When speaking into an IP-enabled phone, your voice is converted into packets of data that get sent across your network to the person on the other end of the call. Your network connection – local data network and Internet – is essentially a freeway across which your voice packets travel to their destination. If those packets arrive at their end point safely and on time, then your voice conversation will be clear. If they don’t, that means any or all of three things are happening:
Packet Loss – When a large amount of traffic on the network causes dropped packets, that’s packet loss, which results in extraneous noise on the call, a delay in receiving the voice communication and even dropped calls.
Latency – Latency, delays in delivering packets, does not affect the quality of the delivered audio, but it negatively impacts a conversation between users. With a 100ms delay, for example, callers’ voices overlap each other. With a 300ms delay, the conversation becomes impossible to follow.
Jitter – When certain packets of information arrive out of order and the conversation becomes jumbled, you’ve got jitter. If jitter is creating a delay of more than 50ms, your call quality will degrade massively, resulting in choppy voice or temporary glitches.