Relay unit and frame tracing method

Abstract

In a relay unit for relaying frames between a sending source and a receiving end by transmitting the frames from a transmitting-receiving buffer to the receiving end after the frames received from the sending source have temporarily been stored in the transmitting-receiving buffer, the frames are in the transmitting-receiving buffer, while the storage positions of the frames in the transmitting-receiving buffer are being managed in order of storage. Each time a new frame is stored in the transmitting-receiving buffer after the number of the frames in the transmitting-receiving buffer has reached a predetermined number, the storage area, in which the oldest frame among the frames is stored, is released from the transmitting-receiving buffer. With this arrangement, by contriving how to utilize the transmitting-receiving buffer, tracing a frame can be performed at high speeds, without providing a dedicated storage area for storing trace information and incurring complexity of the process.

Description

BACKGROUND OF THE INVENTION [0001] (1) Field of the Invention [0002] The present invention relates to a relay unit and a frame tracing method that relay frames between a sending terminal and a receiving terminal belonging to different networks and are suitable for use in a network relay unit for managing the history of the process of relaying such transmission-reception of frames. [0003] (2) Description of the Related Art [0004]FIG. 13 is a block diagram for explaining an example of how a general relay unit is used. A relay unit (network relay unit) 100 shown in the diagram relays the transmission-reception of a frame (packet) between a plurality of networks (in FIG. 13, three networks A to C). The relay unit 100 is respectively connected to the networks A to C through I / O interfaces 101a to 101c such that a frame can be transmitted and received between the networks A to C. [0005] For instance, when a frame is transmitted from a sending terminal belonging to the network A through th...

AI Technical Summary

Benefits of technology

The present invention provides a relay unit and a frame tracing method that can efficiently store and release frames in a transmitting-receiving buffer without incurring complexity or adding manufacturing costs. The relay unit includes a management table that stores the frames in order of storage, and a control section that manages the storage of each frame by referring to the management table. The control section causes the transmitting-receiving buffer to hold the frames and release the storage area for each frame, based on a predetermined number of frames. The frame tracing method involves releasing the storage area for the oldest frame when a new frame is stored, and managing the frames in the transmitting-receiving buffer by referring to the management table. The invention provides a faster and more efficient way to trace frames in a relay unit.

Problems solved by technology

Besides, processing such as dividing and reconstituting of frames is also unnecessary.

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