JPH09331331A - Atm group communication system and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain communication between computers belonging to a prescribed group by referring a grouping table, returning an address resolution protocol reply packet by a 1st server means when a terminal computer belongs to the same group and allowing a 2nd server means to send a broadcast packet only to terminals of the same group. SOLUTION: A grouping table denoting a group to which a terminal computer 26 and a LAN emulation client 23 belong is provided on a group management server 13. A LAN emulation server 11 refers the table and returns an address resolution protocol reply packet when a terminal belongs to the same group and returns no reply packet with respect to a request packet from other groups than the same group. A broadcast server 12 sends a broadcast packet only to a terminal computer of the same group or a packet not connected directly to an ATM channel between terminal computers.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ATM (Asynchr)
onous Transfer Mode) In computer communication in which Ethernet packets are converted into ATM cells and transmitted between computers using a network, an AT that can perform communication only between computers belonging to a predetermined group
The present invention relates to a group communication system by M.

[0002]

2. Description of the Related Art Up to now, a computer communication system has been widely constructed in which data is packetized and transmitted between computers by utilizing a communication line such as Ethernet or Ethernet and a telephone line (or public line). In general, for connection between Ethernets, bridges or routers are installed at both ends, and Ethernet packets (IP packets in the case of routers) are converted into a protocol on a communication line for communication. That is, Ethernet work packet or IP packet is converted to HDLC.
(High Level Data Link Control) and other protocols were used to encapsulate and transmit. In the case of HDLC,
The packet is mapped between the start flag and the end flag and transmitted on the communication line.

In recent years, an ATM network for dividing data into 53-byte cells for transmission has started to be used as a form of communication network. Especially, since it is highly compatible with computer communication, its application to computer networks is rapidly progressing. It's starting. ATM is expected to be used for high-speed computer communication because it has a higher transmission rate than Ethernet and can perform high-speed switching or routing in cell units based on cell addresses.

LAN / WAN using ATM communication system
(LAN: Local Area Network, WAN: Wide Area Network) configurations include LAN emulation for cellizing and transmitting Ethernet frames (packets) and IP over ATM for cellizing and transmitting IP packets.

The LAN emulation is to transfer an Ethernet MAC frame (Media Access Control) frame into ATM cells by using an ATM adaptation layer (AAL) and transfer it. It is suitable for mixed networks with existing LANs.
The system configuration of this LAN emulation is shown in FIG.

Reference numeral 21 is a LAN emulation server (hereinafter referred to as "L") that manages LAN addresses and ATM addresses.
E server), reference numeral 22 denotes a broadcast server (Broadcast and Unknown Packet Server) that processes broadcast packets and packets that are not directly connected to the ATM line between terminal computers.
Hereinafter referred to simply as a broadcast server). Further, reference numeral 23 indicates a LAN emulation client (hereinafter referred to as LE client) for converting an Ethernet packet and an ATM cell. The LE client 23 converts an Ethernet packet into an ATM cell or converts an ATM cell into an Ethernet work packet. Processing is performed, and the terminal computer 26 may be directly accommodated, or a plurality of terminal computers may be accommodated by a hub or the like. Reference numeral 24 is an ATM switch, which switches ATM cells according to cell header information (address). Reference numeral 25 indicates Ethernet (hub). Reference numeral 26 represents a terminal computer,
This terminal computer 26 is connected to the Ethernet or directly to the LE client. LE
The client 29 is an example in which a terminal computer is directly connected.

Reference numerals 28 and 27 denote lines connected to the LE server 21, the broadcast server 22 and the LE client 23 via the ATM switch network, and a reference numeral 26 fixedly connects the lines. PV
C (Permanent Virtual Circuit), reference numeral 28 is an SVC (Switched Virtual Circuit) which is connected to the circuit at each communication.
cuit). The PVC 27 is used for transmitting a broadcast packet, an unknown packet, or an ARP packet, and the SVC 28 is used for transmitting a data packet.

The broadcast server 22 transfers broadcast packets and unknown packets (packets not directly connected to the ATM line between terminal computers) to all LE clients 23.

Next, the operation of the system shown in FIG. 3 will be described with reference to FIG. When communicating between terminal computers, the sequence is as follows. MAC from LE client 23 to LE server 21
The correspondence between the address and the ATM address is registered. ARP from LE client 23 to LE server 21
(Address Resolution Protocol: LE-ARP) request is transmitted. ATM from LE server 21 to LE client 23
An ARP reply including the address as information is returned. Signaling is performed between LE clients (for example, the LE client 23 by using the returned ATM address).
And the LE client 29) set a VC connection. Start communication between terminal computers.

As described above, when communication is started, the connection is set by the signaling of ATM by the information (ARP reply) from the LE server 21, and the ATM cell is transferred. Therefore, routing / switching is AT
Since it is realized by hardware on the M switch, it is possible to perform higher speed processing than the conventional bridge or router by software processing.

Ethernet packets are ATMAAL5
It is placed on (ATM Adaptation Layer 5) and transmitted. FIG. 5 shows a layer structure (cell structure conversion) when transmitting. Here, an Ethernet packet is an Ethernet packet header 31 and an Ethernet data 32.
It is composed of Reference numeral 33 is a trailer for ATM cells, and indicates a pad for adjusting the number of bytes of the ATM cells. Reference numeral 34 indicates the structure of an ATM cell, which is composed of an ATM header 35 and an ATM data section 36. Reference numeral 37 shows the structure of the ATM header 35 in more detail. Note that reference numeral 36
The SDU of the data part shown in (1) is an abbreviation for Service Data Unit and indicates the definition on the ATM adaptation layer.

[0012]

As described above, the conventional L
In the AN emulation, communication is possible between the registered LE clients or terminal computers connected thereto, but since it is not managed by the group, there is a specific limitation among the registered LE clients. It was difficult to perform group communication in which only members communicate.

That is, in general communication, LE is used.
Although the server sends an ARP request to the server, the LE server does not associate addresses for each group, but associates addresses with arbitrary terminal computers. Could not be done. Further, in the case of broadcast packets (including unknown packets), the broadcast server forwards them to all LE clients as they are, so it was not possible to forward the broadcast packets only to the terminal computers in the same group for communication.

It is an object of the present invention to utilize an ATM network to transfer Ethernet packets between computers.
AT in inter-computer communication for cell transmission
An object of the present invention is to provide an ATM group communication system that can perform communication only between computers belonging to a predetermined group by utilizing the high-speed switching characteristics and ARP operation, which are the characteristics of M. Another object of the present invention is to provide an ATM group communication system capable of collectively performing grouping control by copying a grouping table of a group management server with an LE server and a broadcast server.

[0015]

The first aspect of the present invention is to:
According to the ATM group communication system by Ethernet emulation, LAN emulation client means for converting Ethernet packets into ATM cells, ATM switching means for switching the cells according to a destination address, and correspondence between Ethernet addresses and ATM addresses are performed. AT directly between the first server means and the broadcast packet or terminal
A second server means for transmitting a packet not connected to the M line, and a fixed virtual line is set in advance between the terminal connected to the Ethernet and the first and second server means for communication. When performing the AT, the AT corresponding to the first server means from the calling side terminal
An address resolution protocol request packet for requesting M address information is transmitted, and an address resolution protocol response packet containing the ATM address from the first server means as information is used for each communication with the receiving terminal. In the ATM communication system including means for setting a switched virtual circuit connected to the terminal and performing communication, a grouping table indicating a group type to which the terminal or the LAN emulation client means belongs is provided, and the first server means, By referring to this grouping table, in the case of the same group and corresponding addresses, an address resolution protocol response packet is returned, and for address resolution protocol request packets for terminals other than the same group The second server means refers to the grouping table, and is directly connected to the broadcast packet or the ATM line connection between the terminals only to the terminals in the same group, including means for not returning the address resolution protocol response packet. It is characterized in that it includes means for transmitting a packet that is not present.

The first and second server means may be mounted on the same computer, and the grouping table may be mounted on the computer.

A second aspect relates to an ATM group communication method, which is a LAN emulation client means for converting Ethernet packets into ATM cells, an ATM switching means for switching the cells according to a destination address, and an Ethernet address. AT directly between the first server means for associating an ATM address with a broadcast packet or terminal.
A second server means for transmitting a packet not connected to the M line is provided, and a fixed virtual line is set in advance between the terminal connected to the Ethernet and the first and second server means for communication. When performing a call, the originating terminal sends the corresponding ATM to the first server means.
An address resolution protocol request packet for requesting address information is transmitted, and an origination terminal communicates with a recipient terminal by an address resolution protocol response packet containing the corresponding ATM address from the first server means as information. ATM that establishes a switched virtual circuit that is connected to every communication
The communication method includes a group management server having a grouping table indicating a group type to which the terminal or the LAN emulation client means belongs, and the group management server is provided to the first server means and the second server means. The contents of the grouping table are transferred and registered, and the ATM is transferred from the LAN emulation client unit to the first server unit.
The correspondence between the address and the address of the terminal on the Ethernet to which the terminal belongs is registered in the first server means, and the LAN emulation client means connected to the originating terminal connects the first server means with the address resolution. When the protocol request packet is transmitted and the transmission request from the transmission side terminal is a broadcast packet or a packet which is not directly connected to the ATM line between the terminals, the second server means refers to the contents of the grouping table, and the same. Terminals belonging to group or L
Send only to AN emulation client means,
When the transmission request from the transmission side terminal is a packet with address correspondence, the first server means responds to the address resolution protocol request packet by
Referring to the contents of the grouping table, an address resolution protocol response packet containing an ATM address as information is returned when the addresses are in the same group and addresses correspond to each other. When the addresses do not belong to the same group, the address resolution protocol response packet is returned. It is characterized by not sending back an optional protocol response packet.

The group management server is provided with a grouping table indicating which group the terminal MAC address belongs to. When an ATMARP (Address Resolution Protocol) request packet is transmitted from the originating terminal computer, the LE server, which is the first server means, refers to this grouping table and belongs to the same group and addresses are associated. Returns an ATMARP response packet. The originating side terminal computer establishes a connection with the receiving side terminal computer of the acquired ATM address for communication. The BU server which is the second server means transmits a broadcast packet or an unknown packet (a packet not directly connected to the ATM line between the terminal computers) only to the terminal computers in the same group.

The present invention is different from the prior art in that a grouping table of terminal computers is placed in a server, broadcast packets are transmitted only to terminal computers in the same group, and A
The difference is that the ATMARP response packet is controlled not to be returned to the TMARP request.

According to the present invention, therefore, it is possible to perform inter-group communication in ATM communication, and not only between arbitrary terminal computers but between computers belonging to a predetermined group.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an example of an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a system configuration example which is an embodiment of the present invention. FIG. 2 is a flow chart showing the operation of this system. The same components as those in FIG. 4 are designated by the same reference numerals.

In FIG. 1, reference numeral 11 is an LE server for managing LAN addresses and ATM addresses, and reference numeral 12 is a broadcast server for processing broadcast packets and packets not directly connected to the ATM line between terminal computers. (Broadcast and
Unknown Packet Server). Reference numeral 13 indicates a group management server that manages a grouping table for group communication. As in FIG. 4, LE clients 23 and 29 for converting Ethernet packets and ATM cells are provided. In this case, the LE client 29 is an example in which a terminal computer is directly accommodated.
The E client 23 is an example in which a plurality of terminal computers 26 are accommodated by a hub 25 (Ethernet). Reference numerals 14 and 28 denote PVCs which are fixedly connected to the line, and reference numeral 28 denotes an SVC which is connected to the line each time communication is performed.

Here, in the embodiment of the present invention, LAN emulation clients 23 and 29 for converting Ethernet packets into ATM cells, and an ATM switch 24 which is an ATM switching means for switching these cells according to a destination address, A LAN emulation server 11, which is a first server means for associating an Ethernet address with an ATM address,
A broadcast server 12, which is a second server means for transmitting a broadcast packet or a packet not directly connected to the ATM line between the terminals, is provided, and terminal computers 26 (plural) connected to the Ethernet and L
A fixed virtual line (PVC) 27 is set in advance between the AN emulation server 11 and the broadcast server 12, and when performing communication, the corresponding ATM address information is sent from the terminal computer on the calling side to the LAN emulation server 11. A switch that transmits an address resolution protocol request packet to be requested, and is connected with the terminal computer on the receiving side every time communication is performed by an address resolution protocol response packet including the ATM address from the LAN emulation server 11 as information. A including means for setting a virtual circuit (SVC) 28 and performing communication
In the TM communication method, the group management server 13 is provided with a grouping table indicating the group type to which the terminal computer (26) or the LAN emulation client 23 (29) belongs, and the LAN emulation server 11 refers to this grouping table to identify the same group. If there is a correspondence between the addresses, an address resolution protocol response packet is returned,
The broadcast server 12 includes means for not returning an address resolution protocol response packet to an address resolution protocol request packet for a terminal computer other than the same group. And a packet which is not directly connected to the ATM line between the terminal computers.

Next, a connection sequence for communication between terminal computers in this system will be described with reference to FIG. LE client (2
, 29) or a grouping table indicating the group type to which the terminal computer belongs is created and transferred or registered in the LE server 11 and the broadcast server 12. The correspondence between the MAC address and the ATM address is registered in the LE server 11 from the LE client. An ARP request is sent from the LE client (for example, 23) connected to the sending terminal computer to the LE server 11. When the type of the packet to be transmitted is a broadcast packet or an unknown packet, the grouping table is referred to and the packet is transmitted from the broadcast server 12 to the LE clients belonging to the same group. In the case of a packet having a corresponding address, the grouping table is referred to, and if the originating terminal computer or the originating LE client and the destination terminal computer or the destination LE client belong to the same group, L
The E server 11 returns an ARP reply including the ATM address as information to the LE client. The LE clients use the returned ATM address to set up a VC connection between the LE clients by signaling. Start communication between terminal computers.

As shown in FIG. 6, the Ethernet packet (frame) can be placed on the ATMAAL5 (ATM adaptation layer 5) and transmitted.

Next, a specific example of the grouping table configuration will be shown. This table structure is based on M of the terminal computer.
It is possible to determine which group the AC address belongs to. For example, A method to create a table of addresses belonging to a group like As described above, there is a method of tabulating the correspondence between addresses and groups.

As a result, the group management server 13, L
Based on the information from the E server 11, a VC connection can be set up between terminal computers or LE clients belonging to the same group by ATM signaling, and ATM cells can be transferred. Therefore, since routing or switching is realized by hardware on the ATM switch, group communication processing can be performed at a higher speed than the conventional bridge or router by software processing.

Further, in the ATM group communication system according to the present invention, the group communication in which only the limited members among the registered LE clients or the terminal computers connected thereto are further communicated with the ATM network. It can be realized above.

In the description of the above embodiment, the group management server, the LE server and the broadcast server are implemented in separate computers, but these functions can be implemented in a single computer. . The implementation form of these functions is a structure which can be changed as needed. In this case, group communication can be managed by one server computer, which facilitates system management.

[0031]

As described above, according to the present invention, A
In computer communication in which an Ethernet packet is converted into ATM cells and transmitted between computers using a TM network, high-speed switching characteristics and ARP operation, which are features of ATM, are used to perform communication only between computers belonging to a predetermined group. It is possible to realize an ATM group communication system capable of performing ATM. Moreover, system management becomes easy by implementing all the functions in one server computer.

[Brief description of drawings]

FIG. 1 is a diagram showing a system configuration according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the system of the present invention.

FIG. 3 is a diagram showing a configuration of a conventional system.

FIG. 4 is a flowchart showing the operation of a conventional system.

FIG. 5 is a diagram showing a layer structure of an ATM packet.

[Explanation of symbols]

11, 21 LE server (LAN Emulation Server) 12, 22 Broadcast server (Broadcast and
Unknown Packet Server) 13 Group management server 23, 29 LE client 24 ATM switch 25 Ethernet (hub) 26 Terminal computer 14, 27 PVC (Permanent Virtual Circuit) 28 SVC (Switched Virtual Circuit) 31 Ethernet packet header 32 Ethernet data 33 ATM cell Trailer 34 ATM cell 35 ATM header 36 ATM data section 37 ATM header structure

Claims (3)

[Claims] 1. LAN emulation client means for converting an Ethernet packet into an ATM cell, ATM switching means for switching this cell according to a destination address, and first server means for associating an Ethernet address with an ATM address. A second server means for transmitting a broadcast packet or a packet not directly connected to the ATM line between the terminals, and fixed in advance between the terminal connected to the Ethernet and the first and second server means. When a virtual line is set up and communication is performed, an address resolution protocol request packet for requesting corresponding ATM address information is transmitted from the calling side terminal to the first server means, and the first server is transmitted. ATM address from the means An ATM communication method including means for setting a switched virtual line connected to a receiving terminal at each communication with an address resolution protocol response packet included as information and performing communication, wherein the terminal or the LAN A grouping table indicating the group type to which the emulation client means belongs is provided, and the first server means refers to this grouping table to send an address resolution protocol response packet when the addresses are in the same group. The second server means includes means for returning the address resolution protocol response packet to the address resolution protocol request packet for terminals other than the same group, and the second server means for transmitting the address resolution protocol response packet. Reference, ATM group communication system, characterized in that it includes means for transmitting a packet that is not directly ATM line connection between the broadcast packets or terminal only for the same group terminal. 2. The ATM according to claim 1, wherein the first and second server means are mounted on the same computer, and the grouping table is also mounted on the computer.
Group communication method. 3. LAN emulation client means for converting an Ethernet packet into an ATM cell, ATM switching means for switching this cell according to a destination address, and first server means for associating an Ethernet address with an ATM address. A second server means for transmitting a broadcast packet or a packet not directly connected to the ATM line between the terminals, and fixed in advance between the terminal connected to the Ethernet and the first and second server means. When a virtual line is set up and communication is performed, an address resolution protocol request packet for requesting corresponding ATM address information is transmitted from the calling side terminal to the first server means, and the first server Corresponding ATM address from means In the ATM communication method, the originating terminal sets up a switched virtual line to be connected to the receiving terminal every time the communication is performed by the address resolution protocol response packet including the address as the information. And a group management server having a grouping table indicating a group type to which the LAN emulation client means belongs, and the group management server transfers the contents of the grouping table to the first server means and the second server means. The LAN emulation client means registers in the first server means the correspondence between the ATM address and the address of the terminal on the Ethernet to which the terminal belongs in the first server means. LAN Emi connected to When the resolution client request packet is transmitted from the communication client means to the first server means and the call origination request from the call originator terminal is a broadcast packet or a packet which is not directly connected to the ATM line between the terminals, the second Server means refers to the contents of the grouping table and transmits only to terminals belonging to the same group or LAN emulation client means, and if the calling request from the calling terminal is a packet with address correspondence, Server means for the address resolution protocol request packet,
Referring to the contents of the grouping table, an address resolution protocol response packet containing an ATM address as information is returned when the addresses are in the same group and addresses correspond to each other. When the addresses do not belong to the same group, the address resolution protocol response packet is returned. ATM group communication method characterized by not sending back a response protocol response packet.