COX Says My Cable Modem Is to Blame

Question

CMD31T.&nbsp; It was working fine until August 1.&nbsp; Then it seemed to take forever to resolve domain names (spinning activity widgets while "waiting for xxxx.com..." displayed in status bars).&nbsp; Speed tests (both Cox and Speedtest.net) showed up and down speeds in expected range.&nbsp; However both showed very high latency.&nbsp; It looked to me like COX DNS servers were pathetically slow.&nbsp;COX support responded that my upstream channel power was showing too low, and that I should replace the modem (with on of theirs, of course).&nbsp; However, when I look I see power numbers that look to be in the range others have reported as good. (See below).&nbsp;QUESTION: What should the power be on both upstream and downstream channels?&nbsp; And is downstream power coming off the cable, while upstream power is supplied by the modem?&nbsp;ConnectionStartup ProcedureProcedure&nbsp;&nbsp; &nbsp;Status&nbsp;&nbsp; &nbsp;CommentAcquire Downstream Channel&nbsp;&nbsp; &nbsp;813000000 Hz&nbsp;&nbsp; &nbsp;LockedConnectivity State&nbsp;&nbsp; &nbsp;OK&nbsp;&nbsp; &nbsp;OperationalBoot State&nbsp;&nbsp; &nbsp;OK&nbsp;&nbsp; &nbsp;OperationalConfiguration File&nbsp;&nbsp; &nbsp;Complete&nbsp;&nbsp; &nbsp;Security&nbsp;&nbsp; &nbsp;Enabled&nbsp;&nbsp; &nbsp;BPI+Downstream Channel 0Lock Status&nbsp;&nbsp; &nbsp;Locked&nbsp;&nbsp; &nbsp;Modulation&nbsp;&nbsp; &nbsp;256 QAMChannel ID&nbsp;&nbsp; &nbsp;1&nbsp;&nbsp; &nbsp;Symbol rate&nbsp;&nbsp; &nbsp;5360537Downstream Frequency&nbsp;&nbsp; &nbsp;813000000 Hz&nbsp;&nbsp; &nbsp;Downstream Power&nbsp;&nbsp; &nbsp;0.5963 dBmVSNR&nbsp;&nbsp; &nbsp;38.2578 dBmV&nbsp;&nbsp; &nbsp;Correctables&nbsp;&nbsp; &nbsp;39Uncorrectables&nbsp;&nbsp; &nbsp;607&nbsp;&nbsp; &nbsp; &nbsp;&nbsp; &nbsp;Downstream Channel 1Lock Status&nbsp;&nbsp; &nbsp;Locked&nbsp;&nbsp; &nbsp;Modulation&nbsp;&nbsp; &nbsp;256 QAMChannel ID&nbsp;&nbsp; &nbsp;2&nbsp;&nbsp; &nbsp;Symbol rate&nbsp;&nbsp; &nbsp;5360537Downstream Frequency&nbsp;&nbsp; &nbsp;819000000 Hz&nbsp;&nbsp; &nbsp;Downstream Power&nbsp;&nbsp; &nbsp;0.2748 dBmVSNR&nbsp;&nbsp; &nbsp;38.2578 dBmV&nbsp;&nbsp; &nbsp;Correctables&nbsp;&nbsp; &nbsp;42Uncorrectables&nbsp;&nbsp; &nbsp;454&nbsp;&nbsp; &nbsp; &nbsp;&nbsp; &nbsp;Downstream Channel 2Lock Status&nbsp;&nbsp; &nbsp;Locked&nbsp;&nbsp; &nbsp;Modulation&nbsp;&nbsp; &nbsp;256 QAMChannel ID&nbsp;&nbsp; &nbsp;3&nbsp;&nbsp; &nbsp;Symbol rate&nbsp;&nbsp; &nbsp;5360537Downstream Frequency&nbsp;&nbsp; &nbsp;825000000 Hz&nbsp;&nbsp; &nbsp;Downstream Power&nbsp;&nbsp; &nbsp;-0.7921 dBmVSNR&nbsp;&nbsp; &nbsp;38.2578 dBmV&nbsp;&nbsp; &nbsp;Correctables&nbsp;&nbsp; &nbsp;25Uncorrectables&nbsp;&nbsp; &nbsp;541&nbsp;&nbsp; &nbsp; &nbsp;&nbsp; &nbsp;Downstream Channel 3Lock Status&nbsp;&nbsp; &nbsp;Locked&nbsp;&nbsp; &nbsp;Modulation&nbsp;&nbsp; &nbsp;256 QAMChannel ID&nbsp;&nbsp; &nbsp;4&nbsp;&nbsp; &nbsp;Symbol rate&nbsp;&nbsp; &nbsp;5360537Downstream Frequency&nbsp;&nbsp; &nbsp;831000000 Hz&nbsp;&nbsp; &nbsp;Downstream Power&nbsp;&nbsp; &nbsp;-0.8271 dBmVSNR&nbsp;&nbsp; &nbsp;38.6054 dBmV&nbsp;&nbsp; &nbsp;Correctables&nbsp;&nbsp; &nbsp;11Uncorrectables&nbsp;&nbsp; &nbsp;541&nbsp;&nbsp; &nbsp; &nbsp;&nbsp; &nbsp;Upstream Channel 0Lock Status&nbsp;&nbsp; &nbsp;Locked&nbsp;&nbsp; &nbsp;Modulation&nbsp;&nbsp; &nbsp;64QAMChannel ID&nbsp;&nbsp; &nbsp;3&nbsp;&nbsp; &nbsp;Symbol rate&nbsp;&nbsp; &nbsp;5120 Ksym/secUpstream Frequency&nbsp;&nbsp; &nbsp;38600000 Hz&nbsp;&nbsp; &nbsp;Upstream Power&nbsp;&nbsp; &nbsp;47.0000 dBmVUpstream Channel 1Lock Status&nbsp;&nbsp; &nbsp;Locked&nbsp;&nbsp; &nbsp;Modulation&nbsp;&nbsp; &nbsp;64QAMChannel ID&nbsp;&nbsp; &nbsp;1&nbsp;&nbsp; &nbsp;Symbol rate&nbsp;&nbsp; &nbsp;5120 Ksym/secUpstream Frequency&nbsp;&nbsp; &nbsp;25800000 Hz&nbsp;&nbsp; &nbsp;Upstream Power&nbsp;&nbsp; &nbsp;47.0000 dBmVUpstream Channel 2Lock Status&nbsp;&nbsp; &nbsp;Locked&nbsp;&nbsp; &nbsp;Modulation&nbsp;&nbsp; &nbsp;64QAMChannel ID&nbsp;&nbsp; &nbsp;2&nbsp;&nbsp; &nbsp;Symbol rate&nbsp;&nbsp; &nbsp;5120 Ksym/secUpstream Frequency&nbsp;&nbsp; &nbsp;32200000 Hz&nbsp;&nbsp; &nbsp;Upstream Power&nbsp;&nbsp; &nbsp;46.5000 dBmVUpstream Channel 3Lock Status&nbsp;&nbsp; &nbsp;Locked&nbsp;&nbsp; &nbsp;Modulation&nbsp;&nbsp; &nbsp;64QAMChannel ID&nbsp;&nbsp; &nbsp;4&nbsp;&nbsp; &nbsp;Symbol rate&nbsp;&nbsp; &nbsp;2560 Ksym/secUpstream Frequency&nbsp;&nbsp; &nbsp;17600000 Hz&nbsp;&nbsp; &nbsp;Upstream Power&nbsp;&nbsp; &nbsp;46.5000 dBmV&nbsp;&nbsp;

vkdelta · Answer

QUESTION: What should the power be on both upstream and downstream channels? And is downstream power coming off the cable, while upstream power is supplied by the modem?

your DS power is very good (ideally 0 dB)

you US power is good as well (lower 40s ideally but max to higher 40s)

yes, DS is recieved power level whereas upstream power is coming from modem.

your problem may not modem itself. Modem does not process DNS packets. It is just a passthrough bridge.

Unless you are having too many T3/T4 timeouts which are causing disconnection, it should be a Router or network issue.

nwmc · Answer

Your response is what I expected - it seems COX is just doing whatever it takes to make me go away rather than deal with the problem. (I still think it is their DNS servers, especially since they connected me to servers in a city much farther than was the case prior to this problem.) It is ridiculous that it takes 30 secs to 1 minute of "Looking for <insert domain name here> followed by "Waiting for <insert domain name here>" for email and web pages, and then waiting even more for the page to fill out all those inserted ads that come from other domains. And the change from responsive to "world-wide wait" happened literally overnight when I changed nothing - no software updates, same router, same modem.

Anywat, thanks for confirming that it I don't need to spend more money on a new modem or rental from COX.

wmc

vkdelta · Answer

you might want to do wireshark capture and check what is happening. if your DNS is slow, change to public DNS servers on your laptop such as 4.2.2.2 or 8.8.8.8 and see what happens.&nbsp;

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COX Says My Cable Modem Is to Blame

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