Time Transfer and Clock Synchronization Analysis over Spine-Leaf Networks Ortega Ruíz, Alberto Vázquez Rodríguez, Víctor Megías Núñez, Carlos González Peñalver, Jesús Rodríguez Álvarez, Manuel Díaz Alonso, Javier Ros Vidal, Eduardo Spine-Leaf PTP Datacenter This work was supported partially under AMIGA-8 grant (PID2021-123930OB-C22) funded by the Spanish Ministry of Science, Innovation, and Universities; partially under DAIS grant (No. 101007273-2 within the ECSEL Calls and PCI2021-121967) funded by MCIN/AEI /10.13039/501100011033 and EU NextGenerationEU/ PRTR; partially under INTARE grant (TED2021-131466B-I00), funded by MCIN/AEI /10.13039/501100011033 and the European Union NextGenerationEU/ PRTR; partially under Ayudas para contratos predoctorales para la formacion de doctores/as 2022 (PRE2022-103110) funded ´ by MCIN/AEI /10.13039/501100011033 and ESF+; and partially by the Formacion de Profesorado Universitario (FPU20/05842 and FPU20/01857) funded by MCIN/AEI /10.13039/501100011033. The integration of a time synchronization and time transfer system in data center networks is an increasingly common demand. Since moving the entire infrastructure of a data center network to switches with time-dedicated hardware is nowadays a considerable expense of resources, it is convenient to analyze and study it. In this paper we work on real hardware, presenting a characterization of the problem for a Spine-Leaf network by means of load variation tests proposed by the ITU, using the PTP protocol and common non-PTP aware switches. Through this study we manage to show, thanks to real measurements, the problem of dynamic asymmetry and how it affects the time distribution. Additionally, it is shown that if the network load is quadrupled, the PTP pk-pk offset through the network does not even double. Finally, thanks to long-term tests, we can conclude that time synchronization in a Spine-Leaf network shows considerable resilience to load changes. 2026-03-03T12:39:36Z 2026-03-03T12:39:36Z 2024-10 conference output Ortega Ruíz, A.; Vázquez Rodríguez, V.; Megías Núñez, C. [et al]. (2024). Time Transfer and Clock Synchronization Analysis over Spine-Leaf Networks. IEEE International Symposium on Precision Clock Synchronization for Measurement, Control, and Communication (ISPCS), Tokyo, Japan, 2024, pp. 1-6, doi: 10.1109/ISPCS63021.2024.10747714 https://hdl.handle.net/10481/111849 10.1109/ISPCS63021.2024.10747714 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Institute of Electrical and Electronics Engineers