intermittent Speeds and Instability

Recently moved to a new house in 28078 (250 down), performed my service transfer, hooked up my supplied modem/router, and everything was working. I decided to purchase an SB6183/Archer A7 combo to strengthen the net in my house, but I have only made it worse. 


Installed the SB6183, updated Spectrum with the MAC, and everything seemed good to go. Shortly after I start dropping connection on hardwire and wifi devices. After some investigation and noticing that my DS and US power/SNR were out of spec, I went to the cable box outside. Inside the cable box, I found several splitters and disconnected coax that I went to work on. I have tested several different setups  from no splitter (direct to modem), 1 splitter, 2 splitters and all options provided different results (all tested without router), but all still were unstable.


The snips below are from my current setup which is a single 2-way splitter, one line to the modem and the other is still open (terminators on the way).  With this setup the modem never disconnects (2 blue lights), but still have unstable net and connectivity issues. 


Can anyone take a look and provide me with some insight?







Proven Sharer

Re: intermittent Speeds and Instability

No hostility intended, but when a self-installed subscriber-owned internet modem doesn't work, it is generally best to call Spectrum for help, rather than rearranging the site cabling without knowing why it was wired in a certain fashion. 

Let's summarize the equipment you have connected: 

Spectrum 200 Mbps internet service (a speed upgrade from previous home?)


Arris SB6183 16 x 4 DOCSIS 3.0 300 Mbps modem (customer-provided) connects to Spectrum using RG-6U coax cable 


Archer A7 Gigabit Dual Band MU-Mimo Wireless 802.11ac Internet Router (customer-provided) connects to modem over CAT-5e ethernet cable.  You made a good selection!


Looking at the signal report page, your US (upstream) side looks good, but the DS (receive) levels appear a bit high and noisy, bumping or exceeding +10 dBmV.  Signals that strong should display an SNR above 40 if the incoming signal is clean and the drop line is properly grounded, but yours are only in the mid 30's.   For some reason the error counters in your SB6183 modem were reset to zero or disabled, so we don't have that valuable data to work with.  

Your modem made several attempts to re-calibrate its internal auto-level circuitry.  The clue is the status message "Received response to Broadcast Maintenance Request, But no Unicast Maintenance Opportunities Received.  T4 Timeout.

That tells us that your modem completely lost incoming signal on at least one DS channel for more than three seconds, which forced it to reset and restart. 

When a change in signal level causes a T3 or T4 outage, it can take one overnight service window (1 AM to 5 AM) before this error gets resolved.  If you see that message appear again the next day, it often means there is an intermittent loose connection on the main overhead cable which a Spectrum line maintenance crew has to locate and repair.  A loose or corroded connector swaying in the wind or a break in your drop line can also cause loss of DS signal.