User guide

19
5 Frequently Asked Questions
SL-Dante-SPK
User Guide
Does Dante require special switches?
No. However, we strongly recommend that gigabit switches be used due to the clear
advantages in performance and scalability.
What is the minimum requirement for switches in a Dante network?
All Ethernet switches are capable of working with Dante. However, please be aware
that there are some features on some kinds of switches that will allow you to build
larger and more reliable Dante networks.
While gigabit switches are recommended, 100 Mbps switches may be used in limited
scenarios.
• For channel counts of 32 or more, gigabit switches are essential. QoS is
required when using Dante in networks that have 100 Mbps devices. QoS
is also recommended for gigabit switches on networks that share data with
services other than Dante.
• For lower channel counts (<32), a 100 Mbps switch may be used as long as
it supports proper QoS, and QoS is active. The use of 100 Mbps switches
without QoS is not recommended or supported.
What features are important when purchasing a switch?
Dante makes use of standard Voice over IP (VoIP) Quality of Service (QoS) switch
features, to prioritize clock sync and audio trac over other network trac. VoIP QoS
features are available in a variety of inexpensive and enterprise Ethernet switches.
Any switches with the following features should be appropriate for use with Dante:
• Gigabit ports for inter-switch connections
• Quality of Service (QoS) with four queues
• Diserv (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.
Can I use switches with EEE (Energy Ecient Ethernet or Green Ethernet) in my
Dante network?
Short answer: No.
Long answer: EEE (Energy Ecient Ethernet) is a technology that reduces switch
power consumption during periods of low network trac. It is also sometimes
known as Green Ethernet and IEEE802.3az. Although power management should
be negotiated automatically in switches that support EEE, it is a relatively new
technology, and some switches do not perform the negotiation properly. This may
cause EEE to be enabled in Dante networks when it is not appropriate, resulting in
poor synchronization performance and occasional dropouts.
Therefore we strongly recommend that:
1. If you use managed switches, ensure that they allow EEE to be disabled.
Make sure that EEE is disabled on all ports used for real-time Dante trac.
2. If you use unmanaged switches, do not use Ethernet switches that support
the EEE function because you cannot disable EEE operation in these
switches.
What is Quality of Service (QoS)?
Quality of Service (QoS) is a feature of managed switches, which ensures that
certain types of network packets (e.g. clock sync and audio packets) get preferential
treatment and are “moved to the front of the line” ahead of other trac. This is
achieved by attaching a priority number to each packet, which is then used by the
switches to ensure that high priority packets get processed before lower priority
packets.