Did you see a problem with MDD waiting too long?
Did you see a problem with MDD waiting too long?
After not getting MDD Timeout messages for 11 years, in mid-April I started seeing one per day on average. My Spectrum field tech came out and changed all the connections from the street to my modem. The problem didn't go away. A second tech took another look and replaced the drop wire coming from the street. It still wasn't fixed. Even though I had no splitters, I did have a coupler (the first tech removed it), so I moved the modem to my garage so there was only an 8-foot RG6 coax line from the grounding block where the drop came from the street. The problem didn't go away either. I bought a new modem and it still wasn't working.
Downstream power levels are in the 3 to 6.5 dBmV range, while SNR is between 40.9 and 41.4. Upstream power is around 43 to 44 watts. These numbers were exactly the same on both the old modem and the new one. When the first tech was out, he took away a forward antenna that Spectrum had installed years ago because they thought upstream power levels were too high (50 to 51.5 watts). Now a field tech is coming out again. It seems like it's definitely not my modem or my wiring causing the MDD Timeouts. Any ideas?
I was told by both techs that it could be due to a loose connection, but everything looks tight and I have brand new coax from the tap on the street. Did someone else post something similar where the issue was in the Node? Any help would be great? The new modem is DOSCIS 3.1 which I am also new to. It's a Netgear model. There are three dozen locked downstream channels, channel twenty-five isn't listed because it shows as OFDM channels somewhere lower. Channel twenty-five appears locked with power at 7.3 dBmV on the signal meter. The screen also shows millions and increasing numbers of Uncorrectable Codewords and Correctable Codewords for each other—they are roughly the same number.
No Uncorrectable Codewords came from other posts about signal levels, so I am right that channel thirty-two is used for CFDM. But can anyone explain what the Codewords mean? Thanks for any help!
Do you have a real problem? Does your connection sometimes go down or cut out? The MDD message shows up as a warning on my modem, which usually isn't a big deal by itself. If you see other messages too, that might point to something bigger. With the code word stuff, the main thing is that there are very few "uncorrectable" code words left. Those represent data that got damaged so bad it had to be thrown away. The other two categories mean packets didn't have errors and those with errors were fixed by your modem. There are extra bits sent in the packets just so a single bit can sometimes get corrected, but this type of method usually can't really fix multi-bit data loss issues.
I had internet go down for a few minutes on May 7th, but it came back after rebooting the modem. My neighbor on the same line stayed online. Aside from that hiccup, I haven't seen any drops in my house or anywhere else, but with eleven years of never getting an MDD error at this spot before, seeing one every single day for a whole month makes me nervous. It feels like something is breaking and could be like the canary singing inside the coal mine. In twenty years of using cable modems, I never saw an MDD error once in my life, so this really stands out to me as something different going on.
I've spoken with 4 support people. The first guy said he couldn't see the MDD errors, but when I pressed something, he asked for help and showed me how to find them. Neither of us knew what those errors were. Next 3 people could see them too, but still didn't know what they meant. The first Field tech also didn't get it. He called another Field tech who told him a loose connection was the problem. He fixed all those connections. Then I moved the modem to where the drop comes into the house. There were still errors showing up. Even after swapping out my new modem and coax cable (RG11), things stayed bad. A Field tech is coming over again today. 😞
Yes - the MAC address in the Event log is the MAC address of the modem. The issue is between the modem and the plant. No set pattern or time of day when it occurs - most days one error logged somedays no errors followed by two errors the next day. On the old modem Arris SB6190) on some days would see a T3 Timout or Partial service 2 - 3+ hours later. On the new modem (Netgear CM2000), I have only had two MDD errors but both had a "CM-STATUS message sent. Event Type Code: 4;" sent 10 seconds later. Most likely just a difference in the way the different modems log things. When this was first noticed all laptops had been powered off for 4 weeks and the MDD errors started after they were powered off and were logged on average once a day even though computers were all power off. When the new modem was provissioned yesterday my router was disconnected as I was plugged directly into the modem with my laptop and was in that config when the two errors were logged in the modems' event log. Received a call from the Field Engineer supervisor this morning. He had been researching the issue and agreed that it is nothing on my end - basically eveything has been removed to a direct connection and the new modem. Something in the plant end. He had reached out already to the mainteance group (group that supports the plant - tap, node, etc.) and they told him the line needed to be balanced. He wasn't sure what that meant but I do see that the OFDM channel is about 1 db lower right now that it was this morning and the the down stream channels power levels are in a tighter range. At this point we are going to sit tight and see if the balancing resolved the issue or not and will touch base in a few days. The only other item that points to the plant is the the neighbor who is on the same tap (just the two of us) apparantly has a "crap load" of errors on her line. So tjhe supervisor will be reviewing that as well. MAC address is the address of the modem. Issue is between the modem and the plant. Errors are logged even when all computers are powered off. No pattern as to when it occurs other than most days have one error logged, some days have zero but others have two. While gone for the past 6 days, ahd 8 errors logged. MDD messages are sent every couple of seconds to the modem and are logged as a timeout when not received is my understanding at a high level. Not a computer related issue as when the modem was provissioned yesterday it was connected directly to the modem and two errors were logged while in this config - nothing reported in stability history or event viewer for the time frame of the errors. And as I said - when this first occured all computers were powered off for 4 weeks. Field tech supervisor escalated to the maintenance group this morning who told him the line needed to be balanced. Noticed afterwards that the power level on the OFDM channel is about 1 db lower than this morning and that the power levels on teh downstream channels seem to be tighter. Going to watch logs for a few days and see if that fixed it. In the meantime he is working with the maintenace group to have them check the tap and node, as the last field tech reported that the neighbor who is the only other one on the tap had a crap load of errors - he just wouldn't provide me with more info - privacy and all.
Updated: The Field Supervisor checked the device I'm working with closely. They noticed that the signal strength is low on some of our main routes, which isn't good when we expect a higher amount of them to happen at other times too. This happened twice in a row for this specific area compared to usual patterns. They are still calling up the maintenance team right now about it.