2
3
Audio Streams
•
UDP on Ports 6511 through 6766 as needed
•
Each packet contains 16 samples of up to 16 channels
•
3000 packets per second per stream
•
100 to 1100 bytes per packet or 1.65 ~ 3.31 Mbps per stream – packet
size depends on channel count
•
Audio sampling is 32 bit floating point format
•
Up to 128 streams in and out of each Q-Sys Core
•
1 Stream in and/or out for each I/O Frame or Page Station
•
100 acknowledgements are sent every second and contain
receiver-side stats
Control
•
TCP and HTTP for Control Data and Core redundancy
•
1 Mbps or less – dependant on connections to User Control Interfaces
(UCI’s) or AMX and Crestron
QoS
•
Ensures timely delivery of packets
•
Employs DiffServ or Differentiated Services Code Point (DSCP)
•
DSCP 63 normally reserved for Network Admin
•
DSPC 46 EF (Expedited Forwarding) for PTP
•
DSPC 34 AF (Assured Forwarding) for Audio data
•
DSPC 0 for control data
•
Minimum of 4 egress queues per switch port with Strict Priority
Queuing – other selection schemes (e.g. round robin, shaped
round robin, fair queuing, guaranteed minimum bandwidth) are
not recommended
•
Each Q-Sys switch port must have 40kB of egress queue
memory available
•
Note: Don’t enable bandwidth throttling on ports connected
to the Cores
QDP and Multicast Routing
•
For Q-Sys to work across a Layer-3 network, you will need to
configure the network to route the multicast addresses used
by the PTP Clock and Discovery protocols. Q-Sys devices
implement the Internet Group Management Protocol (IGMP).
IGMP allows Q-Sys devices to register to receive specific
multicast addresses.
•
QDP – Device Discovery – 224.0.23.175 – registered to QSC
•
– Used to find Q-Sys products on the network by name
regardless of IP address
•
IEEE 1588 – 224.0.1.129 ~ 224.0.1.132 – Registered to IEEE
Latency
•
Time on Wire @ 1 GB
≤
12 micro seconds
•
Time on Switch @ 1 GB
≤
10 micro seconds
•
Allowed Time on Network = 243 micro seconds
•
Option to increased buffer size for larger networks
via Designer software
Switch Requirements
•
Must be a managed, non-blocking Gigabit switch with
bandwidth meeting or exceeding “wire speed” bridging
•
Must support DiffServ QoS
•
Packet forwarding delay of less than 10 micro seconds
•
No Jumbo frames on any Q-LAN paths
Bandwidth Usage
•
Bandwidth equation: Mb = (1.77 x total stream count) + (1.54 x
total channel count)
•
Dual network redundant configurations will produce the same
bandwidth on both ports
