Packet Loss Concealment is a set of heuristics employed by a Media Engine to overcome packet loss problems.

When a stream of packets is received by the media engine, it is not guaranteed that everything sent gets received.

In case not all packets are received, and no FEC is employed (or is usable), packet loss concealment comes into play.

Packet loss concealment isn’t standardized anywhere and is left for the implementer of the media engine and codec.