Fault detection and protection switching

Sub-50ms Protection Switching

Telecom transport networks are designed to recover from failures within fifty milliseconds, matching the legacy SONET/SDH protection switching target. This sub-fifty-millisecond requirement ensures that mobile services experience minimal disruption — voice calls survive without noticeable glitch and data sessions continue without TCP timeout. Protection switching involves three phases: failure detection using BFD, loss of signal, or OAM CCM loss typically within ten to thirty milliseconds, signaling to the protection mechanism within five to ten milliseconds, and traffic switchover to the…