英语语法分析

For diagnosing problems, HSSI offe four loopback tests.

诊断问题，HSSI进攻四回路测试。

Like ISDN and DSL, HSSI operates at the physical layer of a network, using the standard Open Systems Interconnection (OSI) model.

像ISDN和dsl, HSSI运营网络的物理层，使用标准的开放系统互连(osi)模型。