Method and apparatus for determining transmission line for message transmission and reception in network system

• US 5,172,372 A
• Filed: 06/05/1991
• Issued: 12/15/1992
• Est. Priority Date: 06/05/1990
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Konishi, Kuniyoshi
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Jung, Min
• Application Number:
  US07/710,776
• Time in Patent Office: 559 Days
• Field of Search: 370/85.13, 370/85.14, 370/85.12, 370/85.1, 370/85.15, 370/85.9, 370/94.3, 340/825.05
• US Class Current: 370/401
• CPC Class Codes: H04L 12/4604 LAN interconnection over a backbone network, e.g. Internet, Frame Relay
• CPC Class Codes: H04L 2212/00 Encapsulation of packets
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/742 Route cache; Operation thereof

Abstract

When the first message from a station is received by a LAN interface in a LAN connector unit, a source station address and a bridge port address are registered in an address translation table, and a flag T2 is set. This message is transmitted to the respective interfaces in the LAN connector unit by broadcast. Upon receiving this message, a flag T4 is set in the interface, and flags T1 are set in the other interfaces. When a WAN interface in another LAN connector unit receives the first message, a flag T2 is set. This message is transmitted from the WAN interface to the respective interfaces in the LAN connector unit by broadcast. The WAN interface is determined as an input/output interface associated with this message, and a flag T4 is set. A flag T1 is set in other interfaces. When the WAN interface receives a delayed message, since the flag T1 is already set therein, this interface is determined not to be an input/output interface for this message. A flag T3 is set in this interface.

Claims

1. A network system comprising:

a plurality of first networks, each having at least one station;

a plurality of second networks;

a plurality of interfaces, each of the interfaces being coupled to one of the first and second networks; and

a plurality of internal networks, each of the interfaces being coupled to one of the internal networks, and

wherein each of the interfaces includes;

a table for registering a station address and a corresponding interface address with respect to a source station and a destination station, and set/reset states of a plurality of flags;

control-means for, when a first message from the source station is received by the interface itself through one of the first networks, altering said table to register a station address of the source station and an interface address of the interface itself, causing said table to set a first flag, and transmitting the first message to one internal network coupled to the interface itself by a broadcast,

wherein the control means, when a message from the one internal network is a message transmitted by the interface itself, altering said table to set a second flag and aborts the message from, the one internal network,

the control means, when a message from the one internal network is a first message from the source station, altering said table to register the station address of the source station and the interface address of another interface which transmits the first message to the internal network, altering (the) said table to set a third flag, and transmits the first message to one of the first and second networks, and

the control means, when a message from one of the second networks is received by the interface itself and when the third flag is to be set into the table, aborts the message from the one second network.

2. The system according to claim 1, wherein each of the first networks includes a local area network.

3. The system according to claim 1, wherein each of the second networks includes a wide area network.

4. The system according to claim 1, wherein each of the interfaces further includes memory means for storing a message to be received.

5. The system according to claim 1, wherein when the first flag is to be set into the table of a receiving interface which a message is received, with respect to the station address of the source station included in the received message, and when the interface address of a source interface included in the received message is different from the interface address registered into the table of the receiving interface, the receiving interface aborts the received message.

6. The system according to claim 1, wherein after the first flag is set into the table of the interface, the control means determines whether or not the one interface itself is one of multiplexed interfaces coupled to the same first network.

7. A method for determining a transmission line for a message transmission and reception in a network system, the method comprising the steps of:

receiving a message by an interface;

registering a station address of a source station and interface address of the interface, setting a first flag, and transmitting the received message to an internal network by broadcast, when the received message is a first message source station through a local area network;

setting a second flag and aborting the received message when the received message is a message transmitted by the interface;

registering the station address of the source station and the interface address of the interface, setting a third flag, and transmitting the received message to one of the local area network and a wide area network, when the received message is a first message from an internal network; and

aborting the received message when the received message is a message from the wide area network and when the third flag is to be set.

8. The method according to claim 7, wherein when the first flag is to be set with respect to the station address of the source station included in a message to be received, and when the interface address of a source interface included in the received message is different from the interface address to be registered, the received message is aborted.

9. An apparatus for coupling a plurality of local area networks to a plurality of wide area networks, each of the local area networks having at least one station, the apparatus comprising:

a plurality of interfaces for transmitting and receiving a message; and

an internal network for connecting the interfaces one another, and

wherein each of the interfaces includes register means for registering a station address and a corresponding interface address with respect to a source and a destination, and set/reset states of a plurality of flags; and

control means for altering the register means to register a station address of a source station and an interface address of the interface itself, altering the register means to set a first flag, and transmitting the message to the internal network by a broadcast, when a message from the source station through one of the local area networks is a first message,

wherein the control means alters the register means to set a second flag and aborts a message from the internal network when the message from the internal network is a message transmitted from the interface itself,

the control means alters the register means to register the station address of the source station and the interface address of another interface which transmits the first message to the internal network, causes the register means to set a third flag and transmits the message from the internal network to one of the local area networks and the wide area networks, when a message from the internal network is a first message from the source station, and

the control means aborts the message from the wide area networks when the message from the wide area networks is received and the third flag is to be set.