What are the QoS issues of Voice over IP?
TOP The key QoS issues of Voice over IP are delay, packet loss, voice quality and ease of use. The end-to-end delay is calculated as the sum of packet assembly delay, propagation delay, processing delay and variable delay. In general, the acceptable end-to-end delay should be less than 250 ms. To minimize the delay, some ITSPs may provide guaranteed bandwidth, prioritization of voice packets over data packets. The packet loss is usually caused by the errors due to transmission and networking devices, such as buffer overflows. Three common ways to cope with the packet loss problem are interpolating between received packets, replaying a previous packet, and playing an appropriate noise level. The voice quality relates to the compression software, which includes the following elements – voice encoding/decoding, DTMF tone detection/generation, echo cancellation, voice activity detection, comfort noise generation, and jitter buffer handling. The ease of use represents how long users can pic
