Characterizing Network Performance for Enterprise Networks

Kurt Tutschku [University of Wuerzburg] and Herbert Baier [InfoSim GmbH]

In your paper we presented a new metric, denoted as "Network Comfort", which is used for evaluating the overall network performance. Network Comfort characterizes the system performance by comparing the instantaneous network performance with best performance seen during network operation so far. Network Comfort maps the system performance to an easy to recognize value in the interval from zero to one (see Attachment). The concept of Network Comfort is similar to "Fun Factor" introduced by Charzinski (2000).

Whereas the Fun Factor represents a more theoretical metric, the Network Comfort is directly suited for network operation and performance management. Using Network Comfort, the network administrator can more rapidly identify bottlenecks and he is therefore capable to react more quickly. Network Comfort is based on Round Trip Time measures using ICMP packets and therefore introduce small additional traffic load in the network. This is especially useful for characterizing performance in networks with small bandwidth links. Furthermore, the concept of Network Comfort exhibits a huge versatility. It can also be extended to application performance measurements. We present an example of "Web Comfort", which characterizes the download performance of a web page.

In our paper we show results from a typical IP-based intranet of a German insurance company where Network Comfort is used in daily operation. The intranet comprises about 300 locations, 600 switches and routers and 12000 personal computer and workstations. Most of the links are 128Kbits ISDN and 2Mbits leased lines. We show how Network Comfort is used to visualize performance degradation and to identify network bottlenecks.

Literature: J. Charzinski, "Fun Factor Dimensioning for Elastic Traffic", Proc. ITC Specialist Seminar on IP Traffic, Monterey, CA, USA, Sep. 2000.