PLM Series Network Configuration Guide
13
Code Point (DSCP) protocol, and it must implement
strict priority control over at least the top two priority
levels. (3Com is an example of a provider that typi-
cally prioritizes only the top level.) See References
and Definitions in section 7 for more on DSCP.
Internal switch forwarding latency of 4 µs or less is
recommended.
Several switches have been tested by
Lab.gruppen and not all behave according
to their datasheets. Some others that
comply with general specifications have a
tendency to drop packets, and therefore cannot be
recommended.
LinkSys SRw224g4
19 inch rack-mountable
•
24 x 10/100 switched RJ45 ports
•
4 x 10/100/1000 switched RJ45 ports
•
2-SFP slots for use with fiber optic connections
•
RSTP supported
•
Secure remote monitoring software available (freeware)
•
Approved by Audinate, developers of the Dante network
•
Manufacturers link: www.linksys.com
•
6.1.2 Recommended wireless access point:
LinkSys waP200
Access points utilizing the 802.11g or 802.11n
formats are recommended both for their diversity
and bandwidth. A PoE-type (Power over Ethernet /
802.3af) access point that can be powered over its
Ethernet connection is also a good idea, as it is very
easy to place at an optimal location since only one
cable is needed for both network connectivity and
power. (See in section 7 References and Definitions
for more information.)
If the switch doesn’t have PoE, then a mid-
span PoE adapter is needed as well.
6.1 general Recommendations
Critical networks such as those used in profes-
sional audio systems require infrastructure hardware
offering the high level of connectivity and reliability
essential for critical, data-intensive applications.
Additionally, this hardware needs to be robust enough
to survive the rigors of repetitive loading and unloa-
ding, and frequent connection and disconnection.
Lab.gruppen has evaluated a number of hardware
manufacturers in regard to use within a PLM Series
network. Our findings have resulted in the following
hardware recommendations. Of course, there are any
number of scenarios involving systems of various
sizes, logistical and routing requirements, so these
recommendations are to be considered as guidelines
only.
In addition to the recommendations provided, other
products may be equally suited to PLM Series ap-
plications. Lab.gruppen will continue to evaluate and
verify network products as the market for network
devices changes rapidly. Updated information will be
posted at www.labgruppen.com/plm.
6.1.1 Network switches / routers:
LinkSys SRw224g4
Depending on the configuration selected, the
appropriate network switch or router will have enough
ports to accommodate direct connection to each PLM
in the rack as well as connections from rack to rack
where required in the system-wide configuration.
Switches manufactured for mounting into a standard
19 inch equipment rack are generally considered
more appropriate to withstand the rigors of loading
and unloading that can be part of a sound system’s
daily use.
In systems that
DO NOT utilize Dante
, Lab.gruppen
is not providing a specific recommendation. In gen-
eral, however, a switch with RSTP is recommended.
This greatly increases reliability in case of any loss of
information or connection failures. It is also a good
practice to use switches that allow monitoring of
links over the network.
In systems where Dante is used, the switch should
have 1000BASE-T (or better) for switch-to-switch
connections. The switch must support the DiffServe
NeTwORk HaRDwaRe ReCOMMeNDaTIONS 6
