Upstream Link Recovery
The recovery of upstream links (links to the core) can be attained through either MultiChassis EtherChannel
(MEC) or the Equal Cost MultiPath (ECMP) feature.
MEC convergence is consistent and independent of the number of routes. Whereas, ECMP convergence is
dependent on the number of routes. This graph indicates the magnitude of loss in a voice session.
These images show link failure scenarios with MEC and ECMP: