JPH03259695A - Electronic exchange - Google Patents

Abstract

PURPOSE:To relieve the load of main controller by providing a control channel control means to a subscriber circuit, analyzing a service access point identifier of a received layer two-frame and transferring the frame to a corresponding controller. CONSTITUTION:When a D channel control circuit 14 of a subscriber circuit 13 receives two-frames through D channel from a terminal equipment (not shown), the control circuit 14 discriminates whether or not the frame is an information frame including an information field shown in figure. When the frame is the information frame, a service access point identifier 31 of the frame is extracted and analyzed. When the value of the service access point identifier 31 is '0', the received frame is transferred to a main controller 11 and when the value is '16', the frame is transferred to a packet controller 12. When the value of the service access point identifier 31 is '63', the frame is transferred to a management entity control section 15.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a digital communication exchange, and more particularly to an electronic exchange that decentralizes service processing.

[Conventional technology]

In response to increasingly sophisticated and diversified communication needs, digital communication is rapidly developing, and even in this digital communication, several protocols have been proposed and are being put into practical use. As one example, the integrated service digital network (hereinafter referred to as 15DN) is attracting a lot of attention. This l
5DN is a digital network that can provide all telecommunications services such as telephone, data, and facsimile in an integrated manner, and provides users with an inexpensive and single interface.

In this 15DN, for example, the interface between a general home user and the network consists of two information transmission channels (hereinafter referred to as B).
It's called a channel. ) and one control signal transmission channel (
Hereinafter, it will be referred to as the D channel.

) is configured as one set. Connection settings with the other party's terminal are performed through the D channel, but once the connection with the other party is established, subsequent information transfer is performed through the B channel. The final connection release is then performed again through the D channel. For the D channel, which performs such call control and is also used to transfer user packet information, the protocol is extremely important.

Therefore, in l5DN, communication protocols between users and the network (hereinafter referred to as user/network protocols) are established at layer 1 based on the open system interconnection (O3I) reference model.
Layer 2 is the so-called D-channel link access procedure (LAPD).
It is set as . This layer 2 has an important function of overcoming transmission errors and performing highly reliable transfer of information between the user and the network in units of bit strings called frames.

FIG. 2 shows the structure of a frame used in layer 2 of the D channel (hereinafter referred to as layer 2 frame). This frame is composed of blocks whose basic units are octets (8 bits). First, a start flag 21 indicating the start of a frame is followed by an address 822 for identifying a logical link, and furthermore, a control unit 23 for identifying the frame is arranged. This is followed by an information field 24, such as in an information frame for transmitting information. However, this information field is not included in a disconnection instruction frame for instructing disconnection. Furthermore, a frame check sequence (F
e2) 25. Finally, an end flag 26 indicating the end of the frame is placed.

The address section 22 includes an address section extension bit (EA) 28
, a command response (CR) bit 29, a service access point identifier (SAPI) 31, and a termination point identifier (TEI) 32. Of these, the address part extension bit 28 is a bit that indicates whether or not to continue to the next octet, and the command/response bit 29 is a bit that indicates whether or not the frame continues to the next octet. This is a bit that indicates whether to display a message or report an executed action or state.

The service access point identifier 31 indicates the content of the information to be transferred, and indicates the type of service provided by layer 2.

Furthermore, the termination point identifier 32 is assigned to each terminal device in order to guarantee the portability of the terminal device and to enable one terminal to be used anywhere. The termination point identifier of the terminal device connected to each user/network interface is
It is not registered in the network in advance, but is configured when the need arises. In other words, when a connection request is received from a terminal device, the network verifies whether the value of a given termination point identifier is in use by another terminal device, and then assigns that value as the termination point identifier to that terminal. It is now assigned to the device.

In the electronic exchange in l5DN with the above configuration,
Conventionally, the following service distribution processing has been performed. That is, if the layer 2 frame received from the D channel is an information frame having an information field (FIG. 2), the subscriber circuit in the exchange transfers it to the main controller. The main transfer device that receives this
The access point identifier 31 was analyzed and processing was handed over to the corresponding control unit.

[Problem to be solved by the invention]

In this way, in the conventional electronic exchange in l5DN,
When a layer 2 frame received from the D channel by a subscriber circuit, etc. has an information field, the service access point identifier of the frame is analyzed in the main controller, and the processing is handed over to the corresponding controller. It had become. For this reason, there is a drawback that the burden on the main control device increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a telephone exchange that can reduce the burden on the main controller.

[Means to solve the problem]

In the invention as claimed in claim 1, (1) a communication function for ensuring highly reliable signal transfer is set among communication protocol layers set in several layers between the user and the network; Receiving means includes a service access point identifier for identifying the type of service provided from the layer to the adjacent upper layer, and receives a frame transmitted from the terminal accommodated by the terminal via a predetermined channel; (il)
frame determining means for determining whether or not the frame received by the receiving means is an information frame having an information field for writing user data;
i > analysis means for analyzing a service access point identifier included in the frame when the frame is determined to be an information frame by the frame determination means;
(iv) The electronic exchange is equipped with transfer means for transferring frames to control devices that are previously associated with the respective values in accordance with the values of the service access point identifiers analyzed by the analysis means.

In the invention as claimed in claim 1, when the frame received from the terminal is an information frame, the value of the service access point identifier included in the frame is analyzed, and the control device associated with the frame in advance is sent according to the value. The received frame will be forwarded to the other end.

In the invention as claimed in claim 2, (i) among the communication protocol layers set in several hierarchies between the user and the network, from the layer for setting links for message transfer and error control. Contains a service access point identifier for displaying the type of service provided to the adjacent upper layer, and is sent from a terminal accommodated in the subscriber circuit of the local exchange via a predetermined channel provided for call control, etc. (11) frame determining means for determining whether the frame received by the receiving means is an information frame having an information field for writing user data; iii) analysis means for analyzing the service access point identifier included in the frame when the frame is determined to be an information frame by the frame determination means; and (iv) a main control device for performing call control between the terminal and the network. (v) a packet transfer control device that controls the transfer of user packet information; (vi) a functional module management unit that manages functional modules actually required by the layered communication protocol layer; ) The electronic exchange is equipped with a transfer means for transferring a frame to either the main control device, the packet transfer control device, or the functional module management section in accordance with the value of the service access point identifier analyzed by the analysis means.

In the second aspect of the invention, the frame received from the terminal is transferred to either the main control device, the packet transfer control device, or the functional module management unit, depending on the value of the service access point identifier.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to Examples.

FIG. 1 shows the main parts of an electronic exchange in one embodiment of the present invention.

This electronic exchange is equipped with a main controller 11 that performs call control, etc., and a packet controller 12 that performs packet control, which are connected to each other and are provided in a subscriber circuit 13 that accommodates terminal equipment. It is connected to the D channel control circuit 14. A management entity control section 15 is connected to the subscriber circuit 13, which allocates service access point identifiers to terminal devices.

The operation of the electronic exchange having the above configuration will be explained with reference to FIG.

When the D channel control circuit 14 of the subscriber circuit 13 receives a layer 2 frame via the D channel from a terminal device (not shown) (step ■), the D channel control circuit 14 determines whether the frame is an information frame including an information field as shown in FIG. A determination is made (step ■). If it is an information frame (step ■; Y), the service access point identifier 31 (FIG. 2) of the frame is extracted and analyzed (step ■). When the value of this service access point identifier 31 is “O”, step
) If it is "16" (step ■; Y), the packet is transferred to the packet control device 12 (step ■). Further, if the value of the service access point identifier 31 is "63" (step 2; Y), the frame is transferred to the management entity control unit 15 (step 2).

If the value of the service access point identifier 31 is not any of these (step 2; N), other predetermined operations are performed.

The main control device 11 analyzes the layer 2 frame transferred from the D channel control section 14 and performs call control (step 0). Furthermore, the packet control device 11 analyzes the layer 2 frame transferred from the D channel control section 14, and performs packet control using, for example, the X25 protocol standardized by the ccITT (International Telegraph and Telephone Consultative Committee) recommendations (Step 0). . The management entity control unit 15 analyzes the layer 2 frame transferred from the D channel control unit 14, and performs processing such as # allocating an end point identifier (step 2).

In this way, in this embodiment, a D channel control section is provided in the subscriber circuit, and the service processing is performed by analyzing the service access point identifier of the received layer 2 frame and forwarding the frame to the corresponding control device. Decentralize.

〔Effect of the invention〕

As explained above, according to the present invention, a control channel control means is provided in the subscriber circuit, and the service access point identifier of the received layer 2 frame is analyzed and the frame is transferred to the corresponding control device. Therefore, service processing that was conventionally concentrated in the main control device can be distributed. Therefore, there is an effect that the burden on the main control device can be reduced.

[Brief explanation of drawings]

The drawings are for explaining one embodiment of the present invention, of which FIG. 1 is a block diagram showing the main parts of an electronic exchange, and FIG.
The figure is an explanatory diagram showing the structure of a layer 2 frame for transmitting the D channel, and FIG. 3 is a flowchart for explaining the operation of the electronic exchange shown in FIG. 1. 11... Main control device, 12... Packet control device, 13... Subscriber circuit, 14... D channel control unit, 1 5... ...Management entity control unit, ...Service access point identifier.

Claims (1)

[Claims] 1. Of the communication protocol layers set between the user and the network in several hierarchies, from the layer that sets the communication function to ensure highly reliable signal transfer to the layer adjacent to the receiving means for receiving a frame including a service access point identifier for identifying the type of service provided to the upper layer and transmitted from a terminal accommodated by the receiving means via a predetermined channel; a frame determining means for determining whether or not a received frame is an information frame having an information field for writing user data; and when the frame determining means determines that the frame is an information frame; analysis means for analyzing the service access point identifier included in the service access point identifier; and transfer means for transmitting the frame to a control device associated with each value in advance according to the value of the service access point identifier analyzed by the analysis means. An electronic exchange characterized by comprising: 2. Of the communication protocol layers set up in several layers between users and the network, services provided from the layer that sets up links for message transfer and error control to the adjacent upper layer. receiving means for receiving a frame including a service access point identifier for displaying the type and transmitted from a terminal housed in a subscriber circuit of the own exchange via a predetermined channel provided for call control, etc.; , frame determining means for determining whether or not the frame received by the receiving means is an information frame having an information field for writing user data; and frame determining means for determining whether the frame is an information frame by the frame determining means. an analysis means for analyzing the service access point identifier included in this frame; a main control device for controlling calls between the terminal and the network; and a packet transfer control device for controlling transfer of user packet information. a functional module management unit that manages functional modules actually required by the layered communication protocol layer; and a functional module management unit that manages functional modules that are actually required by the layered communication protocol layer; An electronic exchange characterized by comprising: a transfer means for transferring the frame to either a packet transfer control device or a functional module management unit.