First thing lets understand the jitter -
Jitter is the variation in the time between packets arriving, caused by network congestion, timing drift, or route changes. Its not delay its variation of packet receiving when we map this concept to VoIP then we can not understand the voice properly (in case of delay u can clearly understand the voice but with jitter there is a issue in understanding)
Now precisely you can not say UDP is having jitter or TCP is having jitter, but the probability is high with TCP as it is connection oriented and has high overhead.
