KR100243672B1 - Connectionless network service supporting method in atm - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a connectionless service support method in an asynchronous delivery mode network.

2. The technical problem to be solved by the invention

An object of the present invention is to provide a method for supporting a connectionless service in an ATM network supporting a connectionless network access protocol (CLNAP) and an IOPA service through each interface by classifying physically one ATM interface into two logically. box.

3. Summary of Solution to Invention

The present invention includes a first step of determining a network interface type to be transmitted to drive a corresponding connectionless task; A second step of generating a message suitable for a corresponding connection type from the connection type table by using the connection identifier; A third step of driving a corresponding task corresponding to a network interface type to be transmitted from the connected table by using the connected identifier of the connected data; And a fourth step in which the task receives the extracted connectionless data packet through the connectionless input interface.

4. Important uses of the invention

The present invention is used for ATM networks.

Description

Connectionless service support method in asynchronous delivery mode network

The present invention provides a physically-asynchronous Asynchronous Transfer Mode (ATM) interface to logically connect a broadband integrated service network (B-ISDN) connectionless data bearer service (BCDBS: B-ISDN connectionless data bearer service). Network access protocol through each interface by dividing the ATM interface supporting Internet Protocol (IP) function and the ATM interface supporting IP over ATM (IPOA) directly to virtual connection of ATM network. (CLNAP: ConnectionLess Network Access Protocol) and a method for supporting a connectionless service in an ATM network supporting IOPA services.

Currently, the Internet provides a variety of services such as information retrieval and exchange, e-mail as well as e-commerce. In addition, it is possible to transmit information between several networks using a transmission control protocol / Internet protocol (TCP / IP), and mainly use a local area network (LAN).

However, the Internet communication service using the LAN has many problems in terms of service quality, delivery speed, and efficiency in order to process new and various application services stably and efficiently as desired by users.

Therefore, a method of supporting a connectionless service such as a LAN is essential in a high speed communication network such as B-ISDN.

The most commonly used application service is based on TCP / IP.

However, since TCP is a connected service but IP supports a connectionless service, an overlay method for providing a connectionless IP service to a connected ATM network is required to accommodate existing TCP / IP application services in an ATM network.

The present invention devised in response to the above-described requirements, the ATM interface to support the B-ISDN connectionless data bearer service (BCDBS) logically one physical ATM interface, and the Internet protocol (IP) functions ATM network Its purpose is to provide a connectionless service support method in ATM networks that support connectionless network access protocol (CLNAP) and IOPA services through each interface by dividing into ATM interfaces that support IPOA. have.

Figure 1a is a block diagram of an Internet Protocol (IP) over asynchronous delivery mode (IOPA) interworking system to which the present invention is applied.

1B is a structural diagram of an Internet Protocol Over Asynchronous Delivery Mode (IOPA) protocol stack used in the present invention.

Figure 2a is a block diagram of a local area network (LAN) interworking system to which the present invention is applied.

2B is a schematic diagram of a Broadband Integrated Services Digital Network (B-ISDN) connectionless data bearer service (BCDBS) protocol stack used in the present invention.

Figure 3a is a block diagram showing an example of a system to which the present invention is applied.

3B is a structural diagram of a protocol stack supporting the system of FIG. 3A.

4A to 4C are structural diagrams of a table used in the present invention.

5 is a state diagram illustrating a connectionless service support method between software blocks to which the present invention is applied.

6A and 6B are a flowchart illustrating an embodiment of a method for supporting connectionless service according to the present invention.

* Explanation of symbols for the main parts of the drawings

31: Logical Internet Subnet (LIS)

32: Connectionless Service Funtion (CLSF)

33: B-ISDN Connectionless Data Bearer Service (BCDBS) Router

34: Local Area Network (LAN)

In order to achieve the above object, the present invention provides a method for supporting a connectionless service in an asynchronous delivery mode network, wherein the connectionless output interface receives a connectionless data packet from a connectionless task and determines a network interface type to be transmitted, and then connects the connectionless connection. A first step of driving a task; A second step of the connected task generating a message suitable for the connected type from the connected table by using the connected identifier received from the corresponding disconnected task; A third step of driving the corresponding connectionless task corresponding to the network interface type to be transmitted from the connected table by using the connection identifier of the connected data received from the connected task at the connected output interface; And a fourth step of the connectionless task receiving the connectionless data packet extracted from the connectionless task through the connectionless input interface.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

There are two ways to support connectionless service in ATM network.

One is the Telecommunication Standardization Sector of International Telecommunication Union (ITU-T) for interworking connectionless networks such as LANs and Metropolitan Access Networks (MANs) via B-ISDN. It is suitable for public networks by using the ConnectionLess Network Access Protocol (CLNAP) recommended by

The other is the IPOA method, which maps existing connectionless network layer (IP) protocol functions directly to virtual connections of an ATM network for use of connectionless media access control (MAC) and TCP / IP application software. . This method is mainly used for private networks using the Virtual Path Identifier / Virtual Channel Identifier (VPI / VCI).

Therefore, in order to communicate with ATM end systems and B-ISDN / LAN interworking devices, it is necessary to support the CLNAP protocol used to link a connectionless network such as a LAN to an ATM network and IPOA support to accommodate existing TCP / IP application software. Is required.

FIG. 1A is a block diagram of an Internet Protocol (IP) over asynchronous delivery mode (IOPA) interworking system to which the present invention is applied. In FIG. 1, "11" represents a Logical Internet Subnet (LIS), and "12" represents an IPOA. Represent each router.

The logical Internet subnet (LIS) 11 is composed of an ATM Address Resolution Protocol (ATM ARP) router 111 for resolving an address of an ATM and a plurality of IPOA systems 112 having the same IP subnet address. .

In the LIS 11, a plurality of IPOA systems 112 communicate through an ATM connection, communication with other LIS 11 is through an IPOA router 12, and an ATM address is located in each LIS 11. It is interpreted in the ARP server 13.

1B is a structural diagram of a protocol stack of the IPOA system 112 used in the present invention.

The Internet Protocol Over Asynchronous Transfer Mode (IOPA) protocol includes the Internet Protocol (IP), Logical Link Control / SubNetwork Attatchment Point (LLC / SNAP), ATM Adaptation Layer 5 (AAL5). , Asynchronous Transfer Mode (ATM), and Physical Layer (PHY).

The IPOA system 112 communicates using AAL5 of the AAL types in the ATM network. Therefore, in order to exchange the IP data packet between the IPOA system 112, the IP data packet must be converted into AAL5 data and transmitted through the ATM connection. In this case, what is used is LLC / SNAP encapsulation.

That is, the IP data packet is encapsulated using LLC / SNAP and stored in the payload of AAL5 data and transmitted.

FIG. 2A is a configuration diagram of a local area network (LAN) interworking system to which the present invention is applied, where “21” is a local area network (LAN), “22” is a B-ISDN connectionless data bearer service (BCDBS) router, and "23" represents a ConnectionLess Service Funtion (CLSF), respectively. This represents the interworking between existing LANs 21 using BCDBS.

The BCDBS router 22 enables communication of existing LANs 21 through an ATM network.

Each BCDBS router 22 communicates using the CLSF 23 in the ATM network. At this time, data is transmitted between the BCDBS router 22 and the CLSF 23 using the CLNAP protocol.

2B is a structural diagram of a B-ISDN connectionless data bearer service (BCDBS) protocol stack used in the present invention.

The BCDBS protocol consists of Internet Protocol (IP), Connectionless Network Access Protocol (CLNAP), ATM Adaptive Layer 3/4 (AAL3 / 4), Asynchronous Transfer Mode (ATM), and Physical Layer (PHY).

Each BCDBS router 22 communicates via an ATM network using AAL3 / 4 type. Thus, in order for existing LANs 21 to communicate using the BCDBS router 22, IP data packets must be converted to AAL3 / 4 data and transmitted over an ATM link. For this purpose, LLC / SNAP is used for the CLNAP protocol or the IP protocol can be defined above.

3A is a diagram illustrating an example of a system to which the present invention is applied. This allows the communication device having one ATM network interface to communicate with the IPOA system and simultaneously with the BCDBS router 33 so that the communication device having one ATM network interface can simultaneously support the existing LAN 34.

Logical Internet subnet (LIS) 31 includes asynchronous delivery mode (ATM) address resolution protocol (ARP) server 311, Internet protocol (IP) over asynchronous delivery mode (IOPA) system 312, and internet protocol over asynchronous delivery. Mode / connectionless data bearer service (IPOA / BCDBS) system 313.

The IPOA / BCDBS system 313 can communicate with a plurality of IPOA systems 312 in the LIS 31 of the ATM network, and the BCDBS router 33 by ATM connection with the BCDBS router 33 through the CLSF 32. It is possible to access the existing LAN 34 via.

In order to simultaneously accommodate IPOA and BCDBS, as shown in FIG. 3B, both the LLC / SNAP encapsulation and CLNAP protocols must be supported, and the AAL type must have a protocol stack structure supporting both AAL5 and 3/4.

Protocols supporting IPOA and BCDBS simultaneously include Internet Protocol (IP), Connectionless Network Access Protocol (CLNAP), and Logical Link Control / Subnetwork Addition (LLC / SNAP), ATM Adaptation Layer 5 and 3/4 (AAL5 and 3). / 4), asynchronous delivery mode (ATM), and physical layer (PHY).

In order to support both IPOA and BCDBS in one physical ATM network interface, ATM network interface is logically divided into IPOA network interface supporting IPOA and BCDBS network interface supporting BCDBS.

Therefore, when establishing an ATM connection, a network interface type (BCDBS or IPOA) and an AAL type (AAL3 / 4 or AAL5) may be designated to connect with the IPOA system 312 or the BCDBS router 33.

Tables required for establishing an ATM connection with the BCDBS router 33 or the IPOA system 312 are as shown in Figs. 4A to 4C.

4A-4C show the structure of the Asynchronous Transfer Mode (ATM) Connection Table, ATM Address Resolution Protocol (ATM ARP) Table, and Network Interface Table, respectively.

The Asynchronous Connection Mode (ATM) connection table (see FIG. 4A) includes a connection identifier (cid), a virtual path identifier (vpi), a virtual channel identifier (vci), an AAL type, a network interface type (if_no), a state, and ATM addresses are stored.

The ATM ARP table (see FIG. 4B) stores state, connection identifier (cid), network interface type (if_no), IP address, and ATM address.

The network interface table (refer to FIG. 4C) is constructed to call a different function according to the network interface type in IP by designating a corresponding network interface function according to the network interface defined at the time of communication device initialization. For example, in IP, different functions are called depending on whether the network interface of the next destination of the IP data packet is IPOA or BCDBS.

5 is a state diagram illustrating a connectionless service support method between software blocks to which the present invention is applied.

First, the IP task 51 transmits IP data through the IP output interface 52 (501).

IP output interface 52 then runs IPOA task 54 if the next destination network interface type of the IP data packet is IPOA, and BCDBS task 55 if the next destination network interface type of the IP data packet is BCDBS. Drive (503).

Next, IPOA task 54 generates an LLC / SANP Encapsulation data packet and transmits data to AAL task 58 via the AAL input interface 504 (506). At this time, the connection identifier (cid) of the corresponding data generated from the ATM ARP table (see Figure 4b) is transmitted together.

In addition, the BCDBS task 55 generates a CLNAP data packet and transmits the data to the AAL task 58 via the AAL input interface 56 (505) (506).

Finally, the AAL task 58 finds the corresponding AAL type in the ATM connection table (see FIG. 4A) using the connection identifier (cid), generates an AAL3 / 4 or AAL5 message, and transmits data to the ATM layer.

Conversely, when the AAL task 58 first receives data from the ATM layer, it uses the linkage identifier (cid) of that data to find the network interface type in the ATM connection table (see FIG. 4A) to determine the network interface type of the message. In addition to the header, it is sent to the AAL output interface 57 (507).

The AAL output interface 57 then uses the connection identifier (cid) to drive the IPOA task 54 if the ATM network interface type is IPOA (508), and to drive the BCDBS task 55 if the ATM network interface type is BCDBS. (509).

Next, the IPOA task 54 extracts an IP data packet from the received data and transmits it to the IP task 51 through the IP input interface 53 (510) (512).

In addition, the BCDBS task 55 extracts an IP data packet from the received data and transmits it to the IP task 51 through the IP input interface 53 (511) (512).

Looking at this in more detail, Figure 6a shows a connectionless service support method from the IP layer to the AAL layer, Figure 6b inversely shows a connectionless service support method from the AAL layer to the IP layer.

A method of supporting a connectionless service from the IP layer to the AAL layer (see FIG. 6A) is as follows.

First, IP data is received from IP task 51 at IP output interface 52 (601) to determine the next destination network interface type of the IP data packet to be transmitted (602).

If the network type to be transmitted is BCDBS, the BCDBS task 55 is started (603), the BCDBS task 55 generates a CLNAP header excluding the destination address (604), and then the ATM ARP table (FIG. 4B) is searched for the CLNAP header. In step 605, the destination address is inserted into the AAL input interface 56 by inserting the connection identifier (cid) into the message header.

Meanwhile, if the network type to be transmitted is IPOA, the IPOA task 54 is driven (606), the LLC / SNAP encapsulation is performed in the IPOA task 54 (607), and then the ATM ARP table (FIG. 4B) is retrieved and connected. The identifier (cid) is inserted into the message header (608) and sent to the AAL input interface 56 (609).

Finally, the data received through the AAL input interface 56 uses the connection identifier (cid) in the AAL task 58 to find the corresponding AAL type in the ATM connection table (FIG. 4A) to generate the corresponding AAL message ( 610) Send data to the ATM layer.

In addition, a method of supporting a connectionless service from the AAL layer to the IP layer (see FIG. 6B) is as follows.

First, after receiving the AAL message from the AAL task 58, the network interface type is found in the ATM connection table (FIG. 4A) using the connection identifier (cid), and the network interface type is inserted into the header of the message (611). Send to output interface 57 (612).

Thereafter, the network interface type to be transmitted is determined by using the connection identifier (cid) of the corresponding data received by the AAL output interface (57) (613).

If the network interface type to be transmitted is BCDBS, the BCDBS task 55 is driven (614), and the IP data packet is extracted from the data received by the BCDBS task 55 (618) through the IP input interface 53 (618). 51). If the data received by the BCDBS task 55 is a protocol other than the IP data packet, the data is separately processed (615).

Meanwhile, if the network interface type to be transmitted is IPOA, the IPOA task 54 is driven (616), and the IP data packet is extracted (617) from the data received from the IPOA task 54 (618) through the IP input interface 53 (618). ) Is transmitted to the IP task 51.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the spirit of the present invention for those skilled in the art to which the present invention pertains, and the above-described embodiments and accompanying It is not limited to the drawing.

According to the present invention as described above, since a single physical ATM network interface can support different services IPOA and B-ISDN connectionless data bearer service (BCDBS) at the same time, a system supporting only IPOA and only a system supporting only BCDBS Transient communication is possible, and by adding LAN interface, existing LAN and B-ISDN can be linked.

Claims (8)

A method of supporting a connectionless service in an asynchronous delivery mode network, A first step in which the connectionless output interface receives the connectionless data packet from the connectionless task, determines a network interface type to be transmitted, and then drives the corresponding connectionless task; A second step of the connected task generating a message suitable for the connected type from the connected table by using the connected identifier received from the corresponding disconnected task; A third step of driving the corresponding connectionless task corresponding to the network interface type to be transmitted from the connected table by using the connection identifier of the connected data received from the connected task at the connected output interface; And A fourth step of the connectionless task receiving the connectionless data packet extracted from the connectionless task through the connectionless input interface; Connectionless service support method in an asynchronous delivery mode network comprising a. The method of claim 1, The network interface types to be transmitted in the first and third steps are respectively, The B-ISDN Connectionless Data Bearer Service (BCDBS) interface and Internet Protocol (IP) functions are mapped directly to the virtual connections of the ATM network (IPOA: IP Over ATM). Connectionless service support method in an asynchronous delivery mode network, characterized in that the interface. The method of claim 2, The first step is, A fifth step of receiving disconnected data from the disconnected task at the disconnected output interface; Determining a next destination network interface type of a connectionless data packet to be transmitted at the connectionless output interface; A seventh step of driving the corresponding connectionless task if the network type to be transmitted is a broadband integrated data network connectionless data bearer service (BCDBS); And An eighth step of driving the corresponding connectionless task when the network type to be transmitted directly maps (IPOA) Internet protocol functions to a virtual connection of an asynchronous delivery mode network; Connectionless service support method in an asynchronous delivery mode network comprising a. The method according to claim 1 or 3, The second step, A ninth step of generating a connectionless network access protocol (CLNAP) header excluding a destination address in a broadband integrated data network connectionless data bearer service (BCDBS) task; A tenth step of searching for a connection type resolution table and inserting a destination address into the connectionless network access protocol header and inserting a connection identifier (cid) into a message header and transmitting the connection address to the connection type input interface; An eleventh step of encapsulating logical link control / subnetwork addition points (LLC / SNAP) in a task of directly mapping to a virtual connection of an asynchronous delivery mode network (IPOA); A twelfth step of searching for the connection-type address analysis table and inserting a corresponding connection identifier (cid) into a message header and transmitting it to the connection-type input interface; And A thirteenth step of identifying a corresponding connection type in the connected table by using a connected identifier (cid) in the connected task from the data received through the connected input interface and generating a corresponding connected message; Connectionless service support method in an asynchronous delivery mode network comprising a. The method of claim 4, wherein The third step, A fourteenth step of receiving a connected message from the connected task, finding a network interface type from the connected table by using a connected identifier (cid), inserting a network interface type into a header of the message, and transmitting it to the connected output interface; A fifteenth step of determining a network interface type to be transmitted using a connection identifier (cid) of corresponding data received at the connected output interface; A sixteenth step of driving the connectionless task if the network type to be transmitted is a broadband integrated data bearer connectionless data bearer service; And Step 17 of driving the corresponding connectionless task when the network type to be transmitted directly maps (IPOA) Internet protocol functions to a virtual connection of an asynchronous delivery mode network; Connectionless service support method in an asynchronous delivery mode network comprising a. The method of claim 5, The fourth step, An eighteenth step of extracting connectionless data from the BDC task and transmitting the connectionless data to the connectionless task through the connectionless input interface; And A nineteenth step of extracting a connectionless data packet from data received in a task of directly mapping to a virtual connection of an asynchronous delivery mode network and transmitting the connectionless data packet to the connectionless task through the connectionless input interface; Connectionless service support method in an asynchronous delivery mode network comprising a. The method of claim 6, The linked tables of the second, third, thirteenth, and fourteenth stages are respectively: Includes connection identifier (cid), virtual path identifier (vpi), virtual channel identifier (vci), asynchronous delivery mode adaptive layer (AAL) type, network interface type (if_no), state, and asynchronous delivery mode address. Connectionless service support method in an asynchronous delivery mode network, characterized in that the. The method of claim 7, wherein The linked address resolution table of steps 10 and 12, respectively, Connectionless services in an asynchronous delivery mode network, including state, connection identifier (cid), network interface type (if_no), Internet protocol (IP) address, and asynchronous delivery mode (ATM) address. How to apply.

Images