JPS60223254A - Packet exchange system - Google Patents

Abstract

PURPOSE:To attain a change of the physical position of a terminal device by designating a terminal device of remote side with a subscriber number which does not depend upon said physical position and also switching the connection to a substitute terminal device. CONSTITUTION:When an intra-office subscriber number table exchange device 2a receives a connection request signal 13 from a terminal device 1a, the existence of a subscriber number (i) is checked with reference given from a subscriber number set in an incoming call subscriber number field to an intra-office subscriber number table set within the device 2a. If no coincident subscriber number exists, a code is set in a command response code field to show a connection request. Then the number (i) is set in the incoming call subscriber number field, and an address control signal 14 is transmitted to exchange devices 2b and 2c respectively. An exchange device 2c transfers to the intra-office subscriber number table included in the device (c) based on a subscriber number set in the incoming call subscriber number field within the corresponding signal. When no desired number exists, the signal 14 is disused. While (i)of the corresponding terminal physical address 74 is decided when the corresponding number exists.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a packet switching system comprising a plurality of switching devices connected to a trunk line and a plurality of terminal devices fi connected to the switching device. It concerns an improved system.

[Prior art]

Traditionally, this type of packet switching system has been designed specifically for a ring-shaped local area network consisting of a plurality of switching devices connected to a single closed ring-shaped trunk line and a plurality of terminal devices connected to this switching device. network is known. This method uses a part of the subscriber number directly as a physical address indicating the housing location of the switching equipment and the terminal equipment within the switching equipment. Therefore, since the subscriber number depends on the physical location of the terminal device, when making a dial connection, or when specifying the substitute reception terminal device as a terminal device connected to another exchange device, the subscriber number depends on the physical location of the terminal device. This method has the disadvantage that it is necessary to know the physical location of the device in advance.

[Summary of the Invention] The present invention was made with the aim of improving the drawbacks of the conventional devices as described above. In a packet switching system consisting of This allows the terminal device on the called side to be specified by a subscriber number that is independent of the physical location of the terminal device, and also allows the specified terminal device to be incapable of communication. The present invention provides a packet switching system in which it is possible to specify proxy reception at certain times.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a ring-type packet switching system which is an embodiment of the present invention. In the figure, l
a, lb, lc, ld are terminal devices, 2a, 2b, respectively
, 2c are switching devices, and 3 is a ring-shaped trunk line. Each exchange device 2a.

2b and 2c are constructed by a processing device exclusively for exchange, or by using a microcomputer, a minicomputer, or the like. The ring-shaped trunk line 3 is, for example, a coaxial cable, an original fiber, or the like.

20 is a block diagram showing a switching device in the packet switching system of FIG. 1; In the figure, 2 is a switching device similar to each switching device 2a, 2b, 2c in FIG.
They are a CPU (central processing unit), a 5-company storage device, and a 6-wire communication device. The storage device M5 stores various programs and data that are read out and processed by the CPU 4.
The communication device 6 is hardware that includes a transmission control device and the like for transmitting signals between the terminal device [1 and the exchange device 2]. The storage device 5 includes an in-office subscriber number table 7, a proxy reception table 8. There is an exchange processing unit 9 and the like.

30 is a format diagram showing the format of a signal transmitted during call connection in the packet switching system of FIG. 1; In the figure, 10 is a command response code field;
11 is a called subscriber number field, and 12 is an additional data field. In addition, each command response code field 1
0. Called subscriber number field 11. The arrangement order of the additional data fields 12 may be determined in any manner, but it must be determined in advance by agreement between the exchange devices 2. In the command response code field 10,
A code indicating the type of signal (for example, the type of address control signal or response to an address control signal) is entered, and the called subscriber number field 11 contains a code that indicates the type of signal (for example, the type of address control signal or response to an address control signal). Enter the assigned subscriber number.

FIG. 4 is a diagram showing the stored contents of the intra-office subscriber number table in the switching device of FIG. 2. In the figure, 71 existing in the intra-office subscriber number table 7 is the physical address of the switching device, 72 is the number of terminal devices connected to the switching device, 73 is the subscriber number, and 74 is the terminal physical address.

In the example shown in FIG. 4, for the subscriber numbers 73 (1) to lnl of the terminal devices connected to the switching device 2,
to ti+ of the corresponding terminal physical address 74 (n
) is provided.

The fifth figure is a diagram showing the stored contents of the proxy reception table in the exchange device of FIG. 2. In FIG. 1, reference numeral 81 in the substitute reception table 8 indicates a terminal physical address, and reference numeral 82 indicates an alternative subscriber number. In the example shown in FIG. 5, for the terminal physical addresses 81 (1) to - of the terminal device 1 connected to the corresponding switching device, the corresponding alternative subscriber numbers 82 (1) to - is provided.

FIG. 6 is a diagram showing an example of a signal sequence between a terminal device and a switching device in the first packet switching system.

In the example shown in No. 61kK, the terminal device 1a connected to the exchange device 2a makes a dial call to the terminal device 1c connected to the exchange device 2b to request connection, and the terminal device IC is unable to communicate. Therefore, the signal sequence between the switching devices 2a, 2b, and 2c when requesting connection to the alternative terminal device 1d connected to the switching device 2c is shown. In FIG. 6, 13 is a connection request signal, 14 is an address control signal from the switching device 2a, and 15 is a connection request signal from the switching device 2a.
The address control signal from b, 16 is an incoming call signal.

Next, the operation of the exchange system of the present invention described above will be explained with reference to FIGS. 1 to 6. Now, when the switching device 2a receives the connection request signal 13 from the terminal device 1a, the subscriber number set in the called subscriber number field IIK indicated in the connection request signal 13 is used to identify the in-office subscriber in the switching device 2a. Refer to the number table 7 and check whether (U) of the subscriber number 73 exists. As a result, if there is no one in the subscriber number 73 that matches the subscriber number indicated in the connection request signal 13. , a code indicating a connection request is set in the command response code field 10, and the subscriber number 73 (iJ
and transmits the address control signal 14 to the switching devices 2'b and 2c. When the switching device 2c receives the address control signal 14, the switching device 2c refers to the subscriber number set in the called subscriber number field 11 in the signal to the in-office subscriber number table 7 held within the switching device 2c. death,
If it does not exist, the address control signal 14 is discarded. When the switching device 2b receives the address control signal 14, the switching device 2b refers to the subscriber number set in the called subscriber number field 11 in the signal to the in-office subscriber number table 7 held within the switching device 2b. If it exists, determine the (il) of the corresponding terminal physical address 74. If the terminal device f!tic corresponding to the tit of this terminal physical address 74 is unable to communicate, the li of the terminal physical address 74 is determined. Alternate subscriber number 82 with reference to substitute reception table 8
li) and enters the alternative subscriber number 82 in the called subscriber number field 11 within the received address control signal 14.
(il) and transmits the address control signal 15 to the secular exchanges 2a and 2c.When the exchange 2c receives the address control signal 15, it sets the called subscriber number field 11 in the signal. In-house subscriber number table 7 held in the switching device 2c
li) of the corresponding terminal physical address 74 is determined, and an incoming call signal 16 is sent to the terminal device 1d to notify that there is a connection request.

〔Effect of the invention〕

As explained above, this invention does not depend on the physical location of the terminal equipment in a packet switching system consisting of a plurality of switching equipment connected to two trunk lines and a plurality of terminal equipment connected to the switching equipment. The terminal device on the other side can be specified by the subscriber number, and the connection can be switched to an alternative terminal device when communication is not possible with the terminal device on the other side, so the physical Even when the location is changed, it is extremely easy to designate the receiving terminal device and switch the connection to an alternative terminal device without changing the subscriber number as in conventional examples of this type. This has excellent effects.

[Brief explanation of drawings]

Figure 1 is a block diagram showing a ring-type packet switching system which is an embodiment of the present invention. Figure 2 is a block diagram showing a switching device in the packet switching system of Figure 1. In the packet switching system shown in the figure,
40 is a format diagram showing the format of the signal transmitted at the time of call connection; FIG. 40 is a diagram showing the stored contents of the local subscriber number table in the second switching device; and FIG. FIG. 6, which is a diagram showing the storage contents of the reception table, is a diagram showing an example of a signal sequence between the terminal device and the switching device in the packet switching system of FIG. In the figure, 1. la~1d...Terminal device, 2゜2a
~2c... Switching device, 3... Trunk line, 4... CP
U (central processing unit), 5... Storage device, 6... Communication device, 7... In-office subscriber number table, 8... Alternate reception table, 9... Exchange processing unit, 10... - Command response code field, 11... Called subscriber number field, 12... Additional data field, 13... Connection request signal, 14.15... Address control signal, 16
...-incoming call signal, 71...physical address of switching equipment,
72...Number of terminal devices, 73...Subscriber number, 74.
81...Terminal physical address, 82...Alternative subscriber number. In each figure, the same reference numerals indicate the same or equivalent parts. Agent Masuo Oiwa Figure 1 Figure 3 Figure 4 Figure 5 Figure 5 Dan 2 Name of the invention Packet switching system 3 Person making the amendment Representative Hitoshi Katayama Department 5 Detailed description of the invention in the specification to be amended "Explanation" column 6 Contents of amendment (1) Specification i, page 8, lines 4-5, "Indicated...
- Amend "from the subscriber number" to "from the indicated subscriber number." (2) "Field 11" on page 8, lines 11-12 of the same book.
"Set the subscriber number indicated in the connection request signal 13 in field 11."

Claims (1)

[Claims] In a packet switching system consisting of a plurality of switching devices connected to a trunk line and a plurality of terminal devices connected to the switching device, the switching device is configured to manage subscribers assigned to the terminal devices. An in-office subscriber number table showing the correspondence between a number and a terminal physical address showing the accommodation position in the exchange equipment to which the terminal equipment is connected, and an alternative terminal equipment when the terminal equipment is unable to communicate. When the terminal device receives the substitute reception table indicating the subscriber number and the called subscriber number specified by dialing, and refers to the in-office subscriber number table, if the called subscriber number exists, A means for converting the called subscriber number into the physical address of the terminal for switching connection, and a means for converting the called subscriber number into the physical address of the terminal and, if the called subscriber number does not exist in the in-office subscriber number table, a means for converting the called subscriber number into the terminal physical address and using the trunk line from the switching device. , means for transmitting an address control signal containing the terminating subscriber number to all other switching devices; Referring to the table, if the terminating subscriber number does not exist, the address control signal is discarded, and if the terminating subscriber number exists in the intra-office subscriber number chifur, the terminating subscriber number If the terminal device that received the call is unable to communicate with the means for converting the incoming call into the terminal physical address and processing the incoming call, the device refers to the proxy reception table from the terminal physical address of the terminal device and determines an alternative. If there is a terminal designation, the packet includes means for setting the subscriber number of the alternative terminal device in the received address control signal and transmitting it to all other switching devices. exchange system.