Q-SYS Networking & 3rd Party Telephony Integration

The Q-SYS Q-LAN network uses Layer 3 DiffServ QoS. This type of QoS deploys differently on different networks and therefore requires user intervention to set up properly. Because of this, unmanaged switches are not acceptable for use in a Q-SYS network.

Switches used with a Q-SYS system must meet the following minimum requirements:

Non-blocking wire-speed gigabit Ethernet bridging. No dropped packets due to internal bandwidth constraints.

Must generate no 802.3x flow control messages.

Must have at least 80 kB total egress buffering available per port for audio class of service with minimum of 40 kB dynamically available, for the audio class.

Packet forwarding decision time must be 10 μs or less.

Forwarding decision time is defined as the interval from a packet's end, on ingress, to its beginning on egress. Forwarding decision time excludes the store-forward time determined by packet length.

Must have DiffServ (DSCP) support.

Must have at least four egress queues per port

Must be able to recognize and prioritize two high-priority traffic classes by DSCP values or other means in addition to best-effort traffic.

Has strict priority queuing support.

(NOTE: weighted round-robin, weighted fair queuing, or other selection methods do not provide the latency guarantees required by Q-LAN)

Q-SYS utilizes a standards-based layer-3 Gigabit Ethernet implementation. As such, it depends on correctly configured Gigabit Ethernet switches. Below is a link to the list of qualified switches as well as a link to a list of disqualified switches. “Qualified" switches will presumably work with Q-SYS, based on their published specifications and laboratory testing by QSC of at least one similar switch model. The list of qualified switches represents the extent of testing done by QSC and does not represent an exhaustive list of network equipment that meet Q-SYS requirements.

"Disqualified" switches will not work properly in all conditions because they either do not meet requirements as described in their published specifications or have failed QSC laboratory testing. A popular switch may be listed as "not recommended" when its published specifications are incomplete or difficult to interpret and laboratory testing indicate it does not meet requirements. This is not an exhaustive list of switches that fail to meet Q-SYS requirements. Do not conclude that a switch's absence from this list is therefore an endorsement that it meets Q-SYS requirements.

Q-SYS is a flexible platform with support for SIP telephony integration with 3rd party phone systems. The link below contains resources to understand Q-SYS integration with 3rd party SIP telephony and POTS (Plain old telephone services) integration.

These lists are dynamic; as network vendors continue to develop new equipment, QSC continues to test additional switches and add them to their respective lists; check back for additions and updates. QSC tests the switches with one Q-SYS Core and one switch. In complex networks, even a qualified switch may cause connectivity issues if it is configured incorrectly. The Network section of the table of contents in the Q-SYS Help file provides details on switch setup, configuration, and network performance requirements. Our experience is that a Q-SYS system deployed on a network that meets all these requirements will function properly.

For further details about the following switches, see their manufacturers' web sites.