Device, method and system for transmitting frames

Abstract

In between network devices interconnected by plural optical channels, logical paths are defined according to upper traffic and also priority of the traffic. The network device includes: a frame forming section for reading user packets out of a buffer section composed of plural buffers defined for the respective paths on transfer schedule, and forming path frames having a specified frame length and individual ordinal numbers with respect to each path; a switch for selecting output channels to equally distribute the path frames by round robin scheduling; and data transmitting part for transmitting data on the logical paths. Thus, it is made possible to realize a frame transfer system capable of performing data transmission, which satisfies QOS (Quality Of Service) required for user traffic, on the WDM networks connected by plural OCHs.

Description

technical field [0001] The present invention relates to an apparatus, method and system for transmitting frames in data transmission between network systems interconnected by a plurality of OCHs (Optical Channels) using optical channels on an optical wavelength division multiplexing network that transmits service data of various capacities . Background technique [0002] WDM (Wavelength Division Multiplexing) has attracted attention as a technique for increasing the transmission capacity of each optical fiber by multiplexing signals with different wavelengths. In WDM, a plurality of OCHs (Optical Channels) connect network systems to opposite network systems. Recommendation G.872 of ITU-T and the like define OCH as a channel for transmitting user signals on a per-wavelength basis. [0003] At the same time, with the improvement of optical devices related to WDM, it has become possible to establish OCH connection and disconnect OCH at high speed between network systems. The...

AI Technical Summary

Problems solved by technology

[0012] However, virtual connection is only a technology for STM transmission, and the effect of statistical multiplexing will not be obtained in the case of transmitting user data to multiple OCHs

Therefore, reduction in link cost cannot be achieved with statistical multiplexing effects

[0013] In addition, another drawback of this technology is that when an error occurs in the OCH connection, the entire STM frequency band must be backed up to restore the connection

For the same reason, the prior art described in Japanese Patent Application Laid-Open No. 2000-22733 has a defect that it cannot be applied to data transmission on OCH at this stage

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