Cisco Qos Exam Certification Guide: Ip Telephon... Site
Voice traffic is uniquely sensitive to network conditions that do not typically affect standard data like emails or file transfers. Key technical hurdles include:
The time it takes for a voice packet to travel from the source to the destination. Excessive delay causes unnatural pauses in conversation. Cisco QOS exam certification guide: IP telephon...
While voice calls require relatively low bandwidth (e.g., 80 kbps for G.711), this capacity must be guaranteed to prevent drops. The QoS Toolkit Voice traffic is uniquely sensitive to network conditions
Voice packets that are dropped due to congestion. Losing even 1% of voice traffic can significantly degrade call quality. 80 kbps for G.711)
The variation in the arrival time of packets. High jitter results in robotic or broken audio.