SLIDING TIMER EXPIRY TO REPORT FAULTS TO ETHERNET RING PROTECTION MECHANISM

The G.8032 Ethernet Ring Protection (ERP) protocol, detects failure and au-tomatically switches traffic path. To avoid different race conditions and un-necessary switching operations, it uses different timers. One of the static tim-er configured today is Hold-off timer. After detecting a failure ERPS will not switch immediately, it will wait for this time and if the failure is not cleared before the timer expiry, then actual switching happens. This wait period is added to avoid unnecessary switching due to link flaps. So even when an ac-tual failure is detected ERPS will wait till this timer expiry, until then traffic loss will be seen. Currently, the timer range is between 100ms to 10s which is configured by the operator. If the timer is kept very less, frequent unnecessary switching will happen. If the timer is kept very high, traffic loss will be seen for that time. The objective of this work is to propose a Sliding/Adaptive Tim-er expiry algorithm incorporated inside the ERPS module itself instead of stat-ic Hold-Off timer