You did not say what the Verizon Field techs 'found' as to a problem. What did they find to make them determine to change out the ONT's? (They usually would not without obvious issue.) Which model of ONT do you have? What are your cable configurations? Any switch or hubs in the mix? Did they swap routers? You did not specifically mention running any TCP\IP Optimizers, only the speed tests. Do you have an ethernet connection to the router from the ONT or just a coax? As a test, have you tried using new cables? If you do not have ethernet to the router from the ONT, have you asked to have the ethernet port enabled on the ONT so you can try running a cable from there to your router to test that type of connection? When the field tech(s?) came out and used their own laptops to test, didn't they find that "all was well?" What are you trying to upload? How much data at a time? What size files? Are you always attempting to upload to the same sight? Is the sight \ the sites you are attempting to upload to restricting you in any way? Are they filtering your upload? If 'degradation of the good' is occurring, with enough information, this issue can be resolved. My knowledge of this process tells me several things: IF Verizon did change an ONT, and especially if more than once, they either HAD to find something in their network to be 'an issue', or they were going way beyond business requirements to please the customer, AND once they started this process they would not have just left telling you that although they have found something in their network, they just can't fix it. If a point is realized where all is working at acceptable metrics, as you admit that it is, but then only a part of the whole is degraded over time, but the Verizon network is still checking-out good, it has to be local. It may be the actiontec router, if that is what you are using. But if they gave you a new one to attempt to fix your issue and it still occurs, it could be a defect in the design of the same router that works for everybody else that uses it, or, it most likely would be something on your computer. You mentioned several PC's and a MAC, including a fresh install on a PC. As a person who has been building and\or maintaining and\or repairing hardware and\or software and\or networks for over 30 years, I can tell you that it is almost impossible to guarantee that any two or more computers that have been in use are ever going to be exactly the same at the same point in time, so the point of view that "if it works on one it should also work on the other" is way outdated. Turning that around, though, is not to say that if it's not working on one, it shouldn't work on the others As a person who investigates the pros and cons of choosing one service provider over another, I can tell you that Verizon is not in the business of maintaining or fixing computers, only the network to your house for those computers to access the internet. I believe that in some areas they have rolled out a premium service where maintaining\fixing your computers is available, called Expert Care, but that is a service contracted out to Fire Dog, at Circuit City, I believe. With that said, you absolutely have to diligently scan your computers for viruses or other bugs. Lately I like to regularly run the smitfraudfix.exe in safe mode, then run several updated anti-virus and anti-spyware programs before I KNOW my systems are “clean”. As to a fresh install, well, that absolutely requires that the most updated service packs and patches are installed and again updated (sp3 is not required in XP, but sp2 is a requirement in XP) before you can test it. Also, and perhaps the fix for this, try rebuilding your TCP\IP stacks.