Embodiments provide systems and methods for diagnosing a network and identifying problems in a network which reduce the data transfer rate of data through the network. One embodiment of a method for network diagnosis may include infusing data into a network upstream and downstream of a portion of the network relative to a library drive, querying the drive at intervals over time for drive data to determine the data transfer rate at the drive and comparing the data transfer rate of the data infused upstream of the device or network portion with the data transfer rate of the data infused downstream of the device or network portion to determine throughput. By comparing the data transfer rate of data infused upstream and downstream of a network device or network portion, problem devices in a network may be identified.