Characterizing the Impact of Congestion in Modern HPC Interconnects. - Lorenzo Piarulli; Marco Faltelli; Dirk Pleiter; Karthee Sivalingam; Dancheng Zhang; Kexue Zhao; Matteo Turisini; Francesco Iannone; Aldo Artigiani; Daniele De Sensi (CoRR, 2026)