Procedure

Q-SYS networks can span long distances, including over a WAN, if they keep within certain strict propagation delay limits:

• Q-SYS traffic must travel across the network with extremely low latency: no more than 280.8 µs for PTPv2 clock signals and 288.8 µs for RTP Q-SYS audio data. Switch hops, cable and fiber lengths, serialization time, and even packet time all count against this latency budget.
• Each switch hop (within the LAN or connecting WAN and LAN) adds to the traffic latency—typically 10 to 50 µs.
• Cat-5e and Cat-6 network cable have a velocity factor (VF) of about 0.65, so it will take Ethernet traffic about 0.505 µs to traverse a 100-meter link.
• Data propagates in single-mode fiber (VF = 0.66) at a velocity of about 198 m/µs, approximately two-thirds of the speed of light in free space. Therefore, it takes about 5.05 µs to traverse 1 kilometer.
• Using 10 GbE fiber links between switches instead of 1 GbE reduces the serialization time from 12 µs to 1.2 µs.
• PTP signals have a packet time of 0.8 µs and RTP packets (used for Q-SYS audio) are 8.8 µs.

Add all the time requirements together. They must fit within the latency budget for Q-SYS to work properly.

Examples