SDH

例句：

1. 1. The SDH protocol is used to transfer data between two computers.
   SDH协议用于在两台计算机之间传输数据。
2. 2. The SDH network was designed to support high-speed internet access.
   SDH网络被设计来支持高速互联网接入。
3. 3. The SDH system is a reliable and efficient way to transmit large amounts of data.
   SDH系统是一种可靠且高效的数据传输方式。