本文介绍了公用和专用分组交换数据网的现状后，说明了开展标准的增值业务系统的重要性。

In this paper, after analysing the status on public and private PSDN, the significance of standard-based value added service systems is indicated.

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最后建议全国只建一个分组交换公用数据网。

Finally, we consider it more advisable to establish only one PSPDN in our country.

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