BadEvilYoda
join:2006-02-04
Ashburn, VA
|  [Slow Speed] Can this downstream power level be accurate?
I've been noticing a decrease in speed issue the last few days, and this morning being Saturday finally had a chance to look into it. My question - can this downstream power level reading possibly be correct, from the internal diag screen? (because it's WELL outside any range I have ever seen posted here). The internal connectors and splitting all done by an Adelphia tech, with the modem off one leg of a 2 way splitter. Never had issues before (and I realize it's an older and non-recommended Adelphia modem, which likely explains the log entries) The modem has not lost sync, uptime is 2 days (when I pulled my Linksys WRT54GS v2.1 router out of the network as an experiment and cold-started the modem).
I'm in Ashburn, VA 20147.
Any thoughts would be appreciated, especially concerning the downstream power level and whether that can have the speed decreasing effect or if they are unrelated - or simply an erroneous reading in this modem version - since I don't see how I manage to be connected at all if thats the real signal level.
Modem is a Linksys BEFCMU10v2, DOCSIS 1.1
Modem MAC: 00:06:25:06:5F:04
Hardware Version 4.0
Software Version 1.1.5 (linksys_ver2_1.1_hx_sbefcmu10v2_115-1015_i_000000.bin)
Signal
This page provides important information about the status and quality of the communications
between your cable modem and the cable modem network.
Downstream Channel
The data shown in the table below provides information about the signal coming from the
network to your cable modem.
Lock Status Locked
Modulation QAM256
Channel ID 0
Symbol rate 5360537 sym/sec
Downstream Frequency 625781200 Hz
Max Bit Rate No Limit
Downstream Power 43.69 dBmV
SNR 34 dB
Upstream Channel
The data shown in the table below provides information about the signal being transmitted to the network from your cable modem.
Lock Status Locked
Modulation 16 QAM
Channel ID 2
Symbol rate 2560 ksym/sec
Upstream Frequency 33008497 Hz
Max Bit Rate No Limit
Upstream Power 50.75 dBmV
And these are the latest log entries (with redacted server IP as irrelevant info):
2006-02-03 10:11:45 error SW upgrade Failed after download - Incompatible SW file SW file:befcmu10v2_109-1015.bin - SW server:68.168.(redacted)
2006-02-03 10:11:45 error Improper Code File Controls
Code File: befcmu10v2_109-1015.bin - Code File Sever:68.168.(redacted)
2006-02-03 10:11:45 error SSD: Error PKCS#7 format!
2006-02-03 10:11:20 notice SW Download INIT - Via NMS SW file:befcmu10v2_109-1015.bin - SW server:68.168.(redacted)
2006-02-02 10:08:38 error SW upgrade Failed after download - Incompatible SW file SW file:befcmu10v2_109-1015.bin - SW server:68.168.(redacted)
2006-02-02 10:08:38 error Improper Code File Controls Code File: befcmu10v2_109-1015.bin - Code File Sever:68.168.(redacted) |
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Champer
join:2004-04-07
Buffalo, NY
clubs:
| I didn't even realize our tools could read that high, but sure enough. Modem Rx Level 43.6 dBmV is accurate, call in and have a truck roll. 
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Johkal
Cool Cat
Premium,MVM
join:2002-11-13
Happy Valley
clubs:
 ·Comcast Digital Vo..
 ·Comcast
·Vonage
| reply to BadEvilYoda
Re: [Slow Speed] Can this downstream power level b
It looks like a firmware version older than yours is tring to get pushed "1.0.9". I don't understand how any Linksys firmware is being pushed to you. You need to call Tech support and ask what is going on.
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MacLeech
The one and only
Premium
join:2001-07-14
SoCal
4 edits | reply to BadEvilYoda
Re: [Slow Speed] Can this downstream power level be accurate?
That particular modem is based off the Scientific Atlanta Webstar DPX110...
The firmware revisions are very similar, but branded by each company.
One of the issues that firmware version (1.1.5) had was inaccurate downstream signal level reporting.
I don't think it was a straight off by 10dB sort of error either. I believe it was inaccurate in increasing percentages the higher the signal level was.
I commonly saw levels reported by the modem in the higher 20s, low 30s when the actual level reported by my signal meter was in the low to mid teens.
Which would make the original poster's signals in the upper teens, low 20s most likely, if read by a tech's signal meter. Which is still on the high side, but not nearly as bad as the 40s its actually reporting. In fact, looking up the MAC and doing a quick check of all the other modems connected to the same interface shows the next highest reported receive level for a modem being around 17 dbMv.
The only way you could actually get levels in the 40s like that is with cascaded house amps or very severely misbalanced distribution amps, coupled with a house amp or incorrectly built distribution system. Since his is the only modem with signals that high, I'd bet money that its the modem receiving signals in the high teens combined with the firmware issue.
Also if the levels were really that high, the total overall signal (including the channels other then the modem data channels) would overload the receiver in the modem and it more than likely wouldn't sync at all.
Adelphia has pushed firmware for those particular model of modems before because of the close relationship to the SA WebStars and the issues they had.
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For official Adelphia support, contact Adelphia. I'm just here for advice... |
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gheezer
Compooters R Us
Premium
join:2002-12-20
Henrietta, NY
| Re: [Slow Speed] Can this downstream power level b
That's an awesome summary.
I saw the lone modem sitting there int he red too, but had no knowledge as to WHY 40db down...
I remember the SA reporting bug now, and you just opened my eyes a bit. Good post Mac!
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BadEvilYoda
join:2006-02-04
Ashburn, VA
| reply to MacLeech
Re: [Slow Speed] Can this downstream power level be accurate?
Thanks for the excellent information - I was under the impression that level couldn't be right and still let me connect at all. Looks like it's time to upgrade the old workhorse anyway to a DOCSIS 2.0 compliant modem w/ current firmware. (I've had it on two different cable networks for about 3 years now, so it was a well-spent $100. It might not help the speed issue, but it doesn't seem like it could hurt.)
Thanks again for all the replies and excellent information. I'll report post-modem-upgrade. |
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