KR100442056B1 - Method of Offering Multi-channel Service in the RAS - Google Patents

Abstract

The present invention relates to a method for providing a multi-channel service (RAS) in a RAS (Remote Access Server), and in particular, in a RAS interworking with an exchange, an effective multi-channel internet ( Internet) service for providing a multi-channel service in a RAS to provide a service.

The present invention provides a process for detecting a call connection request of an ISDN subscriber through a first B-channel, establishing a call, connecting a corresponding B-channel with a subhighway, and performing PPP access on the corresponding B-channel for each channel; Recognizing the origination of the MLPPP call on the second B-channel when the ISDN connection is completed and checking whether the first ML call connected to the second call is in another RAS when the MLPPP access is made; Requesting a call transfer to the exchange side during a call through a PRI matching unit when the first ML call exists in another RAS; When the exchange receives the call transfer request, receiving the PRI destination number information, retrying the call connection, and transmitting a response to the call transfer request; Receiving the response to the call switching request and transmitting the MLPPP progress information for the second call to the RAS having the first timeslot.

Description

Method of Offering Multi-channel Service in the RAS}

The present invention relates to a method for providing a multi-channel service in RAS, and more particularly, a method for providing a multi-channel service in a RAS to provide an efficient multi-channel Internet service in one RAS as a call switching function between RASs during data communication in a RAS interworking with an exchange. It is about.

In general, AODI is implemented based on the existing exchange and Bandwidth Allocation Control Protocol (BACP). The AO is implemented in the form of X.25 packet, and the calling party is connected by D-channel packet and directly linked with the exchange. The RAS side, which acts as a server for Transmission Control Protocol (IP) / IP (Internet Protocol), is connected by B-channel packets, and the corresponding DI is connected by a general ISDN (Integrated Services Digital Network) data call. Therefore, short data is delivered in the form of always connected AO. Here, the existing exchange that can handle the ISDN subscriber includes an X.25 packet handler function.

The basic concept of AODI is that ISDN D-channel X.25 calls are generated between the client and the ISP (Internet Service Provider). MLP (Multi-link Protocol) and TCP / IP It is encapsulated in an X.25 logic circuit that is passed by.

In this case, the B-channel does not use the Q.921 and X.25 encapsulation used in the D-channel, but directly uses the MLP, ie a circuit-switched connection between the subscriber and the ISP is created on that B-channel. In this case, IP packets are delivered through PPP (Point to Point Protocol) encapsulation on the corresponding B-channel. In addition, using X.25 on the D-channel, of course, is not the most efficient protocol stack, but it is possible to use the existing packet handlers at the exchange to implement AODI. Packet linking is used as the Primary Link (PL) of the MLP.

Then, a simple network configuration for a conventional AODI service is composed of a PC 10, a switch 20, a RAS (31, 32), and the Internet 40, as shown in FIG. Here, AO uses Packet Data Capability (PDS) which is part of the ISDN standard, and the subscriber establishes packet connection to the corresponding RAS (31, 32) on the D-channel, and the bidirectional connection is established by the subscriber. It is generated when the PC 10 is turned on. When the connection is established, the subscriber can exchange data such as an e-mail.

If there is a lot of information that cannot be handled with a 16K D-channel packet connection, the line connection is established using one or two ISDN B-channels, which are automatically established without subscriber involvement. Kbps) is guaranteed. In addition, when the transmission of data is complete, the line connection is released and the subscriber is again online on the D-channel.

In addition, there is a technology using an X.25 dedicated link, that is, a T1 / E1 link, for the AODI service. In this case, it is used separately from the call path of DI. In the case of performing matching between the 20 and the RAS 31 and 32, a specific switching interface processor (SSP) interworking with the corresponding RAS (31, 32) is used in a form that is distinguished from the PRI (Primary Rate Interface) for DI. Because AO calls are centralized and dedicated links, one PRI cannot accommodate both AO calls and DI calls at the same time. In addition, when performing matching between the switch 20 and the RASs 31 and 32 using the B-channel packet, only the failed-up B-channel connection may be supported by the corresponding RAS 31 and 32. have.

On the other hand, when the ISDN subscriber connected to the switch 20 having the call transfer function during the call wants to receive the service of the Internet 40 in conjunction with the RAS 31 and 32, when one or more B-channels are allocated to the service, In case of occupying time slots in the RASs 31 and 32, two or more B-channel services are possible.

However, if the PRI line is grouped by the representative number, it may not necessarily occupy the time slots in the same RAS (31, 32), so the multi-channel service is implemented by passing the data through the transmission path interworking between systems, but at this time As traffic overload occurs due to interworking, the quality of service may be degraded.

In other words, the conventional technology may not necessarily occupy time slots in the same RAS equipment when the PRI lines are bundled with a representative number among multi-channel Internet services using the RAS equipment through the existing E1 PRI interworking. We had to implement multichannel service by passing data through transmission path. Thus, at this time, since traffic overload occurs while interworking between systems, there is a disadvantage in reducing the quality of service.

In order to solve the above-mentioned disadvantages, the present invention provides an efficient multi-channel Internet service as a call switching function between the RAS equipment during the data communication interworking with the exchange (Centurix) and E1 PRI, That is, if the subscriber call is the second call that wants multi-channel access by using the call transfer function of the exchange, the time slot between the exchange and the RAS equipment is released without releasing the subscriber call, and the channel where the first call is already connected A RAS device and a new timeslot and transmit various call progress information on the released second call to the newly allocated RAS device to resume the call connection operation. Even if connected, it enables to receive multi-channel service in the same RAS equipment. The.

1 is a block diagram showing the configuration of a simple network for a conventional AODI (Always on Dynamic ISDN) service (Service).

2 is a block diagram illustrating a configuration for a multi-channel service in a RAS (Remote Access Server) according to an embodiment of the present invention.

3 is a flowchart illustrating a multi-channel service providing method in RAS according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

50: PC (Personal Computer) 60: Exchange

71, 72: RAS 80: Internet

In order to achieve the above object, the present invention detects a call connection request of an ISDN subscriber through a first B-channel, establishes a call, connects the corresponding B-channel with a subhighway, and then applies the corresponding B-channel on each B-channel. Performing a PPP connection to the server; RAS recognizes the origination of MLPPP (Multi-link Point to Point Protocol) call on the second B-channel when the ISDN connection is completed, and the first ML (Multi-link) call connected to the second call is different from the RAS when MLPPP is connected. Checking to see if there is; Requesting a call transfer to the exchange side during a call through a PRI matching unit when the first ML call exists in another RAS; When the exchange receives the call transfer request, receiving the PRI destination number information, retrying the call connection, and transmitting a response to the call transfer request; Receiving the response to the call switching request and transmitting the MLPPP progress information for the second call to the RAS having the first timeslot.

Alternatively, the present invention is characterized in that it further comprises the step of releasing the call connection with the RAS that assigned the second timeslot in the exchange.

In another embodiment, the present invention provides a method for performing MLPPP call access in the same RAS when the first ML call is present in the current RAS or when MLPPP progress information is received for the second call; The method may further include providing a multi-channel service in the current RAS by setting an MLPPP link. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the RAS according to the embodiment of the present invention, the configuration for the multi-channel service is composed of a PC 50, a switch 60, a RAS 71 and 72, and the Internet 80 as shown in FIG. Even if a plurality of calls are connected to different RASs 71 and 72 to subscribers of the exchange 60, one system (for example, the first RAS) is provided through the call transfer function and the call progress information transfer function of the exchange 60. (71)) to efficiently perform the multi-channel service.

A method of providing a multi-channel service in a RAS according to an embodiment of the present invention will be described with reference to the flowchart of FIG. 3.

First, when the ISDN subscriber of the exchange 60 makes a call through the first B-channel, the PRI matching unit (not shown in the drawing for convenience of description) performs Q.931 call processing through the corresponding exchange 60. It is performed while exchanging necessary messages with the subscriber matching unit (not shown in the drawings for convenience of description) during the operation. Here, a call connection request message requesting service from the relay line matching unit to the subscriber matching unit may be included in the message transmitted and received between the relay line matching unit (not shown in the drawings for convenience of description) and the subscriber matching unit when communicating through the VME bus. Request Message), Call Connection Confirmation Message (Service Report Message) that responds to the service request from the subscriber matching part to the relay line matching part, and Call Connection Release Request Message requesting service termination from the relay line matching part to the subscriber matching part (Service End) Request message) and a call connection release confirmation message (Service End Report Message) responding to the termination of the service from the subscriber matching unit to the relay line matching unit.

In other words, when an ISDN subscriber requests a call, the relay line matching unit generates a call connection request message and transmits the call connection request message to the subscriber matching unit, and the subscriber matching unit detects the reception of the corresponding call connection request message (step S1). Call setup is performed to perform call setup (step S2).

Accordingly, when the call setup of the second step S2 is completed, the subscriber matching unit connects the ISDN B-channel with the sub-highway based on the call information of the subscriber (step S3), and then each channel. PPP connection is performed on each ISDN B-channel (step S4), and a call connection confirmation message indicating the PPP connection is generated and transmitted to the relay line matching unit (step S5). At this time, it can recognize whether the call is a call requiring a multi-channel, and then data transmission and reception is performed in the same manner as the general RAS (71, 72).

Next, to confirm whether the ISDN connection is made as described above (step S6), if the ISDN connection is not completed in the sixth step (S6), the relay line matching unit generates a call connection release request message to the subscriber matching unit It transmits to the side to release the call connection (step S7).

When the subscriber transmits the multichannel PPP call through the second B-channel when the ISDN access is completed in step S6, the subscriber recognizes the transmission of the multichannel PPP call through the second B-channel ( Step S8) In the same manner as described above, the subscriber matching unit performs the second MLPPP connection, where the first ML call connected to the second call is different from the other system (for example, the second RAS). 72) (step S9).

The operation of the ninth step S9 is as follows. First, a Link Discriminator inquiry request is broadcast to a system different from the current system (e.g., the first RAS 71) (e.g., the second RAS 72), i.e., subscriber matching (i.e., subscriber). (Matching card) transmits an inquiry request signal to the network matching unit (i.e., network matching card) side, and receives an inquiry response message from the network matching card to determine which system the first ML call exists as a result of the response. Able to know. At this time, the inquiry channel between the systems uses a separate communication channel (for example, 10Base-T for operation preservation in the case of 'iGATE').

If, in the ninth step (S9), the first ML call that is connected to the second call does not exist in the current system, the system calls for a call transfer to the switchboard 60 through the PRI matching unit. In step S10), when the switch 60 receives the call transfer request, the exchange 60 receives the corresponding PRI destination number information and attempts to connect to the call again to deliver a response message to the call transfer request.

Then, the system receives the response message for the call transfer request (step S11) and transmits the MLPPP progress information for the second call, which has been performed before, to the system having the first timeslot (step S12). At this time, the exchange 60 releases the call with the system to which the second timeslot is allocated (step S13). At this point, it should be noted that ISDN subscriber calls are not affected at all.

On the other hand, if the first ML call to the second call in the ninth step (S9) exists in the current system, that is, the system with the first timeslot is the current system or the twelfth step (S12) In the case of receiving MLPPP progress information for the second call in step 6), it continuously performs the operation of the MLPPP call connection in the same RAS (71, 72) (step S14) to provide a multi-channel service in the system by establishing an MLPPP link. (Step S15).

Then, when the ISDN subscriber requests call disconnection, the relay line matching unit generates a call disconnection request message and sends it to the subscriber matching unit, so that the subscriber matching unit detects the reception of the call disconnection request message (step). S16) After releasing the call connection, a call connection release confirmation message is sent to the relay line matching unit (step S17).

As described above, according to the present invention, even if a plurality of calls are connected to subscribers of a private exchange network to different RAS systems, the multi-channel service is concentrated to one RAS system through a call transfer function and call progress information transfer function during a call. Roaming service is possible between RAS systems.

Claims (3)

Detect call connection request of an Integrated Services Digital Network (ISDN) subscriber through the first B-channel to establish a call and connect the corresponding B-channel with the subhighway to point to point on the corresponding B-channel for each channel Protocol) connection; RAS recognizes the origination of MLPPP (Multi-link Point to Point Protocol) call on the second B-channel when the ISDN connection is completed, and the first ML (Multi-link) call connected to the second call is different from the RAS when MLPPP is connected. Checking whether it is in a (Remote Access Server); Requesting a call transfer to the exchange side during a call through a primary rate interface (PRI) when the first ML call exists in another RAS; When the exchange receives the call transfer request, receiving the PRI destination number information, retrying the call connection, and transmitting a response to the call transfer request; And receiving the response to the call transfer request and transmitting MLPPP progress information for the second call to the RAS having the first timeslot. The method of claim 1, And releasing a call connection with the RAS which allocated the second timeslot in the exchange. The method of claim 1, Performing an MLPPP call connection in the same RAS when the first ML call exists in the current RAS or when MLPPP progress information is received for the second call; The method of providing a multi-channel service in an LA, characterized by further comprising the step of setting up the MLPPP link to provide a multi-channel service in the current RAS.