PingPlotter Tutorial and Product Manual

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Options - Packet Settings

1. The * next to Packet in the navigation pane to the left indicates that you have not "applied" the changes you've made.

2. There are three separate packet types that PingPlotter can use - ICMP, UDP and TCP:

ICMP using the Windows ICMP.DLL. The default method is the standard Windows ICMP.DLL. This is reliable, and it uses the least amount of CPU (on most operating systems). This method will automatically do manual timings on "less than accurate" operating systems like Windows NT in an attempt to get accuracy to 1ms. This method does not require administrative rights, and it should be the first choice for most users.
ICMP using Raw Sockets. This is for advanced use only. In some rare cases, the standard Windows method doesn't work. PingPlotter can compose it's own ICMP packets, although in most cases this is no more reliable or better than ICMP.DLL. This method does require administrative rights on Windows NT, 2000, XP and Windows 2003.
UDP Packets (Unix-Style). This method will sometimes allow you to trace to a destination that isn't reachable via ICMP, or it 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 if you're getting erratic packet loss, or "Destination Unreachable" in PingPlotter's Trace Graph. This method does require administrative rights on Windows NT, 2000, XP and Windows 2003.
TCP Packets (ie: HTTP, etc). This method (new in version 2.60 of PingPlotter) gives you the opportunity to send TCP packets, which can penetrate some firewalls that UDP and ICMP can't. This requires administrative rights, and may also require WinPcap. This method is not supported on Windows 95, 98, ME or NT, so only attempt to use it for Windows 2000, XP, 2003 or higher.

3. This option allows you to fine-tune your performance a little. By default, PingPlotter will wait for 10 seconds for any packet to return. If the packet doesn't return in 10 seconds, then it is counted as a lost packet. If patience isn't one of your virtues, you can turn this down somewhat. No matter what your value is here, timed out packets will show an "ERR".

Because of the performance enhancements offered by PingPlotter, it's unlikely that this option needs to be changed. If it's set too low, it can cause misleading data to be generated. For best results, leave this at 9999.

4. This can be an interesting number to manipulate. It's really meant for advanced users, so you don't need to change it.

For the most part, PingPlotter sends out multiple packets at the same time, and times everything at once. More precisely, it leaves a tiny interval between each packet so you don't completely saturate your bandwidth when it sends out 30 packets. This time interval is adjusted by this parameter. Most of the time, 35ms is good. This falls within the realm of what a 28.8 modem can perform. If you've adjusted your packet size, or your connection to the Internet is really slow, you might want to crank this number up a little. If you have just oodles of bandwidth, you can crank it down a little. Be aware that too small of a number here can adversely affect your data.

5. This adjusts the size of the packet that PingPlotter sends out to the host. Sometimes routers in the path can be adversely affected by packet size. You can play with the packet size if you suspect that one of the routers is incorrectly configured, or is likely to have problems with larger (or smaller) packets.

Having this number too high will greatly affect your performance. It's best to leave this pretty small. Valid ranges are from 10-512 bytes. Actually, anything up to 32K will be accepted, but using a packet size over 512 bytes is just asking for trouble.

Note that setting this too high can cause the final hop in the trace to appear to be responding poorly. This is because all hops before the final one are timing out and returning a small "Timeout" packet, but the final destination will be returning the full data that was sent. Keep this number small for the most consistent response times.

Conversely, if you want to load your connection down a bit, crank this number up. You may get some "interesting" results.

6. This is a TCP/IP packet header field used to set the Type of Service (ToS) and Differientiated Services Code Point (DSCP) bits. This should be set to 0 unless you need to use it.

7. TCP Specific Settings will only be available if you've selected TCP Packets as your packet type. Here you can specify your target port, and also whether you want to use WinPcap (required for later Windows 2000 service packs in some cases and Windows XP SP2). When in doubt use WinPcap, downloadable from the WinPcap site at winpcap.polito.it/install/default.htm.

8. When this switch is on, PingPlotter still uses multiple threads to do tracing, but the looking up of names is done one at a time. When installing onto a machine running Windows NT 3.51, this option is turned on by default. A symptom of having this switch off under NT 3.51 is that PingPlotter stays in memory even after you close PingPlotter, and when you close Windows NT it notifies you that PingPlotter is still running. If you run into this problem, turn this switch on. Having this feature turned on under Windows 95 and up will negatively impact performance.

9. This option controls the thread count for ICMP, or maximum number of oustanding requests for TCP/UDP. Adjust this number down if resource usage is a problem. Adjust it up if you notice some trace periods are being skipped.

10. This is an advanced option that should probably not be changed. It is used to diagnose network problems when specific data is sent, which is a highly unlikely problem for most networks. By default, PingPlotter sends a packet that includes the application name and version of PingPlotter. If you suspect that your network may be having problems when you send specific byte codes, you can enter the hex code that you want repeated, or a link to a file to read the byte string from. The cargo space for the packet will be padded with this data. Use this in conjunction with the packet size to create the network scenario you're looking to duplicate.

11. The Apply button will apply all the changes you've made to the areas marked with an asterisk (*) and not exit the Options area. OK applies those same settings, and then exits out of the Options area. Cancel negates all changes you've made. If you've been making a lot of changes and not "applying" them, this can be a pretty bad thing to do. Conversely, if you want to scrap all your changes and start over again, Cancel is the button for you.