JP2783270B2 - ISDN terminal adapter device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention connects a terminal device to an integrated services digital network (hereinafter referred to as "ISDN").
I using ISDN B-channel packet service
The present invention relates to an SDN terminal adapter device.

[0002]

2. Description of the Related Art A conventional ISDN terminal adapter device is installed in an ISDN subscriber's house, and connects an existing terminal to an ISD terminal.
N. ISDN is provided with a D-channel (for signal transmission) packet service in addition to the circuit switching service. As a specific example of the terminal adapter device, an existing terminal having a synchronization procedure of IBM Corporation, National Bankers Association, or the like is connected to ISDN Packet Services.

In this terminal adapter device,
When a D-channel packet is used, since the packet size is limited to 256 bytes, one frame is divided, which causes problems such as an increase in the number of packets and a decrease in throughput. For this reason, the ISDN often uses a B channel (for information transmission) packet.

[0004] I using the B-channel packet service
The SDN terminal adapter device, as shown in FIG.
Packet disassembly unit 21, outgoing / incoming call control unit 22, common control unit 23, packet control unit 37, call control unit 25, LAPB
Control unit 26, LAPD control unit 27, I interface unit 28, DTE (data terminal device) interface unit 34
It is composed of

The operation of the conventional ISDN terminal adapter device will be described. In response to a call request from an existing DTE connected to the DTE interface unit 34 or a call from ISDN, the common control unit 23 controls the call control unit 22. , A B channel path is set between the call control unit 25 and the LAPD control unit 27 with the ISDN.

Next, the common control unit 23 sets a packet-level call using the packet control unit 37 and the LAPB control unit 26 on the set B channel. When data packets can be transmitted and received on the set logical channel, the received data from the existing DTE is decomposed into packet sizes by the packet disassembly / assembly unit 21, and then the packet control unit 37, the LAPB control unit 26, The data is transmitted to the ISDN through the interface unit 28. Further, the data packet from the ISDN is received in the reverse route, assembled into a frame in the packet disassembly / assembly unit 21, and transmitted to the existing DTE.

As a reference gazette, Japanese Patent Laid-Open No. 1-292991
In the publication, a sub-rate demultiplexing circuit is used for each terminal interface in an ISDN terminal adapter, and the ISDN-B
An ISDN terminal adapter device that increases the number of existing terminals that can be accommodated by performing demultiplexing on channel data is disclosed.

[0008]

However, the ISD
When the B channel packets of the basic interface are used by the N terminal adapter device, the number of DTEs that can be used simultaneously on one line is limited to two since two B channels are used. Therefore, when the number of ports is large as in a host computer or when the number of terminals installed in one place is large, there is a problem that the number of lines must be increased.

Therefore, an object of the present invention is to connect a plurality of terminal adapters to an I-interface, set up a B channel path, multiplex packet data transmitted / received on the path, and set a logical channel used by the own terminal adapter. An object of the present invention is to provide an ISDN terminal adapter device that can be used.

[0010]

According to the present invention, an ISD is provided.
ISDN using N B-channel packet service
The terminal adapter device includes a network-side I-interface and a user-side I-interface for connecting the second and subsequent terminal adapters, the number of which is equal to the number of the plurality of terminal adapters connected using the I-interface. Means for performing packet-level multiplexing, and means for selecting a logical channel used by the own terminal adapter from the multiplexed packet data and transmitting and receiving the packet data through the logical channel. Is obtained.

Further, according to the present invention, I
In the SDN terminal adapter device, a packet multiplexing unit having means for performing the packet level multiplexing, and a logical channel to be used by the self terminal adapter in a packet multiplexed by the packet multiplexing unit are selected. A selection processing unit having means for transmitting and receiving the packet data to and from the packet disassembly unit through the logical channel of the packet data. .

[0012]

The first terminal adapter is connected to the ISDN by the network-side I interface, and the second and subsequent terminals are connected by connecting the network-side I interface to the user interface of the immediately preceding terminal adapter. A plurality of terminal adapters are connected to one ISDN.

The packet data multiplexed by the means for performing packet-level multiplexing is notified to each of the terminal adapters connected by the two I interfaces, and each terminal adapter selects a logical channel used by its own terminal adapter. And send and receive packet data.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the ISDN terminal adapter device of the present invention will be described below with reference to FIG. In FIG.
The ISDN terminal adapter device is represented by a first terminal adapter 15 of the first unit and a second terminal adapter 16 of the second unit.

In the ISDN terminal adapter device, the network-side I-interface 8-1 is connected to one port, and the user-side I-interface 9-1 for connecting the second and subsequent terminal adapters is connected to one port. The packet multiplexing communication is provided by providing means for performing logical multiplexing at the packet level by the number of terminal adapters and means for selecting a logical channel used by the own terminal adapter.

Each of the first and second terminal adapters 15 and 16 has a packet disassembly unit 1-1 and 1-2, an outgoing / incoming call control unit 2-1 and 2-2, and a common control unit 3.
-1 and 3-2, call control units 5-1 and 5-2, LAPB
Control units 6-1 and 6-2, LAPD control units 7-1 and 7
-2, network-side I interface units 8-1 and 8-2, D
It is provided with TE (Data Terminal Equipment) interface units 14-1 and 14-2.

Further, the first and second terminal adapters 15 and 16 have setting units 4-1 and 4-, respectively.
2, selection processing units 13-1 and 13-2, packet multiplexing units 12-1 and 12-2, user-side LAPB control unit 11
-1 and 11-2, a user-side LAPD control unit 10-1 and 10-2, and a user-side I interface unit 9-1 and 9-2.

The first terminal adapter 15 is connected to an ISDN line via an I interface section 8-1 on the network side. The second terminal adapter 16 is connected to the user-side I-interface unit 9-1 of the first terminal adapter 15 via the network-side I-interface unit 8-2. Hereinafter, similarly, the I interface units 8-1 and 8-2,
A terminal adapter is connected via 9-1 and 9-2.

Setting units 4-1 and 4-2 for setting whether the first and second terminal adapters 15 and 16 are directly connected to a line or connected to another terminal adapter.
The operation of the common control units 3-1 and 3-2 and the operation of the call control units 5-1 and 5-2 differ depending on the set value of. Here, the common control units 3-1 and 3-2 have means for managing the used logical channel, controlling the disconnection, managing the status, and controlling the entire apparatus. The call control units 5-1 and 5-2 have means for performing call control for B channel path connection.

When a call is requested by the DTE connected to the second terminal adapter 16 via the DTE interface unit 14-2, the call is controlled from the call control unit 2-2 through the common control unit 3-2. A call is requested to the control unit 5-2. The call control unit 5-2 includes a user-side LAPD control unit 10-
2. Send a call request message to the LAPD control unit 7-2. The user-side LAPD control unit 10-2 establishes a link with the LAPD control unit 7-2 of the terminal adapter 16 connected via the user-side I-interface unit 9-2, and transmits a call request message.

The LAPD control unit 7-2 of the terminal adapter 16 which has received the call request message sends the call control unit 5-2.
, A call request message is further transmitted to the next terminal adapter, and a message indicating that the call is being requested is transmitted to the common control unit 3-2.

The LAPD control unit 7- of the terminal adapter 16 receiving the call request message from the call control unit 5-2
2 establishes a link with the LAPD control unit 10-1 on the user side of the terminal adapter 15 via the I interface unit 8-2, and transmits a call request message. The call control unit 5-1 which has received the call request message from the user side LAPD control unit 10-1 of the terminal adapter 15,
A call request message is transmitted to the common control unit 3-1. The call control unit 5-1 recognizes that it is the terminal adapter on the line side by the setting of the setting unit 4-1, and issues a TEI (terminal identifier) request to the LAPD control unit 7-1 to acquire the TEI. After the link is established , a call request message is transmitted. The response from the exchange is transmitted to each terminal adapter through the I interface unit 8-1, the call control unit 5-1, the LAPD control unit 7-1, the user side LAPD control unit 10-1, and the I interface unit 9-1. You. The common control units 3-1 and 3-2 of the first and second terminal adapters 15 and 16 recognize that the B-channel path has been connected.

Next, the common control unit 3-2 of the second terminal adapter 16 makes a call at the packet level. The user-side LAPB control units 11-1 and 11-2 are connected to the LAPB control units 6 and 7 of the first and second terminal adapters 15 and 16 connected via the user-side I interface units 9-1 and 9-2. It has a means for performing link control between 1 and 6-2. The packet multiplexing units 12-1 and 12-2 have means for performing packet-level multiplexing on the B channel. Selection processing units 13-1 and 13-2
Selects a logical channel to be used by its own terminal adapter in the packets multiplexed by the packet multiplexing units 12-1 and 12-2, and selects the packet disassembly units 1-1 and 1-2.
Means for transmitting and receiving packet data to and from the device.

The common control units 3-1 and 3-2 communicate with the packet multiplexing unit 12 through the selection processing units 13-1 and 13-2.
-2 is issued. Packet multiplexing unit 12-
1 and 12-2 use the lowest number of unused logical channels to transmit call packets via the LAPB controllers 6-1 and 6-2, and via the user-side LAPB controllers 11-1 and 11-2. Send a call request and message.

The outgoing call packet is sent to the I-interface unit 9-1 on the user side of the terminal adapter 15 and the LAP on the user side.
D control unit 10-1, packet multiplexing unit 12-1, LAP
It is transmitted to the line through the B control unit 6-1 and the I interface unit 8-1. The network response to this is transmitted via the I interface unit 8-1, LAPB control unit 6-1, packet multiplexing unit 12-1, user LAPD control unit 10-1, and user I interface unit 9-1. The respective terminal adapters 15 and 16 are notified.

The packet multiplexing unit 12-2 of the terminal adapter 16 receives the response from the network and receives the response from the network.
Is notified to the common control unit 3-2 via the command line.

Thereafter, the data from the DTE is decomposed into packets by the packet decomposing / assembling unit 1-2, transmitted through the logical channel in the packet multiplexing unit 12-2 selected by the selection processing unit 13-2, and transmitted from the ISDN. The packet is received on the reverse path.

When a disconnection request is issued from the DTE, a disconnection packet is transmitted through the same route as that used when making a call to disconnect the logical channel. When the disconnection of all logical channels is completed, the common control unit 3-1 of the terminal adapter 15 transmits a disconnection request message to the call control unit 5-1 and the path is disconnected in the same manner as when setting the B channel path.

At the time of an incoming call, an incoming message is transmitted along the same route.
The contention control between the other terminal adapter and its own terminal adapter is performed by -1 and 5-2 to determine the terminating terminal adapter.

[0030]

As described above, according to the ISDN terminal adapter apparatus of the present invention, the terminal adapters are connected to each other via the I interface, and
After setting the channel path, the packet data transmitted and received on the path can be multiplexed, and the logical channel used by the own terminal adapter can be used.

As a result, a plurality of DTEs having protocols of IBM Corporation, National Bankers Association, etc. can be accommodated in one line, and a long packet of a maximum of 4K can be used for each line.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of an ISDN terminal adapter of the present invention.

FIG. 2 is a block diagram showing an example of a conventional ISDN terminal adapter.

[Explanation of symbols]

1-1, 1-2, 21 Packet disassembly / assembly unit 2-1, 2-2, 22 Calling / incoming / outgoing call control unit 3-1, 3-2, 23 Common control unit 4-1, 4-2 Setting unit 5-1 , 5-2, 25 Call controller 6-1, 6-2, 26 LABB controller 7-1, 7-2, 27 LAPD controller 8-1, 8-2, 9-1, 9-2, 28 I interface unit 10-1, 10-2 User side LAPD control unit 11-1, 11-2 User side LAPB control unit 12-1, 12-2 Packet multiplexing unit 13-1, 13-2 Selection processing unit 14- 1, 14-2, 34 DTE interface unit 15 First terminal adapter 16 Second terminal adapter

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04L 12/02 H04M 11/00 303

Claims (2)

(57) [Claims] 1. A ISDN terminal adapter apparatus that utilizes ISDN B channel Paquet Ttosabisu,
A network-side I-interface and a user-side I-interface for connecting the second and subsequent terminal adapters are provided, and packet-level multiplexing is performed by the number of the plurality of terminal adapters connected using the I-interface. And a means for selecting a logical channel to be used by the terminal adapter from the multiplexed packet data and transmitting and receiving the packet data through the logical channel. apparatus. 2. The ISDN terminal adapter device according to claim 1, wherein said packet multiplexing unit includes means for performing said packet-level multiplexing, and said packet multiplexing unit includes: A selection processing unit having means for selecting a logical channel to be used by the own terminal adapter and transmitting / receiving the packet data through the logical channel of the packet data to / from the packet disassembly / assembly unit. Characteristic ISD
N terminal adapter device.