Resource Dimensioning Through Buffer Sampling

Link dimensioning, i.e., selecting a (minimal) link capacity such that the users´ performance requirements are met, is a crucial component of network design. It requires insight into the interrelationship among the traffic offered (in terms of the mean offered load M, but also its fluctuation around the mean, i.e., `burstiness´), the envisioned performance level, and the capacity needed. We first derive, for different performance criteria, theoretical dimensioning formulas that estimate the required capacity C as a function of the input traffic and the performance target. For the special case of Gaussian input traffic, these formulas reduce to C=M + alpha V, where alpha directly relates to the performance requirement (as agreed upon in a service level agreement) and V reflects the burstiness (at the timescale of interest). We also observe that Gaussianity applies for virtually all realistic scenarios; notably, already for a relatively low aggregation level, the Gaussianity assumption is justified.