JP2716888B2 - Packet switching network - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packet switching network, and more particularly, to a method for relaying a packet.

[0002]

2. Description of the Related Art Conventionally, a packet switching network is disclosed in
-32136, JP-A-2-32643, JP-A-62
Japanese Patent Application Laid-Open Nos. 2424241, 61-262338 and 55-140350. Here, for example, the "routing control method" disclosed in Japanese Patent Laid-Open No. 55-140350 discloses that each switching device in the network is provided with a transmission relay line selection priority table for each destination switching device, so that the highest priority which does not cause a failure. Each switching device independently selects a bypass line at the time of failure and relays the packet by a method of selecting a trunk line and transmitting a packet.

[0003]

Since the packet relay in the conventional packet switching network is performed as described above, each switching device has a trunk line priority order selection table and copes with a failure such as each transmission relay. It is necessary to update the status information in the trunk line selection priority table. Therefore, each switching unit must have a large-scale storage area according to the size of the network, complicated fault detection and priority table update logic, and the configuration of the switching unit is complicated. Further, if the failure detection is different for each switching device, there is a possibility that the entire packet relay in the network becomes abnormal.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to perform a simple detour control when each switching device detects a failure at the time of transmitting a packet by a simplified configuration. The purpose is to obtain a packet-switched network that can be used.

[0005]

According to the present invention, there is provided a packet switching network in which a dedicated switching trunk is connected to each switching device in the network.
A detour-only switching device that accommodates these detour relay lines will be installed.

Further, a plurality of detour trunks of each switching device are connected, a plurality of detour-dedicated switching devices accommodating the respective detour trunks are installed, and a selection priority table is set for the detour trunks from each switching device. To have.

[0007]

In the packet switching network according to the present invention, when a switching device detects a fault in a transmission trunk, the packet is unconditionally diverted to a detour trunk line connected to the switching device, and the packet is switched to a destination switching device by a detour-only switching device. Relay the packet.

Further, a plurality of detour trunks are connected, and a detour trunk line priority selection order table is provided. When a fault of the detour trunk line is detected, the detour trunk having the next priority is selected and detoured. The packet is relayed from the bypass switching device accommodating the bypass relay line to the destination switching device.

[0009]

[Embodiment 1] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a configuration of a packet switching network according to an embodiment of the present invention, wherein 1 to 4 are switching devices, 5 is a bypass-only switching device, and 6 to 11 connect switching devices 1 to 4 to each other. Trunk lines 12 to 15 are detour trunk lines connected from the switching devices 1 to 4 to the detour-only switching device 5, respectively.

The switching device 1 outputs a packet from the trunk line 6 when relaying a packet addressed to the switching device 2. Similarly, the switching device 1
9 to output a packet. Further, when any one of the packet output trunks 6, 10, and 9 from the exchange 1 to the other exchange fails, the exchange 1 unconditionally sends the packet to the bypass trunk 12. Similarly, exchange device 2,
If any of the trunks for packet output from 3 and 4 to the other switching unit fails, each switching unit unconditionally sends a packet to the alternate trunk line. When the bypass-only switching device 5 receives the bypass packet from the switching devices 1 to 4,
The packet is transmitted to a bypass trunk line connected to the destination switching device for the packet. As a result, each switching device can perform a simple bypass relay without having a complicated trunk line selection ranking table and without executing a complicated operation of determining a trunk line to be selected next according to a failure state.

Embodiment 2 FIG. Further, in the above embodiment, only one set of the bypass relay line and the switching device dedicated to the bypass is set in the network. However, in order to perform more reliable packet relay, the bypass relay line and the dedicated bypass device accommodating them are accommodated. The switching device may be set in a plurality of networks. FIG. 2 is a schematic diagram showing a network configuration in which two sets of alternate trunk lines and alternate-only switching devices are set as another embodiment. Alternate trunk lines 17 to 20 are second alternate trunk lines of the switching devices 1 to 4, respectively. , And the second bypass relay lines are accommodated in the bypass-only switching device 16.

In this case, when the switching devices 1 to 4 detour a packet, if the first detour trunk has a fault, the packet is sent to the second detour trunk. The detour-only switching device 16 operates in exactly the same way as the detour-only switching device 5, and sends an input detour packet to the destination switching device. Although the detour processing of each switching device is larger than that of the first embodiment, it is a fixed processing of selecting the second detour relay line if the first detour relay line still has a failure. , It can be very simple.

[0013]

As described above, according to the present invention, when the transmission trunk line corresponding to the destination station of a packet has a failure, each switching unit diverts the packet to a fixed detour trunk line and uses the detour-only switching unit. Since the detour relay is performed to the destination switching device, there is an effect that the packet relay process of the switching device can be very simplified.

In addition, when a fault occurs in the detour relay line, the detour relay line having the next priority can be relayed and detoured, and the packet can be relayed from the dedicating switching device to the destination switching device.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a network configuration showing a packet relay method according to an embodiment of the present invention.

FIG. 2 is a schematic view showing another embodiment of the present invention.

[Explanation of symbols]

 1-4 Switching device 6-11 Trunk line 5, 16 Dedicated switching device 12-15, 17-20 Detour trunk line

Claims (2)

(57) [Claims] 1. A packet switching network comprising a plurality of switching devices storing designated trunk lines to be transmitted to relay a packet to a destination switching unit and trunk lines connecting the switching units to each other. If the designated trunk line to be sent is a fault, connect a detour trunk line for fixed detour regardless of the destination of the packet to each switching device,
A detour dedicated switching device that accommodates a detour trunk from each of the switching devices in the network and outputs a detour packet input from the detour trunk to a detour trunk connected to a destination switching device of the detour packet. A packet switching network. 2. The packet switching network according to claim 1, wherein each of said switching devices connects a plurality of alternate trunk lines and sequentially selects a next alternate trunk line in response to a failure of the alternate trunk line. And a plurality of dedicated switching devices for each of a plurality of detour trunks from each switching device.