Packet Forwarding with Swaps

Cameron Matsui, Will Rosenbaum*

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


We consider packet forwarding in the adversarial queueing theory (AQT) model introduced by Borodin et al. In this context, a series of recent works have established optimal bounds for buffer space usage of $$O(\log n)$$ for simple network topologies, where n is the size of the network. Optimal buffer space usage, however, comes at a cost: any protocol that achieves o(n) buffer space usage cannot guarantee bounded packet latency. In this paper, we introduce a generalization of the AQT model that allows for packet swaps in addition to regular forwarding operations. We show that in this model, it is possible to simultaneously achieve both optimal buffer space usage and packet latency when the network is a path of length n. To this end, we introduce an analytic tool we call the smoothed configuration of the network. We employ the smoothed configuration to reason about packet latency for a large family of local forwarding protocols, whereby we derive our main result. We also employ the smoothed configuration to analyze the total buffer space usage of forwarding protocols under stochastic packet arrivals. We show that the total network load is n in its steady state, but that the system takes exponential time in expectation to reach a total load of n.

Original languageEnglish
Title of host publicationStructural Information and Communication Complexity - 30th International Colloquium, SIROCCO 2023, Proceedings
EditorsSergio Rajsbaum, Sergio Rajsbaum, Alkida Balliu, Dennis Olivetti, Joshua J. Daymude
PublisherSpringer Science and Business Media Deutschland GmbH
Number of pages22
ISBN (Print)9783031327322
StatePublished - 2023
Externally publishedYes
Event30th International Colloquium on Structural Information and Communication Complexity, SIROCCO 2023 - Alcalá de Henares, Spain
Duration: 6 Jun 20239 Jun 2023

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume13892 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference30th International Colloquium on Structural Information and Communication Complexity, SIROCCO 2023
CityAlcalá de Henares


  • adversarial queueing theory
  • buffer space usage
  • packet forwarding
  • packet latency
  • packet swaps


Dive into the research topics of 'Packet Forwarding with Swaps'. Together they form a unique fingerprint.

Cite this