Network time synchronization using clock offset optimization

O. Gurewitz, I. Cidon, M. Sidi

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

19 Scopus citations


Time synchronization is critical in distributed environments. A variety of network protocols, middleware and business applications rely on proper time synchronization across the computational infrastructure and depend on the clock accuracy. The "network time protocol" (NTP) is the current widely accepted standard for synchronizing clocks over the Internet. NTP uses a hierarchical scheme in order to synchronize the clocks in the network. In this paper we present a novel non-hierarchical peer-to-peer approach for tune synchronization termed CTP - classless time protocol. This approach exploits convex optimization theory in order to evaluate the impact of each clock offset on the overall objective function. We define the clock offset problem as an optimization problem and derive its optimal solution. Based on the solution we develop a distributed protocol that can be implemented over a communication network and prove its convergence to the optimal clock offsets. For compatibility, the CTP may use the exact format and number of messages used by NTP. We also present methodology and numerical results for evaluating and comparing the accuracy of time synchronization schemes. We show that the CTP substantially outperforms hierarchical schemes such as NTP in the sense of clock accuracy with respect to a universal clock, without increasing complexity.

Original languageEnglish
Title of host publicationProceedings - 11th IEEE International Conference on Network Protocols, ICNP 2003
PublisherInstitute of Electrical and Electronics Engineers
Number of pages10
ISBN (Electronic)0769520243
StatePublished - 1 Jan 2003
Externally publishedYes
Event11th IEEE International Conference on Network Protocols, ICNP 2003 - Atlanta, United States
Duration: 4 Nov 20037 Nov 2003

Publication series

NameProceedings - International Conference on Network Protocols, ICNP
ISSN (Print)1092-1648


Conference11th IEEE International Conference on Network Protocols, ICNP 2003
Country/TerritoryUnited States


  • Clocks
  • Protocols
  • Synchronization

ASJC Scopus subject areas

  • Computer Networks and Communications
  • Software


Dive into the research topics of 'Network time synchronization using clock offset optimization'. Together they form a unique fingerprint.

Cite this