电话系统上的一个选项，允许出局呼叫被放入一根或多根中继线路中。

An option on a telephone system which allows outgoing calls to be put in line for one or several trunks.

youdao

电话系统上的一个选项，允许出局呼叫被放入一根或多根中继线路中。

An option on a telephone system which allows outgoing calls to be put in line for one or several trunks.

youdao