After changing my network architecture, I am unable to use Skype 2.0 because it generates a roughly 1.5 second-delayed echo that makes conversation impossible. The words of the party dialed come in garbled, echoed bursts, followed by silence.
I have already contacted Skype's technical support (weak though it is), but their suggestions were fruitless and aimed at the most basic problems (I used the same headphone-mike setup before and after the problem started, and Skype configuration changes made no difference).
Before the problem started, my Internet (cable) connected to a cable modem, which went to a 2-port hub, which went to a Windows XP SE2 PC running Skype 2.0 (latest version).
The problem started after switching to optical fiber, so that the internet arrives by optical fiber connected to an optical modem, which runs into a Belkin pre-N router (used only in LAN-cable wired mode, not wireless), which runs into a 16-port hub, which runs to my PC via LAN cable. The length of the LAN is about 450 feet/170 meters of Class 6 cable.
If I connect my PC directly to the router (bypassing the hub), the problem still exists but the echo is shorter. If I connect my PC directly to the optical modem, I don't get an internet connection.
I am dialing the same overseas numbers before and after the problem. The problem exists whether I use an IBM PC or a Dell PC, both of which had no problem before the system architecture change. These are not conference conversations. The problem exists whether I dial a person or a recording, a toll or a toll-free number on the other side.
The optical fiber ISP, Belkin and the hub manufacturer all claim their equipment is VoIP compatible.
Useful suggestions on how to eliminate the echo in Skype would be appreciated.