With the highly expanding use of networked on-line multimedia applications in general and Voice Over IP applications in specific, it is vital to assess the quality of service of such applications over public or private networks to identify the problems arising in order to enhance the quality of these applications over networks. This is especially important with increasing large companies utilizing their private intranets for the use of telephone calls to save on their phone budget. The quality of service can be addressed at various levels. This work is concerned with identifying the weak links or hops in a network path of an on-line multimedia application session which contributes to the degradation of the quality of the designated application. Once identified, the degraded hop can be dealt with or potentially replaced by another. Alternatively, the routing table can be altered to bypass the degraded hops.