Delay Tolerant Networks (DTN) are well adapted for situations where the network nodes suffer from intermittent communications due to the high mobility of the nodes and the constantly changing environment. Several research works tried to address this problem and lately, an ants-based protocol named GrAnt, has been proposed as one of the best solutions. In this paper we firstly assess GrAnt performance in much more challenging conditions than those presented by its authors, and secondly, we present a generic methodology based on MMT, an online security monitoring tool that enables real-time analysis of network traffic, to correlate the performance of a DTN protocol (such as GrAnt) with the information stored in its messages in order to validate the reliability of the protocol