Re: Just got uverse and canceled Time warner
02-20-2009 07:51:35 AM
osands wrote:
Thanks. That explains a lot. I'll have to check it out. I am curious though... What do you look for when looking at sync rate and the attenuation? What are acceptable ranges and what do the numbers mean?
DSL Down Up
Current Rate: 25216 kbs 2048 kbs
Max Rate: 52552 kbs Not Available
Current Connection:
Current Noise Margin: 21.5 dB Not Available
Current Attenuation: 25.7 dB Not Available
Current Output Power: 13.3 dBm -6.5 dBm
Current rate: This is the profile rate assigned by AT&T. This is 19200 kbps for the "low" profile that only allows 1HD/3SD. It is 25216 kbps for the normal profile which allows 2HD/2SD. Rumor has it that a 3rd profile will be introduced soon with a 32000 kbps rate, which will allow 3HD/1SD.
Max rate: This is your sync rate, which is the line rate that your RG and the VRAD have established. This ranges from about 70000 kbps if the VRAD is in your backyard, down to around 30000 kbps at 3000-3500 feet.
Line capacity: This isn't shown, but can be calculated as Line Capacity = Current Rate * 100 / Max Rate. This is the percent of the line that is in use. If this figure exceeds about 70% you will begin to have pixelation, picture freezes, and dropouts. If the figure exceeds 80% most technicians will bump you to a lower profile or refuse to install.
Current Noise Margin: Think of this as a signal-to-noise ratio for the line. It tells you to some degree how far away from the VRAD you are as well as how much line noise or interference your line is picking up. Ranges from 30 dB if the VRAD is in your backyard down to ~ 12 dB for 3000-3500 feet. This number should be consistent with the distance inferred from the max rate, the attenuation, and the upstream output power. If its inconsistent, your line has more or less noise than expected, which can indicate a bridge tap or other interference.
Attenuation: A measure of how much quieter the signal has gotten at your house as compared to how loud it was when it left the VRAD. Ranges from 10 dB with the VRAD in your backyard to 30 dB at 3000-3500 feet. This number should be consistent with the distance inferred from the max rate, the current noise margin, and the upstream output power. If it's inconsistent, it can indicate high-gauge wiring (28 AWG instead of 26) or a bridge tap.
Current output power: The downstream number here can vary a lot depending on many different factors, so kind of ignore that one. The upstream output power, though, can tell you about distance. This is the power level (compared with a reference level) that your RG is using to send information back to the VRAD. The upstream direction uses lower frequencies than the downstream direction, and is more affected by bridge taps, so bridge taps can show up here. Ranges from -10 dB (close to the VRAD) to +15 dB (high power level required to overcome distance and/or bridge tap). This number should be consistent with the distance inferred from the max rate, the attenuation, and the current noise margin.
Collected for 26 days 8:05:06
DSL Since Reset Current 24H Current 15M Time Since
Last Event
Link Retrains: 0 0 0 0:00:00
DSL Training Errors: 1 0 0 26 days 8:02:51
Training Timeouts: 2 0 0 26 days 8:03:15
Loss of Framing Failures: 0 0 0 0:00:00
Loss of Signal Failures: 0 0 0 0:00:00
Loss of Margin Failures: 0 0 0 0:00:00
Cumulative Seconds w/Errors: 1182 43 2 0:02:54
Cumulative Sec. w/Severe Errors: 9 0 0 1 day 19:28:36
Corrected Blocks: 1559476917 569269730 6075498 0:00:02
Uncorrectable Blocks: 2238 43 2 0:02:54
DSL Unavailable Seconds: 112 0 0 26 days 8:02:53
In this chart, the error rates can show you how well the line is performing. For each line, compare the time since the last event with the time that the statistics have been collected for.
Link Retrains, DSL Training Errors, Training Timeouts, Loss of Framing Failures, Loss of Margin Failures, and DSL Unavailable Seconds should all always be zero, except for when the RG first starts up. For example, if the statistics have been collected for 15 days, all of these should show 15 days since the last event (or 0:00:00 if none of those events ever occurred, even at the last startup). If any of these happen during normal RG operation, there is a line problem.
Cumulative Seconds with errors: Ideally should be zero. However, a few here and there might be acceptable, but it does indicate that there's some line interference going on. If there are no picture freezes or pixelation, then don't worry about it.
Cumulative Seconds with severe errors: Ideally should be zero, but their presence indicates that there is definitely a line problem.
Uncorrectable Blocks: Ideally should be zero, or very low (single digits). More than 5-10 per hour is definitely a line problem.
Corrected Blocks: Ideally should be zero, but you can also run up millions of these without any problem. By themselves, they don't indicate an issue.

