Internetworking of DQDB subnetworks: A maximum throughput analysis

Abstract

This paper investigates the throughput performance of a system made up of a number of IEEE 802.6 subnetworks interconnected among each other, in overload conditions. The approach adopted in mode\ling the internet system enable us to leave any technical implementation issue regarding the Interconnection Unit (IU) out of consideration. In this respect, the IU is viewed as a black box characterized by some basic functionalities which may be met by a wide range of interface protocols. An analytical methodology is presented which allows us to solve some relevant design problems. In particular, we show that by non-linear programming algorithms it is possible to determine the best location and protocol of the IU interfaces on condition that the maximum system throughput is achieved. Finally, we provide some numerical examples concerning two identical DQDB subnetworks interconnected by IUs, located at either the middle or the headend of the subnetworks.

On the number of touching pairs in a set of planar curves

“…A family of Jordan arcs in which any pair of curves intersect at most once (apart from the endpoints) will be called a family of pseudo-segments. Our starting point is this conjecture of János Pach [10]: Conjecture 1. Let C be a family of pseudo-segments.…”

Density Theorems for Intersection Graphs of t-Monotone Curves

“…Interestingly, Theorem 1.4 does not hold if one drops the simple condition. That is, there exists a family F of n 1-monotone curves in the plane, with at least n 2 /4 disjoint pairs, such that for any two subsets F 1 , F 2 ⊂ F of size Ω(log n) each, there exists a curve in F 1 that crosses a curve in F 2 [15].…”