In this paper we review two Packet Loss Concealment (PLC) techniques, focusing on voice over packet networks. The first technique is based on Sinusoidal Modeling and the second one is based on Adaptive Lattice Modeling. Both techniques exploit look-ahead samples in order to improve their performance. In VoIP applications, look-ahead samples are commonly available from jitter buffers, without additional algorithmic delay over the jitter buffer inherent delay. The target location for these techniques is at the decoder side eliminating interoperability and standardization overhead. The proposed techniques were found to be more immune to high packet loss rate.