Interoperability Now!
8-1
8
NXU-2B FAQ (Frequently Asked Questions)
8.1
General
This section provides answers to some frequently asked questions about the installation and
operation of the NXU-2B.
How much network bandwidth does the NXU-2B consume?
The NXU-2B bandwidth usage varies depending on the application. When COR is inactive and
no audio is being transmitted across the link, the bandwidth usage is essentially zero, since a
small “keep-alive” packet is only sent every 4 seconds. When COR is activated and the default
voice compression method is used, audio will be sent across the link at approximately 15Kbps.
If a full-duplex connection is active (COR is active on each end) then the total bandwidth usage
for audio will be approximately 30Kbps. Selecting a different voice compression method will
increase the bandwidth accordingly. Voice compression method 2 will require approximately
18Kbps (half-duplex), method 3 will require 27Kbps, method 4 will require 36Kbps, and method
5 will require approximately 70Kbps. If RS-232 data is being sent simultaneously then the
bandwidth will be increased by the RS-232 data rate, plus the TCP overhead.
My application does not provide a COR line. What should I do?
COR is usually obtained from a radio and indicates that a signal is being received. If you do not
have a COR line, or a line that performs this function, then you can either tie the NXU-2B COR
line to its active state or you can use VOX mode. VOX mode is preferred since enabling COR
permanently will cause data to flow continuously across the link, even if no audio is present.
I have a 1000 Mbps (Gigabit) Ethernet. Can I connect the port on the NXU-2B to my
network?
Most 1000Mbps equipment (switches, routers) will work with either 10Mbps or 100Mbps
connection, so it should work without any problems. Check with your network administrator if
you’re unsure about your network equipment capabilities.
Where can I find a description of the VoIP protocol used by the NXU-2B?
The NXU-2B protocol is proprietary and not available to end-users without a license. Contact
JPS for further information.
My system uses pilot tones and/or tone keying. Does the NXU-2B support this?
Yes. Pilot tones and keying tones are not normally needed on the NXU-2B (due to its support
for hardware COR and PTT lines) but are supported and will work with the proper vocoder
selection. Tones are not supported when using the 13 Kbps vocoder (VOCODER 1). You must
use one of the higher bit-rate vocoders to use any type of tone signaling.
Summary of Contents for NXU-2B
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Page 18: ...NXU 2B Operations Manual 1 10 End of Section One...
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