Tracert lets you determine, exactly where the bottleneck is, e.g. maybe at 57th Street, maybe at Hunter, maybe somewhere else. Then I call up QVT or Telnet. Each of them ask for two pieces of identification. The rest is the same as before. With telnet you connect to a remote computer and you need to have a user account on that computer to get in.
Nothing changes here.
If you are more adventurous, consider using a Windows based telnet program. This concerns the so-called terminal emulation. The default setting usually works best. I then ask for the acs menu. It does not depend on which ISP you use.