JPS6163137A - Mutual connection system of local area network - Google Patents

Abstract

PURPOSE:To attain communication in and between local area circuit networks without notifying a terminal device except a repeater node by using a data link layer address field to attain routing. CONSTITUTION:A terminal node, e.g., 3A sets a station address of a terminal node 3A to a sender station address SSA to communicate a packet. A relay node 4A sets an inter-area communication bit and an area number alpha to an address SSA of a packet received from the terminal node 3A and the result is a transmitted to a repeater node 4B. The node 4B sets an inter-area communication bit and area number of a destination station address DSA of the packet received from the node 4A to logical '0' and transits it to the terminal node 3D. Then the relay node sets the inter-area bit and area number to the address SSA of the received packet from the inter-area and the inter-area communication bit and the area number of the address DSA of the reception packet are cleared from the outside of the area.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is applicable to a plurality of local area networks (LANs) having a bus type or ring type structure that enable broadcast communication, such as a public network, a leased line, or a heterogeneous LAN. It relates to a routing method for interconnecting via a network.

(Prior art) Conventionally, as a technology in this field, for example, "The
Ethernet A Local Area Ne
twork Data Link Layer and
Physical Layer 5 specific
ions, DEC/Intel/Xerox, 198
2-11 J and “Internet Transport Protocol, Fuji Xerox.

As described in 1981.1, 2J, in a LAN with a path type or ring type structure that enables broadcast communication, the fifth
As shown in the figure, mutual communication between terminal nodes is realized by having a destination station address (DSA) and a source station address (SSA') in one header of a packet that transfers information. In communication within a LAN, communication between all nodes is possible without going through a relay node, but communication between terminal nodes connected to different LANs must go through one or more relay nodes. become.

Such conventional communication between LANs is as shown in Figure 6.
The network layer (i.e., relays through one or more communication networks and provides network connections between devices where users are present) is added to the header of Nogukerato.
This method had a destination network address (DNA) and a source network address (5NA), and was realized by converting all address information at a relay node.

(Problems to be Solved by the Invention) However, in such a conventional system, (1) the amount of routing/address information at the relay node and the overhead in address translation are large;

■ When moving a terminal node, it is necessary to change address information not only at the relay node but also at the terminal node.

■ When mutually independent LANs are combined, it is necessary to change the address information of both the relay node and the terminal node.

There were drawbacks such as.

(Means for Solving the Problems) The present invention has been made to solve these drawbacks, and it enables mutual communication between LANs via public networks, leased lines, different LANs, etc. What is the routing method (i.e., route selection and relaying method) and the data link layer (i.e., the data link control procedure that sends and receives data between two devices and handles transmission errors on the communication line)? The present invention provides a local area network interconnection method that is efficient and allows for easy system configuration changes by using the address field of .

(Function) According to the present invention, the routing at the relay node only needs to be aware of the area and not the node number of the terminal mate. In addition, each terminal node can communicate using the address of the communication terminal node related to inter-area communication and intra-area communication, and the area number of the own address and intra-area node address is set to “0”.
” By remembering this, you can eliminate the above problem.

Embodiments of the present invention will be described in detail below with reference to the drawings.

(Embodiment) FIG. 1 is a device configuration diagram and an address system diagram for explaining the present invention in detail. In the same figure, IA, IB, I
C is the communication medium of LAN, 2 people, 2B is a leased line or public network, 3 is 3B to 3H are terminal nodes, 4A, 4B, 4C
is a relay node.

Within the broken line, that is, one LAN constitutes one area, and are given area numbers α, β, and γ, respectively. Terminal nodes 31.3B to 3, relay node 4, 4B, 4
C is given a 7-card number of A, B, C, and D, respectively. The station address of each node consists of an area number and a node number, as shown in FIG. The first bit sent on the station address line is used to distinguish between intra-area communication (*=O) and inter-area communication (*=1). Each terminal node remembers its own node address only as a node number (remembered as an area number 'On'). Also, only packets addressed to the own node and broadcast packets (DSA=all""1') can be received. Each relay node must be able to receive broadcast packets addressed to its own node as well as regular packets addressed to other areas. Then ζ sets the inter-area communication bit (* in Figure 2) of the destination station address (DSA).
) is 1" when communicating outside the area, each relay node is able to receive all * = 1 *, and each terminal node is capable of receiving DSAs addressed to nodes in other areas. = 1 and transmit (remember the station address of the node in the other area as *=1).

Next, a communication example will be explained based on the device configuration shown in FIG.

(1) Intra-area communication An example of communication between the terminal nodes 3A and 3B in FIG. 1 is shown in FIG. Since the terminal nodes 3A and 3B are in the same area, they communicate with each other using the area number °'0'', and the relay nodes 4A, 4B,
Communicate without going through 4C.

(2) Inter-Area Communication An example of communication between the terminal nodes 3A and 3D in FIG. 1 is shown in FIG. The terminal node 3A uses the station address of the terminal node 3D (area number = B, node number = B, book = 1)
to the destination station address DSA, and your own station address (area number = 0, node number = = A,
*:=Q) is set as the source station address SSA, and ``nogukera'' is communicated.

The relay node 4A sets the inter-area communication bit (*=1) and the area number @ in the d'ticket source station address SSA received from the terminal node 3A, and transmits it to the relay node 4B.

The relay node 4B sets the inter-area communication bit and area number of the destination station address DSA of the packet received from the packet 4A to 'O' and transmits it to the terminal node 3D. S.S.A.
The inter-area communication bit and area number are set, and the inter-area communication bit and area number of the DSA of the packet received from outside the area are cleared.

(Effects of the Invention) As explained above, according to the present invention, routing at relay nodes only needs to be aware of the area and not the node number of the terminal node, and each terminal node can perform inter-area communication, It is possible to communicate using the address of the communication terminal node regardless of internal communication, and by remembering the area number of the own station address and the area node address as 0'', there are the following advantages.

■ The amount of information and overhead for routing at relay nodes are both small.

■ Terminal nodes other than relay nodes do not need to be aware of intra-LAN communication and inter-LAN communication.

■ There is no need to change routing information even if nodes are added or removed.

■ When a new LAN is connected to the network, there is no need to change each terminal mate, and only a slight change to the relay node is required.

■ When mutually independent LANs are connected, there is no need to change the address information of nodes other than relay nodes.

■ Communication confined to one LAN does not affect the router.

[Brief explanation of drawings]

FIG. 1 is a device configuration diagram and address system diagram for explaining the present invention in detail, FIG. 2 is a diagram showing station addresses used in the present invention, and FIG. 3 is an example of intra-area communication according to the present invention. FIG. 4 is a diagram showing an example of inter-area communication according to the present invention, FIG. 5 is a general LAN format, and FIG. 6 is a diagram showing a conventional LAN communication format and format. Diagram showing. IA, IB,,IC... LAN communication medium, 2A, 2B... Dedicated line or public network1. ? A,
3B, ~, 3H...terminal node, 4A, 4B, 4C
...Relay node, A. B, C, D...Node number, α, β, γ...Area number Patent applicant Oki Electric Industry Co., Ltd. Procedural amendment (voluntary) 60.3.27 Showa Year Month Day

Claims (1)

[Claims] There are a plurality of local area networks (LANs) with a bus-type structure or a ring-type structure that enable broadcast communication, and the devices connected to each LAN have addresses such as destination addresses and source addresses. In a communication control method that performs communication using packets containing fields, in a data communication system that interconnects the LANs via a plurality of relay devices, routing is performed using the address field of the data link layer. A distinctive local area network interconnection method.