JPH10257074A - Packet communication method and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packet communication method and its device to prevent the burden of a processing regarding management in a group communication from being concentrated on one part. SOLUTION: When a packet which is transmitted from one terminal 1 belonging to a specified group and formed into an ATM cell by an edge device 10 reaches a center device 20, the ATM address corresponding to all terminals belonging to the group is extracted from a grouping table in a managing part 22 in a multi-cast processing part 23 and the packet (ATM cell) is transmitted to each of the corresponding edge devices 10 with an ATM switch 21. Address discrimination of the packet by the terminal at one point is unnecessitated by passing the packet if it is addressed to all the terminals and passing the packet only when it is connected with the corresponding terminal if the packet is addressed to a specified terminal, thus the burden of the processing is reduced in each of the edge devices 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packet communication method and apparatus for packetizing and transmitting data between terminals such as computers.

[0002]

2. Description of the Related Art Conventionally, as a communication system for transmitting data between terminals such as computers, there is a system for transmitting data in packets using a communication line such as Ethernet or Ethernet and a telephone line.
In this case, a bridge or a router is installed at both ends for the connection between the Ethernets, and an Ethernet packet (an IP packet or the like in the case of a router) is converted into a protocol on a communication line for communication. That is, Ethernet or IP packets are transferred to HDLC (High Level Data
(In the case of HDLC, a packet is mapped between a start flag and an end flag and transmitted over a communication line.)

In recent years, as a form of a communication network, 53
ATM networks that transmit data by dividing them into byte cells have begun to be used, and their application to computer networks is rapidly advancing, particularly because of their high compatibility with computer communications. ATM is expected to be used for high-speed computer communication because its transmission rate is higher than that of Ethernet and it is possible to switch or route at high speed in cell units based on cell addresses.

[0004] As a packet communication method using ATM,
Some Ethernet frames are transmitted as cells, and the system configuration is shown in FIG.

[0005] In the figure, 1 is a terminal such as a plurality of computers,
2 is a LAN for accommodating the terminal 1 (here, Ethernet)
It is. Reference numeral 3 denotes a group management table, which is a group management server for managing the group of the terminal 1; 4, an LE (LAN Emulation) server for managing the LAN address (MAC address) and the ATM address; This is a broadcast server that processes packets delivered to all terminals belonging to the group. Reference numeral 6 denotes an LE client for converting between an Ethernet packet and an ATM cell, and is connected to one terminal 1 directly or to a plurality of terminals 1 via a hub or the like constituting the LAN 2.

An ATM switch 7 switches an ATM cell according to cell header information (address).
Each terminal 1 is accommodated via the LE client 6 or via the LE client 6 and a hub or the like constituting the LAN 2, and the group management server 3 and the LE server 4
And a broadcast server 5.

[0007] In the figure, an arrow indicated by a broken line 8 indicates a flow of a broadcast packet in a group, and an arrow indicated by a solid line 9 indicates a flow of a unicast packet (a normal packet delivered to one specific terminal). ing.

FIG. 2 shows a specific configuration example of the grouping table. In the figure, 3-1 is a table describing the MAC addresses of the terminals belonging to each group for each group, and 3-2 is the MAC address of each terminal. 9 is a table describing the correspondence between addresses and groups. Each of these can determine to which group the MAC address of the terminal belongs.

FIG. 3 is a flowchart showing the operation of the system. The operation will be described below.

Prior to communication between terminals, the following preprocessing is performed. (1) From each LE client 6 to the group management server 3
To send the MAC address of the connected terminal. (2) Grouping information is transmitted from the group management server 3 to the LE server 4 and the broadcast server 5. (3) Register a grouping table on the LE server 4 and the broadcast server 5.

After registration of the grouping table, communication between terminals is performed as follows. (1) ARP (Adress Resolution Protocol) from the LE client 6 to which the calling terminal is connected to the LE server 4
Send the request. (2) In the case of a broadcast packet, the broadcast server 5 broadcasts in the same group by referring to the grouping table. (3) In the case of a unicast packet, the ARP reply including the ATM address of the destination as information is returned if the called terminal is in the same group with reference to the grouping table. (4) The LE client 6 has the A included in the ARP reply.
A VC connection is set between the LE clients 6 by signaling using the TM address. (5) Communication between the terminals 1 is started.

[0012]

A line (PVC: Perm) that is fixedly connected between the LE client and each server
anent Virtual Circuit), but LE
A unicast packet between clients is transmitted and received by a connected circuit (SVC: Switched Virtual Circuit) every time communication is performed. Therefore, since the routing / switching is realized in hardware on the ATM switch,
Although faster processing is possible than a bridge or router using conventional software processing, the procedure for starting a connection is complicated and the load is concentrated in one place, and the processing load is particularly heavy on some devices on the network side. Was.

As described above, in the conventional packet communication method using ATM, it is possible to perform group communication in which communication is performed only between specific limited members among registered LE clients or terminals connected thereto. , L
In the classification and grouping processing of the packet types in the E server, it was necessary to temporarily decode the cell, extract the terminal address from the header information of the packet, and search the grouping table.

An object of the present invention is to provide a packet communication method and apparatus capable of realizing packet communication between terminals belonging to a predetermined group without concentrating a load at one place.

It is an object of the present invention to provide a packet communication method and apparatus capable of realizing packet communication between terminals belonging to a predetermined group with a reduced processing load on the network side.

[0016]

According to the present invention, in order to solve the above-mentioned problems, a plurality of terminals are connected to a network accommodating a plurality of lines connected directly to at least one terminal or via a LAN, and Transfer a packet from any one terminal belonging to the given group to a specific other terminal belonging to the given group, or transfer a packet from any one terminal belonging to the given group to another given terminal belonging to the given group. A packet communication method for simultaneously transferring all packets transferred from an arbitrary terminal belonging to a predetermined group to the network to all the terminals belonging to the predetermined group. And copies it to each line, and if the packet is a packet addressed to all terminals belonging to a predetermined group, the line Is transmitting, the packet is characterized in that to transmit only on the line corresponding to the corresponding terminal if the packet is certain other terminals addressed belonging to a predetermined group.

According to the present invention, a packet transferred from one terminal in a predetermined group is transmitted regardless of whether it is addressed to all terminals in the group or to a specific other terminal. What is necessary is just to copy and transmit the number of lines corresponding to the terminals in the predetermined group, and it is not necessary to determine the destination of the packet in one place for each terminal. Therefore, management during group communication performed only between limited members,
The processing can be performed not for each terminal but for each line, and accordingly, the processing load is small. Especially, the processing load does not need to be concentrated on a part of the network side and the processing can be performed at high speed.

At this time, the line is a virtual line formed on the ATM network, and the packet is transmitted over the ATM.
When cells are transferred and transferred, it is possible to perform management during group communication for each ATM address, and there is no need to decode ATM cells into packets at one place.
The processing can be performed at high speed without the load being concentrated.

According to the present invention, in order to solve the above-mentioned problems, a plurality of terminals and a network accommodating a plurality of lines connected directly to at least one terminal or via a LAN are provided. A packet from any one terminal is transferred to a specific other terminal belonging to the predetermined group, or a packet from any one terminal belonging to the predetermined group is transferred to all other terminals belonging to the predetermined group. In a packet communication device that simultaneously transfers to the same, all packets transferred from any one terminal belonging to a predetermined group are copied by the number of lines corresponding to all other terminals belonging to the predetermined group, Means for transmitting to all the other terminals belonging to the predetermined group a line corresponding to the predetermined group; A means is provided for each line to transmit packets destined for all terminals to which they belong, and to transmit packets destined for specific other terminals belonging to a predetermined group only when connected to the terminal. Features.

According to the present invention, a packet transferred from one terminal in a predetermined group is transmitted regardless of whether the packet is addressed to all terminals in the group or a specific other terminal. Copies are transmitted by the number of lines corresponding to the terminals in the predetermined group and transmitted. If a packet is addressed to all terminals in the predetermined group, transmission is performed by means provided for each line. If it is addressed to a specific other terminal, transmit it only when it is connected to the relevant terminal, so that group communication only between limited members can be performed at high speed without concentrating the load at one place Can be.

Here, there is provided a grouping table for indicating a correspondence between a line and a group, and a management unit for managing the grouping table.
When receiving a packet from one terminal belonging to a group, a multicast processing for extracting lines corresponding to all terminals belonging to the group from the management unit and transmitting the packet to all lines except the source line among them. Unit is provided in the network, and the addresses of the connected terminals are registered. If the destination address of the packet is all terminals belonging to the predetermined group, the packet is passed. In addition, if an edge device having a filter function unit that passes if the address is registered is provided on each line, the packet is transferred from one terminal in a predetermined group by the management unit and the multicast processing unit At any time, regardless of whether it is addressed to all terminals in the group or to certain other terminals, The packet can be sent to all corresponding lines, and each edge device allows the packet to pass through the line if the packet is addressed to all terminals in the predetermined group, and to the specific other terminal in the predetermined group. In this case, it is possible to pass through the line only when the terminal is connected to the corresponding terminal, thereby transmitting a broadcast packet and a unicast packet within the group.

A grouping table indicating the correspondence between the line and the group is provided, and a management unit for managing the grouping table is provided. When a packet from one terminal belonging to the group is received,
A line corresponding to all the terminals belonging to the group is extracted from the management unit, and a multicast processing unit for transmitting a packet to all lines except the line of the transmission source and an address of the connected terminal are registered. If the destination address of the packet is all terminals belonging to the predetermined group, pass the packet, and if it is a specific other terminal belonging to the predetermined group and the address is registered, pass the filter function unit corresponding to each line. If provided in the network, when a packet is transferred from one terminal in a predetermined group by the management unit and the multicast processing unit, it is sent to all terminals in the group or to a specific other terminal. Irrespective of whether or not there is, the packet can be transmitted to all the lines corresponding to the terminals in the predetermined group. If the packet is destined for all terminals in a given group, it is passed to the line, and if it is destined for another specific terminal in the given group, it is passed to the line only when connected to the terminal. As a result, transmission of a broadcast packet and transmission of a unicast packet within a group can be performed, and traffic of ATM cells on a downlink can be reduced.

Further, at this time, when the line is a virtual line formed on an ATM network and the packet is converted into an ATM cell and transferred, the management at the time of group communication is performed for each ATM address. This eliminates the need to decode the ATM cells into packets at one place, and the processing can be performed at high speed without the load being concentrated.

[0024]

FIG. 4 shows a first embodiment of a packet communication method and apparatus according to the present invention.
1 are denoted by the same reference numerals. That is, 1
Is terminal, 2 is LAN, 10 is edge device, 20 is ATM
Switch 21, management unit 22, and multicast processing unit 2
3 is a center device.

The edge device 10 includes a filter function unit 11 that performs packet filtering of a received packet based on a destination address included in a packet header, converts the packet into an ATM cell, and connects the terminal to the center device.

The ATM switch 21 switches ATM cells according to cell header information (address). The management unit 22 manages a grouping table indicating a correspondence between an ATM address of the edge device 10 and a group. The multicast processing unit 23 acquires the group information from the management unit 22 and multicasts the ATM cells to the edge devices 10 in the group via the ATM switch 21.

A fixed virtual circuit (PVC) is set in advance between the edge device 10, the management unit 22 and the multicast processing unit 23, and communication of all ATM cells is performed by the PV.
Via C.

In the communication between the terminals, the packet from the transmitting terminal is converted into an ATM cell by the edge device 10 and then transmitted to the multicast processing unit 23. The multicast processing unit 23 multicasts the ATM cells to all the edge devices 10 in the group without discriminating between broadcast and unicast (copy the cells by the number of edge devices in the group, and set the destination address for each edge device. Then, the edge device 10 transmits the multicast A
The TM function is decoded into packets, and the filter function unit 11
Filter packets through.

In the figure, the arrow indicated by the broken line 31 indicates the flow of the intra-group broadcast packet. The packet transmitted from the terminal 1 is converted into an ATM cell by the edge device 10 and transmitted to the multicast processing unit 23. The multicast processing unit 23 sends the A of the source edge device 10
The ATM cell is multicast using the ATM switch 21 to all the edge devices except the edge device 10 of the transmission source in the same group as the TM address. The edge device 10 that has received the ATM cell decodes the ATM cell into a packet, recognizes the broadcast from the header information of the packet by the filter function unit 11, and then transmits the packet to all the terminals 1 connected to the edge device 10. I do.

The arrow indicated by the solid line 32 indicates the flow of the unicast packet. The packet transmitted from the terminal 1 is converted into an ATM cell by the edge device 10 and transmitted to the multicast processing unit 23. The multicast processing unit 23 uses the ATM switch 21 to multicast ATM cells to all the edge devices 10 except for the edge device 10 of the transmission source, which are in the same group as the ATM address of the edge device of the transmission source. . The edge device 10 that has received the ATM cell decodes the ATM cell into a packet, extracts the destination terminal address from the packet header information in the filter function unit 11, and if the destination terminal address indicates the connection terminal, the corresponding Send the packet to the called terminal.

FIG. 5 shows a specific configuration example of the grouping table. In the figure, 22-1 is a table describing ATM addresses of edge devices belonging to each group for each group, and 22-2 is each edge device. 2 is a table describing the correspondence between ATM addresses and groups. Each of these can determine to which group the ATM address of the edge device belongs.

FIG. 6 is a flowchart showing the operation of the system. The operation will be described below.

Prior to communication between terminals, the following preprocessing is performed. (1) Register the address of the terminal connected to the edge device 10 in the filter function unit 11. (2) The management unit 22 registers the grouping table. (3) The multicast processing unit 23 acquires the group information from the management unit 22, and configures a grouping table.

After the pre-communication processing, communication between the terminals is performed as follows. (1) The edge device 10 that has received the packet from the calling terminal 1 converts the packet into an ATM cell, and transmits the ATM cell to the multicast processing unit 23 via the ATM switch 21. (2) The multicast processing unit 23 refers to the grouping table and transmits the ATM cell to all the edge devices 10 except the source edge device 10 in the same group. (3) The edge device 10 decodes the cell into a packet, extracts the destination address from the header information, and
Pass to 1. (4) The filter function unit 11 analyzes the destination address, and if the packet is a broadcast packet, transmits the packet to all the terminals 1 connected to the edge device 10, and is a unicast packet and the terminal to which the destination address is connected. , The packet is transmitted to the corresponding receiving side terminal 1.

As described above, the entry used in the grouping table is not a terminal address such as a MAC address but an ATM address, so that the size of the grouping table can be reduced as compared with a case where the terminal address is an entry. , Makes management easier. Also,
In communication between terminals belonging to the same group, the multicast processing unit 23 can perform processing without distinction between unicast and broadcast, and there is no need to decode ATM cells into packets and extract the header information of the packets.
The burden is reduced, and high-speed communication becomes possible.

As described above, in the system according to the present invention,
Among the registered edge devices or terminals connected thereto, it is possible to further facilitate management for performing group communication in which communication is performed only between specific limited members and reduce processing load on the network side. It becomes possible.

Although the case has been described where the management unit 22 and the multicast processing unit 23 are implemented as separate devices, these functions can also be implemented on the same device. Further, the functions of the edge device 10 and the connection terminal 1 can be implemented on the same device. The implementation of these functions is a configuration that can be easily changed as needed.

FIG. 7 shows a second embodiment of the packet communication method and apparatus according to the present invention, in which the same components as those in FIG. 1 are denoted by the same reference numerals. That is, 1 is a terminal,
2 is a LAN, 40 is an edge device, 50 is a center device comprising an ATM switch 51, a management unit 52, a multicast processing unit 53 and a filter function unit 54.

The edge device 40 converts a packet into an ATM cell and connects the terminal to the center device.

The ATM switch 51 switches ATM cells according to cell header information (address). The management unit 52 manages a grouping table indicating the correspondence between the ATM address of the edge device 40 and the group. The multicast processing unit 53 acquires the group information from the management unit 52, and multicasts the ATM cells to the filter function unit 54 that accommodates the edge devices 40 in the group via the ATM switch 51. The filter function unit 54 performs packet filtering of the received packet based on the destination address included in the header of the packet.

A fixed virtual circuit (PVC) is set in advance between the edge device 40, the management unit 52, and the multicast processing unit 53, and communication of all ATM cells is performed by the PV.
Via C.

In the communication between the terminals, the packet from the transmitting terminal is converted into an ATM cell by the edge device 40 and then transmitted to the multicast processing unit 53. The multicast processing unit 53 multicasts the ATM cell to all the filter function units 54 accommodating all the edge devices 40 in the group without discriminating between broadcast and unicast (copies the cells by the number of edge devices in the group, Address is set for each edge device.) Each filter function unit 54 decodes an ATM cell into a packet or extracts packet header information from the ATM cell as it is, and performs packet filtering. The ATM cells that have passed through the filter function unit 54 are transmitted to the edge device 40. The edge device 40 decodes the ATM cell into a packet, and sends the packet to all the subordinate terminals if it is a broadcast packet, and sends it to the corresponding terminal if it is a unicast packet.

In the figure, the arrow indicated by the broken line 61 indicates the flow of the intra-group broadcast packet. The packet transmitted from the terminal 1 is converted into an ATM cell by the edge device 40 and transmitted to the multicast processing unit 53. The multicast processing unit 53 determines the A of the source edge device 40.
The ATM switch 51 is used to transmit the A to the filter function unit 54 which is in the same group as the TM address and accommodates all the edge devices except the source edge device 40.
Multicast the TM cells. The filter function unit 54 decodes the received ATM cell into a packet or extracts packet header information from the ATM cell as it is, recognizes that the broadcast is a broadcast, and passes the cell. The passed ATM cell is the edge device 40
The edge device 40 decodes the ATM cell into a packet, recognizes that the packet is a broadcast, and transmits the packet to all the terminals 1 to be connected.

The arrow indicated by the solid line 62 indicates the flow of the unicast packet. The packet transmitted from the terminal 1 is converted into an ATM cell by the edge device 40 and transmitted to the multicast processing unit 53. The multicast processing unit 53 uses the ATM switch 51 for the filter function unit 54 that is in the same group as the ATM address of the source edge device and accommodates all the edge devices 40 except the source edge device 40. To multicast the ATM cells. The filter function unit 54 receives the received AT
Decode M cells into packets or use AT
The packet header information is extracted from the M cell, and the destination terminal address is further extracted. If this indicates the terminal connected to the edge device accommodated by itself, this cell is passed. The passed ATM cell is transmitted to the edge device 40. The edge device 40 decodes the ATM cell into a packet and transmits the packet to the corresponding terminating terminal 1.

The grouping table may be the same as that of the first embodiment shown in FIG.

FIG. 8 is a flowchart showing the operation of the system. The operation will be described below.

Prior to communication between terminals, the following preprocessing is performed. (1) The address of the terminal connected to the edge device 40 is registered in the filter function unit 54. (2) The management unit 52 registers the grouping table. (3) The multicast processing unit 53 acquires the group information from the management unit 52 and configures a grouping table.

After the above-mentioned communication pre-processing, communication between terminals is performed as follows. (1) The edge device 40 that has received the packet from the calling terminal 1 converts the packet into an ATM cell, and transmits the ATM cell to the multicast processing unit 53 via the ATM switch 51. (2) The multicast processing unit 53 refers to the grouping table and sends out the ATM cells to all the filter function units 54 accommodating all the edge devices 40 except the edge device 40 of the transmission source in the same group. (3) The filter function unit 54 extracts the destination address from the ATM cell including the header information of the packet. (4) The filter function unit 54 analyzes the destination address and, if it is a broadcast packet, stores the edge device 4
0, and if the packet is a unicast packet and the destination address indicates a terminal connected to the accommodated edge device 40, the ATM cell is transmitted to the corresponding edge device 40. (5) The edge device 40 decodes the ATM cell into a packet, transmits a packet to all connected terminals 1 if it is a broadcast packet, and transmits a packet to the corresponding receiving terminal 1 if it is a unicast packet. .

According to this embodiment, similarly to the first embodiment, there is no need to distinguish between unicast and broadcast in the multicast processing unit.
Since there is no need to decode the TM cell into a packet and extract the header information of the packet, the load is not concentrated, and high-speed communication is possible. Further, in the present embodiment, the traffic of the ATM cells flowing in the downlink from the center device to the edge device is reduced as compared with the case of the first embodiment.

Although the case has been described where the management unit 52 and the multicast processing unit 53 are implemented as separate devices, these functions can also be implemented on the same device. Further, the functions of the edge device 40 and the connection terminal 1 can be implemented on the same device. The implementation of these functions is a configuration that can be easily changed as needed.

In each of the embodiments, the case where the present invention is implemented on an ATM network has been described.
It can also be implemented on a TM (Synchronous Transfer Mode) network.

[0052]

As described above, according to the present invention,
In the communication that packetizes and transmits data, it is not necessary to manage each terminal in group communication that is performed only between limited members, and the processing load is concentrated at one place In particular, it is possible to prevent the load on some devices on the network side from increasing, and to perform processing at high speed.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing an example of a conventional packet communication method and its device.

FIG. 2 is a diagram showing an example of a conventional grouping table.

FIG. 3 is an operation flowchart of the system of FIG. 1;

FIG. 4 is a first diagram illustrating a packet communication method and apparatus according to the present invention;
Configuration diagram showing an embodiment of the present invention

FIG. 5 is a diagram showing an example of a grouping table according to the present invention.

FIG. 6 is an operation flowchart of the system of FIG. 4;

FIG. 7 shows a second example of the packet communication method and apparatus of the present invention.
Configuration diagram showing an embodiment of the present invention

8 is an operation flowchart of the system of FIG. 7;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Terminal, 2 ... LAN, 10, 40 ... Edge device, 1
1, 54: filter function unit, 20, 50: center device,
21, 51 ... ATM switch, 22, 52 ... management unit, 2
2-1, 22-2... Grouping table, 23, 53
... Multicast processing unit.

Claims (6)

[Claims] A plurality of terminals are connected to a network accommodating a plurality of lines connected directly to at least one terminal or via a LAN, and packets from any one terminal belonging to a predetermined group are transmitted to the predetermined group. In a packet communication method for transferring to a specific other terminal belonging to a given group, or simultaneously transferring a packet from any one terminal belonging to a given group to all other terminals belonging to the given group, All packets transferred from any one terminal belonging to the group to the network are copied by the number of lines corresponding to all the other terminals belonging to the predetermined group, and transmitted to each line, If the packet is a packet addressed to all terminals belonging to a predetermined group, the packet is transmitted on the line, and the packet belongs to a predetermined group. A packet communication method in which a packet addressed to a specific terminal is transmitted only on a line corresponding to the terminal. 2. The packet communication method according to claim 1, wherein the line is a virtual line formed on an ATM network, and the packet is converted into an ATM cell and transferred. 3. A network comprising a plurality of terminals and a network accommodating a plurality of lines directly connected to at least one terminal or via a LAN, wherein packets from any one terminal belonging to a predetermined group are transmitted to the predetermined group. A packet communication device for transferring to a specific other terminal belonging to a given group or simultaneously transferring a packet from any one terminal belonging to a given group to all other terminals belonging to the given group; All packets transferred from any one terminal belonging to the group are copied by the number of lines corresponding to all other terminals belonging to the predetermined group, and all other terminals belonging to the predetermined group are copied. And a means for sending the packet to a line corresponding to the terminal. If the packet is a packet addressed to all terminals belonging to a predetermined group, Is sent, the packet communication apparatus is characterized by providing means for transmitting only when connected to the appropriate terminals are if packets of certain other terminals addressed belonging to a predetermined group for each line corresponding. 4. A grouping table indicating a correspondence between a line and a group, the grouping table managing the grouping table, and when receiving a packet from one terminal belonging to the group, all terminals belonging to the group are received from the management unit. The network is provided with a multicast processing unit that extracts the line corresponding to, and sends out the packet to all the lines except the source line, and registers the address of the connected terminal, and the destination address of the packet is An edge device provided with a filter function unit on each line that allows all terminals belonging to a predetermined group to pass through, and a specific other terminal belonging to the predetermined group to pass if its address is registered is provided on each line The packet communication device according to claim 3, wherein: 5. A grouping table for indicating a correspondence between a line and a group, wherein the grouping table manages the grouping table, and when a packet from one terminal belonging to the group is received, all terminals belonging to the group are received from the management unit. And a multicast processing unit for transmitting packets to all lines except for the transmission source line, and the addresses of connected terminals are registered, and the destination address of the packet belongs to a predetermined group. If all terminals pass,
4. The packet communication apparatus according to claim 3, wherein a filter function unit corresponding to each line, which is a specific other terminal belonging to a predetermined group and passes if its address is registered, is provided in the network. 6. The packet communication device according to claim 3, wherein the line is a virtual line formed on an ATM network, and a packet is converted into an ATM cell and transferred.