User's Manual

Fortress ES-Series CLI Guide: Networking and Radio Configuration
35
NOTE: Do not
change the Trans-
mit Control setting
unless you are working
with Fortress technical
support to troubleshoot
a problem
3.2.3.3 Setting the FastPath Mesh Transmit Control Level
The FP Mesh transmit control setting determines the resiliency
level used for the transmission of control packets. This setting
balances the trade-off between the resiliency of the control
packet versus the air time consumed to send the routing
update.
Specify the transmit control level with the
set mesh command:
# set mesh -transmitcontrol auto|aggressive|moderate|conservative|ultra-conservative
Setting the level to aggressive sends control packets in the
most efficient but least reliable way;
ultra-conservative sends
control packets in the most reliable but least efficient way. The
default is
auto .
You must be logged on to an
administrator-level account to
change configuration settings (refer to Section 2.2).
3.2.3.4 Setting Multicast Video Clamping Thresholds
Multicast video is particularly challenging in a wireless
environment due the amount of data transmitted over the
shared wireless channel
. A video stream can affect data
between other stations, and in turn be affected by other traffic
on the channel. In addition, video codecs are highly sensitive to
packet loss, which is common with multicast traffic due to the
lack of delivery retries. Even a .5–1% loss of packets can
render an MPG2 video unwatchable.
If the Mesh Point tries to stream video over a low-quality link
(low signal strength, or slow data rate), the video traffic can
clog the channel and use much of the bandwith, while the video
received is of no benefit.
Multicast clamping enables you to tune your network to prevent
multicast traffic from being sent over low-quality links. You can
essentially “clamp” the multicast stream when the Mesh Point
detects that the signal strength and bit rate are inadequate to
carry multicast video traffic.
Use
set mesh with the -rssi and -rate options to define the
Received Signal Strength Indicator (RSSI) and bit-rate
thresholds (in dBm and Mbps, respectively) at which clamping
takes effect. Multicast clamping is disabled (
off) by default.
Once enabled, the Mesh Point will stop sending multicast traffic
whenever the link quality drops below either of the specified
thresholds. When the link quality improves by 5 dBm beyond
the lower limits, the node will resume sending IPv4 multicast
traffic.
# set mesh -rssi <dBmValue> -rate <MbpsValue>
You can supply threshold values for both -rssi and -rate or
for only one parameter.