System for supporting communications among ATM devices, device for supporting data transmission, method for sending data, and computer program product

Abstract

A first communication device receives an ATM cell bound for a second ATM device from a first ATM device via an ATM interface, and then the first communication device sends a data frame including the ATM cell to the second ATM device via wide area Ethernet. In addition, the first communication device sends a synchronization frame to the second ATM device via the wide area Ethernet continuously at a predetermined time interval in accordance with a clock frequency of the first ATM device. A second communication device receives the synchronization frame and measures a clock frequency of the first ATM device in accordance with a time interval of receiving the synchronization frame so as to reproduce a clock having the same frequency as the measured clock frequency. After that, the second communication device sends the clock to the second ATM device via an ATM interface.

Description

[0001]This application is a continuation of Ser. No. 11 / 113,107 filed Apr. 25, 2005, the disclosure of which is incorporated herein by reference in its entirety.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a system and a method for supporting communications among plural ATM devices.[0004]2. Description of the Prior Art[0005]FIG. 23 shows a conventional method for connecting ATM devices 5. A device such as an ATM terminal or an ATM exchange having an ATM (Asynchronous Transfer Mode) interface (hereinafter referred to as an “ATM device 5”) performs communication with other ATM devices 5 via an ATM network as shown in FIG. 23. The ATM network enables a fast communication of multimedia data or the like. Therefore, a service for connecting ATM devices 5 to each other via the ATM network so as to establish a WAN (Wide Area Network) or the like is widespread.[0006]However, a cost necessary for constructing and managing the ATM network is ...

AI Technical Summary

Benefits of technology

The present invention allows for communication between ATM devices through a wide area Ethernet network. This is achieved by a device that receives data frames containing ATM cells from another device and converts them into an ATM cell for transmission to the destination device. The device also receives control frames and reproduces a clock with the same frequency as the transmission side clock frequency. This clock is then transferred to the destination device through an ATM interface. The technical effect of this invention is the improved flexibility and efficiency of data transmission between ATM devices.

Problems solved by technology

However, a cost necessary for constructing and managing the ATM network is high, so a method for establishing a WAN at a lower cost is desired strongly.

However, in such a method, it is difficult to predict a delay or a degree of dumping of frames in the wide area Ethernet network.

Therefore, it is difficult to synchronize a clock of a lower order ATM device 5 with a clock of a higher order ATM device 5 of communication in the wide area Ethernet network.

Accordingly, communication between ATM devices 5 cannot be performed well in the above-mentioned method.

However, there is not proposed a method in which a wide area Ethernet network is used instead of the ATM network for communication between ATM devices 5.

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