Pete,<br><br>An seems to happen if a response packet (time exceeded or reply) is not received before the "Time Interval" is exceeded. The link that I am tracing often has delays from 1500 to 4500 ms and it seems I have to exceed this to ensure PP doesn't get confused about which outbound packet caused this inbound one.<br><br>Cheers<br><br>Frank.<br><br>