找考题网-背景图
单项选择题

A.Protects signals when a ring switch failsB.Protects s……

What is the purpose of Dual Ring Interconnect with D C for SDH rings?()

A.Protects signals when a ring switch fails
B.Protects signals when multiple span switches fail
C.Protects pre-emptible traffic from being dropped when a ring switch occurs
D.Protects signals against any combination of link failure in each ring