Figure 5 shows the output presented by sting. From the command line the user can select the inter-arrival distribution between probe packets (periodic, uniform, or exponential), the distribution mean, the number of total packets sent, as well as the target host and port. Our implementation verifies that the wire time distribution conforms to the expected distribution according to the tests provided in [PAMM98].
We have tested our implementation in several ways. First, we have synthetically dropped packets in the tool and using an emulated network [Riz97] and verified that sting reports the correct loss rate. Second, we have compared the results of sting to results obtained from ping. Using the derivation for ping's loss rate presented in section 2 we have verified that the the results returned by each tool are compatible. Finally, we have tested sting with a large number of different host operating systems, including Windows 95, Windows NT, Solaris, Linux, FreeBSD, NetBSD, AIX, IRIX, Digital Unix, and MacOS. While we occasionally encounter problems with very poor TCP implementations (e.g. laser printers) and Network Address Translation boxes, the tool is generally quite stable.