There are four separate (but somewhat similar) packet types that PingPlotter can use.

•        ICMP using Windows DLL.  The default method is the standard Windows ICMP.DLL.  This is reliable with the least CPU usage (on most operating systems).  This method will automatically do manual timings on less-than-accurate operating systems to attempt to get accuracy to 1ms.  This method does not require administrative rights, and should be the first choice for most users.

•        ICMP using Raw Sockets (advanced use only).  In some rare cases, the standard Windows method doesn't work.  <%SHORPRODUCTNAME%> can compose its own ICMP packets - although in most cases this is no more reliable or better than ICMP.DLL.  This requires administrative rights on Windows NT, 2000, XP and 2003.

•        UDP Packets (Unix-Style).  This method will sometimes allow you to trace to a destination that isn’t reachable via ICMP, or might allow you to reach the internet even if your ISP is blocking ICMP echo requests.  Though not the cure-all for "Destination Unreachable" issues, this is worth a try, especially if you’re getting erratic packet loss or unreachable destination.  This requires administrative rights on Windows NT, 2000, XP and 2003.

•        TCP Packets.  This method (new in 2.60) gives you the opportunity to send TCP packets, which can penetrate some firewalls that UDP and ICMP cannot.  This requires administrative rights, and *might* require WinPCap.  This is not supported on Windows 95, 98, ME or NT (ie: 2000, XP, 2003 or higher only).