switching device, and an inquiry response packet 21 containing the terminal physical address is returned to the switching device 2a. The switching device 2a transmits a connection request packet 22 in which the terminal physical address shown in the inquiry response packet 21 is set in the destination physical address field 15. The switching device 2b that received this connection request packet 22 inputs the destination physical address field 15 in the connection request packet 22.
Knowing that the connection request is addressed to the terminal device 1b, it transmits an incoming call signal 23 to the terminal device 1b. From now on, first, from the terminal device 1b to the exchange device 2
b, the incoming call response signal 24, then the switching device 2
Connection response packet 2 is sent from b to switching device 2a.
5.Finally, each response signal or packet is transmitted from the switching device 2a to the terminal device 1a in the order of the connection response signal 26, and as a result, the terminal device 1
Communication between a and the terminal device 1b becomes possible. In addition, in the sequence described above, each exchange device 2
Transmission of various packets between a, 2b and the switching management device 3 is all performed using the trunk line 4 shown in FIG. Further, when the switching equipment 2a that has received the connection request signal 19 refers to the in-office subscriber number table 8, the subscriber number that matches the called subscriber number indicated in the connection request signal 19 is found to be the in-office subscriber number. If the subscriber number 83 exists in the number table 8, it means that the terminal device that is the subject of the connection request is directly connected to the switching device 2a. The incoming call signal 23 is directly transmitted to the recipient.

〔Effect of the invention〕

As explained above, the present invention provides a packet switching system that includes a plurality of switching devices connected to trunk lines, a switching management device, and a plurality of terminal devices connected to the switching devices. The communication between the exchange management device and the exchange management device is partially synchronized with the communication partner by making it possible to inquire and respond to the physical address of the terminal in response to the incoming subscriber number between the exchange management devices. The packet switching system is structured so that communication between two parties can easily be completed, so a subscriber number that does not depend on the physical equipment of the terminal device can be used, and the switching system can be easily controlled even in times of congestion. This has excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram showing a packet switching system which is an embodiment of the present invention, FIG. 2 is a block configuration diagram showing a switching device in the packet switching system of FIG. 1, and FIG. FIG. 4 is a block configuration diagram showing the exchange management device in the packet switching system of FIG. 1, and FIG. FIG. 6 is a diagram showing the stored contents of the in-office subscriber number table in the switching device shown in FIG. FIG. 8 is a block diagram showing an example of a conventional conversion system, and FIG. FIG. 3 is a diagram showing an example of a sequence of signals and packets among a terminal device, a switching device, and a switching management device in the switching system shown in the figure. In the figure, 1a, 1b, 1c...terminal devices,
2, 2a, 2b... switching device, 3... switching management device, 4... trunk line, 5, 10... CPU (central processing unit), 6, 11... storage device, 7, 12... communication device , 8...Internal subscriber number table, 81,
133...Physical address of switching device, 82...Number of terminal devices, 83...Subscriber number, 84,134...
...Terminal device housing location physical address, 9... Exchange processing unit, 13... All subscriber number table, 131...
... Physical address of exchange management device, 132 ... Total number of terminal devices, 14 ... Exchange management processing unit, 15 ... Destination physical address field, 16 ... Source physical address field, 17 ... Packet header field, 18 ...Additional data field, 1
9, 27... Connection request signal, 20... Inquiry packet, 21... Inquiry response packet, 2
2, 28, 29... Connection request packet, 23, 3
0...Incoming call signal, 24,31...Incoming call response signal,
25, 32... Connection response packet, 26, 33...
...This is a connection response signal. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1. In a packet switching system consisting of a plurality of switching devices and a switching management device connected to a trunk line, and a plurality of terminal devices connected to the switching device, the terminal device is a subscriber that does not depend on its physical location. The terminal physical address, which is assigned a number and indicates the physical location, is the physical address of the switching device to which the terminal device is connected, and the physical address indicating the accommodation position of the terminal device within the switching device. The switching management device includes an all-subscriber number table showing the correspondence between the subscriber numbers and the terminal physical addresses for all the terminal devices accommodated in the packet switching system, and a and means for converting the subscriber number into the terminal physical address by referring to the all subscriber number table and responding to the switching device in response to the inquiry, and the switching device For all the terminal devices connected to the device, an intra-office subscriber number indicating the correspondence between the subscriber number assigned to that terminal device and the physical address indicating the accommodation position of the terminal device in the switching device. table and the called subscriber number designated by the terminal device, and refers to the intra-office subscriber number table, and if the called subscriber number exists in the intra-office subscriber number table, the incoming call is means for converting a subscriber number into the physical address of the terminal for exchange connection; and, if the incoming subscriber number does not exist in the in-office subscriber number table, connecting the subscriber number to the exchange management device using the trunk line; An inquiry is made, and the switching management device sends the relay to the switching device to which the terminal device is connected, according to the terminal physical address converted from the called subscriber number using the all-subscriber number table. means for transmitting a connection request packet including the terminal physical address using a line, and means for converting and connecting according to the terminal physical address included in the connection request packet received from the trunk line. A packet switching system characterized by: