KR970011679B1 - Satellite system - Google Patents

Abstract

An apparatus for communication protocol subscribers service and a method thereof are provided, in which the apparatus for communication protocol subscribers service includes an outer matching processing part (310) for processing messages from external to transmit them to corresponding processing parts, an LAPB packet processing part (320) for LAPB end-to-end communication, an X.25 packet processing part (330) for operating the packet hierarchy functions such as virtual line setting or release and the X.25 end-to-end communication, a frame processing part (340) for processing LAPB frames to set/cut off a data link, and a physical hierarchy processing part (350), wherein the packets may be constructed by satellites so that subscribers in a retired and remote places may be served with the packet exchange service and two protocols due to the software structure per hierarchy.

Description

Communication protocol subscriber service device using satellite and method

1 is a block diagram of a low-speed data dedicated earth station system (VDS-100) to which the present invention is applied.

2 is a diagram of a service structure of the X.25 protocol.

3 is a structural diagram of an X.25 protocol subscriber service apparatus according to the present invention;

4 is a flowchart of execution and protocol processing of the X.25 protocol according to the present invention.

5A and 5B are respectively an address format diagram of the X.25 protocol used in the prior art and an address format diagram used in the present invention.

6 is a flowchart illustrating a call setup process of a VSAT network and a PSDN.

7 and 8 are explanatory diagrams for explaining a call setup and address translation method of a VSAT network and a PSDN subscriber.

9 is a call processing flow diagram of an X.25 protocol connected to a PSDN.

* Explanation of symbols for main parts of the drawings

310: external matching processing unit 320: LAPB packet processing unit

330: X.25 packet processing unit 340: frame processing unit

350: physical layer processing unit 321, 331, 341, 451: queue

The present invention relates to a communication protocol subscriber service device and method using a satellite, and in particular, connects an X.25 subscriber using a satellite without using a land line, and uses an existing public packet switched data network (PSND). The present invention relates to a communication protocol subscriber service device and a method using a satellite that can be connected to and receive all services provided by an existing communication network.

The existing network serving the subscriber using the CCITT Recommendation X.25 protocol shall be connected to the access node in the subscriber's access area and each access node to the terrestrial trunk line to the destination desired by the subscriber.

However, the packet switching network as described above has difficulty in providing a packet service to a subscriber in an area where connection between a wallpaper and a ground link is difficult.

Accordingly, the present invention solves the above problems by constructing a system for connecting X.52 subscribers using satellites without using a land line for X.25 subscriber service, and the existing public data network (PSDN). It is an object of the present invention to provide a communication protocol subscriber service device and method using a satellite that can be provided with all the services provided by the existing communication network by connecting to the network.

In addition, another object of the present invention is designed in a hierarchical structure, according to the subscriber's needs, the communication protocol subscriber service using a satellite that can independently provide a link protocol LAPB (Link Accept Procedure Balanced) protocol and packet protocol X.25 It is to provide an apparatus and method.

In order to achieve the above object, the present invention receives an LAPB / X.25 protocol control message, a local LAPB / X.25 message, a remote LAPB / X.25 message, and the like, and sends them to the processing unit. Processing unit; LAPB for end-to-end communication of the LAPB protocol, which receives the LAPB control message and the LAPB frame of the external matching processor, transmits a local LAPB packet to a remote LAPB protocol, and outputs a remote LAPB packet. A packet processor; X.25 packet is generated by receiving the LAPB control message and the LAPB frame of the external matching processing unit, and transmits the local X.25 packet to the remote X.25 protocol and outputs the remote X.25 packet. An X.25 packet processing unit for packet layer functions such as 25 end-to-end communication and virtual line establishment and release; A LAPB control message, a remote LAPB / X.25 message from a LAPB / X.25 packet processing unit, a remote LAPB packet and a local LAPB / X.25 message from a LAPB packet processing unit are received from the external matching processor, and the LAPB frame is a LAPB packet. Frame processing unit for transmitting and processing LAPB frames that transmits LAPB / X.25 frames to X.25 packet processing units and outputs LAPB / X.25 frames at remote locations to establish and disconnect data links. ; And a physical layer that receives and processes an external control message, sends a local LAPB / X.25 frame received from the outside to the frame processing unit, and receives a remote LAPB / X.25 message from the frame processing unit and outputs the message to the outside. It is characterized by including a processing unit.

In addition, the present invention is a service method applied to a communication protocol subscriber service device using the configuration having the above configuration, when the execution of the protocol is started, initialize all processing units of X.25, the message is input from the external queue A first step of classifying according to the message characteristic, if any; If the message input in the first step is a protocol termination message, a second step of initializing all used memories to terminate the protocol and sending all messages except the termination message to the corresponding processing unit; If the message transmitted in the second step is a LAPB packet processing unit message, the LAPB packet processing unit receives and processes the message, sets an input event of the finite state machine, sends it to the finite state, performs the execution routine, and sends a message. A third step of sending a message to a corresponding processing unit or a remote LAPB protocol, if any, and then waiting for a message reception of the LAPB packet processing unit; If the message transmitted in the second step is an X.25 packet processing unit message, the X.25 packet processing unit handles the message by handing it up, sets the input event of the finite state machine, and sends it to the finite state machine to execute the execution routine. A fourth step of sending a message to a corresponding processing unit or a remote X.25 protocol if there is a message to be transmitted, and then waiting to receive a message from the X.25 packet processing unit; If the message transmitted in the second step is a frame processing unit message, the frame processing unit receives and processes the message, sets the input event of the finite state machine, sends it to the finite state to perform the execution routine, and if there is a message to be transmitted. A fifth step of sending a message to the processing unit and proceeding to a state of waiting for a message reception of the frame processing unit; If the message transmitted in the second step is a physical layer message, the physical layer processor receives and processes the message, and if there is a message to be sent, sends the message to the corresponding processor or the LAPB / X.25 protocol, and then receives the message from the physical layer processor. A service method applied to a communication protocol subscriber service apparatus using a satellite comprising: a sixth step of advancing to a waiting state, wherein an X.25 packet processing unit is executed and an X.25 packet processing unit message is inputted. Determining whether the message is input from a local X.25 protocol or a message input from a remote X.25 protocol. A second step of classifying an input message as an X.25 packet and determining whether the call is a request packet or a call reception completion packet if the local X.25 protocol message is the first step; If the call request packet is the second step, the PSDN call address and the called address of the call request packet are stored in a memory, and the destination address of the VSAT network extracted from the extended address format of the call request packet and the VSAT address of the protocol are used. Generating a new incoming call packet and transmitting the incoming call packet to a remote X.25 protocol; A fourth step of generating a new call connection complete packet using the stored VSAT address and transmitting the call connection complete packet to a remote X.25 protocol if the call reception complete packet is the second step; In the first step, if the X.25 packet processing unit message is a message inputted from a remote X.25 protocol, the input message is classified into an X.25 packet, and the fifth step of determining whether the message is a call request packet or a call reception completion packet. step; A sixth step of generating a new call connection complete packet using the stored PSDN address after the call connection complete packet in the fifth step, and transmitting the generated call connection complete packet to a remote X.25 protocol; And in the fifth step, if the incoming packet is an incoming packet, storing the VSAT calling address and the called address of the incoming packet in a memory and extracting the destination address of the VSAT network and its own PSND address of the protocol. And generating a new incoming packet using the seventh step, and transmitting the generated incoming packet to a remote X.25 protocol.

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

1 is a block diagram of a low-speed data dedicated earth station (VDS-100) system to which the present invention is applied.

The VDS-100 system is a VSAT (Very Small Aperture Satellite Earth Station) system that provides up to 500 terminal stations (VRS-100) around the central station (VSC-100) in the form of a forming network to provide data-only services. The central station (VCS-100) includes a radio frequency (RF) subsystem 111, an intermediate frequency (112) subsystem 112, a DIE subsystem 113, and a network management subsystem (NMS) 114 It is composed of) to perform the central function of the network.

The central station RF subsystem 111 exists between the central station antenna and the IF subsystem to generate 10 MHz, which is a network reference signal, and is responsible for the transmission and reception function for converting the IF signal into an RF signal. IF subsystem 112 is present between the Data Interface Equipment (DIE) subsystem and the RF subsystem to perform the function of converting baseband signals to IF signals. The DIE subsystem 113 is a subscriber access unit and performs functions such as subscriber or host interface, subscriber protocol processing, and satellite access protocol processing.

Network management operation subsystem 114 is responsible for the overall maintenance, operation, management functions of the network. The terminal station (VRS-100) is divided into an outdoor device 121 and an indoor device 122, and performs a subscriber access function by communicating with a central station. The outdoor device 121 has a transmission block frequency converter (TBU: Transmit Block Upconverter) for performing the RF unit transmission function, a low noise block downconverter (LNB) for performing the reception function, and an interface function with the indoor device. It consists of an outdoor regulator (OAB: Outdoor Adapter Box) that performs the operation. The indoor unit 122 may include a power supply unit, a transmitter TX for transmitting an IF signal, a receiver RX for receiving an IF signal, a baseband and controller (BB & C) for performing a terminal station control function, and a subscriber access. And a terminal station DIE board performing a protocol processing function.

The present invention is a subscriber access protocol supporting the X.25 and LAPB protocols, and the user interface card (UIC) board of the central station DIE subsystem 113 and the terminal station indoor device 122 in the network management operation system (NMS) 114. It is downloaded and operated by DIE board of terminal station.

2 shows an X.25 protocol service structure diagram for explaining the logical concept of the present invention. X.25 protocol services use satellites to provide data communication services over virtual lines to the desired destination of the subscriber.

In the present invention, a protocol (LAPB / X.25 protocol) is determined by an operator of the network operation management subsystem 114, and the LAPB and X.25 protocols are composed of three layers (physical layer, link layer, and packet layer). Support subscriber access function. The boards of the DIE subsystem 113 of the central station (VCS-100) are connected to each other by a Time Devision Multiplex (TDM) bus and communicate with a transmission rate of about 56 kbps.

Microtel Data Link Control (MDLC), which is a modification of the satellite link protocol High Level Data Link Control (HDLC), is used. MDLC is a point-to-multipoint protocol and establishes a satellite link of a central station and a terminal station with the same frame structure as that of the LAPB protocol extension format (Mod. 128).

3 is a structural diagram of an X.25 protocol subscriber service device according to the present invention, where 310 is an external matching component, 320 is a LAPB packet component, 330 is an X.25 packet processing component (L3 Component), 340 denotes a frame component and 350 denotes a physical layer processor. The external matching processor 310 has an external queue 311 for receiving an external input of the protocol, and all the processing units 320, 330, 340 and 350 except for the external matching processor 310 have an internal queue for receiving messages generated inside the protocol. (321,331,341,351).

The operation of the subscriber service device having the above configuration is as follows.

The external matching processing unit 310 is responsible for receiving LAPB / X.25 protocol control messages, local LAPB / X.25 messages, and remote LAPB / X.25 messages and sending them to the processing unit. Here, the protocol service is determined by the operator of the network operation management subsystem 114, and the external matching processing unit receives this protocol control message and specifies whether to provide a LAPB protocol service or an X.25 protocol service. The external matching processing unit executes the start-up and termination of the protocol by the operator, receives the protocol control message, sends it to the processing unit 320, 330, 340, 350, and sends the received local LAPB / X.25 message to the physical layer processing unit 350. . Remote LAPB / X.25 messages are divided into LAPB protocol messages and X.25 protocol messages and are transmitted to the corresponding packet processing units 320 and 330.

The LAPB packet processor 320 is in charge of end-to-end communication of the LAPB protocol, and operates by being composed of a message processing block 320A, a finite state machine 320B, a message transmission block 320C, and the like. The message processing block 320A receives and processes an external LAPB control message and a LAPB frame of the frame processing unit 340, and sets an input event of the finite state machine 320B to call the paid state 320B. The finite state machine 320B receives an input event from an old state of the LAPB packet processor 320 to perform each action routine and stores a new state. The message transmission block 320C classifies the transmission message of the finite state machine 320B and sends a local LAPB packet to a remote LAPB packet to the frame processor 340.

The X.25 packet processing unit 330 is in charge of packet layer functions such as end-to-end communication of X.25 and the establishment and release of virtual lines, and the message processing block (LAPB packet processing unit 320). 330A, a finite state machine 330B, and a message transmission block 330C. The message processing block 330A receives and processes an external X.25 control message, receives and processes a LAPB frame of a frame processing unit, generates a LAPB packet, sets an input event of the finite state machine 330B, and calls a finite state machine. . The finite state machine 330B receives an input event from all states of the X.25 packet processor, executes each execution routine, and stores a new state. The message transmission block 330C classifies the transmission message of the finite state machine, transmits the local X.25 packet to the remote X.25 protocol, and sends the remote X.25 packet to the frame processor 340.

The frame processing unit 340 is composed of a message processing block 330A, a finite state machine 340B, and a message transmission block 340C, and is responsible for a function of a link layer, that is, a function of setting and disconnecting a data link by processing a LAPB frame. do. The message processing block 340A receives and processes an external control message, receives a remote LAPB / X.25 message from a LAPB / X.25 packet processing unit, and a local LAPB / X.25 message from a physical layer processing unit. Call the finite state machine by setting the input event of. The finite state machine 340B receives an input event from all states of the frame processor, performs each execution routine, and stores a new state. The message transmission block 340C classifies the transmission message of the finite state machine and sends a local LAPB / X.25 frame to the LAPB / X.25 packet processing unit 320 and 330 and transmits a remote LAPB / X.25 frame to the physical layer processing unit 350. Send to).

The physical layer processing unit 350 receives and processes an external control message as a part having an interface with the physical layer, and sends a local LAPB / X.25 frame received from an external (line driver) to the frame processing unit 340. Sends a remote LAPB / X.25 message through the line driver.

4 is a flowchart illustrating execution and protocol processing of the X.25 protocol according to the present invention.

When the execution of the protocol begins (401), all processing units 310, 320, 330, 340, 350 of the X.25 are initialized (402) and the X.25 protocol waits for message input from the external queue 311 (403).

If an external message of the protocol is input (403), it is classified according to the message characteristics (404), and if there is a protocol termination message, and if it is a protocol termination message (405), all used memory is initialized (406) to terminate the protocol. All messages except this are sent to the processing unit 320, 330, 340, 350 (408).

If the message sent to the processing unit 320, 330, 340, 350 is a LAPB packet processing unit message, the LAPB packet processing unit 320 receives the message (409), processes it (413), sets the input event of the finite state machine, and sends it to the finite state machine. In operation 417, the finite state machine performs a corresponding execution routine according to an input event. In step 420, if there is no message, the process moves to the waiting state for receiving a message from the LAPB packet processing unit (409). After sending to the network (424), the process moves to the state (409) waiting for the message reception of the LAPB packet processing unit.

On the other hand, if the message sent to the processing unit (320, 330, 340, 350) is an X.25 packet processing unit message performs the function of the X.25 packet processing unit 330 through the same processing procedure as the case of the LAPB packet processing unit message.

If the message sent to the processor 320, 330, 340, or 350 is a frame processor message, the frame processor 340 receives the message (411), processes it (415), and the finite state machine receives an input event to perform an execution routine (419). ). If there is a message to be sent to the other processing unit (422), the message is sent to the processing unit (426), and the process proceeds to the message reception waiting state (411) of the frame processing unit.

Finally, if the message sent to the processing unit 320, 330, 340, 350 is a physical layer processing unit message, the physical layer processing unit 350 receives the message (412), processes and classifies it (416), and then another processing unit or local LAPB / X.25. After determining whether there is a message to be sent to the protocol (423) and sending it to the processing unit or the LAPB / X.25 protocol (427), the physical layer processing unit proceeds to the message reception waiting state (412).

5 shows the format of an address of the X.25 protocol. In general, the address format of the X.25 protocol uses the same X121 address format as that of FIG. 5A. The present invention can designate all the central station and terminal station ports in the satellite network by configuring 10 digits (BCD Digits), such as the 5B diagram, to indicate the address inside the VSAT.

The addressing method of the present invention is applied to an internal routing method for designating a component and a terminal station of a central station in a satellite, and delivers an X.25 packet to a desired destination. Routing specifies the location of the card, represented by the rack, self, and slot of the central station, and the location of the port connected to that card, and the location of the terminal number and port connected to that terminal. One port of the central station or the terminal station supports multiple fixed virtual circuits (PVD) and multiple switched virtual circuits (SVC) to allow multiplexing. Up to 32 virtual circuits are supported in the current system (PVC: 16, SVC: 16). The PVC is confedure by the operator in the network management system 114, and the SVC specifies the destination desired by the subscriber.

In FIG. 5, GN denotes a digit for representing a local group, ST denotes a digit for recognizing a central station and a terminal station, SN denotes a digit for indicating a terminal station number, PN denotes a port number, and SA denotes a digit representing a sub address. Represent each.

The present invention can be provided with the service of the existing network by connecting the subscriber station to the central station or terminal station to the public data network (PSDN). FIG. 6 shows an overall flowchart of a call setup process of a VSAT network subscriber and a PSND subscriber, and the call setup process is described in detail with reference to FIGS. 7 and 8.

7 illustrates a call setup and address conversion process between the VSAT network and the PSDN when the VSAT network and the PSDN are connected as described above, and FIG. 7A illustrates a call setup flowchart of the PSDN subscriber. X.25 of the central station A receiving the call request packet from the PSDN stores the calling address PD and the called party address PC of the PSDN as shown in ①② of FIG. 8A, and then calls the VSAT. An incoming call packet changed to the address VB and the called address VA is transmitted to X.25 of the terminal station b. X.25 of the terminal station receives the incoming call packet as ⓒⓓ in Fig. 8B and transmits it to the subscriber terminal and receives call accept packet from the subscriber terminal as in ⑦⑧ of Fig. 7A. Connected) packet and send it to the central station (A) with X.25. X.25 of the central station A receiving the call connection complete packet converts the VSAT addresses (VA, VB) to the PSDN using the call address (PD) and the called address (PC) of the stored PSDN as shown in ⓔⓕ in FIG. 7B. The call is established by sending the call connection completion packet changed to the address (PC, PD) to the PSDN network.

FIG. 7B shows a call setup flow diagram of a VSAT network subscriber. X.25 of a terminal station C includes a PSDN destination address PD in an extended address format from a subscriber terminal, as shown in FIG. Receives a call request packet, generates an incoming call packet, and sends it to X.25 of the central station (D). X.25 of the central station (D) receiving the incoming call packet stores the calling address (VA) and the called address (VB) in the VSAT as shown in ⑨ of FIG. 8B, and then the calling address (PC) and the called address of the PSDN. The incoming call packet changed to the address PD is transmitted to the PSDN. In addition, X.25 of the central station D receives the call reception completion packet from the PSDN as ⑤⑥ in FIG. 8A and converts the PSDN addresses (PC, PD) to the VSAT addresses (VA, VB) using the stored VSAT addresses (VA, VB). The call connection completion packet, which has been changed to VB), is sent to X.25 of the single station C. The X.25 of the terminal station C that has received the call connection completion packet is a call connection completion packet as shown in FIG. 8B. The call is established by sending a message to the subscriber terminal.

9 is a call processing flowchart of an X.25 protocol connected to a PSDN, and is performed by the following processing procedure.

In the X.25 protocol, the X.25 packet processing unit 330 performs an X.25 call setup process. When the X.25 packet processing unit is executed (801), the X.25 packet processing unit waits for an X.25 packet processing unit message through the internal queue 331 of the X.25 packet processing unit (802).

When an X.25 packet processing unit message is input (802), it is determined whether the message is input from a local X.25 protocol or a message is input from a remote X.25 protocol (803). The X.25 protocol message is classified as an X.25 packet (804) and compared whether it is a call request packet or a call accept packet (806).

If the call request packet, the PSDN call address and the called address of the call request packet are stored in the memory (808), and the call request packet of the X.25 protocol connected to the PSDN includes the VSAT network destination address in the extended address format. After the new incoming packet is generated using the destination address of the extracted VSAT network and its own VSAT address of the protocol (810), the incoming packet is transmitted to the remote X.25 protocol (814), and the execution of the initial message is received. Moved to standby state 802.

On the other hand, it is a call reception completion packet received after receiving and executing an incoming call packet, and generates a new call connection completion packet using the stored VSAT address (811), and the call connection completion packet is a remote X.25 protocol. 815 and execution is transferred to the initial message waiting state 802.

If the X.25 packet processing unit message is a message input from a remote X.25 protocol (803), the input X.25 protocol message is classified as an X.25 packet (805) and is a call request packet or a call reception completion packet. Cognitive is compared 807.

After receiving and executing the call request packet, if the call connection complete packet is a received packet, a new call connection complete packet is generated using the stored PSDN address (812), and the generated call connection complete packet is stored at the remote X. The protocol is sent 816 and execution is moved to state 802 instead of initial message reception.

On the other hand, if the incoming packet is 807, the incoming packet stores the extended address and the called address in memory (809), and the incoming packet of the X.25 protocol connected to the PSDN is the VSAT network destination address in the extended address format. Since the new incoming call packet is generated using the destination address of the extracted VSAT network and its own PSDN address of the X.25 (813), the incoming call packet is transmitted to the remote X.25 protocol ( 817) The action is moved to the initial message waiting state 802.

As described above, in the present invention, since a private packet network can be configured using satellites, a packet switched service can be provided to subscribers in areas where connection between island walls and terrestrial links is difficult, and a link protocol is provided because it has a layered software structure. It is designed to accommodate both X.25 protocols, including LAPB and link protocols, and can support each of the two protocols as required by the subscriber. In addition, the present invention can connect to the public data network (PSDN) at the subscriber station port of the central station or the terminal station, the VSAT network subscriber can be provided with the service provided by the existing public data network.

Claims (6)

An external matching processor 310 which receives LAPB / X.25 protocol control messages, local LAPB / X.25 messages, and remote LAPB / X.25 messages from the outside and sends them to the processing unit; Receives LAPB control message and LAPB frame of the external matching processing unit 301, local LAPB packet is transmitted to the remote LAPB protocol, and outputs the remote LAPB packet, end-to-end communication of the LAPB protocol LAPB packet processing unit 320 in charge; Receiving the LAPB control message and the LAPB frame of the external matching processor 310 generates an X.25 packet, and transmits the local X.25 packet to the remote X.25 protocol, and outputs the remote X.25 packet An X.25 packet processor 330 for packet layer functions such as end-to-end communication of X.25 and establishment and release of virtual lines; The LAPB control message and the remote LAPB / X.25 message of the LAPB / X.25 packet processing unit 330, the remote LAPB packet and the local LAPB / X.25 message of the LAPB packet processing unit 320 are transmitted from the external matching processor 310. The LAPB frame is transmitted to the LAPB packet processing unit 320, the LAPB / X.25 frame is transmitted to the X.25 packet processing unit 330, and outputs a LAPB frame to output a remote LAPB / X.25 frame. A frame processor 340 for processing a function of establishing and disconnecting a data link; And receive and process an external control message, send a local LAPB / X.25 frame received from the outside to the frame processing unit 340, and receive a remote LAPB / X.25 message from the frame processing unit and output it to the outside. Communication protocol subscriber service device using a satellite, characterized in that it comprises a physical layer processing unit (350). The LAPB packet processing unit (320) of claim 1, further comprising: a message processing block (320A) for receiving and processing an external LAPB control message and a LAPB frame of the frame processing unit (340), and setting an input event; A finite state unit 320B which receives an input event set in the message processing block 320A, performs each action routine, and stores a new state; And a message transmission block 320C for classifying a transmission message of the finite state machine 320B and transmitting a local LAPB packet to a remote LAPB protocol, and transmitting the remote LAPB packet to a frame processor 340. Communication protocol subscriber service device using a satellite. The method of claim 1, wherein the X.25 packet processor 320 receives and processes an external X.25 control message, receives and processes a LAPB frame of a frame processor to generate an X.25 packet, and sets an input event. Message processing block 330A; A finite state machine (330B) configured to receive an input event set by the message processing block (330A), perform each execution routine, and store a new state; And a message transmission block 330C which classifies the transmission message of the finite state machine 330B and transmits the local X.25 packet to the remote X.25 protocol and transmits the remote X.25 packet to the frame processor 340. Communication protocol subscriber service device using a satellite, characterized in that it comprises a. The LAPB / X.25 message of the LAPB / X.25 packet processing unit and the local LAPB / X.25 of the physical layer processing unit according to claim 1, wherein the frame processing unit 340 receives and processes an external control message. A message processing block 340A for receiving and processing a message and setting an input event; A finite state machine (340B) configured to receive an input event set by the message processing block (340A), perform each execution routine, and store a new state; The LAPB / X.25 frame is sent to the LAPB / X.25 packet processing unit 320,330 and the remote LAPB / X.25 frame is sent to the physical layer processing unit 350 by classifying the transmission message of the finite state machine 340B. Communication protocol subscriber service device using a satellite characterized in that it comprises a message transmission block (340C). An external matching processor 310 which receives LAPB / X.25 protocol control messages, local LAPB / X.25 messages, and remote LAPB / X.25 messages from the outside and sends them to the processing unit; Receives LAPB control message and LAPB frame of the external matching processor 310, and transmits the local LAPB packet to the remote LAPB protocol, and outputs the LAPB packet of the remote, End-to-End communication of the LAPB protocol LAPB packet processing unit 320 in charge of; Receiving the LAPB control message and the LAPB frame of the external matching processor 310 generates an X.25 packet, and transmits the local X.25 packet to the remote X.25 protocol, and outputs the remote X.25 packet An X.25 packet processor 330 for packet layer functions such as end-to-end communication of X.25 and establishment and release of virtual lines; The LAPB control message, the remote LAPB / X.25 message of the LAPB / X.25 packet processor 330, the remote LAPB packet and the local LAPB / X.25 message of the LAPB packet processor 320 are transmitted from the external matching processor 310. The LAPB frame is transmitted to the LAPB packet processor 320, the LAPB / X.25 frame is transmitted to the X.25 packet processor 330, and the LAPB frame is output to output a remote LAPB / X.25 frame. A frame processing unit 340 which is in charge of a function of setting and disconnecting a data link; And receive and process an external control message, send a local LAPB / X.25 frame received from the outside to the frame processing unit 340, and receive a remote LAPB / X.25 message from the frame processing unit and output it to the outside. In the service method applied to a communication protocol subscriber service device using a satellite having a physical layer processing unit 350, the execution of the protocol is initiated, the mode processing unit 310, 320, 330, 340, 350 of X.25 is initialized, and the external queue 311 A first step (401 to 404) of classifying the message according to the message characteristic when the message is inputted; If the message input in the first step is a protocol termination message, initializing all memories to terminate the protocol and sending all messages except the termination message to the corresponding processing unit (320, 330, 340, 350) (405 to 408); If the message transmitted in the second step is a LAPB packet processing unit message, the LAPB packet processing unit 320 receives and processes the message, sets an input event of the finite state machine, sends the finite state machine to perform a corresponding execution routine, A third step (409, 413, 417, 420, 424) of sending a message to a corresponding processing unit or a remote LAPB protocol if there is a message to be transmitted, and then waiting to receive a message from the LAPB packet processing unit; If the message transmitted in the second step is an X.25 packet processing unit message, the X.25 packet processing unit 330 accepts and processes the message, sets an input event of the finite state machine, and sends the message to the finite state machine for execution. A fourth step (410, 414, 418, 421, 425) of executing a routine, sending a message to a corresponding processing unit or a remote X.25 protocol if there is a message to be transmitted, and then waiting to receive a message from the X.25 packet processing unit; If the message transmitted in the second step is a frame processing unit message, the frame processing unit 340 receives and processes the message, sets an input event of the finite state machine, sends it to the finite state to perform the execution routine, and transmits the message. A fifth step (411, 415, 419, 422, 426) of sending a message to the processing unit if there is a message, and then proceeding to a state of waiting for receiving a message from the frame processing unit; If the message transmitted in the second step is a physical layer message, the physical layer processor 350 receives and processes the message, and if there is a message to be sent, sends the message to the corresponding processor or LAPB / X.25 protocol, and then the physical layer processor. Method of providing a communication protocol subscriber service using a satellite characterized in that it comprises a sixth step (412, 416, 423, 427) proceeding to wait for message reception External matching processor 310 for receiving and processing LAPB / X.25 protocol control messages, local LAPB / X.25 messages, and remote LAPB / X.25 messages from the outside to a corresponding processing unit. LAPB packet processing unit responsible for end-to-end communication of the LAPB protocol that receives a LAPB control message and a LAPB frame, and transmits a local LAPB packet to a remote LAPB protocol and outputs a remote LAPB packet. 320); Receiving the LAPB control message and the LAPB frame of the external matching processor 310 generates an X.25 packet, and transmits the local X.25 packet to the remote X.25 protocol, and outputs the remote X.25 packet An X.25 packet processor 330 for packet layer functions such as end-to-end communication of X.25 and establishment and release of virtual lines; The LAPB control message, the remote LAPB / X.25 message of the LAPB / X.25 packet processor 330, the remote LAPB packet and the local LAPB / X.25 message of the LAPB packet processor 320 are transmitted from the external matching processor 310. The LAPB frame is transmitted to the LAPB packet processor 320, the LAPB / X.25 frame is transmitted to the X.25 packet processor 330, and the LAPB frame is output to output a remote LAPB / X.25 frame. A frame processing unit 340 which is in charge of a function of setting and disconnecting a data link; And receive and process an external control message, send a local LAPB / X.25 frame received from the outside to the frame processing unit 340, and receive a remote LAPB / X.25 message from the frame processing unit and output it to the outside. In a service method applied to a communication protocol subscriber service apparatus using a satellite having a physical layer processing unit 350, an X.25 packet processing unit is executed and a X.25 packet processing unit message is inputted. A first step (801 to 803) for determining whether the message is input from a protocol or a message input from a remote X.25 protocol; A second step (804, 806) of classifying the incoming message into an X.25 packet and determining whether it is a call request packet or a call reception completion packet if it is a local X.25 protocol message in the first step; If the call request packet is the second step, the PSDN call address and the called address of the call request packet are stored in a memory, and the destination address of the VSAT network extracted from the extended address format of the call request packet and the VSAT address of the protocol are used. Generating a new incoming packet, and then transmitting the incoming packet to a remote X.25 protocol (808, 810, 814); A fourth step (811, 815) of generating a new call connection completion packet using the stored VSAT address and transmitting the call connection completion packet to a remote X.25 protocol if the call reception completion packet is the second step; In the first step, if the X.25 packet processing unit message is a message inputted from a remote X.25 protocol, the input message is classified into an X.25 packet, and the fifth step of determining whether the message is a call request packet or a call reception completion packet. Steps 805 and 807; If the call connection complete packet is generated in the fifth step, a new call connection complete packet is generated using the stored PSDN address, and then the sixth step (812,816) of transmitting the generated call connection complete packet to a remote X.25 protocol is performed. ); In the fifth step, if the incoming call packet is stored, the VSAT call address and the called address of the incoming call packet are stored in the memory, and a new incoming call is made by using the destination address of the VSAT network extracted from the extended address format and its own PSDN address of the protocol. And a seventh step (809, 813, 817) of transmitting the generated incoming call packet to a remote X.25 protocol after generating the packet.