OSN 3500 series is a new-generation optical transmission system developed by Huawei. It adopts a unified switching architecture and can function as an MPLS/MPLS-TP-based packet device or a TDM device. When working with other devices of Huawei, OSN 3500 supports various networking modes, including the pure packet mode, hybrid networking (packet + TDM) mode, and pure TDM mode, achieving optimal processing for packet services and traditional SDH services. Thus, OSN 3500 efficiently transmits voice and data services over the same platform.