User's Manual

Appendix C. DS.11 FAQ
User's Guide C-2 BreezeNET BU-DS.11/RB-DS.11
Why are there 11 channels and only 3 usable?
The IEEE802.11 specification calls out 11 selectable channels (USA) between
2414MHz and 2462MHz. Because of the transmission bandwidth of the DS
modulation, only 3 channels are non-overlapping. Those are channels 1, 6, and 11,
therefore, only 3 systems may be co-located. The other channels may be used,
however, if used with another DS system co-located on another nearby channel, the
overlap will cause them to share the bandwidth yielding no increase in aggregate data
bandwidth. When operating in a single channel network, the other channels may be
used to move away from any in band interference that may exist.
What if the DS.11 link experiences interference?
If interference is affecting the DS.11 link, one of the other channels may be selected
to operate away from the frequency of the interference. Also, physically re-locating
the antennas may help.
What is the typical latency of a BU-DS.11/RB-DS.11?
A point to point link would realize about 3mS latency.
Can the BU-DS.11/RB-DS.11 firmware be upgraded?
Yes, the firmware in the BU-DS.11/RB-DS.11 is stored in flash and is upgraded using
the built in TFTP server.
Can just anyone erase my BU-DS.11/RB-DS.11 flash or change the firmware?
No, the TFTP server in the BU-DS.11/RB-DS.11 requires the SNMP write community
name (password) to perform an upgrade.
Can I corrupt my firmware flash when upgrading to a new version?
If the TFTP file transfer is interrupted during a flash update it is possible to corrupt the
firmware. Fortunately, the DS.11 has a backup flash, which contains the previous
version for firmware. If the primary flash is corrupt, then the backup is automatically
used to return the unit to an operating state.
When does the back up flash image get upgraded?
After completing a firmware upgrade, the backup flash containing the old firmware
version is overwritten with the new version on the new power on cycle.