So, what makes for an acceptable level of latency within your network, and what does latency begin to directly impact the quality of your VoIP calls and other services? Well, at the end of the day, the level of interruption or delay in your conversation will be subjective.
But what we can do is determine at what level of delay, measured in milliseconds, certain forms of interruptions might begin to occur. According to this in-depth information from Cisco:
“One-way (mouth-to-ear) transmit delay should not exceed 150 ms (per G.114 [protocol] recommendation).”
Meaning, when you ping another user or network, it should not take more than 150ms for that ping to reach that recipient. Beyond that, Cisco also recommends:
“The round trip delay should not exceed 300 ms whenever possible.”
So as congestion, and therefore latency, increases, so does jitter. Again, according to Cisco:
“Average one-way jitter should be targeted at less than 30ms”
Therefore, we are looking at acceptable limits as follows:
Max One-Way Delay: 150ms
Max Round Trip Delay: 300ms
Max Jitter: 30ms
What happens now if you determine that your latency or jitter are beyond acceptable levels? There is actually quite a bit you can do, we’ll break that done one-by-one.