Is synchronization required for non-traditional services such as voice-over-IP?
A. The answer to this topical question depends on the performance required (or promised) for the service. Usually, Voice-over-IP is accepted to have a low quality reflecting its low cost (both relative to traditional PSTN voice service). If a high slip-rate and interruptions can be accepted, then the voice terminal clocks could well be free-running. If, however, a high voice quality is the objective (especially if voice-band modems including Fax are to be accommodated) then you must control slip occurrence to a low probability by synchronization to industry standards. You must analyze any new service or delivery method for acceptable performance relative to the expectations of the end-user before you can determine the need for synchronization.
