When I upgraded my package a few months ago my speeds were fine at 25/25 . Then a few weeks later the download speed gained by 5mbps. Then about last week my upload drastically decreased to 16mbps. I did everything that I can think of to using the tcp optimizer, resetting router, unplugging red plug from battery box, changed ip,
This is not likely on my end but something to do with verizon and my connection.
Just ran a speedtest on the verizon one and got 7.8x mbps. This is insane. No wonder my uploadspeeds to youtube were horrad. I have had this exact same problem when I had a lower tier from verizon. Good speeds when I upgraded thena ll of a sudden slow speeds a few months later. 😐
As others have pointed out the Verizon Speed test is not without its issues. A much more useful test (because it tells you where the limitation are), is the Argonne National Laboratory test.
The other issue I am aware of involves Vista and Windows 7, where the 'receive' window is dynamically adjusted. In the testing I have done, the receive windows does adjust to the traffic, but not very quickly (and not fast enough to impact most speed tests). In one Windows 7 system I look after with 25/25 service, it usually ends up as about 10/10 until I have run the test several times, and the network receive window has finally been expanded to a size more suitable for 25/25 service. The problem is the window size is adjusted based upon actual use, not capability.
Anyway, run the test, and look at results as well as the statistics and 'more information'. The test does a very good analysis of the connection from end to end.