CHAPTER 6: REMOTE DEVICE ALERTS
6-8
MDU Solutions
®
– UCrypt
®
Monitoring Server - Operation Manual
2. Note if the loss of lock occurs during maintenance windows indicating external causes.
3. Note if other alerts trigger at almost the same time, again indicating external causes.
4. A single loss on a specific tuner very occasionally or rarely may be considered normal.
5. Recurring losses of lock over time on a specific tuner may indicate a hardware problem especially if other tuners in
the UCrypt equipment operate normally.
6 .11 UCrypt High Tuner Discontinuities/Minute Error
6 .11 .1 Refers to
MPEG level packet loss at a specific QAM tuner (Tuner #0 to #5) on a specific Host card (Card #0 to #9).
This is the
packet loss related to a QAM multiplex and not a specific program within the multiplex. There may be bit error correction in the
system but this problem is reporting uncorrectable bit errors resulting in packet loss as this is measured post error correction.
This should always be zero under the best circumstances but some uncorrectable errors may still occur but are not visible in
the picture up to about 500/minute, therefore the UCrypt will only begin to send alerts where the discontinuities exceed 200/
minute.
6 .11 .2 Repetition of Alert
The UCrypt will send an alert each time there are more than 200 discontinuities recorded on a specific QAM in a one minute
time frame.
6 .11 .3 Customer Symptoms
Customer experiences noticeable artifacts and/or other impairments starting at an error level of about 500 discontinuities/min,
with impairments escalating with higher levels of discontinuities up to and including loss of all programs on the affected tuner
for the most severe conditions for the duration that the error condition exists. The resulting customer experience will be both
random and variable depending on the conditions causing the error and it is not possible to quantify them further.
6 .11 .4 Urgency
Low - High.
6 .11 .5 Cases Where Alert is Likely a Result of:
Outside influence or normal operation
If the number of discontinuities is low (a few hundred per minute) and infrequently reported, this is considered normal as just
about all cable plants experience some brief moments of signal impairment for a multitude of reasons. If the discontinuities are
above 500/minute and occur frequently and across many QAM tuners, urgent attention is indicated as there are likely system
problems with the level and/or signal quality hitting the input to the equipment. If the discontinuities are above 500/minute and
occur frequently on a single QAM tuner only, this typically indicates either a problem with the level and/or signal quality on the
particular QAM frequency at the UCrypt input.
An Internal Issue
If the discontinuities are above 500/minute and occur frequently on a single QAM tuner only, it may indicate a potential
hardware issue with that particular tuner.
6 .11 .6 Probable Causes
1. Input RF levels are either not set to the UCrypt’s ideal operating range, certain QAM levels are unbalanced on the
plant or the SNR or MER of the QAM signal is below the threshold the equipment can handle without errors.
2. Plant maintenance had been occurring at the time of the error.
3. Hardware tuner internal to the UCrypt is failing.
6 .11 .7 Next Steps
1. Check if the program has corrected itself by checking ‘status’ of the program on ‘Channel View’ page.
2. Analyze the log to determine if there have been multiple tuners sending alerts at about the same time. If multiple
tuners are reporting problems especially if they reside on different host boards, this indicates a problem external to
the UCrypt.
3. Analyze the log to determine if the errors are occurring at times when plant or headend maintenance may be occurring.
4. Check the ‘All Tuner Diagnostics’ page on the UCrypt GUI and ensure all tuned frequencies are showing signal levels
between 0 and +15 dBmV and SNRs greater than 32 dB.
5. If symptoms point to external causes, then measurement of plant carrier levels and MER may be required.
