An NQA TCP test uses a three-way handshake to measure the time it takes to set up a TCP connection between an NQA client and a TCP server. Figure 1 illustrates a network on which an NQA TCP test is performed. The NQA TCP test process is as follows:
The NQA client (Device A) sends a TCP SYN message to the TCP server (Device B) to set up a TCP connection.
Upon receipt, the TCP server accepts the request and responds to the NQA client with a TCP SYN Ack message.
The NQA client returns an Ack message to the TCP server, which indicates that a TCP connection has been successfully set up.
The NQA client can calculate the time used to perform the three-way handshake and set up the TCP connection to the TCP server by subtracting the time when the NQA client received the TCP SYN message from the time when the NQA client sent the TCP SYN message and Ack message. The data obtained is used to evaluate the performance of the TCP protocol on the network.