# Pseudo-Separation for Assessment of Structural Vulnerability of a Network

## TL;DR

This paper introduces pseudocut problems as a new way to assess network vulnerability by analyzing how network functionality is affected when nodes are sufficiently separated, with applications in communication networks.

## Contribution

It generalizes classical cut problems, analyzes their computational complexity, and provides approximation algorithms with practical evaluation for network vulnerability assessment.

## Key findings

- Pseudocut problems are broadly relevant to network reliability.
- Three approximation algorithms are proposed for pseudocut problems.
- Experimental evaluation demonstrates the utility of the algorithms in communication networks.

## Abstract

Based upon the idea that network functionality is impaired if two nodes in a network are sufficiently separated in terms of a given metric, we introduce two combinatorial \emph{pseudocut} problems generalizing the classical min-cut and multi-cut problems. We expect the pseudocut problems will find broad relevance to the study of network reliability. We comprehensively analyze the computational complexity of the pseudocut problems and provide three approximation algorithms for these problems. Motivated by applications in communication networks with strict Quality-of-Service (QoS) requirements, we demonstrate the utility of the pseudocut problems by proposing a targeted vulnerability assessment for the structure of communication networks using QoS metrics; we perform experimental evaluations of our proposed approximation algorithms in this context.