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by Steve Taylor and Larry Hettick

Guaranteed voice quality – coming soon to an SLA near you?

Opinion
Jul 30, 20032 mins
NetworkingVoIP

* How voice-quality measurements can be turned into SLA tools

In the last newsletter we mentioned the emerging capability to assess voice quality on a continuous basis. This capability, which was discussed extensively in a paper that Steve authored recently for Nortel, leads to an interesting new twist on service-level agreements.

The fundamental assumption is that the quality of VoIP remains a major question that must be addressed in many implementations. The tools are now available to take that question and turn it into a capability that actually surpasses what traditional networks can do. It’s possible for VoIP service providers to commit in an SLA to a given voice quality that’s measured on a continuous basis.

The key to this commitment is having the information necessary to enforce the SLA. Using advanced voice quality measurement techniques, one can measure the quality at the beginning of a call, during a call, and at the end of the call. These measurements can be used to determine if a call of short duration terminated because there was poor quality. Likewise, the end-of-call quality can be used to determine if there was a quality problem that caused the call to be terminated.

These ongoing measurements can be made and the call quality converted into a quantitative “R-value,” which is somewhat similar to a traditional “Mean Opinion Score” or MOS value. Since the information is available continuously and for every call, it’s reasonable now for a service provider to guarantee to the jittery (pun intended) customer that the R-value will be of at least a certain quality for a given percentage of the calls. In fact, there’s even room here for tiered Gold/Silver/Bronze with differential parameters based on factors like quality, percentage of calls, percentage of call-minutes, and destination (domestic vs. international).

Bottom line? Service providers have the tools to go beyond meeting an objective by turning these measurements into a tactical advantage and including them in an SLA.