There will always be a certain amount of jitter on a connection over a network because the switches each packet passes through will experience variable demand. Remember the packets in one stream travel across the network, interspersed with packets from other streams. The possibility of every packet arriving at every switch and being processed immediately is slim and gets slighter with more network traffic present. The longer the route of the transmission, the higher the likelihood of jitter because packets will have to pass through more switches and routers.