JPS63110843A - Relay control system in packet switching network - Google Patents

Abstract

PURPOSE:To transmit supervisory results to adjacent stations, to decide on an optimum relay line, which is regarded as bypass conditions, and to prevent a packet in a packet switching network from missing by supervising the state of a transmission buffer corresponding to a selected relay line in its own station and the station of reception buffers in the adjacent stations connected to the relay line. CONSTITUTION:The functional block of a reception buffer supervising means 1 in the system periodically supervises reception buffers 45-47 in relay lines 39, 36 and 40. At that time a reception buffer residual measurment module 101 receives the timing when it supervises from a timer 102, measures the residuals of the buffers 45-47, decides whether packet reception is feasible or not, judging from the decision 103 of the reception state of the relay lines, and outputs information on the packet reception to a control packet generation and transmission means 2. A control packet processing means 3 in a packet exchange 32 processes the control packet, and applies its information to a relay line decision means 4. Results that a transmission buffer supervising means 41 periodically supervises the relay lines 35-37 are applied to the relay line decision means 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for efficiently relaying packets within a packet switching network.

[Conventional technology]

Figure 3 is a diagram showing an example of the configuration of a packet switching network (31).
is a packet originating station, (32) and (33) are packet relay stations, and (34) is a packet receiving station. (35), (
3G).

(37) and (38) are the relay routes connected to the relay station (32), especially (38) is the relay route between the relay station (33), and on (3rd) the packets are connected to the relay station (32). This is the relay route I used when I came to 32). Similarly, (39), (4
0) is a relay path connected to the relay station (33).

FIG. 4 is a diagram for explaining the conventional method for relaying packets input from the relay station (38) at the relay station (32). In FIG. This is a means of determining one. (32).

(34), (35), (38), (37), (39),
(40) is the same part as in FIG. (41) is means for monitoring the status of the transmission buffer in the relay station (32), and in this example, relay! 8 (35), the transmission buffer (43) corresponding to the relay path (38), and the transmission buffer (44) corresponding to the relay path (37). ing. On the other hand, (45), (4ft), and (47) are relay stations (34ft).
), the receive buffer corresponding to the relay path (39) is (45), the receive buffer corresponding to the relay path (3B) is (46), and the receive buffer corresponding to the relay path (40) is (47). ), FIG. 5 is an execution flowchart of the relay route determining means (4) described in FIG.

Next, the operation will be explained. In FIG. 4, the transmission buffer monitoring means (41) is connected to two transmission bars (41) corresponding to each relay route.
42), (43), and (44) are monitored. The monitored information is periodically sent to the relay route determining means (4) and recorded. This recorded information is then used in the flowchart shown in FIG. 5 as follows. First, in the relay route selection process (21), when one relay route is selected from the predetermined relay route selection priority table, the next route is selected based on the information from the above-mentioned transmission buffer monitoring means (41). Check whether there is a shortage of transmission buffers on the relay route (
22). If YES, return to the relay route selection process in (21) again and select the next relay route, NO
If so, in the other relay route determination process (24), the failure state of the relay route is further taken into consideration, and one relay route to be relayed is finally determined, and the process ends.

[Problem that the invention seeks to solve]

As described above, in the conventional packet relay control method in a packet switching network, the relay route was determined without taking into account the state of the receive buffer at the adjacent station connected to the relay route, so it was difficult to transmit packets even when there was a shortage of receive buffers. There was a problem in that the packet was discarded by the neighboring station as a result.

This invention was made to solve the above-mentioned problems, and aims to eliminate the loss of packets within the network and provide a high-quality packet switching network.

[Means for solving problems]

The relay M control method for packet switching according to the present invention monitors the status of the transmitting buffer corresponding to the selected relay route within its own station, monitors the status of the receiving buffer of the adjacent station connected to the relay route, and transmits the monitoring results. The optimum relay route is determined by sending the information to the adjacent station and using the results of monitoring the transmission buffer status.

[Effect]

The relay control method according to the present invention uses the status of the receiving buffer of the exchange connected to the relay route as a detour condition when selecting a relay route. prevent packet loss.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (1) means for monitoring the reception buffer corresponding to the relay route, and (2) means for receiving the output from the reception buffer monitoring means (1) and creating a control packet that includes the reception buffer status for the relay route. and the neighboring station (in this example (32
), and (3) processes the control packet from the adjacent station (in this example, the exchange shown as (34)) and sends the information to the relay route determining means (4). It is a means to output. Note that the same reference numerals as in FIGS. 3 and 4 indicate the same or corresponding parts.

1 and 1 are the receiving buffer monitoring means (1) in FIG. 1.
) is a detailed functional block diagram. In the figure, (iot) is a reception buffer remaining amount measurement module, (102) is a timer module, and (103) is a trunk line reception state determination module. Figures 1 and 2 are examples of control packets created by the control packet creation/transmission means in Figure 1 (11
1) is the relay header area, (112) is the packet identifier area, and (113) to (115) are the receive buffer (45).
) to (47) are entered in this area. 1st and 3rd
The figure is a detailed functional block diagram of the transmission buffer monitoring means (41) in FIG. 1. In the figure, (12+) is a transmission buffer remaining amount measurement module, (122) is a timer module, and (123) is a trunk line transmission state determination module. Other symbols are the same as in FIG. 1. FIG. 2 is an execution flowchart of the relay route determining means (4) of FIG. 1.

Next, in the first UgJ whose operation will be explained, the reception buffer monitoring means (1) operates as follows based on the detailed functional blocks shown in FIG. Each relay port T! (39)
, (38), (40) receive buffer (45
), (4El).

In order to periodically monitor the remaining capacity of the receiving buffer (47), the receiving buffer remaining capacity measurement module (101) receives the timing to monitor the remaining capacity of the receiving buffer from the timer (102), and receives the timing to monitor the remaining capacity of the receiving buffer (45), (413), (47). ), and the relay line reception status determination module (103) determines whether packets can be received for each of the relay lines (39), (3B), and (40), and this information is used for control purposes. It is output to the packet creation/transmission means (2). This output is sent to the control packet creation/transmission means (2) to create a control packet as shown in FIGS. 1 and 2, for example. In FIGS. 1 and 2, (111) is a relay header to which destination station and originating station information is attached in order to efficiently transmit the packet within the packet switching network. (112) is a packet identifier that identifies whether it is a data packet or a control packet. (113) to (115) are reception buffer states, and here, as an example, each reception buffer has information on whether or not reception is possible for each bit, and if it is ON, it is not possible to receive, and if it is OFF, it is possible to receive. do. The NI'8 packet created in this manner is transmitted to the destination station through relay processing at the packet switching center (34).

The control packet processing means (3) of the packet switching center (32) which received this control packet sends the information in the reception buffer to the relay route determining means (4). On the other hand, the transmission buffer monitoring means (41) sends the state of the transmission buffer of the trunk line to the relay path determination means (4) in the flow shown in FIG. 103.

In Figures 1 and 3, each trunk line (35), (36)
, (37) in the transmit buffer (42).

In order to periodically monitor (43) and (44), the transmission buffer remaining amount measuring module (121) receives the timing to monitor the remaining amount of the transmission buffer from the timer module (122), and then monitors the transmission buffer (42), (44) periodically. 43), (
44), and the relay line transmission status determination module (123) measures the remaining capacity of the relay lines (35), (3El), (3El), and
7) It is determined whether or not packet transmission is possible for each of them, and the information is output to the relay route determining means (4).

Next, the operation flow in the relay route determining means (4) will be explained based on FIG. 2. First, when one relay route is selected from the predetermined relay route selection priority table in the relay route selection process (21), it is then determined whether the transmission buffer γ of the relay route is insufficient (22). Judge by.

If YES, the process returns to the relay route selection step (21) again and selects the next relay route. If NO, based on the information from the control packet processing means (3), it is determined in step (23) whether or not there is a shortage of reception buffers on the relay route. If YES, the process returns to step (21) for selecting a relay route and selects the next relay route. If NO, in the step (24) for determining the relay route, the failure state of the relay route is further taken into consideration, and one relay route to be relayed is finally determined, and the process ends.

In the above embodiment, the control packet creation/transmission means (
In 2), a control packet containing the reception buffer status of all relay routes connected to the switching center was created and sent, but the control packet creation , a control packet containing only the state of the reception buffer of the relay route connected to the adjacent station may be created and transmitted.

〔Effect of the invention〕

As described above, according to the present invention, when relaying a packet, in the process of determining a relay route, not only the transmission buffer status 7g of the relay route but also the reception buffer status of the adjacent station connected to the relay route are considered. This has the effect of providing a highly accurate bucket switching network with no packet loss.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram for explaining a relay control method of a packet switching network according to an embodiment of the present invention, FIG. 1-1 is a detailed functional block diagram of a reception buffer monitoring means, and FIG. 1-2 is a diagram illustrating a relay control method of a packet switching network according to an embodiment of the present invention. An explanatory diagram for explaining the control packet format in one embodiment, FIGS. 1 and 3 are detailed functional flowcharts of the transmission buffer monitoring means, FIG. 2 is a flowchart in one embodiment of the present invention, and FIG. 4 is an explanatory diagram for explaining a conventional packet switching network, and FIG. 5 is a flowchart for explaining the operation of FIG. 4. (1) is reception buffer monitoring means, (2) is control packet creation/transmission means, (3) is control packet processing means, (4) is relay route determination means, (41) is transmission buffer monitoring means, (42) ~(44) are transmitting buffers, and (45)~(47) are receiving buffers. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] In a packet switching network that selects one relay route and relays packets according to a relay route selection priority table set in advance for each destination station, transmission that monitors the remaining capacity of the transmission buffer corresponding to the selected relay route within the local station. A buffer monitoring means, a receiving buffer monitoring means for monitoring the remaining amount of the receiving buffer in an adjacent station connected to the relay path, and transmitting the receiving buffer monitoring result to the adjacent station, where the optimal processing is performed based on the sending buffer monitoring result. 1. A relay control method in a packet switching network, comprising a relay route determining means for determining a relay route.