| 单词 | tandem switch |
| 释义 | tandem switch Also known as a backbone switch and a core switch, a tandem switch is a high-capacity switch positioned in the physical core, or backbone, of a Public Switched Telephone Network (PSTN), where it serves to interconnect edge switches, or Central Office (CO) switches. In the traditional PSTN hierarchy, a tandem might be a Class 1 regional toll center, Class 2 sectional toll center, Class 3 primary toll center, or Class 4 tandem toll center. An access tandem switch serves to connect local exchange carriers (LECs), i.e., local telephone companies, to the interexchange carriers (IXCs), i.e., long distance carriers, over dedicated interoffice trunks, known as access trunks. In a contemporary PSTN, a tandem switch 74570c20.qxd 9/12/07 12:44 AM Page 475 |
| 随便看 |
|
科学参考收录了5291条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。