User guide

Release 9.4.2 Release Notes
Issue 1, May 2009 Page 16
5 Notes and Reference
5.1 NOTES
Table 6 lists notes new for this release.
Table 7 lists continuing notes first mentioned in previous Release Notes.
Table 6: New Notes for Release 9.4.2
Product
Family
Description
Discussion and Recommendations
All
A derived
temperature is
now shown on a
module’s web
page (10379)
The temperature is board (not ambient air) temperature. Different
hardware vintages use different methods for deriving temperature. Newer
hardware vintages will see a temperature indication that tracks more
closely with temperature changes and is more consistent from radio to
radio, whereas older hardware vintages may see significant differences
between radios and from the same radio over time.
All
Disable TCP
ACK prioritizing
in broadcast
video
applications
(10263)
When optimizing a system for broadcast video, on the AP’s Configuration
=> General page configure Prioritized TCP ACK to Disabled.
In a system being used for internet access or similar applications
prioritizing TCP ACKs improves downloading of FTP files and other
activities making significant use of TCP ACKs under heavy load.
However, in a system being used for broadcast video or video
surveillance, prioritizing TCP ACKs can cause sporadic choppy video in
the uplink.
PTP
54200
5.4-GHz OFDM
BHs may see a
600 kbps
reduction in
uplink or
downlink
throughput
(9574)
Guard times in the OFDM PTP scheduler were increased slightly,
changing the ranges at which time slots are lost to air delay. Depending
on the distance between BHs and the configured Downlink Data %, this
may or may not affect a given installation. For example, at 0 miles and
50% Downlink Data the uplink/downlink slots change from 33/33 in
Release 8.4.3 to 33/32 with Release 9.4.2, resulting in 600 Mbps less
downlink throughput. However, at 3 miles the slots are 32/32 for both
Release 8.4.3 and Release 9.4.2 resulting in no change in throughput
between the releases.