JPH0697963A - Packet switching system - Google Patents

Abstract

PURPOSE:To avoid the falling into an uncommunicable state without using a multi-link procedure function, to reduce loads to a system in terms of softwares and hardwares due to the use of the multi-link procedure function and to prevent the decline of throughput by the overhead of the softwares. CONSTITUTION:A call information containing part 9 for containing information for the two terminals of first call information and second call information for one logical channel is provided in a packet switchboard 4. A terminal switching function 10 for switching a communicating opposite side from the terminal of the first call information to the terminal of the second call information and executing permanent virtual circuit communication based on the information of the call information containing part 9 at the time of the fault of an opposite terminal containing circuit is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packet switching system for transmitting and receiving packets by a permanent virtual circuit communication system.

[0002]

2. Description of the Related Art Permanent packets in packet switching networks
In virtual circuit (hereinafter abbreviated as PVC) communication, normally, when a terminal accommodation line failure occurs, communication becomes impossible until the failure is recovered.

Therefore, in order to prevent such a communication-impossible state from occurring in terminals of high importance,
The conventional packet switching system has taken the measures shown in FIG.

In FIG. 2, reference numeral 1 is a packet switch for setting a PVC link, 2 is a terminal (packet terminal) accommodated in the packet switch 1, and each of these packet switches 1 and 2 has a multi-function. Link procedure functions 1a and 2a are provided. Then, between the multi-link procedure function 1a and the multi-link procedure function 2a, a plurality of lines (two lines L1, L in this example) are provided via the layer 2 protocol functions 1b, 2b, respectively.
2) is connected. That is, the line used for packet transmission / reception between the layer 3 protocol function 1c provided in the packet switch 1 and the layer 3 protocol function 2c provided in the terminal 2 uses the mutual multilink procedure function. In this configuration, any one of a plurality of lines can be selected.

Conventionally, in such a system configuration, a multi-link procedure is used, and, for example, when the line L1 to be used has a failure, another normal line L2 is selected, so that communication failure occurs. Prevent the occurrence of inconvenience.

[0006]

However, in the conventional packet switching system shown in FIG. 2, both the packet switching device 1 and the packet terminal 2 are equipped with a multilink procedure function which is heavy in terms of hardware and software. In addition, there is a problem in that software overhead is generated due to the multilink procedure function even during normal communication, resulting in a decrease in throughput.

The present invention has been made in view of the above circumstances, and is a packet switching system for transmitting and receiving packets by a permanent virtual circuit communication system, which has a multilink procedure function when a failure occurs in a terminal accommodation line. It is possible to avoid falling into a state where communication is not possible even without using, and to reduce the burden on the hardware and software system due to the use of the multilink procedure function, and at the same time, the throughput due to the software overhead. It is an object of the present invention to provide a packet switching system capable of preventing the degradation of the packet.

[0008]

A packet switching system according to the present invention transmits and receives packets by a permanent virtual circuit communication system, and is a packet switching system for establishing a link for permanent virtual circuit communication. Has a call information accommodation unit and a terminal switching function.

Here, the call information accommodating section uses, as communication destination information for setting the link, the first call information and the second call information for one logical channel corresponding to one destination.
The information for two terminals including the call information is stored.

Further, the terminal switching function detects a fault in the other terminal accommodating line based on the cause of the packet, and if the other terminal accommodating line is normal, sets a link to the other terminal based on the first call information and sets the permanent terminal. ·virtual·
The circuit communication is executed, and when the line of the other terminal accommodating line fails, the link is switched to the other terminal based on the second call information and the permanent virtual circuit communication is executed.

[0011]

The packet switching system according to the present invention uses the first call information for one logical channel corresponding to one partner as communication partner information for setting a PVC link in the packet switch in the system. By storing the information for two terminals, that is, the second call information and the second call information, it is possible to prevent communication failure when the terminal accommodation line fails. It is possible to avoid falling into a state where communication is not possible without using the function, and reduce the load on the hardware and software system due to the use of the multilink procedure function, and at the same time, due to the software overhead. It is possible to prevent a decrease in throughput.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an outline of a system configuration of an embodiment of a packet switching system according to the present invention. Reference numerals 4 and 5 in FIG. 1 indicate packet transmission by a permanent virtual circuit communication system. A packet switch that performs transmission and reception, 6 is a terminal (packet terminal) accommodated in the packet switch 4, and 7 and 8 are both packet switches 5.
It is a terminal (packet terminal) accommodated in.

Each of the terminals 7 and 8 has an individual line 7.
The packet exchanges 5a and 8a are accommodated in the packet switch 5, but both are provided for one logical channel corresponding to one communication partner of the terminal 6.

With respect to such a terminal configuration, the packet switch 4 for setting a link for permanent virtual circuit communication in response to a communication request from the terminal 6 has a call information accommodating section 9 and A terminal switching function 10 is provided.

As shown in FIG. 3, the call information accommodating section 9 uses the first call for one logical channel corresponding to one destination as communication destination information for setting the link. It is configured to accommodate information for two terminals, that is, the information 11 and the second call information 12. In each of the first call information 11 and the second call information 12, identifier information J1 and call information J2 are described. The identifier information J1 describes an identifier for confirming whether or not it is currently being used. As the described identifier, "ACT" indicating that it is currently being used, and being on standby. "SB
"Y", "NRG" indicating that the corresponding terminal is not registered
and so on. First call information 1 for one logical channel
When the first and second call information 12 are added, the first call information 11 is set to the identifier “ACT” and the second call information 12 is set to the identifier “SBY” in the initial value.

The call information J2 is a concrete description of the call information of the corresponding terminal. In this example, the call information J2 of the first call information 11 is normally (when no line failure has occurred). Information of the terminal 7 is described as communication partner information at that time. Further, the call information J2 of the second call information 12 includes
Information of the terminal 8 is described as communication partner information when a line failure occurs.

In response to a communication request from the terminal 6, the terminal switching function 10 searches the call information accommodating portion 9 on the corresponding logical channel, and the call information whose identifier is "ACT" (usually the first A link is set up based on the call information 11) to perform permanent virtual circuit communication. However, the terminal switching function 10 monitors the cause of the packet from the packet switch 5 on the communication partner side, and the reset packet of the cause failure of the partner terminal is received from the packet switch 5 to thereby prevent the failure of the partner terminal accommodation line. To detect.

Then, in the case of a failure of the line accommodating the other terminal,
The call information accommodating section 9 is searched again on the corresponding logical channel to check whether or not the alternative second call information 12 is registered. If the alternative second call information 12 is registered, it is used until then. The identifier of the first call information 11 is changed from "ACT" to "S".
"BY", and the identifier "S" of the second call information 12
Rewrite "BY" into "ACT". Further, the cause of the packet received from the packet switch 5 is converted into a reset of the other terminal and returned, and the link is switched to the other terminal based on the second call information 12 to execute the permanent virtual circuit communication.

In the packet switching system having the above-mentioned configuration, the communication destination information for setting the PVC link in the packet switch 4 in the system is the first for one logical channel corresponding to one destination. By storing information for two terminals, that is, the call information 11 and the second call information 12, it is possible to prevent communication failure at the time of the terminal accommodation line failure. , It is possible to avoid falling into a state where communication is not possible without using the multilink procedure function, and at the same time reduce the load on the hardware and software system resulting from the use of the multilink procedure function. Throughput can be prevented from decreasing due to software overhead.

It should be noted that, in the above-described one embodiment, it was explained that only one packet switch 4 was equipped with the call information accommodating section 9 and the terminal switching function 10, but in the same manner, the other packet switch 5 Of course, the call information accommodating section 9 and the terminal switching function 10 may be provided.

[0021]

The packet switching system according to the present invention is
As communication partner information for setting a PVC link in the packet switch in the system, information for two terminals, that is, first call information and second call information for one logical channel corresponding to one partner. This is to prevent communication failure when the terminal accommodation line fails, and when the terminal accommodation line fails, communication is disabled even without using the multilink procedure function. It is possible to avoid the fall, reduce the load on the system in terms of hardware and software due to the use of the multilink procedure function, and at the same time, prevent the decrease in throughput due to the overhead of software.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a conventional packet switching system.

FIG. 3 is a configuration diagram of a call information accommodation unit according to an embodiment of the present invention.

[Explanation of symbols]

 4,5 packet switch 6,7,8 packet terminal 9 call information accommodating section 10 terminal switching function 11 first call information 12 second call information

Claims (1)

[Claims] 1. A packet switching system for transmitting and receiving a packet by a permanent virtual circuit communication method, wherein a packet switch for setting a link for permanent virtual circuit communication is provided for setting the link. As the communication partner information, a call information accommodating unit that accommodates information for two terminals, that is, the first call information and the second call information for one logical channel corresponding to one partner, and the partner by the cause of the packet When a failure of the terminal accommodation line is detected and the partner terminal accommodation line is normal, a link is set to the partner terminal based on the first call information to set a permanent
And a terminal switching function for executing a virtual circuit communication and for switching a link to the partner terminal based on the second call information to execute a permanent virtual circuit communication when the line for accommodating the partner terminal fails. Packet switching system.