Ok. I had this problem early on in my setup and it came down to a few things I needed to modify.
Here are my thoughts on possible issues:
1. NIC. That Realtek NIC really stinks and from the combination of your older system while capable could easily be taking up more than 75% of your PCI us capacity. The Realtek NICs use minimal offload so they are inturrupt heavy and use lots of CPU resources. You can get an Intel Pro PCIe adapter used on ebay or if you look around for $15. It will be 100/1000.
2. MoCA 1.0 - Both of your routers D,E run on the old Moca standard which while it has QoS does not do a good job. I had a pair of Netgear MCAB001 (MocA 1.0) and whenever both were in operation, I would get the Network quality issue. I rectified by running Cat 6 directly to both points. As your basement router is really just for ONT connectivity and the switch for basement, you really can't do much. You could call Verizon and tell them you are having network issues (you are) and they may update it to a modern one w/ GB port which will go well with your Intel NIC. If you go the Intel way you have to turn off flow control. This leaves your Rev D router. You can get a swap from Verizon and see if that helps (pro won't because I have a Rev F which is MoCA1.1 and had the issue. You can get a used AT Moca 1.1 bridge which only serves that purpose. This way you really don't have to configure anything.
Also if they give you a rev I, the switch in it is GB like I said earlier and much more powerful.
The bridge here ($75 for twin pack). You can keep it an use it or sell the other on ebay or CL. People are always looking for them:
»
www.amazon.com/gp/offer- ··· tion=newI would start w/ the Intel NIC (CT Pro) and see if that clears anything up. Worst case for $15 or so you have a modern NIC that you can use in your next system for the next 10 years and it does offload and interrupt management.
If that doesn't help, then try going to MoCa 1.1 adapters and have Verizon get you a newer gateway....
I also had issues and I upgraded to a GB switch, but if you get a newer Actiontec from Verizon then it will be powerful enough.
I would also check your MoCA stats in the router, and try changing channels to see if that helps. I also ALWAYS recommend to cap off any splitter or outlet 100% to minimize MoCA interference.
Example:
»
www.amazon.com/Type-75-O ··· resistorHTH