Users Guide

Table Of Contents
1048 Ethernet Ring Protection
Revertive and Non-Revertive Operation Modes
ERP defines two operation modes: Revertive and Non-Revertive.
Revertive
In revertive mode, when failures in the link are removed, the traffic channel is
restored to the working transport entity and RPL is blocked. When revertive
operations are used, the ring will not revert back immediately. Reversion does
not start until the Wait-To-Restore (WTR) timer has expired.
Non-Revertive
In non-revertive mode, RPL is continued to be used by traffic channel, even
after a failure condition has been resolved.
ERPS Subrings
Ethernet Ring Protection also supports interconnection of multiple rings.
Interconnection of two rings means that two rings might share the same link
or share the same node.
Figure 26-2. Sub-Ring with VC and without VC