JP3216898B2 - Subscriber line controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a subscriber line controller for an ISDN switching system, and more particularly to a D channel control system for a basic interface.

[0002]

2. Description of the Related Art Conventionally, in this kind of ISDN switching system, a data link layer terminating device is installed one-to-one with a physical layer terminating device, and a terminal terminating point identifier (hereinafter referred to as "TEI") assigned to a subscriber terminal. Is always registered in the corresponding data link layer terminating device.

[0003]

In this conventional ISDN switching system, since the data link layer terminating device is installed one-to-one with the physical layer terminating device, when the number of subscriber terminals accommodated increases, the data link layer terminating device increases. There has been a problem that the number of terminal devices also increases.

[0004] In addition, in order to connect a physical layer terminating device to an arbitrary data link layer terminating device and use it, it is necessary to match the TEI allocation status between the subscriber line controller and the subscriber terminal. was there.

An object of the present invention is to reduce the size of a subscriber line control device by sharing a data link layer terminator between a plurality of subscriber lines.

[0006]

In order to achieve the above object, the present invention provides a subscriber line (hereinafter referred to as a "subscriber line") of a basic interface in which a network and a user are physically connected on a one-to-one basis. In the ISDN switching system that activates and stops the physical layer for each call, the physical layer terminating device of the subscriber line can be connected to any data link layer terminating device, and the physical layer is activated only when the physical layer is activated. Means for connecting the terminating device to the data link layer terminating device;
It is called "TEI". ) Is added for each subscriber line, the TEI of the subscriber line is read out when the physical layer of the subscriber line is activated and registered in the data link layer terminating device, and when the physical layer is stopped, the data link layer terminating device is transmitted to the data link layer terminating device. Means for deleting all the registered TEIs and registering the TEIs in the data link layer terminating device only when the physical layer is activated.

[0007]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a subscriber line controller according to an embodiment of the present invention, and FIGS.
FIG. 5 is a sequence diagram showing exchange of signals between a main control device and a subscriber terminal during outgoing and incoming calls.

In FIG. 1, a subscriber line controller includes activation and deactivation of a physical layer, allocation control of a data link layer terminating device, TEI allocation control of a subscriber terminal, and layer 3 control.
A TEI storage device 11 for storing, for each subscriber terminal, a TEI assigned to the subscriber terminals accommodated in the subscriber lines 81,..., 8M of the basic interface; , 2N that perform protocol control of the data link layer of the channel, and D channel data 61 from the data link layer terminators 21,..., 2N.
, 6N and the D-channel data 71,..., 7M from the physical layer terminating devices 41,..., 7M, and the physical layers of the subscriber lines 81,. Terminating physical layer terminating devices 41, ...,
4M (M> N), and main controller 10 and TE
I storage device 11, data link layer terminating device 21,.
.., 2N, the concentrator switch 30 and the physical layer terminating devices 41,..., 4M are connected by a control bus 50.

First, the operation of making a call from a subscriber terminal accommodated in the subscriber line 8M will be described with reference to FIGS. 1 and 2.

Main controller 10 is a physical layer terminator 4
When a physical layer activation request from the subscriber terminal is detected via M, the usage status of the data link layer terminating device is investigated. Assuming that the data link layer terminating device 2N is empty, the main control device 10 transmits the D channel data 7M from the physical layer terminating device 4M and the D channel data 6N from the data link layer terminating device 2N. The TEI connected by the concentrator switch 30 and assigned to the subscriber terminal accommodated in the subscriber line 8M is referred to as the TEI.
The data is read from the storage device 11 and registered in the data link layer terminating device 2N. Then, the physical layer terminating device 4M
, A physical layer activation display is performed on the subscriber terminal.
If the TEI is not assigned to the subscriber terminal, the subscriber terminal transmits an ID request, so that the main control device 10
Transmits the ID assignment, updates the TEI value of the TEI storage device 11, and registers the TEI assigned to the subscriber terminal in the data link layer terminating device 2N. When communication of the data link layer and the layer 3 message is performed and the physical layer is stopped, the main control device 10 transmits a physical layer stop request and confirms the physical layer stop display via the physical layer terminating device 4M. Then, all the TEIs registered in the data link layer terminating device 2N are deleted, and the hub switch 30 is released.

Next, the operation of receiving a call to a subscriber terminal accommodated in the subscriber line 8M will be described with reference to FIGS.

The main controller 10 checks the use status of the data link layer terminating device, and if the data link layer terminating device 2N is vacant, the main controller 10
Is the D channel data 7 from the physical layer terminating device 4M.
M and the D channel data 6N from the data link layer terminating device 2N are connected by the concentrator switch 30 and T assigned to the subscriber terminal accommodated in the subscriber line 8M.
The EI is read from the TEI storage device 11 and registered in the data link layer terminating device 2N. Then, transmission of the physical layer activation request and confirmation of the physical layer activation display are performed via the physical layer terminating device 4M. Subsequent procedures are the same as for calling.

[0014]

As described above, the subscriber line control device of the present invention connects the physical layer terminating device and the data link layer terminating device only when the physical layer is activated. The data link layer terminating device can be shared, and the effect of reducing the size of the subscriber line control device can be obtained. Further, only when the physical layer is activated, the TEI assigned to the subscriber terminal is registered in the data link layer terminating device, so that the assignment status of the TEI can be matched between the subscriber line controller and the subscriber terminal. This has the effect that the same function as when the physical layer terminating device and the data link layer terminating device are installed on a one-to-one basis can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram of a subscriber line controller according to an embodiment of the present invention.

FIG. 2 is a sequence diagram showing exchange of signals between a main control device and a subscriber terminal during a call.

FIG. 3 is a sequence diagram showing exchange of signals between a main control device and a subscriber terminal during an incoming call;

[Explanation of symbols]

Reference Signs List 10 Main control device 11 TEI storage device 21,..., 2N Data link layer termination device 30 Concentrator switch 41,..., 4M Physical layer termination device 50 Control bus 61,..., 6N, 71,. , 7M D channel data 81, ..., 8M subscriber line

Continuation of front page (58) Fields investigated (Int.Cl. ⁷ , DB name) H04L 12/02 H04M 11/00 303 H04M 1/00 H04Q 3/545

Claims (1)

(57) [Claims] An ISDN exchange for starting and stopping a physical layer of a subscriber line (hereinafter, referred to as a "subscriber line") of a basic interface in which a network and a user are physically connected on a one-to-one basis. A system for connecting a physical layer terminating device of a subscriber line to an arbitrary data link layer terminating device and connecting the physical layer terminating device and the data link layer terminating device only when the physical layer is activated; Terminal termination point identifier assigned to the terminal (hereinafter, referred to as
It is called "TEI". ) Is added for each subscriber line, the TEI of the subscriber line is read out when the physical layer of the subscriber line is activated and registered in the data link layer terminating device, and when the physical layer is stopped, the data link layer terminating device is transmitted to the data link layer terminating device. Means for deleting all registered TEIs and registering the TEIs in the data link layer terminating device only when the physical layer is activated.