Dear QoS Expert,
My question is base on QoS Student Guide Page 1-13.
According the last line of this page written that "By minimizing delay, you can also reduce jitter (delay is more predictable)". I though that the delay is not predictable. Does it mean that the delay hopefully predictable or any other meaning about this?
Thank you for your kind support guys!
This may be a definitional issue.
I think delay is the time it takes to cross the network. These are defined within the Service Level Agreement if it exists. On the Internet there is sometimes a SLA if you only access sites within that Internet Service Provider. Generally they say 99% will arrive within X ms. For example X might be 300ms
Consider the SLA is always achieved the first UDP packet takes 200ms , the second 150 and the third 250 so they could arrive out of sequence or more likely with a small gap before the second and a long gap before the third. So the voice messages speeds up and slows down. This is normal called jitter because it is jitterly. This is solved by using a jitter buffer.
Thank you for your feedback Conwyn,
But if possible, can I ask the service provider to provide jitter buffer? Does it hardware configuration or IOS configuration?
It is explained better than I by http://www.cisco.com/en/US/tech/tk652/tk698/technologies_tech_note09186a00800945df.shtml
See the playout-delay keyword. I assume it is a function of the DSP (PVDM2-x).