network audit tool

network audit tool can cause voice quality degradation if it is excessive. The goal commonly used in designing networks to support VoIP is the target specified by ITU standard G.114 (which, incidentally, is currently under revision): This states that 150 ms of one-way, end-to-end (from mouth to ear) delay ensures user satisfaction for telephony applications. A design should apportion this budget to the various components of network delay (propagation delay through the backbone, scheduling delay because of congestion, and access link serialization delay) and service delay (because of VoIP gateway codec and dejitter buffer).

If the network audit tool delay becomes too long, the conversation begins to sound like two parties talking over a satellite link or even a CB radio. The ITU G.114 states that a 150-ms one-way (mouth-to-ear) delay budget is acceptable for high voice quality, but lab testing has shown that there is a negligible difference in voice quality mean opinion scores (MOS) using networks built with 200-ms delay budgets. Thus, Cisco recommends designing to the ITU standard of 150 ms. If constraints exist and this delay target cannot be met, the delay boundary can be extended to 200 ms without significant impact on voice quality