Atec JDSU-DSM-6300 - Manual (Page 6)

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DSAM-6300 DigitAl Service AnAlySiS Meter
Voice over IP (VoIP) Testing
The DSAM-6300 VoIPCheck option enables service validation over a DOCSIS con-
nection. With VoIPCheck, the DSAM-6300 can test VoIP services independently of
the VoIP specification being used. VoIPCheck can segment RF issues from IP issues,
helping to eliminate organizational finger pointing. The DSAM-6300 measures packet
statistics, including packet loss, jitter, and delay, as well as call-quality results such as
R-value and MOS. With its in-depth results analysis capability, the DSAM-6300 can
determine the source of call-quality problems, expediting the troubleshooting process.
Enhanced Downstream Spectrum
Technicians must be able to see how the network is behaving and troubleshoot spec-
trum-related problems. Most technicians do not require a fully featured and expensive
spectrum analyzer, and the DSAM’s enhanced downstream spectrum mode equips
them with an “everyday” spectrum analyzer. It lets users choose between two resolu-
tion bandwidth (RBW) settings, 330 kHz or 30 kHz, and modify the amount of time
spent measuring each frequency step, or dwell time of the analyzer, to a setting from
1 to 25 milliseconds. It also lets users see from 4 MHz to 1 GHz in 10 or 50 MHz spans.
Furthermore, if viewing return-path frequencies, technicians can activate an internal
low-pass filter to eliminate intermodulation distortion caused by relatively high-level
higher frequencies on the meter input, providing a cleaner upstream view.
Sweep
Service quality depends on transmitting signals with the highest carrier-to-composite
noise and the lowest intermodulation distortion. The majority of all transmission errors
can be detected by measuring the frequency response of the network. A sweep trace
reveals every physical error in the network that influences transmitted signals. Also,
since sweep results are independent of transmission methods and formats, it is the most
effective and efficient method for technicians to set up the right gain versus frequency.
The VoIPCheck voice-quality verification test runs
over the DSAM’s cable-modem DOCSIS connec-
tion. It allows for segmentation between HFC and
IP issues by showing at which side of the CMTS
data impairments are present.
The DSAM’s enhanced downstream spectrum
mode equips technicians with an “everyday”
spectrum analyzer.
Forward Combiner
Out
SDA-5500
SDA-5510
Out In
In
Splitter
Headend or Hub Site Distribution Plant
Optical
Transmitter
Optical
Transmitter
Optical
Transmitter
Reverse Combiner
Optical
Transmitter
Node
Node
Node
Optical
Transmitter
Optical
Transmitter
FORWARD SWEEP
Meter receives sweep pulses and reference
levels transmitted from headend or hub site and
displays difference levels (delta).
RETURN SWEEP
Meter generated sweep pulses transmitted from field and
received in headend or hub site.
RETURN SWEEP
Headend or hub site transmits received sweep pulse levels back
to originating field meter for display of difference levels (delta).