KR20010063689A - Method for AO/DI service between exchange and remote access server - Google Patents

Abstract

PURPOSE: An AO/DI(Always On Dynamic Interface) service method between an exchange and a remote access server is provided to use an on-demand B channel connecting method when a local exchange and an RAS(Remote Access Server) are interlocked with a PRI(Primary Rate Interface). CONSTITUTION: If an AO(Always On) call is attempted, a system decides whether a channel for AO is currently used(ST41). If so, the system decides whether a call number available for the corresponding AO channel is below a maximum call number(ST43). If so, the system uses an X.25 procedure to the corresponding AO channel, and sets up the AO call(ST44). If a channel for AO is currently not used, or if a call number available for the corresponding AO channel is over the maximum call number, the system uses a Q.931 procedure to a PRI(Primary Rate Interface) channel, and sets up an AO call channel, then updates a state managing table for the current available PRI channel(ST46).

Description

Method for AO / DI service between exchange and remote access server}

The present invention relates to an AO / DI (Always On Dynamic Interface) service method between an exchange and a remote access server. Particularly, in order to support AODI in a national exchange, a matching form with a RAS (Remote Access Server) is provided. AO between the exchange and the remote access server that dynamically allocates the AO channel via an on-demand B-channel connection when used as a Rate Interface (1.5 Mbps). / DI service method.

In general, AO / DI service is a new bi-directional network service that combines packet-switching and circuit-switching technology in the Integrated Services Digital Network (ISDN) network with Internet access technology.

Enables ISDN subscribers to maintain constant access to TCP / IP-based services (Internet or intranet) over low-speed (9.6 Kbps) D-channels without having to dial each time. The subscriber can access the service network at a speed of up to 128Kbps.

In this case, AO (Always On) means that the service consumer is always connected to the service provider through the D-channel of ISDN, while DI (Dynamic ISDN) has two 64Kbps B channels in addition to the D-channel as the data throughput increases and decreases. It is dynamically allocated and deallocated, providing on-demand bandwidth from 9.6 Kbps up to 128 Kbps.

At this time, in order to dynamically combine two B channels, MultiLink Point-to-Point Protocol (MLPPP), Bandwidth Allocation Protocol (BAP) and Bandwidth Allocation Control Protocol (BACP) ) Is used.

In ISDN, access and release of the B channel are performed within a few seconds (2 to 3 seconds), so the dynamic allocation of bandwidth is performed without the subscriber feeling.

1 is a block diagram of an AO / DI service system of a general exchange and a remote access server.

As shown therein, reference numeral 1 denotes a terminal adapter, 2 denotes an AO / DI system which is a switch, and 3 denotes a RAS. A terminal such as a telephone or a PC is connected to the terminal adapter 1, a public switching telephone network (PSTN) is connected to the AO / DI system 2, and the Internet is connected to the RAS 3 equipment.

Therefore, conventional AO / DI service is implemented through PRI (Primary Rate Interface, Primary Group Rate Interface (1.5Mbps)) interworking between exchange and RAS equipment, and fixed path as data path for AO call at both ends of exchange and RAS equipment. After entering the command manually, the service was executed.

All AO calls in the existing exchanges were processed in conjunction with the RAS through PHM (PacketHeader Module) inside the exchange.

However, in the related art, there is no technique in which on-demand B channel connection is used to configure the matching between the switch 2 and the RAS 3 equipment for the AODI service. That is, the AO channel between the local exchange and the RAS is used by setting the appropriate AO channel according to the agreement between the operators before the service. This approach is called nailed-up B channel access, which does not dynamically handle AODI services. In addition, the AO channel, which is already set up by the operator, is not appropriate in terms of resource utilization because the AO channel, which is already set up by the operator, does not function as a DI channel regardless of its use.

2 is a flowchart illustrating a general AO / DI service method.

Therefore, in the AODI subscriber (D channel packet subscriber) and RAS (incoming PRI) B channel packet call processing, the Q.931 call providing procedure is omitted by using a nailed-up B channel access method of the local exchange.

The necessary information is transmitted to the network by inserting 0xCF in the first octet of the user data field of the originating X.25 CR (Call Request), inserting desired values in the call and call address fields of the CR, Incoming call shall transmit LAPB (Link Access Procedure on B Channel) data link to specific B channel of PRI, and data transmission rate should be able to transmit 9.6Kbps for D channel packet call and 64Kbps for B channel packet call.

3 is a flowchart illustrating a conventional AO call connection method.

As shown in the figure, if there is an AO call attempt, a call is set up using a X.25 call procedure on a nailed-up B channel (ST21) (ST22).

4 is a flowchart illustrating a conventional AO call release method.

As shown in the figure, when there is an AO call release, a call is released to a preset-up B channel using an X.25 call procedure (ST31).

So, to support nailed-up connection, Q.931 call provisioning procedure is omitted and LAPB data link establishment request is required by network or RAS, and it consists of processing for the requested partner first. After receiving or transmitting UA (non-code confirmation frame), the RAS transitions to the UP state. After the state transition, the RAS determines whether to transmit a restart packet according to its presence and state.

1. When attempting an AO call, the Q.931 channel selection process is omitted as the meaning of the nailed-up B channel.

2. When an AO call is attempted, an IC (incoming call) packet is transmitted through the link of PH linked with RAS.

3. The subsequent packet setup procedure is the same as the current packet call setup.

However, in this conventional technology, there is no limit to the AODI service capable of interworking the RAS and the exchange by the on-demand B channel connection type, and when the B channel packet is used for interworking with the RAS, the nailed-up scheme changes the network. There were many problems and the RAS function was improved so that it could not be flexibly coped with when supporting on-demand B channel connection.

In addition, if the number of acceptable calls of the failed-up link is exceeded when the service is expanded, the quality of service is deteriorated due to the need for renegotiation between the exchange and the RAS. The AO channel set by is not appropriate in terms of resource utilization because it does not function as a DI channel regardless of its use, and if there is a failure of the channel set for AO, the AO channel cannot be set dynamically. There was also a disadvantage that can not service.

Accordingly, the present invention has been proposed to solve the conventional problems as described above, and an object of the present invention is to use on-demand B channel access method when using a matching form with RAS as PRI to support AODI in a local exchange. The purpose of the present invention is to provide an AO / DI service method between an exchange and a remote access server that can dynamically allocate an AO channel to perform a service.

In order to achieve the above object, AO / DI service method between an exchange and a remote access server according to an embodiment of the present invention,

If there is an AO call attempt, a first step of determining if there is a channel currently being used for AO; If there is a channel currently being used for AO, determining whether the number of possible calls for the AO channel is less than or equal to the maximum lake; If the number of possible calls for the corresponding AO channel is less than or equal to the maximum lake, establishing a AO call using the X.25 procedure for the AO channel; If there is no channel currently being used for the AO or the maximum number of possible calls for the AO channel is large, the AO call channel is established using the Q.931 procedure on the corresponding PRI channel, and then the state management for the currently available PRI channel is performed. The technical configuration is characterized by performing a fourth step of updating a table.

In order to achieve the above object, AO / DI service method between an exchange and a remote access server according to an embodiment of the present invention,

If there is an AO call release, a fifth step of determining whether there is another AO call in a channel currently in use; A sixth step of releasing the AO call using the X.25 procedure for the AO call if there is another AO call in the current channel; If there is no other AO call on the currently used channel, releasing the AO call channel using the Q.931 procedure on the available PRI channel; The technical configuration is characterized by performing an eighth step of updating a state management table for a currently available PRI channel after the sixth or seventh step.

1 is a block diagram of an AO / DI service system of a general exchange and a remote access server;

2 is a flowchart illustrating a general AO / DI service method;

3 is a flowchart illustrating a conventional AO call connection method;

4 is a flowchart illustrating a conventional AO call release method.

5 is a flowchart illustrating an AO call connection method in an AO / DI service method between an exchange and a remote access server according to an embodiment of the present invention;

6 is a flowchart illustrating an AO call release method in an AO / DI service method between an exchange and a remote access server according to an embodiment of the present invention;

7 is a flowchart illustrating an AO / DI service method using an on-demand access method used in the present invention.

Explanation of symbols on the main parts of the drawings

1: terminal adapter 2: switchboard

3: remote access server

Hereinafter, an embodiment according to the technical idea of the AO / DI service method between the switch and the remote access server according to the present invention will be described.

5 is a flowchart illustrating an AO call connection method in an AO / DI service method between an exchange and a remote access server according to an embodiment of the present invention.

As shown in the figure, if there is an AO call attempt, a first step (ST41) (ST42) for determining whether there is a channel currently being used for AO; A second step (ST43) of determining whether the number of possible calls for the AO channel is less than or equal to the maximum lake, if there is a channel currently being used for the AO; A third step (ST44) of establishing an AO call using the X.25 procedure on the AO channel if the number of possible calls on the AO channel is less than or equal to the maximum lake; If there is no channel currently being used for the AO, or if the maximum number of possible calls for the AO channel is large, then the AO call channel is established using the Q.931 procedure on the applicable PRI channel and then the state management for the currently available PRI channel. A fourth step ST46 is performed to update the table.

In the fourth step ST46, when updating the state management table for the currently available PRI channel, the state of the call assigned to the current channel, the number of calls assigned to the current channel, and the number of calls that can be handled by one link are processed. Update in the state management table.

6 is a flowchart illustrating an AO call release method in an AO / DI service method between an exchange and a remote access server according to an embodiment of the present invention.

As shown in the figure, if there is an AO call release, there is a fifth step (ST51) (ST52) for determining whether there is another AO call in the channel currently being used; A sixth step (ST53) of releasing the AO call using the X.25 procedure for the AO call if there is another AO call in the current channel; If there is no other AO call on the channel currently being used, a seventh step (ST54) of releasing the AO call channel using the Q.931 procedure on the available PRI channel; After the sixth or seventh step, an eighth step ST56 of updating the state management table for the currently available PRI channel is performed.

In the eighth step (ST55), when updating the state management table for the currently available PRI channel, the status of the call assigned to the current channel, the number of calls assigned to the current channel and the number of calls that the link can handle Update in the state management table.

The operation of the AO / DI service method between the switch and the remote access server according to the present invention configured as described above will be described in detail with reference to the accompanying drawings.

First, the necessity of AO / DI by analyzing the current status and traffic characteristics of the current Internet service is as follows.

Recently, Internet users have exploded due to graphical user interface (GUI), e-commerce, and marketing on the World Wide Web (WWW), which has simplified Internet access, such as Mosaic or Netscape Navigator. Doing. Here, the Internet connection in the existing public network (PSTN / ISDN) is connected to the Internet service provider by circuit switching, so that the public network designed for voice communication in a few minutes is intermittent and has a heavy load due to data communication and internet traffic, which has a characteristic of long-term occupancy. Increasingly, Internet users are dissatisfied with relatively slow service speeds and want faster access.

In order to solve the problem of the public network, services such as cable modem and digital subscriber line (xDSL) have been recently provided. However, considering the characteristics of the Internet traffic, simply increasing the bandwidth is not an appropriate solution.

So let's analyze the characteristics of Internet traffic. For example, when accessing the World Wide Web (WWW), which is the most widely used Internet application, a user experiences frequent connection delays.

"Web site found. Waiting for reply".

"Connecting to site xxx.xxx.xxx.xx"

"Opening picture display.gif."

Of these delays, the only one that can be solved by the increase in bandwidth is the last message, i.e. the download of the graphic file. Other delays are due to the processing speed of the Internet backbone, routers and servers and are always the same regardless of the connection speed from the subscriber to the Internet Service Provider (ISP).

In addition, when analyzing subscribers' actual internet service usage tendency, low bandwidth of 9.6Kbps or less is used in most time zones, and when downloading 64 ~ 128Kbps high speed, graphic downloading or sending mail with large attachments when surfing the web And so on. Even if the user mainly surfs the Internet, the user should visit a specific web site, download the desired information to his PC, read the page, find the necessary data, and then move on to the next page. It does not require bandwidth.

Taken together, these are some of the things that can be improved by simply increasing the connection bandwidth in an existing Internet service environment. Therefore, as the bandwidth of the link is increased to increase the access speed, the utilization of the entire link may be reduced, which may result in an ironic result. Bandwidth is a network infrastructure for providing services, which means costs, so the cost of loss due to underutilization of bandwidth goes to service users, network operators or ISPs.

The analysis on the current state of the Internet service provision and the traffic tendency shows that what is required in the existing Internet communication environment is not a simple increase in bandwidth. Therefore, there is a need for a new type of access service that can provide the required bandwidth at all times, on demand, and without waste. And, AO / DI service is the solution that best satisfies these requirements at this time.

This AO / DI service is a new two-way network service that combines the packet and circuit switching technology of the ISDN network with the Internet technology, and does not require dialing every time the Internet is connected, and uses the low / high speed bandwidth variably according to the subscriber traffic. Can be.

In addition, AO / DI service basically provides all the advantages of the existing ISDN service. That is, it has 10 times faster call connection and release time than analog modem, simultaneous use of voice and data communication, various voice call supplementary services, and high transmission bandwidth (up to 128Kbps). And it is easy to provide service through existing network infrastructure.

In addition, AO / DI service provides advantages such as low-cost, always-on access and efficient use of bandwidth without unnecessary waste on the subscriber side, and the switch of circuit-switched network with variable allocation of low / high-speed bandwidth according to internet traffic from the network operator side. Provides the advantage of efficient use of resources, the spread of subscriber-oriented on-demand bandwidth ISDN service, the provision of a variety of information that is always alive from the Internet service provider (ISP) side, and the introduction of packet multiplexing technology using limited circuits. As a result, there is an advantage that can provide services to more users at the same time.

For this reason, compared to cable modems that guarantee only high-speed bandwidth or xDSL services, AO / DI services are an advanced service that suits the requirements of telecommunication users and network operators.

In these AO / DI services, the AO field includes transaction-based applications such as push data such as e-mail, stock information, news, weather forecast, and traffic information, automatic data collection, credit card inquiry, and automatic teller machine (ATM) processing, It has application fields such as telemetery and alarm system, and DI field has applications such as e-mail transmission / reception, graphic file upload / download, web surfing and remote video conferencing with graphic files. .

5 is a flowchart illustrating an AO call connection method in an AO / DI service method between an exchange and a remote access server according to an embodiment of the present invention, and FIG. 6 is an AO between an exchange and a remote access server according to an embodiment of the present invention. A flowchart showing the AO call release method in the / DI service method.

Here, in AODI, AO is implemented in the form of X.25 packet, DI is connected by general ISDN data call, and short data is delivered in AO form always connected according to user's use. This service automatically allocates and releases B-channels when more bandwidth is required without the need for additional dialing. In the AO call, the calling party is a D channel packet connection, the RAS is a B channel packet connection, and the DI call is an ISDN data call connection.

On-demand B channel packet is a B channel packet service that performs channel negotiation through Q.931 process when providing B channel packet to the called party.

In addition, the dictionary meaning of nailed-up B channel access means that the fixed path is reserved in advance and not used for other purposes regardless of the existence of the call. However, in relation to on-demand B channel packet, it is used comprehensively as follows. In other words, when a Call Offering to a subscriber or a RAS, this refers to a connection type in which a call is provided on a B channel mutually agreed between the network and the RAS by omitting the Q.931 channel selection process.

Furthermore, RAS (Remote Access Server) is a device that works directly with the exchange and acts as a server for TCP / IP, the Internet protocol.

Therefore, the present invention supports AODI service extensively, and provides AODI service with the same level as existing data network access service, and can be applied even after enhancement of functions of local exchange and RAS.

Therefore, Q.931 signaling is used to configure AO channel between the local exchange and RAS for the on-demand B channel access method. This follows Q.931 packet signaling.

In addition, the B channel dynamically agreed between the local exchange and the RAS is managed in a table related to the AO channel. For future AO calls, access is made using the X.25 procedure rather than the Q.931 process. However, this is possible in a range not exceeding the number of calls that can be accommodated by the corresponding packet link in one AO channel in the local exchange.

In addition, the local exchange manages the number of calls that can be accommodated by the corresponding packet link in one AO channel.

This is divided into the operations of the national exchange and RAS as follows.

First, the local exchange supports Q.931, which uses PRI as a matching form with RAS to support AODI.

In addition, the national exchange dynamically manages an independent table for the AO channel, which can be stored in a separate table for the configured AO channel or dynamically deleted when the AO channel is released.

In addition, the national exchange manages the call for the B channel for the PRI AO currently in use. Therefore, when attempting an AO call, the call count currently being used for the AO channel is managed, and if it is smaller than the maximum call count that can be handled by one AO channel, the call is attempted using the X.25 procedure without the Q.931 procedure. If the AO call attempt is larger than the maximum call count that can be handled by one AO channel, the new AO channel is set using the Q.931 procedure to provide a call. In addition, if there is no call currently used on the AO channel when the AO call is released, the channel is released using the Q.931 procedure.

On the other hand, RAS supports the Q.931 procedure when using PRI as the matching form with the exchange to support AODI. Also, RAS should register calling number for AO call in AO channel (for authentication). However, for on-demand channel access method, RAS must manage calling number by interface and not AO channel.

7 is a flowchart illustrating an AO / DI service method using an on-demand access method used in the present invention.

This is similar to the ITU-T Q.931 Recommendation Appendix II incoming call offering procedure as shown in FIG. 7 in the called party (RAS: PRI) B channel packet scenario.

This Q.931 procedure is on the D-channel and follows the X.25 procedure on the corresponding B-channel after performing the Q.931 procedure.

As such, the present invention performs service by dynamically allocating an AO channel through an on-demand B channel access method when using a matching form with RAS as a PRI to support AODI in a local exchange.

Although the preferred embodiment of the present invention has been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments. Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

As described above, the AO / DI service method between the exchange and the remote access server according to the present invention is dynamically changed by using an on-demand B channel access method when interworking a local exchange and a RAS with a PRI for an AODI service. The effect is to be flexible and proactive in service.

In addition, when the conventional RAS supports only nailed-up B channel packets, and reserves B channel packets in the network in accordance with the prior meaning of nailed-up, the exchange has various limitations and many modifications. On the contrary, the present invention does not need to allocate the AO channel in advance by using the on-demand B channel access method, so that the resource can be efficiently used.

Claims (4)

If there is an AO call attempt, a first step of determining if there is a channel currently being used for AO; If there is a channel currently being used for AO, determining whether the number of possible calls for the AO channel is less than or equal to the maximum lake; If the number of possible calls for the corresponding AO channel is less than or equal to the maximum lake, establishing a AO call using the X.25 procedure for the AO channel; If there is no channel currently being used for the AO, or if the maximum number of possible calls for the AO channel is large, then the AO call channel is established using the Q.931 procedure on the applicable PRI channel and then the state management for the currently available PRI channel. And performing a fourth step of updating the table. 2. The method of claim 1, wherein in the fourth step, when updating a state management table for a currently available PRI channel, the status of a call assigned to the current channel, the number of calls assigned to the current channel, and a call that one link can handle. AO / DI service method between an exchange and a remote access server, wherein the number is updated in a state management table. If there is an AO call release, a fifth step of determining whether there is another AO call in a channel currently in use; A sixth step of releasing the AO call using the X.25 procedure for the AO call if there is another AO call in the current channel; If there is no other AO call on the currently used channel, releasing the AO call channel using the Q.931 procedure on the available PRI channel; Performing an eighth step of updating a state management table for a currently available PRI channel after the sixth or seventh step. 4. The method of claim 3, wherein in the eighth step, when updating the state management table for the currently available PRI channel, the status of the call assigned to the current channel, the number of calls assigned to the current channel, and the call that one link can handle. AO / DI service method between an exchange and a remote access server, wherein the number is updated in a state management table.