was it from the client to the server or the other way around? 4172 is the pcoip protocol so it sounds like regular View trafic
you can control the PCOIP traffic by:
1- AD template of "View PCoIP General Session Variables"
View PCoIP Session Variables – pcoip.adm – Contains policy settings related to the PCoIP display protocol.
View PCoIP Client Session Variables – pcoip.client.adm – Contains policy settings related to the PCoIP display protocol that affect Horizon Client for Windows.
2- minimize the Scanning , printing and Multimedia (HD multimedia , YouTube )
use printer , USB and scanner redirection as it will compress the files
3-disable Audio, Analog audio, HD audio in Wyse thin/Zero client which is enabled by default