JPH0435438A - Packet exchange system - Google Patents

Abstract

PURPOSE:To execute packet communication through the use of a D-channel by permitting a service access point identifier to fetch layer information of packet control procedure information and to transfer it to exchange means exchanging layer information of a packet control procedure. CONSTITUTION:The processing functions of a layer 1 and a layer 2 and the exchange means 3 and 5 where the service access point identifier fetches information on the layer 3 of packet control procedure information and information on the layer 3 of the packet control procedure is exchanged are provided for an ISDN central office interface part 8 or ISDN extension interface parts 6 and 7. Thus, a packet processing can be distributed in the ISDN central office interface part 6 or the ISDN extension interface parts 6 and 7 in accordance with service access point identifier information in the packet on the D-channel of ISDN and packet communication using the D-channel can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a packet switching system in a private branch exchange that supports ISDN D-channel packet communication.

[Prior Art] FIG. 3 shows a conceptual diagram of a conventional switch supporting packet communication.

In Figure 3, 51.52 is CCITT Recommendation X, 25
The packet terminal 3 is a packet handler (P) for communicating with other packet terminals via the digital line 58 connected to the ISDN packet network 100 as necessary.
HM). 54 is a time division switch, 55 is a main control section that controls the overall control shown in FIG. 3, and 56 is a telephone line network 57 (P
59.60 is the interface (I/F) that controls the interface with the packet terminal.
It is.

In the above configuration, for example, from the packet terminal 51
The transmitted packet is placed on the highway inside the exchange via F59. This transmission packet is sent as a layer 2 signal from the time division switch 54 to the packet handler 53, and is sent to the IS via the digital line 58 under the control of the main controller 55.
The data is sent to a desired destination terminal connected to the DN packet network 100. Here, for example, if the transmitting packet terminal is the packet terminal 52 connected to the self-time division switch 54, the packet is exchanged from the packet handler 53 to the packet terminal 52 via the time division switch 54.

[Problems to be Solved by the Invention] However, in the conventional ISDN, packet communication using the D channel, which is a control channel, is not provided.

Packet communication using the D channel is based on the protocol nomi CC.
ITT Recommendation X, 31. Q, 93. It was only determined by X, 25, etc.

As described above, in the past, when attempting to perform packet communication, ISDN could not be used and the exchange As a function, it had to be equipped with a so-called packet handler function, transmit all layer 2 signals, and receive exchanged layer 2 signals by the packet handler function.

[Means for Solving the Problems] The present invention has been made for the purpose of solving the above-mentioned problems, and includes the following configuration as one means for solving the above-mentioned problems.

That is, in a private branch exchange that supports ISDN D channel packet communication, ISDN81! The interface section or the ISDN extension interface section is provided with layer I and layer 2 processing functions, and exchange means for extracting layer 3 information of packet control procedure information from the service access point identifier and exchanging layer 3 information of the packet control procedure.

[Operation] In the above configuration, packet processing is performed by the ISDN 8-wire interface unit or the ISDN according to the service access point identifier information in the packet on the ISDN D channel.
Distributed execution is possible at the DN extension interface unit, and packet communication using the D channel is possible.

[Example] Hereinafter, an example according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the concept of an embodiment according to the present invention.

In FIG. 1, 1 and 2 are ISDN terminals having a D-channel packet function, and 3 is for communicating with other packet terminals via an ISDN station line interface 8 connected to the ISDN packet network 100 as necessary. packet handler (PHMD), 4 is a time division switch for line switching, 5 is the main control unit that controls the overall control, 6 and 7 are IS
A DN extension interface that separates information channels and control channels. 8 is an ISDN office line interface,
9 is an ISDN line connected to the ISDN packet network 100.

JSDN extension interface 6.7 and IS in this example
In the DN office line interface 8, the information channel (
B channel) information and control channel (D channel) information are multiplexed. Call control procedure information with the main control unit 5 is communicated using the control channel 12.

Normally, in order to support ISDN, layer 2 L
The APD (CCIT Q, 921) protocol is essential and usually supports layer 2 and layer 3 call control information. However, in this embodiment, since the ISDN extension line interface 6.7 and the ISDN office line interface 8 separate/multiplex the information channel (B channel) information and the control channel (D channel) information, the ISDN Extension interface 6.7 and I
The SDN station line interface 8 is L for packet communication.
Processing up to layer 2 in APD control is performed, and packet-level processing at layer 3 is performed by a packet handler 3, which is another switching function, so as not to increase the buffer capacity of the interface or the processing load. IS
In controlling communication with the DN station 119, as described in CCITT Recommendation . For this reason, it is not possible to allocate processing in each of the above-mentioned configurations only based on the value of the service access point identifier (hereinafter referred to as rsAPIJ). However, except for incoming calls, SAP I
If is “0”, it is a call control procedure, and if 5API is “1”, it is a call control section procedure.
6H”, it can be determined that it is a packet control procedure.

Therefore, in this embodiment, focusing on the above points, SAP I
When is “0”, data is sent to the main control unit 5, and the 5API
When is "16H", the packet is controlled to be sent to the packet handler 3, thereby controlling to distribute the processing of each layer. By adopting this method of distribution,
The load on the interface side is small, protocol control can be executed by the ISDN interface (6 to 8), and transmission data, etc. processed by Rake 3 can be reliably sent to Packet Handler 3. , packet communication using the D channel, which is a control channel, can be realized.

FIG. 2 shows the protocol between the ISDN office line 9, the extension interface 6.7, the main control unit 5, and the packet handler module 3, and the allocation status of signal transfer destinations according to the 5API in this embodiment.

As shown in Figure 2, first, the L of ISDN interface 8
The APD checks whether the SAP I of the packet on the D channel from the ISDN station line 9 is "0" or "16H", and if 5API is "0", it is a call controller procedure, and the main controller 5 and performs predetermined packet exchange.

If SAP I is "16H", it is determined that this is a packet control procedure, and the packet is transferred to the packet handler 3 for predetermined packet exchange.

In the eighth embodiment described above, the main control unit 5 and the packet handler 3 use a common bus, but a configuration in which different buses are used is naturally within the scope of the present invention, and It is clear that communication using a dual-baud (RAM) such as that used in a multi-CPU system is also within the scope of the present invention.

As explained above, the main control unit 4 and the packet handler 3
By separating this as an exchange function, the load on the main control unit 4 during packet data communication can be extremely reduced, and unnecessary mutual communication can be reduced, which is highly effective. Therefore, it is possible to obtain a remarkable effect of enabling packet communication using not only an information channel but also a control channel.

[Effects of the Invention] As explained above, according to the present invention, packet processing can be distributed and executed at the ISDN office line interface section or the ISDN extension line interface section according to the service access point identifier information in the packet on the ISDN D channel, Enables packet communication using the D channel.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the concept of an embodiment according to the present invention. FIG.
FIG. 3 is a block diagram of a switch that supports conventional packet communication. In the figure, 1, 2...ISDN terminal, 3...Packet handler (PHMD), 4.54...Time division switch,
5, 55... Main control unit, 6, 7... ISDN extension line interface, 8... ISDN office line interface,
9...ISDN line, 51.52...Packet terminal, 53...Packet handler (PHM), 56...
Telephone, 57... Telephone line network, 59. 60... Interface (I/F).

Claims (2)

[Claims] (1) A packet switching method in a private branch exchange that supports ISDN D-channel packet communication, which has layer 1 and layer 2 processing functions in the ISDN central office line interface section or ISDN extension line interface section of the private branch exchange, and provides services. A packet switching method characterized in that an access point identifier extracts layer 3 information of packet control procedure information and transfers it to an exchange means for exchanging layer 3 information of packet control procedure. (2) The packet switching system according to claim 1, wherein the switching means has a switching function different from that of main control.