JPH03101333A - Bypass system for hybrid switching type lan - Google Patents

Abstract

PURPOSE:To guarantee a normal operation as a whole packet switching loop by detaching a packet node where abnormality occurs from a system when abnormality occurs in the certain packet node. CONSTITUTION:A line node 5 switches transmission and reception so that a packet node 4a where abnormality occurs is detached from the system when abnormality is detected. When abnormality occurs in the packet node 4a, the line node 5 switches the transmission and reception for the packet node 4a from the packet node 4a to a packet node 4b, and by passes the packet node 4a. Thus, the normal operation is guaranteed as the packet switching loop even if abnormality occurs in the packet nodes 4a and 4b, and the reliability of a network can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a loop network bypass method,
In particular, it relates to a bypass method for a hybrid switched LAN.

[Prior Art] There are two types of loop networks: circuit switching and packet switching. Each type has its advantages and disadvantages, and is often used depending on the field of application.However, recently, hybrid exchange type L that incorporates the advantages of both types has been introduced.
AN is attracting attention. In the case of a hybrid switched LAN, both terminals suitable for circuit switching and terminals suitable for packet switching can be connected together.

FIG. 3 shows an example of the configuration of a hybrid switching type LAN.

As a configuration of a hybrid switched LAN, each node (hereinafter referred to as a line node) la to 1d of a circuit switched loop network has one or more nodes of a packet switched loop network (hereinafter referred to as a packet node).
There is a configuration in which 2a to 2f are connected.

FIG. 4 shows a frame structure of a hybrid switched LAN. Packet switched data is transmitted on the loop transmission line 3 using a part of the area (packet data transmission area) 22 within the transmission frame 21.

Data is exchanged between line nodes 1a to 1d and packet nodes 2a to 2f at line node lb.

When only one packet node 2c, 2f is connected as in case 1d, the line node is connected to a plurality of packet nodes 2a, as shown in line nodes la and lc, which both transmit and receive data to and from that packet node.

If 2b; 2d and 2e are connected, the line node is 1
Sending data to one packet node 2a, 2d and receiving data from another packet node 2b, 2e, between packet nodes 2a, 2b, 2d.

2e are physically connected separately to perform data transmission, and as a whole, one packet switching loop is constructed as shown in FIG.

FIG. 5 shows the intra-node page note data transmission order when three packet nodes 4a to 4c are connected to one line node 5.

The line node 5 takes out the data in the intra-frame allocation area 22 sent from the previous line node on the loop transmission path 3, and sends it to the packet node 4a. The packet nodes 4a to 4b and 4b to 4c are transmitted through a packet inter-node transmission path 6 consisting of separately connected lines. Then, the packet node 4c sends the data to the line node 5, which writes the data into the intra-frame allocation area 22 and sends it to the next line node.

By repeating this control at each node, the packet-switched data is transmitted as a whole.

[Problem to be solved by the invention] Normally, a loop network has a duplex transmission path,
In the event that an abnormality occurs in a node or a disconnection occurs between nodes, loopback control is performed to prevent the entire system from going down. In the example shown in FIG. 3, it is also possible to perform loopback control if there is an abnormality in the line node or if one part of the loop transmission line 3 is disconnected.

However, loopback control can be performed by
It is only the line-switched loop that actually performs data transmission on the loop transmission path 3, and loopback control cannot be performed on the packet-switched loop that relies on the line-switched loop for transmission on the loop. Therefore, if an abnormality occurs in a certain packet node or if the transmission line 6 between packet nodes is disconnected, the middle of the packet switching loop will remain disconnected and cannot be restored, causing the entire packet switching loop to go down. There was a problem.

The purpose of the present invention is to solve the above-mentioned drawbacks of the prior art, and to
Hybrid switching type LA that enables normal operation of the entire packet switching loop by disconnecting that node from the system when an abnormality occurs in one packet node.
The purpose of the present invention is to provide N bypass methods.

[Means for solving the problem] The bypass method of the hybrid switching type LAN of the present invention is as follows:
One or more packet nodes, which are nodes of the packet-switched loop network, are connected to each line node, which is a node of the circuit-switched loop network, and a part of the transmission frame of the circuit-switched loop network is connected. of,
By allocating it for packet-switched data transmission,
In a hybrid switched LAN that enables both circuit-switched and baguette-switched transmission, when multiple packet nodes are connected to one line node, the line node sends packet data to a certain packet node. However, packet data is received from another packet node, and packet data is transmitted by making separate physical connections between the packet nodes. If an abnormality occurs in a packet node, the line node This dynamically switches which packet node sends and receives data to and from the packet exchange loop, and disconnects the packet node in which an error has occurred from the packet exchange loop.

[Operation] When an abnormality occurs in a certain packet node, the line notebook operates to disconnect the abnormal packet node from the packet exchange loop by dynamically switching which packet node to send and receive data to. Therefore, even if an abnormality occurs in a packet node, normal operation of the entire packet switching loop is guaranteed.
As a result, network reliability is greatly improved.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 and 2.

Here, as in FIG. 5, one line node 5 has three
An example will be described in which three packet nodes 4a to 4C are connected.

Normally, the line node 5 is set to transmit data to the packet node 4a and receive data from the packet node 4C. Here, the line node 5 is the packet node 4a
4C to which data is to be transmitted and received is not fixed, but can be dynamically switched under control within the line node 5.

Next, as a connection between the line node 5 and the packet nodes 4a to 4c, a monitoring line is provided in addition to the data transmission line.The zero line node 5 always checks whether the packet node is operating normally through the monitoring line. Monitor. Items to be monitored include whether the packet nodes are operating normally and whether the line 6 connecting between the packet nodes is broken.

When the line node 5 detects an abnormality, the line node 5 detects the packet node (4a in FIG. 1) where the abnormality has occurred.

In FIG. 2, transmission/reception is switched so that 4b) is separated from the system.

Figure 1 shows the bypass formed at this time.

This is shown in solid line in FIG. FIG. 1 shows that when there is no abnormality in the packet node 4a, the line node 5
Switch the transmission/reception of 4a to the node from 4a to /l b,
Back! - Figure 4 does not show that the node 4a is bypassed. FIG. 2 is a diagram showing that when an abnormality occurs in the bug node IC, reception from packet node 1 (:) is switched from 4c to 71b, and packets 1 to t1c are bypassed. It is.

Up to now, we have only explained the case where an abnormality occurs in the packet node, but if there is a disconnection between packet nodes 4a and /11), the transfer order is the same as in Figure 1. ．． If there is a disconnection between the packet nodes 4a and 4c from the packet switching loop, the same transmission Jli as in FIG. 2 is used to disconnect the packet nodes 4a and 4c from the packet switching loop.

Further, when only one packet node is connected to a line node, if an abnormality occurs in that node, the line node controls to stop receiving data from that packet node. As a result, the data in the allocated area within the frame flows directly to the next node, resulting in a bypass state.

[Effects of the Invention] As explained above, according to the present invention, even if an abnormality occurs in a certain packet node, the packet node in which the abnormality has occurred is disconnected from the system, and the entire packet switching loop can continue to operate normally. As a result, a highly reliable system is provided.

[Brief explanation of drawings]

1 and 2 are diagrams showing the order of intra-node packet data transmission in the event of an abnormality according to the present invention, and FIG.
FIG. 4 is a diagram showing an example of a frame configuration of a hybrid switched LAN, and FIG. 5 is a diagram showing an intra-node packet data transmission order during normal operation. In the figure, 1a to 1d are nodes of a circuit-switched loop network (line nodes), 2a to 2f are nodes of a packet-switched loop network (packet nodes), 3 is a loop transmission path, and 4a to 4c are packet-switched loop networks. 5 is a node (line node) of a circuit-switched loop network, and 6 is a transmission path between packet nodes.

Claims (1)

[Claims] 1. Connect one or more packet nodes, which are nodes of the packet-switched loop network, to each line node, which is a node of the circuit-switched loop network, and use a part of the transmission frame of the circuit-switched loop network to In a hybrid switched LAN that enables both circuit-switched and packet-switched transmission by allocating data for packet-switched data transmission, when multiple packet nodes are connected to one line node, the line node transmits packet data to one packet node, receives packet data from another packet node, performs packet data transmission by making separate physical connections between packet nodes, and transmits packet data to one packet node. A bypass method for a hybrid switched LAN characterized in that when an abnormality occurs, a line node dynamically switches which packet node to send/receive data with, and the packet node with which the abnormality occurs is separated from the packet switching loop.