Signal levels

Your downstream power levels are too low. How do the upstream power levels look?

The DPQ3212 doesn't report upstream power levels. :( The tech tomorrow should be able to get that info, though.

Just curious, are you saying someone at Cox told you a DPQ3212 doesn't report upstream power levels?

Also, I agree the signal levels look borderline for DOCSIS 3.0 standards, but what are the real life symptoms? What made you check your signal levels in the first place?

Not Cox, the modem itself. The status page only reports the downstream levels and there's no other pages accessible that report on the cable signal). The modem may report upstream readings, but I haven't gone digging into the Cisco tech library to find out how to pull that via SNMP (and if Cox has any sense they've blocked SNMP from the Ethernet side of the modem anyway, you can do way too many things with SNMP access and security there is best described as "cheesecloth after someone got through ripping gaping holes in it with a chainsaw").

Real-world symptoms? Intermittent bouts of lag/stalling, with persistent connections (games, VPNs) ceasing to respond for anywhere from 5-20 seconds, 100% packet loss while it's occurring. It's affecting multiple computers simultaneously, all of which are covered by good anti-virus software that hasn't reported any malware infections, so it's unlikely to be a problem with malware or the computers themselves. Rebooting the computers, the router and the cable modem doesn't help. Reseating the Ethernet and coax cable connectors doesn't help. A wide variety of sites across the 'net are all affected simultaneously, and since it's unlikely that a dozen different backbone providers all lost routers at the same moment and recovered at the same moment with nobody reporting the outage that points to a problem no further upstream than Cox. So I do a quick check of the modem status to see if it's showing anything obvious, and low and behold there's signal levels much lower than what I normally see.

Every time I've seen this problem it's turned out to be either Cox wiring (mostly techs doing installations mucking up the connections in the junction box with splitters or filters where they shouldn't be) or a failing modem (Cox equipment in my case so their responsibility to diagnose and replace if needed). Although in one case it was equipment at the head-end having gone flaky.

I probably should see upstream, but the modem status page only includes the downstream readings. Probably it's just how it's configured. They had some excess stuff connected in the demarc box and he changed the splitters around to reduce the splitter loss on the line feeding the cable modem's outlet. Now I'm seeing:

Considerably improved. I think the rest of the low signal's down to the actual in-wall wiring itself, since there's a good strong signal at the demarc. Nothing that can be done about that short of running a new cable to feed the modem. This is the hardware/firmware info, in case anything jumps out as being blatantly off:

Is your problem really resolved?  It shows an answer, but I can't figure out what they did to fix your problem.  I'm having the same issue - had 3 techs in 4 visits, change plugs, test new modem, nothing worked.

It did resolve my problem, at least for the moment. The fix was to shuffle the splitters around to minimize the number and size of splitters feeding the outlet with the cable modem. The feed originally came in to a single 4-way splitter in the demarc box, with one leg feeding a 2-way splitter on the outlet feeding the cable modem and TV. The tech rewired it so the feed went into a 2-way splitter (less loss), with one leg feeding the outlet with the cable modem and the other feeding the 4-way which fed the TV-only outlets (the TV boxes are OK with weaker signals).

Another trick would be to isolate the cable modem on it's own outlet. I have 2 feeds from the outside pillar to the demarc box. If I only had the cable modem on one outlet with no cable TV box, the tech could've hooked that outlet directly to one incoming feed with no splitters and used the other feed for the other outlets (the TV master and child boxes all need to be on the same feed so the in-home network between them works right).

The check I'd ask him to run in your case would be to check signal at 4 places: the pillar where the cable arrives at the property, the demarc box where the feed from the pillar splits and connects to the in-home wiring, the outlet at the wall, and the end of the cable going from the wall outlet into the modem. The spot where the signal takes a nose-dive will tell you which portion of the wiring the problem lies in. The easy ones are the pillar, the demarc and the end of the modem cable. The first two are Cox's issue to fix, either their outside or neighborhood wiring or the head-end. The last usually just requires replacing the cable from the wall to the modem, one common problem's using cable with too small a central wire that's not making good contact and isn't carrying signal well. I save all the cables from the Cox self-install kits for good-quality spares. The worst case is good signal at the demarc and a weak signal at the outlet. That means the in-the-wall wiring's bad, and it's a pain to replace/rewire since homes don't have conduit or suspended ceilings and pulling new cable's tough. If the cable modem's near an outside wall Cox may be able to run exterior cable along the house and punch a small hole through the wall to bring the cable inside and to the modem.

We seriously need to move to conduit from outside in to a central phone closet and channel along the ceiling for comms wiring.

Thanks for your speedy reply.  I'm waiting for a tech to visit - I think they gave up on me, but I will pass along your post info. What's weird is they ran a cable directly from the tap to a brand new modem and it did the same cycling down of speed. My problems started after a service outage 7 weeks ago, before that I've had no problems since I started with Cox in 2005.

On a new cable directly from the demarc to a brand-new modem, if it's not getting acceptable speed and signal (check the modem's status page, usually at http://192.168.100.1/) then it's almost certainly a problem with the signal coming into the demarc. If the signal's strong but speed drops, that may be an indication your hardware and wiring's OK but there's congestion in the area. That happens when there's too many people on a single piece of head-end hardware, or if you've got a lot of people doing lots of BitTorrent downloads and/or HD video streaming and chewing up a lot of bandwidth at the head-end. The tech can't check for congestion, but Cox's network engineers should be able to. They may not be able to fix it quickly, though, since it requires changes to the upstream hardware and distribution network.

Thank you Scott Pickett for setting up a service call with a real Cox employee instead of a contractor.  After 3 visits from End2End with each doing one little piece that did not fix my problem of slow speed, I went to the Cox store and talked to Scott about my frustration - he made sure my next appointment was with a Cox specialist who had experience in all systems.  I have Cox Phone and Internet only.  Scott (from the COX store) also replaced my 1 yr old modem (it had a 2 yr warranty) with a new version and confirmed my appointment with a Cox repair technician.  James discovered that I had an old phone modem that could have been interfering with the internet signal coming into my house. It also could have been the internet modem, but when the End2End technician did a test from the tap with a brand new modem the slow speeds continued, so I figured it was not the internet modem.  James the Cox repair person replaced the phone modem and the internet modem and I have not had throttling down to slow speeds for 3 days now.  I'm a much happier person. Thank you Scott for saving a Cox customer for 8 years.