What is the minimum playout delay?
12 bits for Minimum and Maximum delay. This represents a range of 0 – 40950 milliseconds for minimum and maximum (with a granularity of 10 ms).
What is the threshold for delay in wireless voice to become noticeable?
A latency of 20 ms is normal for VoIP calls; a latency of 150 ms is barely noticeable and therefore acceptable. Any higher than that, however, and quality starts to diminish. At 300 ms or higher, latency becomes unacceptable.
What is a playout buffer?
1. Buffer used at the receiver to store received audio packets in interactive real-time applications to compensate for variable network delays.
What is the purpose of using fixed playout delay in VoIP applications?
Question: Fixed playout delay is one technique used in VoIP applications to solve the variation in network delay (i.e. jitter).
How much latency is too much for audio?
So as much as 5 to 6 milliseconds will be fine. With keyboards, the amount should be the same unless they’re playing pads, in which case you can get as high as 20 milliseconds without them or the crowd noticing.
How do you remove the jitter at the receiver for audio by fixed and adaptive play out delay?
Fortunately, jitter can often be removed by using sequence numbers, timestamps, and a playout delay, as discussed below. For our VoIP application, where packets are being generated periodically, the receiver should attempt to provide periodic playout of voice chunks in the presence of random network jitter.
What is a playout delay buffer?
The playout delay buffer is also sometimes referred to as the de-jitter buffer. This diagram illustrates how jitter is handled. If the jitter is so large that it causes packets to be received out of the range of this buffer, the out-of-range packets are discarded and dropouts are heard in the audio.
What is the nominal value of the playout delay?
In fixed mode, the nominal value is the amount of playout delay applied at the beginning of a call by the jitter buffer in the gateway and is also the maximum size of the jitter buffer throughout the call. As a general rule, if there is excessive breakup of voice due to jitter with the default playout-delay settings, increase playout-delay times.
What is the maximum playout-delay for a jitter buffer?
This can extend up to 1700 msec. One issue with configuring high maximum value is the introduction of end-to-end delay. Choose the value of maximum playout-delay such that it does not introduce unwanted delay in the network. This output is an example of the jitter buffer configured for adaptive mode:
Why does the playout delay affect the voice quality?
The constant readjustment of playout delay to erratic network conditions causes voice quality problems that are usually alleviated by increasing the minimum playout-delay value in adaptive mode or by increasing the nominal delay for fixed mode.