JPH0486046A - Isdn packet switchboard - Google Patents

Abstract

PURPOSE:To enable efficient packet communication by providing an extension communication control means to control communication with the extension of an ISDN, and a packet communication control means to communicate packet data stored in respective control means. CONSTITUTION:Extension interface parts 3 and 4 to house the extension of the ISDN are composed of a D-channel link access order processing part (LAPD) 3-1 to execute processings at a layer 2 of the ISDN such as managing a D- channel signal to be communicated by the extension of the ISDN, detection and recovery of signal error and the preservation processing of an information transfer process, extension communication control part 3-2 to execute processings at layers 3 and 1 of the ISDN as call control processings at the extension of the ISDN, link access process balance processing part (LAPB) 3-3 to execute a processing at the layer 2 of an X.25 protocol such as the detection and recovery of the transfer error of the packet, buffer 3-4 to store the packet data and control part 3-5 to manage the buffer 3-4 or to communicate the extension communication control part 3-2 each other. Thus, efficient packet communication is enabled.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an ISDN packet switch that accommodates a plurality of ISDN office lines and extension lines and has a packet communication function.

[Conventional technology]

Conventionally, the protocol for packet communication in a private branch exchange (hereinafter referred to as PBX) that accommodates ISDN office lines and has a packet communication function is based on the data link layer (layer 2) of the protocol layer structure of the OSI reference model. The corresponding data link control procedure (LAPB) and the connection control procedure and data transfer procedure (X, 25 protocol) corresponding to the network layer (layer 3) are defined respectively. The protocol processing unit that executes these protocols is configured as a packet communication processing unit (PHM).

[Problem to be solved by the invention]

However, in the above conventional example, the packet communication processing unit (
The number of packets that can be handled simultaneously is determined by the number of layer 2 LAPB processing units included in the PHM.
As the number of connected packet terminals increases, an ISDN extension interface section and a packet communication processing section (PHM) must also be installed within the PBX, which is a drawback. In addition, since B channel signals (packet data) must be communicated between the office line interface unit or extension line interface unit and the packet communication processing unit via time-division communication paths, some of the time-division communication paths It also had the disadvantage of monopolizing the time throttle. The present invention was made to solve the above problems, and
When performing packet communication, packet data is accumulated and
An object of the present invention is to provide an ISDN packet switch capable of performing efficient packet communication by controlling communication of accumulated data.

[Means to solve the problem]

In order to achieve the above object, the ISDN packet switch of the present invention has the following configuration. That is, it is an ISDN packet switch that accommodates a plurality of ISDN office lines and extension lines, and has a packet communication function, and includes a processing section that executes data link control procedures with the ISDN office lines, and a storage section that accumulates packet data. a station line communication control means for controlling communication with the ISDN station line, a processing section for executing a data link control procedure with the ISDN extension line, and a storage section for accumulating packet data; It includes an extension communication control means for controlling communication with extensions, and a packet communication control means for communicating packet data accumulated by each control means. Preferably, one aspect of the packet communication control means is to perform communication without using a time-division channel.

[Effect]

In the above configuration, when performing packet communication between the accommodated ISDN office line and the extension line, it operates to accumulate packet data and control communication of the accumulated data.

【Example】

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. <Description of Configuration (FIG. 1)> FIG. 1 is a schematic block diagram showing the configuration of a private branch exchange (PBX) in this embodiment. As shown, there are two ISDN office lines and two ISDN
packets between the office line and the extension line, between the office line and the office line, and between the extension line and the extension line, through the corresponding office line interface parts 1 and 2 and the extension ink face parts 3 and 4. It is capable of communication. In the figure, reference numerals 1 and 2 are office line interface units that accommodate ISDN office lines, which manage D channel signals for communication with an ISDN network (not shown), and perform processing such as signal error detection and recovery and information transfer order preservation processing. D channel link access procedure processing unit (which performs processing at layer 2 of ISDN)
LAPD) 1-1, a station line communication control unit 1-2 that performs ISDN layer 3 processing and layer 1 processing that is call control processing with the ISDN network, and detection and recovery of packet transfer errors. The link access procedure balance processing unit (LA
PB) 1-3, a buffer 1-4 for storing packet data, and a control section 1-5 that manages the buffer 1-4 and controls mutually with the office line communication control section 1-2. has been done. On the other hand, 3 and 4 are extension interface units that accommodate ISDN extensions, and manage the D channel signals used for communication on ISDN extensions, and handle ISDN layer 2 such as signal error detection and recovery and information transfer order preservation processing. LAPD 3-1, which performs processing on ISDN extensions, and extension communication control unit 3-2, which performs processing on layer 3 and layer 1 of ISDN, which is call control processing on ISDN extensions, and detection and recovery of packet transfer errors. The LAPB 3-3 performs layer 2 processing of the It is composed of a control section 3-5. 5 is a packet communication processing unit which is a processing unit at layer 3 of the PHM). Reference numeral 6 designates communication path switches for connecting the time division communication paths 9-1, 9-2.9-3.9-4, respectively. Reference numeral 7 denotes a call control processing unit (CC) that performs call control processing such as call setup, disconnection, and recovery in ISDN. 8 is a control bus, and 9-1.9-2.9-3.9-4 is a time division communication path. <Explanation of operation (Figure 2)> Next, the packet terminal connected to the extension interface section 3 connects the ISDN office line and B via the office line interface section 1.
The operation when performing channel packet communication will be described below with reference to the flowchart shown in FIG. First, in step S1, when the packet terminal makes a call request, the extension communication control section 3-2 of the extension interface section 3 detects the call request and notifies the control section 3-5. Based on this notification, the control section 3-5 instructs the LAPD 3-1 to set up a B channel link using the D channel via the extension communication control section 3-2 in step S2. Once the link between the packet terminal and the extension interface section 3 is established, in step S3, processing at layer 2 of the X, 25 protocol on the B channel is performed on the LAPB3-
3 to set up the LAPB link. Next, when the above-mentioned link is set, in step S4,
Start up the packet communication processing unit (PHM) 5, and
Performs processing at layer 3 of the protocol. This process is
This process inputs the packet data sent from the packet terminal via the extension communication control unit 3-2 and stores it in the buffer 3-4.Then, in the continuation (step S5), the stored packet data is controlled. It is transferred to the buffers 1-4 of the office line interface unit 1 via the bus 8. When the above-mentioned transfer is completed, control is transferred from the extension line interface unit 3 to the CC7 in step S6, and the CC7 is transferred to the office line interface unit 1. The controller 1-5 instructs the LAPDI-1 to make a call to the ISDN office line using the D channel and to set up a B channel link.This link Once set, in step S7, LAPBI-3 is started and B
Configure the LAPB link on the channel. Then, when the above-mentioned link is set, in step S8, the packet data accumulated in the buffer 1-4 is transferred to the ISDN office line via the office line communication control unit 1-2, and packet communication is started. . Further, B channel packet communication between ISDN office lines and between extension lines can be performed using the same procedure. Furthermore, when performing D channel packet communication, L
APBI-3 and LAPB3-3 do not configure the LAPB link of layer 2 of the X.25 protocol,
Packet data is directly sent to buffers 1-4 through the D channel. The data is stored in the buffer 3-4, and then packet communication is performed using the same procedure as B channel packet communication. Furthermore, packet communication in which B channel and D channel are mutually converted at each interface section is also possible. According to this embodiment, when performing B channel packet communication, the LAPB processing section of layer 2 of the X.25 protocol is provided in the ISDN office line interface section and the extension line interface section, and the
By providing the processing unit in the packet communication processing unit (PHM), packet data can be communicated between each interface unit via the control bus without going through a time-division communication path, and it can also be transferred to the central office line interface unit or extension line interface unit. B-channel packet communication can be performed without communicating B-channel signals between the PHM and the packet communication processing unit (PHM) via a time-division channel. Therefore, when performing B channel packet communication, the time division communication path is not used, so the time division communication path can be used efficiently. This has the excellent effect of being able to respond simply by adding more units. In addition, in the above-mentioned embodiment, the number of office line interface units and extension line interface units is two each, but
Needless to say, it can be expanded depending on the number of office lines and extension lines to be accommodated.

【Effect of the invention】

As explained above, according to the present invention, multiple ISDN
An ISDN packet switch that accommodates both a central office line and an extension line and has a packet communication function, and includes a processing section that executes a data link control procedure with the ISDN central office line, and a storage section that stores packet data. A station line communication control means for controlling communication with the ISDN office line, a processing unit for executing a data link control procedure with the ISDN extension line, and a storage unit for accumulating packet data, and controlling the communication with the ISDN extension line. Efficient packet communication can be performed by providing an extension communication control means for controlling and a packet communication control means for communicating packet data accumulated by each control means.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram showing the configuration of a private branch exchange (PBX) in this embodiment, and FIG. 2 is a flowchart showing the operation of packet communication in this embodiment. In the figure, 1, 2... central line interface section, 3.4...
・Extension interface section, 5...PHM, 6...Communication path switch, 7...CC, S...Control bus, 1-
1゜3-1... LAPD, 1-2... Office line communication control unit, 1-3.3-3... LAPB, 1-4.3-4.
. . . Buffer, 3-2 . . . Extension communication control unit, 9-1.
9-2.9-3.9-4... Time division communication path. =29

Claims (2)

[Claims] (1) An ISDN packet switch that accommodates multiple ISDN office lines and extension lines and has a packet communication function, including a processing unit that executes data link control procedures with the ISDN office lines, and a storage unit that stores packet data. a station line communication control means for controlling communication with the ISDN station line; a processing unit for executing a data link control procedure with the ISDN extension line; and a storage unit for accumulating packet data; 1. An ISDN packet switch, comprising: an extension communication control means for controlling communication with the controller; and a packet communication control means for communicating packet data accumulated by each control means. (2) The ISDN packet switch according to claim 1, wherein the packet communication control means performs communication without using a time-division channel.