JPH02195755A - Permanent virtual circuit selecting method - Google Patents

Abstract

PURPOSE:To realize communication by a permanent virtural circuit(PVC) and plural terminal equipments by referring to a required table, and selecting the logic channel number of the PVC for a subscriber line. CONSTITUTION:Terminal equipment 3a requests the connection of the subscriber line 17a to a line switching network 16 and instructs an incoming call to select the terminal equipment 3a, terminal equipment 3b, ad the PVC. Then, the table 8 of a packet assembling/disassembling device 2a is referred, and the logic channel number of the PVC corresponding to the subscriber line 17a is selected, and also, a job start packet is generated, and it is transmitted to packet assembling/disassembling device 2b via packet switching devices 1a and 1b, then, communication by the PVC with the equipment 3b is performed. The end of the job of the PVC is performed by the device 2a corresponding to the disconnection request of the line 17a from the equipment 3a corresponding to a job end packet issued to the device 2b.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a permanent virtual circuit in a packet-switched network.
lCircuit) selection method.

(Prior art) If the connection classes between terminal devices in packet switching services are classified according to the usage mode, the other party selection class (Vi
There are two types of calls: ordinary calls (usually abbreviated as VC) and fixed call classes. In the fixed-party class, a permanent virtual communication circuit is formed between terminal devices, so it is called a permanent network virtual circuit (hereinafter abbreviated as PvC).

Figure 4 shows, for example, the technical reference material "Packet switching service interface (PT edition)", December 2, 1985.
Figure 7 is a block diagram illustrating a conventional device based on the use of PVC as shown.

In the figure, (la) and (1b) are packet switching devices, (2a), (2b), and (2C) are packet assembly and disassembly devices, respectively, and (3a), (3b), and (3C) are terminal devices, respectively. (4) is a trunk line, (5) is data that is input from the terminal device (3a) to the packet assembling and disassembling device (2a), and (6) is data that is assembled by the packet assembling and disassembling device (2a) and sent to the packet switching device (la ), from the packet switching device (la) to another packet switching device (1b) via the trunk line (4), and from the packet switching device (la) to another packet switching device (1b),
R get sent from b) to the Norkerato assembly/disassembly device (2b), (2C), (7) is sent to the packet assembly/disassembly device (3
b), the r-data generated by decomposition in (3C) and sent to the terminal device (3).

In the actual configuration of a switching network, there are many packet switching devices, packet assembling and disassembling devices, terminal devices, and trunk lines, but FIG. 4 shows only those parts necessary for explanation.

Data (5) to be transmitted from the terminal device (3a) to the terminal device (3C) is divided into blocks of a certain length, and each block is attached with control information necessary for transfer, such as destination information and error control information. Packet (6) becomes packet (8)
is transferred within the switching network and reaches the packet switching device (1b) to which the terminal device (3C) is connected, and the packet assembling and disassembling device (2C) assembles it as the original data (5) and converts it into data (7). It is sent to the terminal device (3C) as.

In a conventional device, for example, when PvC is set between a terminal device (3a) and a terminal device (3b), a packet (6) corresponding to data (5) sent from the terminal device (3a) is a packet. It enters the packet assembling and disassembling device (2b) via the logical channel set as PVC in the switching device (1b), and is transmitted as data (7) to the terminal device (3b).
) is given to

[Problem to be solved by the invention]

Since the conventional device is configured as described above, the PVC between the terminal device (3a) and the terminal device (3b) is abolished, and the PVC between the terminal device (3a) and the terminal device (3C) is removed. Pv
Therefore, the terminal device (3a) for which PVC is set must limit the communication partner to one terminal device, and there is a problem that it is not possible to communicate with multiple terminal devices. Ta.

This invention was made to solve this problem, and it is possible to set PvC by selecting any one of a plurality of terminal devices to be configured by operating the terminal device on the setting side. An object of the present invention is to obtain a permanent net virtual circuit selection method that can communicate with a plurality of terminal devices to be configured using PVC.

(Means for Solving the Problems) A permanent net virtual circuit selection method according to the present invention includes a plurality of packet switching devices interconnected by a trunk line, a setting terminal device and a plurality of setting terminal devices, Connected between each of these terminal devices and the packet switching device, it packetizes the input data from the terminal device and transmits it to the packet switching device, and also disassembles the packets received from the packet switching device and outputs the data to the terminal device. a circuit switching network connected between the setting side terminal device and the corresponding packet assembling and disassembling device; and a packet assembling and disassembling device corresponding to the circuit switching network and the setting side terminal device. and a table provided in the packet assembling and disassembling device corresponding to the setting side terminal device and showing the correspondence relationship between each of the subscriber lines and the logical channel numbers of the plurality of permanent net virtual circuits; The packet assembling and disassembling device corresponding to the setting side terminal device selects a permanent partial circuit corresponding to this subscriber line from the above table by connecting the setting side terminal device and an arbitrary subscriber line. , a start packet is sent to the set terminal device of the selected logical channel number, and by disconnecting the subscriber line to the setting end terminal device, an end of day packet is sent to the set end terminal device. It is something that

[Function] In this invention, when a setting side terminal device requests connection to an arbitrary subscriber line in a circuit switched network, the packet assembling and disassembling device corresponding to the setting side terminal device is configured to connect to an arbitrary subscriber line. A permanent network virtual circuit to be configured is selected from the table, and a starting packet is sent to the terminal device of the selected logical channel number. Communication will now be possible. On the other hand, the permanent partial circuit is terminated by disconnecting the subscriber line from the setting terminal device and sending a termination packet from the packet assembly/disassembly device corresponding to the setting terminal device to the set terminal device. .

(Embodiment) Fig. 1 is a block diagram of a packet switching network showing an embodiment of the present invention. In Fig. 0, the same reference numerals as in Fig. 4 indicate the same or corresponding parts. Device (2a
), (16) is a circuit-switched network, (
17a) and (17b) are subscriber lines connecting this circuit switching network (16) and the packet assembly/disassembly device (2a).

FIG. 2 is a format diagram of the table (8), which shows the correspondence between the PVC logical channel number and the subscriber lines (17a) and (17b). In the figure, (81) is a logical channel number corresponding to a subscriber line, and (82) is subscriber information.

In this embodiment, #1 corresponds to the subscriber line (17a) and #2 corresponds to the subscriber line (17b).

The logical channel number (81) is a number for specifying each PVC, and is always given to the packet (6) of the packet assembly/disassembly device (2a) and the packet switching device (la). On the other hand, the subscriber information (82) indicates information on the other party's terminal devices (3b) and (3C), but is not necessarily necessary and can be omitted.

FIG. 3 is an explanatory diagram showing a sequence example of PvC selection in the present invention, and in the figure (9) to (15) are signals transmitted for PvC selection and disconnection. Below, the third
The operation of this embodiment will be explained with reference to the drawings.

When the terminal device (3a) selects PVC between the terminal device (3b), 1. First, the floor device (3a) selects a PVC with the terminal device (3b) and requests a connection with the subscriber line (17a) via circuit switching [(16). The packet assembling and disassembling device (2a) receives the connection request (
9), that is, when an incoming call is instructed, a starting packet (l
0) and transmits a starting packet (lO) to the packet assembly/disassembly device (2b) via the packet switching devices (la) and (1b). This starting packet (10)
The packet assembling and disassembling device (2b) that has received the message sends start notification data (
11) and outputs the packet assembling and disassembling device (2).
In response to a), a response packet (12) is sent back.

In addition, at the end of the PvC, the packet assembling and disassembling device (2a) generates the end-of-day packet (13) in response to a disconnection request (15) of the subscriber line (17a) from the terminal device (3a), and the packet assembling and disassembling device ( 2b) End-of-day packet (1
3) Send. The packet assembling and disassembling device (2b), which has received this end-of-day packet (13), outputs end-of-day notification data (14) indicating the end of the PVC to the terminal device (3b), and also outputs the end-of-day notification data (14) to the terminal device (3b). In response, a response packet (12) is sent back.

On the other hand, p between the terminal device (3a) and the terminal device (3c)
VC is also selected by connecting and disconnecting the subscriber line (17a) using the same procedure as in the case of the terminal device (3b).

In addition, in the above embodiment, the case where only the terminal device (3a) and the packet assembling and disassembling device (2a) are connected by the circuit switching network (16) was shown, but the packet assembling and disassembling device (2a)
), (2c) and the terminal devices (3b), (3c),
They may also communicate via a circuit switched network (16).

[Effects of the Invention] As explained above, this invention allows PvC to be set up and disconnected from any set terminal device by the operation from the setting terminal device. This has the advantage of being able to communicate with others.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a packet switching network showing an embodiment of the present invention, FIG. 2 is an explanatory diagram showing a table for subscriber control provided in a packet assembling and disassembling device, and FIG. 3 is a block diagram of a packet switching network according to an embodiment of the present invention. An explanatory diagram showing an example of a PVC selection sequence, FIG. 4 is a block diagram showing a conventional packet switching network. (1a), (1b)...Packet switching device (2a),
(2b), (2c)-”Packet assembly and disassembly device (3a)
, (3b), (3c) One terminal device (6)...Packet (7)...Data (8)...Table (10)...Starting packet (13)...Ending packet (16) )...Circuit switching network (17a), (17b)...Subscriber line (81)...
- Logical channel number Note that the same reference numerals in each figure indicate the same or equivalent parts.

Claims (1)

[Claims] A plurality of packet switching devices, a setting side terminal device and a plurality of setting side terminal devices, which are interconnected by a trunk line,
Connected between each of these terminal devices and the packet switching device, it packetizes the input data from the terminal device and transmits it to the packet switching device, and also disassembles the packets received from the packet switching device and outputs the data to the terminal device. a circuit switching network connected between the setting side terminal device and the corresponding packet assembling and disassembling device; and a packet assembling and disassembling device corresponding to the circuit switching network and the setting side terminal device. with multiple subscriber lines connecting
The device is provided in a packet assembly/disassembly device corresponding to the setting side terminal device, and includes a table indicating the correspondence between each subscriber line and the logical channel numbers of the plurality of permanent net virtual circuits, and is compatible with the setting side terminal device. The packet assembling and disassembling device connects the setting side terminal device to an arbitrary subscriber line, selects a permanent virtual circuit corresponding to this subscriber line from the above table, and also selects the configured logical channel number of the selected logical channel number. A permanent-net virtual circuit selection method, characterized in that a start-of-day packet is sent to the terminal device on the setting side, and a closing packet is sent to the terminal device on the set-up side by disconnecting the subscriber line to the terminal device on the setting side.