I am having a lot of brief connections drops from my modem throughout the day. I have a MOTOROLA 8x4 Cable Modem, Model MB7220, 343 Mbps DOCSIS 3.0 and experience the issues we wired into my router or the modem. The event log is full of " Unicast Ranging Received Abort Response " and " 6 consecutive T3 timeouts while trying to range on upstream channel " errors of the like.
My downstream power is 2.2-2.4 dBmV, SNR 42.5-42.6 dB with many uncorrected packets. The upstream is 39.5-40.7 dBmV. It's my understanding that the upstream could be a bit low and causing the problem. The line from the pole comes to the house and only has one splitter before coming to the modem. It's a GE Digital 2-Way Coaxial Cable Splitter, 2.5 GHz 5-2500 MHz.
Here are some images of what the modem status page looks like. Any ideas? I've tried the usual restating/checking cables/replacing splitter.
The signal stats are good. The first thing to try is swapping out that splitter. It is engineered for satellite systems, not cable systems. It can actually make performance worse by allowing line noise ingress at those higher frequencies that cable systems do not operate on.
Here are some quality brand splitters that Comcast actually uses in different market areas;
Antronix CMC2002H 2-Way Splitter: http://www.amazon.com/Antronix-CMC2002H-2-Way-Splitter/dp/B001E4OH1E
Regal 2 WAY 1 GHZ Splitter: http://www.amazon.com/DIG702867-Regal-WAY-GHZ-SPLITTER/dp/B0018BQMUM/ref=sr_1_2?s=electronics&ie=UTF...
Extreme Broadband BDS102H 2-Way Digital Coax Splitter: http://www.amazon.com/EXTREME-DIGITAL-PERFORMANCE-CABLE-SPLITTER/dp/B007YV0UQW
Holland 2-way horizontal splitter 5-1000 MHz with ground.http://www.3starinc.com/holland_2-way_horizontal_splitter_5-1000_mhz-w-ground.html
Sv-2g 2-way Splitter 5-1000mhz: http://www.amazon.com/Sv-2g-2-way-Splitter-5-1000mhz-Sv2g/dp/B003TH36CK
Bear in mind, I mentioned that *as a place to start*. No guarantees. YMMV. The problem may very well lie somewhere else. Good luck !