Timestamp usage in rtp

Question

I read RTP and I have one question.

Based on what I got, timestamp in rtp is for calculation of jitter and use it to de-jitter our packets. Basically I need it for TSoIP which I just need extract ASI from IP and pass to Modulator to process it.

I really appreciate if someone can help me to understand the usage of timestamp in receiver in order to receive ASi over IP. In other words: I didn`t find any good reference to help me to find what is timestamp and how it works

Answer 1

Here you have a detailed discussion about the jitter and RTP.

The main aspect you are interested is the following:

In the Real Time Protocol, jitter is measured in timestamp units. For example, if you transmit audio sampled at the usual 8000 Hertz, the unit is 1/8000 of a second.

In that page they also mention the relation between the timestamp and the receiver: The difference of relative transit times for the two packets is computed as:

D(i,j) = (Rj - Ri) - (Sj - Si) = (Rj - Sj) - (Ri - Si)

Si is the timestamp from the packet i and Ri is the time of arrival for packet i. You can also check to some examples there.