POS,Packet over SONET/SDH,is a technology of transmitting IP packet over SONET/SDH and it is also a very important transmission technology on Internet. It has the advantage of low cost,high bandwidth utilization efficiency,simple network topology,etc.

• POS即为Packet over SONET/SDH,是一种在同步光网络上承载IP数据的技术,也是当前因特网上一种重要的传输技术,该技术具有费用低、带宽利用率高、网络简单的优点,因此有广泛的应用前景。