Wholesale glossary
Average Call Duration (ACD) is the mean length of answered calls on a route or corridor. Human conversation clusters between two and six minutes; bypass and machine-driven traffic runs far shorter. Sudden ACD collapse on specific corridors is one of the strongest OTT bypass signatures in the CDR stream.
Why it matters
Together with ASR, ACD separates a degraded route from a gamed one. A route can hold a healthy answer ratio while its duration collapses, because the calls answering are not the calls your customers think they are paying for.
What practitioners watch
Track per-corridor baselines. Sustained ACD under 60 to 90 seconds on consumer destinations deserves investigation, especially when it arrives with B-number repetition and A-number uniformity.
Related: OTT Bypass Observatory · Voice Transit Observatory · ASR