n.中央交換

A variation of a traditional Centrex telephony system is called IP Centrex. 傳統(tǒng)的Centrex電話系統(tǒng)的另一種形式稱為IP Centrex。

Centrex frequently uses analog telephone lines for the connections to a business or organization. Centrex經(jīng)常使用模擬電話線路為公司或組織提供電話連接。

Centrex uses the telephone company's central office exchange to route internal calls back to an extension. Centrex使用電話公司的中央辦公室交換機將內(nèi)部電話又路由回到分機號碼上。

Centrex telephony systems are sometimes used by larger organizations, but are most frequently found in government, public, and private organizations. 大型組織有時也使用Centrex電話系統(tǒng),但多數(shù)是在政府、公共部門和私有組織中使用。

For example, with Centrex, the telephone exchange or telephone company's central office knows which extensions are internal. 例如,使用Centrex,電話交換機或電話公司的中央辦公室將知道哪些分機是內(nèi)部分機。