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Chapter 2. Understanding Quality of Service
Chapter 2. Understanding Quality of Service
It is important to ensure that networks over which voice traffic is transported support tight quality of service (QoS) requirements in terms of delay, jitter, and packet loss.
There are many different types of delay, including the following:
• Coder (or processing) delay: This is the time taken by a DSP to compress a block of PCM samples. Coder delay depends on the particular codec being used and processor speed.
• Packetization delay: This is the time it takes to fill a voice packet payload with encoded or compressed speech and encapsulate it with Internet Protocol (IP), User Datagram Protocol (UDP), and Real-time Transport Protocol (RTP) headers.
• Serialization delay: This is the time taken to send a frame out of a network interface.
