A network engineer receives a report about poor quality on an active call between the IP phone of user A over the WAN to the IP phone of user B. Using web access to the phone, the network engineer…

Packet loss exceeding 1% is considered unacceptable for VoIP because codec concealment algorithms cannot adequately reconstruct missing audio frames at that rate, resulting in clearly audible degradation. The conceal seconds value of 7 is a corroborating indicator that the DSP is actively applying concealment to mask the effects of this 3% loss, confirming packet loss as the root cause.

Average jitter of 20 ms is within acceptable limits - the common VoIP guideline is 30 ms or less - so jitter is not the primary problem contributing to the reported poor quality.

Network delay of 1 ms is far below the ITU-T G.114 recommendation of 150 ms one-way maximum, making delay a non-factor in this call quality issue.

Conceal seconds is a symptom metric reflecting how often the DSP must hide missing packets; it indicates packet loss is occurring but is not itself an independent root cause separate from the 3% packet loss already identified.