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IP Quality of Service (IPQos) In the area of integrated services we have focused our initial efforts on test and instrumentation tools to foster early
experimentation with emerging IETF signaling, routing, and transport protocols for real-time traffic. Our tools address the gap between the capabilities of new network services and the requirements and
capabilities of new and existing applications. Two of the most difficult aspects of engineering performance sensitive applications are (1) being able to realistically test and measure the behavior of
such applications in a controlled laboratory environment, and (2) understanding how to map application requirements to new, real-time network services. To address the first issue, we developed the NIST Network Emulation Tool (NIST Net) that enables experimentation with arbitrary IP network performance dynamics in a simple
laboratory setting. The tool allows developers to use inexpensive PC components to experiment with bandwidth, delay, congestion, and corruption dynamics commonly experienced in large, wide area networks (e.g., the
public Internet) and new subnetwork technologies (e.g., xDSL, cable modems). To address the second issue staff members developed the Integrated Services Protocol Instrument (ISPI). The ISPI
tool enables one to measure the performance of real-time data streams transmitted over IP networks and to experiment with resource reservations without modifying existing applications. ISPI is capable of measuring
in real-time the performance seen by applications distributed at various points in the network and to dynamically adjust the real-time attributes of the underlying network service. |
