Focusrite RedNet - A note about Latency

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Numerous makes/models of Gigabit switch have been found to operate satisfactorily with Dante
systems. Recommended manufacturers include Linksys, Dell, HP and Cisco. Note the following
features are required when selecting a switch for use with a RedNet network:
• Gigabit (1000 Mbps) ports
• Quality of Service (QoS) with 4 queues
• Diffserv (DSCP) QoS, with strict priority
• A managed switch is also recommended, to provide detailed information about the operation
of each network link: port speed, error counters, bandwidth used, etc.
Additional information on switch requirements can be found at www.focusrite.com/rednet.
A note about Latency
No digital audio system is “instantaneous”; the term “latency” is used to express the time by which
the audio is delayed in travelling through the system. In practice, latency only becomes a problem
when mixing signals from systems having significantly different delays. The Dante protocol used by
RedNet exhibits very low latency, and you should not experience any problems in normal recording
practice when using it for multichannel audio transport between a DAW and sources or monitoring.
With the RedNet PCIe card in use, round-trip latency can be less than 3 ms (depending on buffer
size and sample rate). If you are using Dante Virtual Soundcard instead of the RedNet PCIe card,
additional processing time is required by the computer. However, you should achieve the same order
of latency as with a FireWire interface.
The precise latency of any given system will be determined by a number of factors, including the
processing speed of the computer, the number of switches in the network, the make/model of switch
used and the network topology.