I have to question the above.
Based on studying up on the subject, and some practical usage, I'm of the opinion that echo is rarely if ever at all caused by the digitized part of a VoIP circuit or route. Network data packets do not repeat or echo like analog voice signals in an analog circuit, like a microphone. And, on the receiving end of the digitized VoIP packet algorithms reconstruct the incoming data in the correct order and do not for example allow overlap, repetition or 'replay' of the same incoming packet. So, for everyone's information, are there any actual examples of why or how the above is a factor in eliminating echo? Note that the above sometimes is a factor in choppy speech, but that is not the same as echo.
In addition, I'll add that the previously mentioned test of doing some calls entirely in the Gmail Call/Chat feature in a browser, there by fully eliminating the Obi device and any analog components, is easier to do that the above reconfiguration of subnets.
