Mobile Ad-hoc Networks (MANET) have been initially proposed for short-session exchanges of small data chunks in emergency and tactical missions, where network' infrastructure is inexistent or temporally broken. The quick rise of processing and communication capabilities of mobile devices allows moving toward offering user-friendly and delay-sensitive multimedia services over a MANET. The integration of multimedia services needs a good understanding of the effects of MANETs on the applications running contexts. This work aims at exploring network delay processes of packet voice communications on mobile ad-hoc networks. To do that, a wide range of representative scenarios has been defined and simulated. The gathered traces have been inspected from qualitative and quantitative perspectives in order to discover (1) dependency between up/down path lifetime and delay variation processes, and (2) features of network delay variation at transport-layer.