travelling class mark

A unique label that identifies a call as it is routed through the network; for example, an identification that the call originated from a coin telephone. Travelling class marks are not presently used, but will be possible with CCIS. It will then become possible to use the same transmission facility in several different traffic networks, each identified by a travelling class mark.; 當一次呼叫通過網絡時，對其進行識別的一種特定的標號，例如，對投幣電話中發出的呼叫 的識別。雖然目前還沒有使用行進分類標記，將來可能與同軸電纜信息系統(CCIS)一道使用 。這樣，在幾個不同的通信網絡中就可以使用同一個傳輸設備，只要給每個通信網絡分配一 個傳輸分類標記即可。