JPH0530104A - Terminal adaptor device for b-channel packet - Google Patents

Abstract

PURPOSE:To uniformly distribute a packet incoming call from plural terminal equipments to two B-channels in the terminal adaptor. CONSTITUTION:A call control section 18 receives an incoming packet call from an ISD network 10. Thus, the call is alternately distributed to a 1st port 14 and a 2nd port 15 for each incoming packet call notice based on channel identifier information added to a setup message from the ISD network 10. Then the load for a terminal equipment for the X.25 packet connecting to the 1st port 14 and the 2nd port 15 is uniformized.

Description

Detailed Description of the Invention

[0001]

The present invention relates to the existing X. The present invention relates to a terminal adapter device for connecting a 25 packet terminal to a B channel packet service of ISDN (Integrated Services Digital Network).

[0002]

2. Description of the Related Art Conventionally, in a packet communication system in which a host such as a database or a personal computer communication center is accessed from a plurality of terminals using a packet switching network, when the number of terminals to be accessed becomes large, It is common to increase the number of lines to support it. In this case, there is a representative number round robin service as a service on the network side for preventing incoming calls from terminals from concentrating on specific lines of a plurality of lines on the host side. This is because by forming a plurality of user / network interfaces as one representative group, when the representative number is called,
It is a service on the network side that makes it receive in order on each interface and distributes incoming calls evenly.

FIG. 4 shows the structure of a conventional incoming call equalizing system of this type. In FIG. 4, reference numeral 1 denotes an ISDN network 2 ₁ to 2 _n which provides a B channel packet switching service, and T points which are n user / network interface points, 3 ₁ to 3.
3 _n are terminal adapters for B channel packets connected to T points 2 _{1 to} 2 _n , 4 ₁ to 4 _n are R points which are n user / network interface points, and 5 _{1 to} 5 _n are R points 4 ₁ to Four
Each of the terminal adapter via the _n 4 _{1 ~4 n}
Connected to the X. 25 packet terminal. 6 ₁ , 6 ₂
Is point T, which is the user / network interface point on the host side,
7 ₁ and 7 ₂ are terminal adapters for B channel packets connected to T points 6 ₁ and 6 ₂ , and these terminal adapters 7 ₁ and 7 ₂ are R points 8 ₁ which are host side user / network interface points. Host system 9 via 8 _2
1 and 9 ₂ , respectively.

In the communication system configured as described above, two lines are prepared on the host side for the _n terminals 5 _{1 to} 5 _n , and these two lines are the representative number round which is a service on the network side. By subscribing to the Robin service, the processing on the host side for arbitrary access from n terminals can be averaged by the host systems 9 ₁ and 9 ₂ .

[0005]

However, in the above-mentioned conventional method, since it depends only on the service on the network side, not only a special additional service charge is required but also on the host side. There was a problem that it was economically disadvantageous because two lines had to be contracted.

[0006] The present invention solves the above-mentioned problems of the prior art, and is the information channel B of the ISDN basic interface.
It is an object of the present invention to provide an excellent terminal adapter in which 1 and B2 are used for packets for both channels and packet incoming calls from a plurality of terminals can be equally distributed to the two B channels.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an X. A terminal adapter which has a first port and a second port to which two host systems each of which is a 25 packet data terminal device can be connected, and which assigns two B channels to these two ports to enable packet communication. When you are notified of incoming packets from the network,
According to the channel identifier information added to the call setup message from the ISDN network, call control means for equalizing the packet incoming call to the first port and the second port is provided for each packet incoming call notification.

[0008]

When the ISDN network receives an incoming call packet from a plurality of terminals of the other party, it notifies the call control means of the terminal adapter of the incoming call of the packet by the "call setup" message. When the call control means accepts the incoming call of the packet, a "response" message is returned to the ISDN network side. If you want to change the channel number specified by the ISDN network side, click "Reply".
Change the channel number by adding the channel identifier information to the message. As a result, the channel number to be used is designated for each packet call from the partner terminal, the packet call from the partner terminal is evenly distributed to the first port and the second port, and the ports are connected to the first port and the second port. X. The load on the terminals for 25 packets is equalized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a block diagram of a terminal adapter for B channel packets according to the present invention. In FIG. 1, 10 is an ISDN network capable of providing a B-channel packet switching service (hereinafter, simply referred to as a network in this section), 11 is a network via a T-point 12 which is a user-network interface on the host side. The connected line connection unit 13 is a B channel separation unit connected to the line connection unit 11.
Separate the B1 and B2 channels of the SDN basic interface. Each line of B1 channel and B2 channel is
It is connected to the respective first port (interface) 14 and second port (interface) 15. Also,
The first port 14 is a user / network interface R
Via point 16, X. 25 packet data terminal device (host system), the second port 15 is connected to the X.25 via the R point 17 which is a user / network interface.
25 packet data terminal device.

Reference numeral 18 denotes a call control unit connected to the line connection unit 11, which distributes the packet incoming call to the first port 14 and the second port 15 for each packet incoming call notification by the call setting message from the network 10. To evenly call in.

In the B-channel packet terminal adapter configured as described above, the operation executed by the call controller 18 will be described with reference to the flowchart of FIG.

The network 10 uses the TTC standard JT-Q931 procedure to notify the terminal adapter of an incoming packet transmitted from a plurality of terminals of the other party via the T point 12. This uses the control channel at T point 12, that is, the D channel. That is, when the network receives an incoming call packet from the partner terminal, the network notifies the call control unit 18 of the terminal adapter of the incoming call packet by a "call setup" message. In this "call setup" message, usable channel numbers are notified by the "channel identifier information element". That is, whether the channel that can be used for packet communication is the B1 channel, the B2 channel, or the D channel is notified. When the call control unit 18 of the terminal adapter accepts the packet incoming call, the process shown in FIG. 2 is executed.

First, in step 101, when a "call setup" message for an incoming call packet is received from the network, in step 102, the channel number specified in the "channel identifier information element" in the "call setup" message is changed. It is determined whether it is the same as the determined channel number of the previous incoming call packet. If "No" is determined here, the process proceeds to step 103, and a "response" is sent to the network without adding the "channel identifier information element" in order to accept the incoming packet with the channel number designated by the network. Send the message back to the network side. If the determination is “Yes”, step 10
In step 4, it is determined whether the channel number can be changed. Here, when it is determined to be "No", step 103
When it is determined to be "Yes", a channel number different from the previously determined channel number is set in the "channel identifier information element", added to the "response" message and returned to the network side. After that, the process returns to step 101 and waits for the next packet incoming call. In this way, the call control unit 1 of the terminal adapter
8 equally distributes incoming packets to the first port 14 and the second port 15, and the X.8 connected to these ports. The load on the terminals for 25 packets can be equalized.

FIG. 3 is an operation sequence diagram according to the TTC standard JT-Q931 of the user / network interface when the network and the terminal adapter of this embodiment receive a packet.

In FIG. 3, the first packet incoming call P1
When the network is received, the network sends the "call setup" message S1 with the B1 channel / changeable and the call number n1 to notify the terminal adapter of the incoming call of the packet. Upon receiving this, the terminal adapter first returns a "response" message A1 on the B1 channel designated by the network. In response to this, the network "acknowledges"
It is accepted by the message AK1. Call number n
1 is held thereafter, and the B1 channel holds the access connection with the packet handler (PH) on the network side for B channel packet communication.

Next, when the second packet incoming call P2 is received, the network uses the "channel identifier information element" as the B2 channel /
It is possible to change the "call setting" message S2 with the call number n2.
The packet incoming call is notified by. The terminal adapter follows the determination flow shown in FIG.
In order to accept this packet incoming call on the channel, the "response" message AK2 is returned to the network without adding the "channel identifier information element". The net accepts this,
The "acknowledgement" message AK2 is returned, and the call number n2 is retained for B2 channel packet communication thereafter. In this example, the activation to establish the access connection between the PH of the network and the terminal adapter is the first packet incoming call from the partner terminal, but this can also be done by the activation button on the operation panel from the terminal adapter side. Is.
After establishing access connections for both B1 and B2 channels,
It is possible to evenly distribute incoming packets that are successively delivered to the B1 and B2 channels.

That is, for the third packet incoming call P3, the network notifies the packet incoming call by the "call setup" message S3 of the call number n3. In this case, since an access connection has already been established for both B1 and B2, the network normally specifies "no channel / changeable" in the "channel identifier information element". In response, the terminal adapter specifies B1 and returns AK3 in a "response" message. On the other hand, in the network, since B1 has already been set up, the call code n3 is sent by the "release" message to which the reason code # 7 "call is received on the set up channel" is added.
Is requested, and the incoming packet P3 causes the incoming call to the B1 channel. The terminal adapter releases the call number n3 by the "release complete" message and waits for the next packet incoming call.

For the fourth packet incoming call P4, the network also designates no channel / changeable in the "call setup" message with the call number n4, as in the previous time. The terminal adapter sends back a "response" message specifying a B2 channel different from the last time. The network requests the release of the call number n4 by the "release" message to which the same reason code # 7 "call is received on the already set channel" is added, and the incoming packet P4 is called to the B2 channel. Similarly, packet incoming calls coming one after another will be sent to the B1 and B2 channels,
That is, incoming calls can be evenly distributed to the first port 14 and the second port 15.

[0020]

As described above, according to the present invention, I
In a terminal adapter that uses two B channels of the SDN basic interface for B channel packet communication, packet incoming calls from a plurality of terminals are used with the ISDN network by using the "channel identifier information element". By negotiating the above, packet incoming call can be equally distributed to two B channels within the terminal adapter, and only one line contract is required, which is economically advantageous.

[Brief description of drawings]

FIG. 1 is a block diagram of a terminal adapter according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation procedure of a control unit 18 in FIG.

FIG. 3 is an operation sequence diagram according to TTC standard JT-Q931 between the terminal adapter shown in FIG. 1 and the ISDN network.

FIG. 4 is a configuration diagram showing a conventional incoming call equalization system.

[Explanation of symbols]

10 ISDN network 11 line connection 12 T points 13 B channel separation unit 14 1st port 15 Second port 16,17 R point 18 Call control unit

Claims (3)

[Claims] 1. A basic interface of an ISDN network and X.
25 is a terminal adapter device for connecting to a 25 packet terminal and performing packet communication, which comprises a line connection means for receiving a call setup message coming from the ISDN network, and an ISDN network via the line connection means. B channel separating means for separating the packet information to be provided into B1 and B2 channels, and the packet information for each packet according to a channel identifier information element included in the call setup message obtained from the line connecting means. A terminal adapter device for B-channel packets, comprising: 2. The call control means is configured to perform the packet communication on the B1 and B2 channels. The terminal adapter device for a B channel packet according to claim 1, wherein the call setting is performed so as to equalize the loads of the 25 packet terminals. 3. The call control means sends a response message to the ISDN network to set the call when changing the channel designation indicated by the channel identifier information element from the ISDN network. The terminal adapter device for B channel packet according to claim 1, wherein the terminal adapter device is changed.