I do not understand how jitter is exactly calculated. I have tried with theese formula, but do not get the same results like Wireshark gets. Can anyone little explain me about this.

If Si is the RTP timestamp from packet i, and Ri is the time of

arrival in RTP timestamp units for packet i, then for two packets

i and j, D may be expressed as

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

The interarrival jitter SHOULD be calculated continuously as each

data packet i is received from source SSRC_n, using this

difference D for that packet and the previous packet i-1 in order

of arrival (not necessarily in sequence), according to the formula

J(i) = J(i-1) + (|D(i-1,i)| - J(i-1))/16

Thanks.