Structured in two sections, this training will be dedicated to both the performance of the network (monitoring,troubleshooting, measurements and optimisation) and to the effect of the end-host in the assessment of the performances and the overall perception of the network behaviour. The training will begin with the end-host. The concept of virtualiziation and how to improve a VM performance will be introduced. Right after the bare-metal performance will be analysed and discussed. In the second part of the event an overview of the current monitoring and troubleshooting strategies (including perfSONAR) will be presented considering different approaches: starting from the problem experienced by the user down to the analysis of the hardware failures or starting from monitoring hardware components up the problems experienced by the users.