It looks like you already have a route change mask set up on hop 3, right? If not, you probably want to add one.

Having an intermediate router show packet loss where downstream routers do not isn't a sign that anything's wrong with this router (or set of routers), just that it doesn't care as much about ICMP as it could. While not entirely normal, this isn't so unusual these days. In most cases, you can "ignore" any packet loss or latency that is added at this router that is not visible in downstream hops.

Now hop 4 does have a tiny bit of latency and packet loss, but not enough to really cause you much greif in your VoIP conversation.

On the other hand, the hop 4 -> hop 5 link has *significant* problems that is almost certainly affecting your VoIP experience. The same packet loss is being reflected downstream as well, although the further you get from this router, the less packet loss, which is a bit interesting.

You might try switching to single-outstanding-request mode (see http://www.nessoft.com/kb/22 for details) just to make sure there's no reporting issue with hop 4/5. This is pretty unlikely, but is a small possibility. It looks like you're using a 1 second trace interval, and that could also be affecting things a bit (some ISPs put rules in place to limit ICMP packet use). Note that I reproduced some of the same information by running from me back to you, though, so I don't think this is much of an issue for you.

More likely is that the link between hop 4 and hop 5 is oversubscribed, is being overused somehow, or has some other problem. You should probably contact your ISP and ask about this packet loss / latency jump. If they are seeing data that is just as acute as you are, they are probably already working on solving this problem.

You probably picked a period that was the worst-case packet loss / latency. Does it get better at different times of day? If you run PingPlotter for 24 or 48 hours, do you see differences based on the time of the day? If so, then you have a pretty strong case that it's a bandwidth limit, or something based on load rather than a hardware failure. Your ISP, setarnet.aw, may need to add additional capacity to solve this problem, or maybe fix some misbehaving hardware.

For a discussion of bandwidth limits / saturation, see http://www.pingplotter.com/tutorial/ScenarioSaturatedPipe.html.

If you want a bit further analysis, post another graph with a bit more time and more samples and we'll comment a bit more on this. In reality, your best bet is to contact your ISP and ask them to explain this problem (focusing on the fact that your VoIP experience is somewhat lacking, and you've used PingPlotter to show where the problem originates, rather than on focusing specifically on the PingPlotter results).

Spyware / adware probably isn't a huge factor here, although it could impact bandwidth use a bit, that probably doesn't represent the majority of network traffic.

- Pete