| 摘要 |
<p>PROBLEM TO BE SOLVED: To effectively apply band limiting to the data quantity in accordance with a band contracted with a user in the case of connecting a user LAN to the wide area LAN of a communication provider through an optical fiber transmission line. SOLUTION: In the optical converter bridge 40 of a provider side, a photophysical layer terminating part 402 receives an Ethernet (registered trademark) frame from the optical fiber transmission line 20 according to its transmission speed, applies waveform processing such as photoelectric conversion to the Ethernet frame and supplies the Ethernet frame to a medium access control part 404. The control part 404 has two MAC switches 414 and 416, a transfer frequency between the MAC switches is set to the speed of the contracted band by the control of a band limitation controlling part 408, and when frames surpassing the band are inputted, the frames are abandoned and the band is limited. A photophysical layer terminating part 406 returns the frames subjected to band limitation by the control part 404 to the speed of a wide area LAN 30 side and transfers the frames.</p> |
