Systems and methods for measuring round trip time in network devices between the device and an endpoint

Abstract

The present disclosure is directed towards systems and methods for measuring round trip time (RTT) in network devices between the device and an endpoint. A network device may be deployed as an intermediary to provide many security and visibility functions. For measuring the server side RTT between the network device and host, the intermediary device identifies the packet that has been sent by the client when it initiated the RTT measurement. The network device remembers the moment T1 when it sees this packet. The host (e.g., the server) will respond to this with a packet that contains the response. The intermediary device remembers the moment T2 when it sees this response. Server side RTT is calculated by the network device as T2−T1. For measuring the client side RTT the network device and client, the intermediary device identifies the packet that the host sends to initiate measurement of RTT. As per the HDX protocol, the client will respond immediately with a new packet or with a bit set in any packet being sent to the host. Just as for server side RTT, the intermediary device can identify these packets and measure the times to calculate the client side RTT.