JPH01166636A - Multiple address communication system - Google Patents

Abstract

PURPOSE:To prevent a frame of a different kind of branch LAN from entering into a branch LAN by providing a means discriminating a multiple address communication frame flowing through a main LAN whether or not it is of the same kind as that of the branch LAN connecting to its own frame into a bridge. CONSTITUTION:When a frame is received from a main LAN 2, bridges 41-45 judge whether a DA of the main LAN frame is addressed to its own bridge address. When they are dissident, whether or not the DA of the main LAN is coincident with the multiple address stored in itself is judged. When dissident, the frame is aborted, and when coincident, the branch LAN frame is generated. Then the routing processing is applied and a frame is sent to a branch LAN 31 or 32.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to LAN interconnection technology, and particularly to a broadcast communication system.

[Conventional technology]

Conventionally, a communication method in a LAN interconnection system in which a high-speed, large-capacity trunk LAN is used to interconnect multiple relatively low-speed branch LANs has been described, for example, in Japanese Patent Laid-Open No. 60-108.
It is described in Publication No. 39. According to this, branch line LA
The frame from N is appended with the address of the destination bridge before being sent to the main LAN, and the address is removed at the destination bridge before being sent to the branch LAN.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology is based on the premise that the routing method, frame format 1, etc. of each branch LAN are the same.

In other words, the case where different types of branch LANs exist is not considered, and in such a case, branch LAN frames are broadcast within the main LAN (such as frames for route search where the destination bridge is not uniquely determined). Therefore, if different types of branch LANs are connected to the main LAN, frames emitted from one branch LAN may be sent to different types with different routing methods, frame formats, etc. There is a problem that it may enter the branch LAN and cause malfunction.

The purpose of the present invention is to prevent such malfunctions.

Even if there are different kinds of supports @LAN, the same type of supports, 1
The goal is to ensure normal communication between iLANs.

Means for Solving Problem c] In order to achieve the above object, the present invention provides a bridge (hereinafter referred to as "bridge") that connects the trunk LAN and the branch LAN.

This system is characterized in that when a frame received from a branch LAN (simply referred to as a bridge) is broadcast to the main aLAN, this broadcast communication is distinguished according to the type of branch LAN.

[Effect]

According to the present invention, by the above means, the bridge connects the trunk LA
It is possible to determine whether the broadcast communication frames flowing within N are of the same type as the branch LAN to which the user is connected, and to receive only frames of the same type. Therefore, a different type of branch line LAN frame will not be received, and malfunctions can be prevented.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Figure 2 shows two types of branch lines LAN31 (31a.

31b, 31c) and 32 (32a, 32b) as main line L
A bridge 41 is connected between the branch lines LAN31 to 32 and the main line LAN2, which indicates the LAN interconnection system accommodated by AN2.
Connect by ~45. Bridges 41-45 are main line LA
Each branch LAN 31 has address 5 that is valid within N2.
A terminal 6 for communication is connected to 32. In such a LAN interconnection system, it is assumed that the terminal 6 communicates only with terminals 6 connected to the same type of LAN as itself.

That is, the system of FIG. 2 logically arranges the branch line LAN so that the part consisting of the branches 11ALAN 31 a to 31 c and the part consisting of the branches 32 a to 32 b are independent from each other, as shown in FIG. 3. The trunk LAN 2 has a closed configuration for each type. In order to realize such a logical configuration, it is necessary to ensure that branch line LAN frames belonging to one type do not enter branch line LAN frames belonging to other types.
．． Routing is performed using the route information written in the frame received from 32 or the address table provided by the bridge. As a result of this routing, if the destination bridge within the main LAN 2 is found, The address of this destination bridge is DA of the trunk LAN frame.
Write in the (Destination Address) field and send. In this case, branch line LAN31
(or 32) with a different branch line LAN 32 (or 31)
) frame does not enter, but the trunk LA
If the destination bridge in N2 cannot be found uniquely (for example, a branch LAN frame for route search, a branch 11 LAN frame whose destination is a terminal not registered in the address table, etc.), the DA of the trunk LAN frame is broadcast by C broadcast. ” and main line LAN2
It is necessary to perform broadcast communication within the network. Since the bridges 41 to 45 receive all broadcast communication frames within the trunk LAN 2,
In this case, a frame from a different type of branch LAN 32 (or 31) may enter the branch LAN 31 (or 32), causing a malfunction.

In order to solve this problem, in the present invention, "broadcast" at,
The responses are distinguished according to the type of branch line LAN 31, 32.

FIG. 1 shows a broadcast communication frame 11 within the main line LAN 2 from the bridge 41 and a broadcast communication frame 12 within the main line LAN 2 from the bridge 42. The bridge 45 considers and receives only the broadcast communication frame 12 as a "broadcast" and does not receive the broadcast communication frame 12. The bridge 45 receives only the broadcast communication frame 12 as a "broadcast" and does not receive the broadcast communication frame 11. The support that you are connected to bridges 41 to 45, ll1l
This is possible by providing "broadcast" addresses according to the types of LANs 31 and 32 as information.

FIG. 4 shows an example of purchasing bridges 41-45.

Branch line LAN'7L/- is branch 1 LAN transmission/reception Ia structure 57
The frame is passed to the frame relay mechanism 58 through the frame relay mechanism 58 and routed by referring to the routing information storage mechanism 60. If broadcast communication within the trunk LAN 2 is required as a result of the routing, the frame is further transmitted from the broadcast address storage mechanism 61 to the branch line LAN 31 or 32. Obtain the broadcast address within the trunk LANZ according to the type of address. This broadcast address is sent to the trunk LA via the trunk LAN transmission/reception mechanism 59 as the DA of the trunk l1ALAN frame.
Send to N2. Frames from the trunk fiLAN2 follow the opposite route.

FIG. 5 is a flowchart showing the operation of each bridge when relaying frames from the branch LAN 31, 32 to the trunk LAN 2. When a frame is received from the branch LAN 31 or 32 (step 100), routing processing is performed (102), and it is determined whether broadcast communication within the model LAN 2 is necessary (104). If broadcast communication is not required, obtain the DA of the trunk LAN frame from the routing information (1
06), if broadcast communication is required, obtain a broadcast address in trunk LAN 2 according to the type of branch LAN (108);
Thereafter, a trunk mLAN frame is created (110) and transmitted to the trunk LAN 2 (112).

FIG. 6 is a flowchart showing the operations of the bridges 41-45 when relaying frames from the trunk LAN 2 to the branch LANs 31-32. When a frame is received from the trunk LAN 2 (120), it is determined whether DA of the trunk LAN frame is the own bridge address (122). Judgment 120
is N.

If so, it is determined whether the DA of the trunk LAN frame matches the broadcast address stored in itself (124). If it does not match, the frame is discarded (126). If they match, the decision 122 is YES. A branch line LAN frame is created in the same way as in step 1 (128), then routing processing is performed (130), and the frame is transmitted to the branch line LAN 31 or 32 (132).

By doing this, normal communication between the same type of support 1@LAN can be guaranteed.

In addition to the embodiments described above, several other variations are possible. This will be discussed below.

In the first modification, the broadcast communication frames transmitted by the bridges 41 and 42 in FIG.
As shown in 2', the DA section shows the same "broadcast", and the branch line L
The configuration is such that information indicating the type of branch line LAN is written in the ANID section. Each bridge 41 to 45 is the trunk LAN2
Look at the branch line LAN ID section in the broadcast communication frame and select the branch line LAN31 to which you are connecting the broadcast communication frame.
Or, it is determined whether to relay to 32 or not.

FIG. 8 shows this modification. Bridge 41~ when relaying frames from branch line LAN31゜32 to main line LAN2
45 is a flowchart showing the operation of step 45.

When a frame is received from branch LAN 31 or 32 (2
00), performs routing processing (202), and connects the main LA
Determine whether intra-N2 broadcast communication is necessary (204);
If broadcast communication is not required, DA of trunk LAN frame
from the routing information (206), creates a trunk LAN frame (208), and transmits the frame to the trunk LAN (214). If broadcast communication is required, mainline LAN
Set the DA of the frame to "broadcast" (210), and select the branch line LA depending on the type of branch line LAN31.32 to which you are connected.
Write the NID and create a trunk LAN frame 212
), and then transmits the frame to the main LAN (214
).

Figure 9 shows the main line LAN2 and branch line LA in this modification.
Bridge 41 when relaying frames to N31 or 32
It is a flowchart which shows the operation|movement of 45. Trunk LAN
When a frame is received from 2 (220), the DA of the trunk LAN frame determines whether it is an own bridge address or a broadcast (222, 224). If this condition is not met, the frame is discarded (228). ), main line LA
When the DA of N frame is broadcast, the branch line LAN ID of the model LAN frame is the branch line LAN31.3 to which you are connected.
2 (226), and if this is not satisfied, the frame is discarded (228). Judgment 2
22 or after the determination 226, create a branch LAN frame 230), perform routing processing (232),
Send the frame to branch line LAN 31 or 32 (234
).

As a second modification, information indicating whether it is "broadcast" or "non-broadcast" may be added to the broadcast frame in the trunk LANZ, that is, in the example of FIG. Those whose DA is "FF F F F" or "F F F E" are considered to be broadcast, and the others are considered to be non-broadcast, but in this modification, as shown in FIG. 10, for example, broadcast/ An area indicating non-broadcasting is provided on the trunk LANZ frame. As shown in Figure 10, in the broadcast frame, “Broadcast J
(For example, "1'"), branch line LAN31゜32
Write information according to the type into the DA section. In this example, the branch line LAN31 is distinguished by DA="0001" and the branch line LAN32 is distinguished by DA="0002".In frames that are not 0 broadcasts, the broadcast/non-broadcast section is marked with "non-broadcast" (for example, 1
By writing 10 II) and writing the destination bridge address in DA, the same effect as in the embodiment can be expected.

〔Effect of the invention〕

According to the present invention, different types of branch line LAN frames do not enter the branch line LAN, and malfunctions can be prevented. Therefore, normal communication can be performed between terminals connected to the same type of branch LAN.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a broadcast communication frame according to an embodiment of the present invention, FIG. 2 is a diagram showing an example of the overall configuration of a LAN interconnection system according to the present invention, and FIG. 3 is a diagram showing the logical structure of the system shown in FIG. 4 is a diagram showing the configuration of the bridge, FIGS. 5 and 6 are flowcharts showing one embodiment of the relay operation of the bridge, and FIG. 7 is a diagram showing a modified example of the broadcast communication frame. 8 and 9 are flowcharts showing the relay operation of the bridge when the frame of FIG. 7 is applied, and FIG. 10 is a diagram showing another modification of the broadcast communication frame. 11.12... Broadcast communication frame, 2... Trunk LA
N, 31 a, 3 l b, 31 c, 3
2a, 32b - Branch LAN, 41-45...
・Bridge, 5... Bridge address in trunk LAN... Terminal, 57... Branch LAN transmission/reception mechanism, 58
. . . Frame relay mechanism, 59 . . . Trunk LAN transmission/reception mechanism, 60 . . . Routing information. - Figure 5 Figure 4 Early I'II! I Hayabusa 8121

Claims (1)

[Claims] 1. Multiple types of branch lines LA each connected to a terminal device
Main line LAN for interconnecting N and the above branch line LAN
and a bridge for connecting each of the branch LANs to the trunk LAN, in which a frame is sent from the terminal device to one of the branch LANs and broadcast within the trunk LAN. , including discrimination information according to the type of the branch LAN, and each bridge determines whether the broadcast communication frame in the trunk LAN is of the same type as the branch LAN to which it is connected and performs a relay operation. A broadcast communication system characterized by: