| 单词 | 30B+D |
| 释义 | 30B+D Synonymous with primary rate access (PRA). Referring to the ITU-T specification for an ISDN interface supporting 30 bearer (B) channels and one data (D) channel. 30B+D is compatible with E-1, and is used outside of North America and Japan. See also ISDN and PRA. |
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