Jitter is defined as varying latency, so if the latency is consistent it's not jitter. And 30ms isn't that bad, as long as it's consistent. You do need to prioritize the traffic just as you would VoIP (SIP etc.). Vidyo may not be using the same QoS/ToS tags as other priority traffic is so you may need to identify the traffic by some other means. Finally, if it's going over the internet THERE IS NO PRIORITIZATION ON THE INTERNET. No matter how you tag the traffic and prioritize it by the time it gets to the other end it will be the same as everything else.
1. QoS throughout you WLAN and LAN being sure that Vidyo is being identified as priority traffic.
2. Make sure you firewall is at least giving outbound Vidyo traffic priority over other traffic. And no, having lots of bandwidth is not the same. Despite what most think, using 10% of your bandwidth isn't like a pipe filled to 10%. It's using 100% of you bandwidth 10% of the time, it's either a 0 or a 1 nothing in between.
3. Your firewall needs to identify the inbound Vidyo traffic tag it as priority traffic and give it priority out it's inside interface. This won't prevent someone's YouTube from interfering with your Vidyo but it will lessen the likelihood of a noticeable problem. Of course the real solution is to block incoming streaming traffic except for your Vidyo.