[VoIP] Call Feature Implication

有些 Call Feature (功能/行為), 會用專業的詞作包裝 ……

藉此篇文章記錄一些專有名詞 

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  • Recall feature
    • Requirements
      • When a Call is in the on-line answered state, the BT network interface will recognise a reduction of the loop current to 1mA or below, for a period in the range of 53ms to 103 ms, as a Recall siganl
  • Ring tone 
    • Behavior: 來電的時候, 電話會有響鈴的狀態, 稱之為 Ring tone or Ring Signal
  • RingBack tone
    • Behavior: 撥打電話出去時, 會進入等待對方接聽電話的狀態, 此時從話機撥出的 Tone, 即稱之為 RingBack Tone 
  • Hold Call
    • Behavior: 當進行一通電話時(active call), 想要保留電話, 但是想要暫停與對方的語音交流, 此時就須要做 Hold Call, Hold Call 可以達到暫停語音封包傳輸以即恢復語音封包傳輸