To measure performance of the ATM service, we installed a remotely accessible Fluke OC3port Plus ATM test device permanently in the TransPAC equipment rack at STAR TAP. The OC3port Plus is connected to an interface of the LS1010 switch. A loopback test point was created by defining a pair of VCs from the OC3port interface, through the trans-Pacific PVP and tied together in the Tokyo XP's FORE Systems' Fore ASX1000. A similar loopback testpoint was created to the vBNS ASX1000. These loopback VCs help gauge cell delay, cell-delay variation and cell-loss rates without disrupting the network. This capability is very important because we don't have a nailed-down circuit--the AT&T domestic portion of the VBR-nrt PVP is provided by a cloud network and we must be able to regularly confirm the performance of our PVP through this cloud.

We will use OC3MON to obtain detailed IP flow analysis, which is important for understanding usage patterns and growth trends. OC3MON connects to an OC-3 fiber pair via an optical splitter that carries 5 percent of the light from each fiber to the receive ports of two ATM NICs installed in a standard PC. One of the OC3MON NICs, attached to an OC3 trunk terminated on a switching device, sees all traffic received by the switching device, while the second NIC sees all traffic transmitted by the switching device. IP packet header information is culled from the reassembled AAL5 PDU. IP flow profile information is derived from the packet headers, including basic counters of packets, bytes and flows; analysis by TCP/UDP application type; flow characteristics; packet traces; AS-to-AS matrixes; and heavy-hitter lists.

TransPAC and APAN also will participate in the Common Solutions Group deployment of Surveyor machines, which provide highly accurate measurements of one-way delay and packet loss within a matrix of Surveyor sites. Accuracy of the one-way measurements is achieved via clocking synchronized to the Global Position System. Information about Surveyor can be found at www.advanced.org/csg-ippm.

Multi Router Traffic Grapher (MRTG, ee-staff.ethz.ch/~oetiker/webtools/ mrtg/mrtg.html) collects and reports switch and router statistics. MRTG is easy to implement and provides a wonderful means of collecting and presenting SNMP-based information, such as utilization, loss and errors, graphically via the Web. One shortcoming with MRTG is that it progressively summarizes the data over time, losing more of the raw detail as the days are rolled into weeks, the weeks into months and the months into years. We're now developing custom methods to save and retain the raw data.

Moving toward the future, we expect link capacity to grow dramatically and anticipate that new solutions will be required for policy routing and QoS/CoS to support ever-increasing performance requirements, and we're keeping a close eye on the progress of MultiProtocol Label Switching (MPLS) as a solution for these needs.

The authors are employed at Indiana University, where Allen Robel manages network research and development, Doug Pearson manages special projects, and Steven Wallace manages IU Bloomington data services. Send your comments on this article to them at robelr@iu.edu, dodpears@iu.edu or ssw@iu.edu.