KR960014426B1 - Closed user group processing method without priority among arbitrary packet user function - Google Patents

Abstract

301-325 setting a physical path by a PIC block according to a call setup request of a CUG function registered subscriber, creating the sending process (BPCCo) which accesses the sending subscriber information in a database, verifying the call set up request packet in order to supply the CUG function in case of a CUG information at the packet inside when the BPCCo receives the call setup request packet from the B25Ho in the sending side and disassembles the packet, requesting a physical path setup of a receiving side by translating a receive number into a number included in the packet inside, reassembling the call setup packet included the CUG information when reporting an arrangement of a logic channel from the receiving side, reporting a verifying result the call setup packet into the B25Ho, reporting the verifying result and moving into a data transfer state by verifying a received call connected packet; and setting the physical path by the receiving side PIC according to the receiving side physical path setting request of a sending state, reporting arranged result of a receiving logic channel and setting a receiving link layer, disassembling received packets when the BPCCt receives a receiving call packet verifying request from the B25Ht, reporting the receiving call packet verifying result into the B25Ht by reassembling the receiving call packet when the receiving subscriber can provide the CUG function, reporting the result, and moving into the data transfer state.

Description

How to handle closed user group without priority among packet random user functions

1 is a hardware configuration to which the present invention is applied.

2 is a general flow diagram in accordance with a temporary embodiment of the present invention.

3 is a detailed flowchart of a CUG origination process according to an embodiment of the present invention.

4 is a detailed flowchart of a CUG incoming process according to an embodiment of the present invention.

3 is a detailed flowchart of a release process according to an embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

1: ASS_I (Access Switching Subsystem for ISDN)

2: ASS_P (Access Switching Subsystem for Packet switching)

3: INS (Interconnecton Network Subsystem)

4: Database

11: IDPA (ISDN D-channel control Processor boar Assembly)

12: ISDN Subscriber Access Processor

13: ASP_I (Access Switching Processor for ISDN)

14, 24: TSP (Time Switch Processor)

15, 25: TSW (Time SWitch)

21: ASP_P (Access Switching Processor for Packet)

22: Packet Handling Module (PHM)

23: Packet Layer Control Processor (PLCP)

31: SSW (Space SWitch)

32: Space Switch Processor (SSP)

33: INP (Interconnection Network Processor)

34: Number Translation Processor (NTP)

The present invention relates to a method for processing closed usage group without priority among packet random user functions.

The non-priority closed user group function is one of the supplementary services provided to the packet-switched subscribers, enabling communication only between subscribers belonging to the closed user group, and communicating with subscribers belonging to other closed user groups or general subscribers. By disallowing it, it provides a function similar to a private network that only allows communication between groups with the same purpose.

Accordingly, an object of the present invention is to provide a method for processing a closed user group without priority among packet random user functions for providing various service opportunities to ISDN packet subscribers in the future according to the development trend of communication network technology.

In order to achieve the above object, the present invention provides a packet internal call control software block (PIC: Packet Inward-call) for performing functions such as packet call control / validation and number translation request in an ASP_P (Access Swithching Processor for Packet) for a packet subscriber. B-channel X having a Control and Packet Call Direction Control (PDC) software block and handling the link layer and packet layer processing functions of the X.25 protocol in a Packet Handling Modjue (PHM) for processing packet data. A B-channel packet call control software block (BCPP: B) having a 25 protocol processing software block (B25H: B-channel X.25 Protocol Handler), and a PLCP (Packet Layer Control Processor) for controlling B-channel packet calls. Closed User Group Without Preferentia among Random Packet User Functions applied to ISDN Packet Switching System with -channel Packet Call Control l) In the processing method, after the PIC block establishes a physical path according to a call establishment request of a subscriber whose CUG function is registered, the originating BPCC block accesses the originating subscriber information from the database to generate a originating process (BPCCo). After the BPCCo receives the call setup request packet from the source B25H block (B25Ho), it decomposes it, performs verification to provide the CUG function when the CUG information is included in the packet, and then includes the number included in the packet. After the called party translates the called number to the destination, it requests the called party's physical path setting.When the called party is informed that the logical channel has been allocated, it reassembles the call establishment packet including the CUG information, and then verifies the verification result of the call establishment packet from B25Ho. If a request for verification of a call connection packet is received from B25Ho, the received call connection packet is verified and the result is notified. In the following steps, after the destination PIC establishes the physical path by the first step and the request of the destination physical path, the destination BPCC block accesses the database of the destination subscriber to provide CUG functions to the destination. If possible, the destination logical channel is allocated to inform the calling party of the allocation result of the destination logical channel, and after setting up the destination link layer, the BPCCt decomposes the received packet when receiving an incoming packet verification request from B25Ht. If the called subscriber can provide the CUG function, the incoming call packet is reassembled to notify B25Ht of the incoming packet verification result, notified to B25Ht, and the request of verifying the call reception packet is received from B25Ht. And performing a verification and reassembly to notify the result, and then transitioning to a data transmission state.

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

FIG. 1 is a hardware configuration diagram to which the present invention is applied, in which '1' is an Access Switching Subsystem for ISDN (hereinafter referred to as 'ASS_I'), and '2'. 'Is an Access Switching Subsystem for Packet Switching (ASS_P'), '3' is an Interconnecton Network Subsystem (hereinafter referred to as' INS '),' 4 'is a database,' 11 'is an ISDN D-channel control processor board assembly (hereinafter referred to as' IDPA'), and '12' is a digital (ISDN) subscriber access processor (ISDN Subscriber). Access Processor (hereinafter referred to as 'ISAP'), '13' is a Digital (ISDN) Access Switching Processor for ISDN (hereinafter referred to as 'ASP_I'), '14' and '24' are time switch processors (Time Switch Processor; hereinafter referred to as 'TSP'), '15', '25' is referred to as Time SWitch (hereinafter 'TSW') '21' is an Access Switching Processor for Packet (hereinafter referred to as 'ASP_P'), '22' is a Packet Handling Module (hereinafter referred to as 'PHM'), and '23' Is a packet layer control processor (hereinafter referred to as PLCP), '31' is a space switch (hereinafter referred to as 'SSW'), and '32' is a space switch processor. Hereinafter referred to as 'SSP', and '33' denotes an internal connection network processor; Hereinafter, 'INP') and '34' represent a Number Translation Processor (hereinafter, referred to as 'NTP').

The ISDN switchboard is largely composed of an ASS_I (1) that matches the ISDN subscriber, an ASS_I (2) that performs the matching exchange of packet data, and an INS (3) that provides a switching function between the ASS_I and the ASS_P.

The ASS_I (1) is connected to the digital network termination device to control the ISDN D-channel, the IDPA 11, the IDPA 11, the ISAP 12, which is responsible for digital subscriber matching, and the ISPA 12. An ASP_I 13 connected to handle a digital subscriber access exchange, a TSP 14 connected to the ASP_I 13 to control a time switch, and a TSW (received by the TSP 14) to perform a time switching function; 15).

The ASS_P 2 is connected to the ASP_I 13 of the ASS_I, which is in charge of packet subscriber access exchange, and is connected to the ASP_P 21, which is connected to the ASP_P 21 to handle packet data by the PHM 22 and the PHM ( 22 is connected to the PLCP 23 for controlling the packet layer, the TSW 25 for performing the time switching function, and the TSP 24 for controlling the TSW 25. In addition, the INS 3 includes an SSW 31 that performs a spatial switching function, an SSP 32 that controls the connection of the SSW 31, an INP 33 that controls an internal connection network, and an NTP 34 that is responsible for number translation. It is composed of

As a software block required for processing a virtual line service B-channel packet local call attached to the above hardware configuration, the ASP_I 13 has a digital subscriber packet mode control block for digital subscriber packet mode control. mode control (hereinafter referred to as 'DPC'), a digital subscriber matching block (Digital Subscriber Interface; hereinafter referred to as 'DSI') that is responsible for digital subscriber matching in the ISAP 12, and a time switch link (TSP 14). Time Swich Link (hereinafter, referred to as 'TSL') and ASP_P 21 include Packet Inward-call Control (hereinafter referred to as 'PIC') that performs functions such as packet call control / verification and number translation request. And a packet call direction control (PDC) block, and the PHM 22 has a B-channel X.25 protocol processing block (B-channel) that is responsible for processing link and packet layers of the X.25 protocol. X.25 Pratocol Handler; hereafter referred to as 'B25H' B-channel packet call control block (B-channel Packet Call Control; hereinafter referred to as 'BPCC') that controls B-channel packet call in PLCP 23, and time switch link in TSP 24. Swich Link (hereinafter referred to as 'TSL'), INP (33) is a switch network control block for controlling the switch network (Swich Network Control; hereafter referred to as 'SNC'), NTP 34 is responsible for number translation Number translation blocks (hereinafter referred to as 'NTR') are implemented.

FIG. 2 is an overall flowchart according to an embodiment of the present invention, which will be described with reference to FIG. 1.

When the digital subscriber requests call setup, it is notified to the PIC block of the ASP_P 21 via the IDPA 11 through the DSI block of the ISAP 12 and the DPC block of the ASP_I 13.

The PIC block sets up the calling physical path and notifies the BPCC block of the PLCP 23. After completing the setting of the calling physical path, the BPCC block reads the status of the calling subscriber and the subscriber information from the database to determine whether to generate the calling process. After the determination, the call setup request packet is awaiting reception (201).

When the originating process is possible, when a call setup request packet is received from the originating terminal to the originating B25H block of the PHM 22 (hereinafter referred to as 'B25Ho'), the B25Ho is referred to as an originating BPCC block (hereinafter referred to as 'BPCCo'). In step 202, the BPCCo requests verification of the call setup request packet. In addition, BPCCo requests number translation and establishment of a destination physical path to the PDC block and the PIC block of the ASP_P 21 (203). The PIC block requests the establishment of the destination B-channel to the DPC block of the ASP_I 13 to set up the destination B-channel.

When the BPCCo receives a call connection packet verification request from B25Ho, the BPCCo performs disassembly, verification and reassembly of the call connection packet (204), and transmits the result to B25Ho so that the call terminal is notified of the call connection result. This leads to a packet call connection state. (205)

In the process of the called party, after the B-channel is set up, the called party's PIC block sets up the called party's physical path and notifies the called party's BPCC block of the completed result.

The called party BPCC block reads the status and information of the called party from the database to determine whether a called party BPCC process (hereinafter referred to as 'BPCCt') is generated (206).

In this case, when generation of BPCCt is possible, a logical channel is allocated (207), and the result is notified to BPCCo to inform that the BPCCo can be sent to the calling terminal, and the called party BPCCt disassembles and reassembles the received incoming packet. The verification result is transmitted to the destination B25H block (hereinafter referred to as 'B25Ht') to be transmitted to the destination terminal (208).

When a call reception packet is received from the B25Ht to the BPCCt block, the BPCCt decomposes the received packet, performs verification, reassembles it, and transmits the result to the B25Ht (209).

Accordingly, the B25Ht block transmits a result to the B25Ho with reference to the received call reception packet, which leads to a packet call connection state (210).

Referring to Figures 3 to 5 will be described in more detail the operation of the present invention.

In the present invention, since the closed user group without preferential processing (hereinafter referred to as CUG ') is dedicated to the BPCC block, only the contents of the BPCC block will be described.

3 is a detailed flowchart illustrating a CUG sending process according to an embodiment of the present invention.

When the subscriber CUG function request is received from the PIC from the calling party, the BPCC block accesses the calling subscriber's database and reads information on the calling subscriber (302). The creation of the process BPCCo is prepared (303). When a call setup request is received from B25Ho (304), the call setup request packet is decomposed (305) to determine whether CUG information is included in the call setup request packet (306).

If it is determined that the CUG information is not included in the call establishment request packet, it is verified whether the CUG function is registered in the exchange by referring to the value of accessing the subscriber's database (313).

If the CUG function is not registered as a result of the verification (314), the call number is requested as a general call state instead of the CUG call (312), and if the CUG function is registered (314), the number registered at the exchange is entered. After preparation for delivery to the called party (315), translation of the called party number is requested (312).

If the CUG information is included in the packet (306), it is verified whether the subscriber has registered the CUG function in the exchange by referring to the value of accessing the database (307).

If the subscriber does not register the CUG function (308) after performing the call release (309), the transition to the standby state, if the subscriber is registered CUG function (308) CUG included in the packet transmitted The information and the CUG information registered by the subscriber check the same information or 310.

If the CUG information included in the packet and the CUG information registered by the subscriber are not the same, after performing call release (309), the system transitions to the standby state, and the CUG information transmitted by being included in the packet and registered by the subscriber If the CUG information is the same, after preparing for delivery to the called party based on the information included in the packet (311), translation of the called number is requested (312).

When the translation result of the called number is notified (316), preparation for the requesting party's physical path establishment request and preparation for delivering the CUG type and CUG number of the calling party to the called party (317) are required to set up the called party's physical path. (318)

When the BPCCo is notified of the logical channel allocation result from the called party (319), the BPCCo reassembles the call establishment request packet including the CUG information (320) and notifies the B25Ho of the verification result of the call establishment request packet (321). ).

When the BPCCo receives the verification request for the call connection packet from the B25Ho (322), the BPCCo decomposes the call connection packet, performs the verification on the packet (323), and notifies the B25Ho of the call connection packet verification result (324). The call connection state by the requested CUG function is established (325).

4 is a detailed flowchart illustrating a CUG incoming process according to an embodiment of the present invention.

When the called party's physical path establishment request is received from the calling party (401), the subscriber's database is accessed to read information about the called party (402), and the recipient's registration of the CUG function is searched (403).

If the called party is not registered in the CUG function (404), after performing the call release (405), it transitions to the waiting state. If the called party is registered in the CUG function (404), the CUG number received from the calling party is received. The CUG number registered at the called party and the called party are verified to be the same number (406).

If the CUG number received at the calling party and the CUG number registered at the called party are different from each other, the call is released (405), and then the system is transferred to the standby state, and the CUG number received at the calling party is registered at the called party. If the CUG numbers are the same, the called logical channel is allocated (407) and the calling BPCCo is notified of the result of assigning the called logical channel (408).

The destination BPCCt requests the destination link establishment to the destination B25Ht for the establishment of the destination link layer 2 (409). When the destination link establishment is notified of completion (410), the BPCCt enters the standby packet packet verification wait state.

When the BPCCt receives the incoming call packet verification request from the B25Ht (411), the BPCCt decomposes the incoming call packet (412) to determine whether the CUG information is included in the incoming call packet (413).

If the CUG information is not included in the incoming call packet, the incoming call packet is verified (414), the incoming call packet is reassembled (416), and the incoming call packet verification result is notified (417). If the CUP information is included therein, (413) it is determined whether the CUG information contained in the incoming call packet is identical to the CUG information registered at the exchange by the called subscriber.

If the CUG information included in the CUG and the CUG information registered in the called subscriber are different from each other, after the call release is performed (405), the process transitions to the waiting state and the CUG is included in the incoming packet. If the CUG information and the called subscriber are the same as the CUG information registered at the exchange, the incoming call packet including the CUG information is reassembled (416) and the verification result of the incoming call packet is notified to B25Ht (417). After the incoming packet is transmitted, when the BPCCt receives the call accept packet verification request from B25Ht (418), the BPCCt decomposes the call accept packet, performs its verification (419), and notifies the result of the call to B25Ht (420). The process transitions to the data transfer state (421).

5 shows a detailed flowchart of the release process according to an embodiment of the present invention.

When the call release request is received in the idle state (501), the BPCC stops the process (the originating or incoming process with which the call release has been received) (502), and the link release request to the B25H to release the resources of the occupying layer 2 Transmit (503), receive the link release result (504), and request physical path release to the PIC (505).

Upon notification of completion of physical path release (506), all information related to the link is initialized (507).

The present invention made as described above enables communication only between subscribers belonging to the closed user group, and does not allow communication with subscribers or general subscribers who do not belong to the closed user group, and thus, between groups having the same purpose. Allows the communication network to have a similar effect to a private network. Therefore, the present invention has an effect that can provide a variety of service opportunities to ISDN packet subscribers in the future in accordance with the development of the communication network technology.

Claims (10)

Packet Inward-Call Control (PIC), which performs functions such as packet call control / verification and number translation request to an ASP_P (Access Switching Processor for Packet) 21 for a packet subscriber. And a packet call direction control (PDC) software block, and a packet handling module (PHM) 22 for packet data processing, which is responsible for the link layer and packet layer processing functions of the X.25 protocol. B, which has a channel X.25 protocol processing software block (hereinafter referred to as B25H) and a packet layer control processor (PLCP) 23, controls B-channel packet calls. -Priority closed user group among packet random user functions applied to ISDN packet switching system with B-channel Packet Call Control software block (hereinafter referred to as 'BPCC') ( Closed User Group Without Prefe In the processing method, the PIC block establishes a physical path to a call establishment request of a subscriber whose CUG function is registered, and then the originating BPCC block accesses the originating subscriber information from the database. After creating the originating process (BPCCo), when BPCCo receives the call setup request packet from the originating B25H block (B25Ho), it disassembles it and performs verification to provide the CUG function when the CUG information is included in the packet. After translating the called number into the number included in the packet, requesting the called party's physical path setting, and upon receiving notification from the called party that the logical channel has been allocated, the call establishment packet including the CUG information is reassembled, and the call is sent to B25Ho. When the verification result of the call setup packet is received and the verification request of the call connection packet is received from B25Ho, the received call connection packet is verified and the result is notified. A first step of the transition to the state (301 to 325); And after the called party PIC establishes the physical path by the request of the called party physical path establishment request, the called party BPCC block accesses the database of the called party and provides the CUG function to the called party. After notifying the originating logical channel allocation result to the calling party and setting up the called link layer, the called party BPCC (BPCCt) decomposes the received packet when the called party packet verification request is received from the called party B25H (B25Ht). If the called subscriber can provide the CUG function using the received CUG information, the receiving subscriber reassembles the incoming packet and notifies the B25Ht of the result of the incoming packet packet verification, and when the request for verification of the call reception packet is received from the B25Ht, the call receiving packet Characterized in that it comprises a second step (401 to 421) to perform a verification and reassembly of the result and notify the result, and then transition to a data delivery state; How to handle closed user group without priority among packet random user functions. The method of claim 1, further comprising: a third step (501 to 507) of stopping a corresponding process when receiving a call release request, releasing the occupied link and the physical path, and initializing link information. How to handle closed user group without priority among packet random user functions. The method according to claim 1 or 2, wherein the first steps (301 to 325), after the PIC block establishes a physical path according to a call establishment request of a subscriber whose CUG function is registered, the originating BPCC block is configured as an originating subscriber. After the BPCCo is generated by accessing the information from the database, when the BPCCo receives the call setup request packet from the B25Ho, the fourth step (301 to 306) decomposing the received setup request packet to determine whether the CUG information is included in the packet. ; If the CUG information is not included in the packet in the fourth step (301 to 306), if the CUG function is registered in the exchange, the subscriber requests the translation using the registered number as the called number, and the CUG information is included in the packet. If the CUG function is registered in the exchange, and the received CUG information and the registered CUG information are the same, the fifth step of requesting the called party to establish a physical path by translating the called number to the number included in the packet (307) To 318); And upon receiving notification that the logical channel has been allocated from the called party, reassemble the call setup packet including CUG information and the like, and notify the verification path of the call setup packet to B25Ho, and receive the request to verify the call connection packet from B25Ho. And a sixth step (319 to 325) of transitioning to a data delivery state after verifying the received call connection packet and notifying the result thereof. 4. The method of claim 3, wherein the fourth step (301 to 306), after the subscriber requests the call setup and the PIC completes the establishment of the originating physical path, the BPCC accesses the database to obtain information about the originating subscriber. A seventh step (301 to 303) for generating a BPCCo if the generation of the originating process (BPCCo) is possible after reading; And BPCCo, when receiving a call setup request from B25Ho, decomposes a call setup request packet to determine whether CUG information is included in the call setup request packet (304 to 306). How to handle closed user group without priority among user functions. 4. The method of claim 3, wherein the fifth step (307 to 318), if the CUG information is included in the call establishment request packet, refers to a subscriber whose CUG function is registered in the exchange by referring to the value of accessing the database. Seventh step (307 to 308) to identify; In the seventh step 307 to 308, if the CUG function is not registered in the switch or the registered subscriber is not the same as the CUG information transmitted by being included in the packet and the registered CUG information, the call is released. If the subscriber is registered to the CUG function, and the CUG information transmitted and included in the packet is identical to the CUG information registered by the subscriber, the eighth step of requesting translation of the called number based on the information included in the packet (309) To 312); If the CUG information is not included in the call establishment request packet, ninth steps (313 and 314) of determining whether the CUG function is registered in the exchange by referring to the value of accessing the subscriber's database; In the ninth step (313, 314), the subscriber who does not have a CUG function registered in the exchange requests the translation of the called number as a general call state instead of a CUG call, and in the case of a subscriber whose CUG function is registered in the exchange. 10th step (312, 315) requesting the translation of the called number to the number registered in the exchange and when receiving a response signal according to the translation request of the called number, the calling party sends the CUG type and CUG number of the calling party to the called party. An eleventh step (316 to 318) of requesting a physical path setting of the packet random user function, characterized in that it comprises a non-priority closed user group processing method. 4. The method of claim 3, wherein the sixth step (319 to 325), when notified by the called party that the logical channel has been allocated, BPCCo reassembles the call setup packet including CUG information and the like, and then sends the call setup packet to B25Ho. A seventh step (319 to 321) of notifying the progress of verification; And when the BPCCo receives the verification request of the call connection packet from the B25Ho, after disassembling and verifying the received call connection packet, notifying the B25Ho of the verification result of the call connection packet, and transitioning to a data transfer state (Step 832. 325); method of processing a closed user group without priorities among random packet user functions. 2. The method of claim 1, wherein in the second step (401 to 421), when a request for establishing a destination physical path is received from a calling party process, the called party PIC establishes a physical path, and then the calling party BPCC determines the destination subscriber. If the called party is registered in the CUG function and the called CUG number transmitted from the calling party and the called CUG number stored in the database are the same, the calling logical channel is allocated. After notifying the BPCCo of the allocation result of the destination logical channel, requesting the destination B25H (B25Ht) to set up the destination link, establishing the destination link, and receiving an incoming packet verification request from B25Ht, the received incoming signal is received. A fourth step (401 to 413) for decomposing the packet to determine whether the CUG information is included in the incoming packet; If the CUG information is not included in the incoming call packet in the fourth step (401 to 413), the incoming call packet is verified and the verification result of the incoming call packet is notified to B25Ht, and the CUG information is included in the incoming call packet. If the CUG information included in the incoming packet is the same as the CUG information registered at the exchange, the B25Ht is notified of the verification result of the incoming packet by reassembling the incoming packet including the CUG information. When receiving a request for verifying a call reception packet from B25Ht, the call reception packet is disassembled, the verification and reassembly thereof is performed, and the verification result is notified to B25Ht, and the transition to the data transfer state is performed (414 to 421). Method for processing a closed user group without priority among random user functions of the packet, characterized in that it comprises a; 8. The method of claim 7, wherein the fourth step (401 to 413), after receiving the setup request signal of the called party physical path from the calling party process, the called party PIC establishes the physical path, and the called party BPCC determines A sixth step (401 to 404) of accessing the database to read information on the called subscriber to determine whether the called subscriber registers the CUG function; And if the called subscriber is not registered in the CUG function in the sixth step (401 to 404), or the called subscriber is registered in the CUG function, but the CUG number transmitted from the calling party and the called CUG number stored in the database are not the same. If the receiving subscriber is registered in the CUG function and the CUG number transmitted from the calling party and the called CUG number stored in the database are the same, the called logical channel is allocated to the calling party (BPCCo) after allocating the called logical channel. Informs the result of the allocation, sets the destination link to B25Ht to set up the called party's link layer-2, and sets up the incoming link.When the incoming packet verification request is received from B25Ht, the received incoming packet is decomposed and received. A seventh step (405 to 413) of identifying whether the CUG information is included in the packet; How to handle non-priority closed users. 8. The method of claim 7, wherein the fifth step (414 to 421), if the CUG information is not included in the incoming packet, verify the incoming packet, reassemble the incoming packet, and then verify the verification result. A sixth step (414, 415) for determining whether the CUG information included in the incoming call packet is identical to the CUG information registered at the exchange when the called subscriber is included in the incoming call packet; In the sixth step (414, 415), if the CUG information included in the incoming call packet and the CUG information registered by the called subscriber in the exchange is different, the call is released, and the incoming CUG information and the incoming call packet included in the incoming packet are different. If the CUG information registered by the subscriber is the same, the seventh step (416, 417) of reassembling the incoming call packet including the CUG information and the like, and notifying B25Ht of the verification result of the incoming call packet; And receiving the call receipt packet verification request from BPCCt B25Ht, disassembling the call reception packet, performing verification and reassembly thereof, and notifying the verification result to B25Ht, and transitioning to the data transfer state (418 to 421). Method for processing a closed user group without priority among the random user functions of the packet, characterized in that it comprises a. 3. The method of claim 2, wherein the third step (510 to 507), upon receiving a call release request, the BPCC stops the process (the originating or terminating process from which call release was received) and occupies the occupied link layer-2 resource. A fourth step (501 to 503) for requesting the release of the link to the B25H to release it; A fifth step (504 to 507) of requesting physical path release to the PIC upon receiving the release result of the B25H, and initializing all information related to the link upon being notified of completion of the physical path release. How to handle closed user group without priority among user functions.