We have been using a voice over IP line for our business in Mexico via a 1Mb cable modem connection. Recently the calls have been choppy. I have tested the bandwidth and the latency (100 ms to Yahoo server in US) and they seem fine. However, I have been running a trace and there is packet loss of 10-50% on almost every hop (17 hops on average) to Yahoo's US server. We are connected via a netware 24-port 10/100 switch which is connected into a Vonage VOIP appliance which is connected into a motorola cable modem. I have a similar setup at my home in Mexico and experience great call quality and minimal packet loss. The only other relevant information is they recently put a filter on our cable modem, with the hopes of improving the quality, it does not seem to have worked I guess.
If anyone could help map out what I should do to test and find the source of this packet loss problem, that would be great.