ART refers to Application Response time and the ART report helps identifying the most latent applications in the network based on their response times. The report shows client packets, server packets, transactions, retransmission, new connections, responses and traffic. Drilling down a particular application shows the following graphically:
You have to configure the Cisco devices to export the ART information to the NetFlow Analyzer server to get the statistics. You can get the detailed information on ART based on each NBAR2 application exported by the device.
You can drill down each NBAR 2 application and get the details information on Client Packets, Server Packets, Retransmissions, Transactions, Connections, Responses and Traffic.
Application Response Time is only supported for Cisco ASR and ISRG2 routers. Please refer the below link to configure ART is ASR routers: