We describe one of the new activities at the RIPE-NCC. The goal of the project is to measure the delay and packet-loss rate between hosts on the Internet as well as the routes between those hosts. Both the delay and packet-loss rate determine the quality of a connection over the Internet. Our project focusses on obtaining information about the quality of service between Internet Service Providers (ISP's), although the experimental techniques can also be used for measuring the properties of the network of a single ISP. At the moment, the project is still in the beta test phase. some experimental effects still have to be understood. However we have started to to provide ISP's with (almost) real-time information about the performance of their networks. For our project, we developed test-boxes consisting of a PC running the FreeBSD operating system and a GPS-based clock module. The clock module is used to synchronize the local clock with an accuracy of down to 100ns. The software on the boxes can send data packets to other test-boxes. The packets are time-stamped at the application layer by the sending test-box, as well as at the data-link layer of the receiving test-box. From this, one can calculate the time that the packet needed to travel from one box to another. A test on an unloaded network showed that this setup can measure delays with accuracies of the order of 0.01 ms. Not all packets will arrive on the receiving host and by comparing the number of packets sent against the number of packets that arrive, one can determine the packet-loss rate. The software on the test-boxes also determines the path that a data packet follows to travel from one test-box to another. This information is interesting in itself and has already been used to explain changes in the network performance. At this time we have appoximately 20 test-boxes deployed at ISP's participating in this project. In this talk, we will describe the hardware and software of the project in more detail as well as present first results obtained with the test-boxes that have been installed so-far.

Daniel Karrenberg is an active member of both the Unix and Internet communities since the early 80s. He is a co-founder of the German Unix User Group and Reseaux IP Europeens (RIPE). He has been actively involved in the early days of EUnet both on the technical and the organisational side. Daniel started and currently heads the RIPE NCC, an association of more than 1100 Internet service providers, which is charged with coordinating the technical operations of the Internet in Europe and surrounding areas.