how can I get exact travel time from server to client in miliseconds of each live data I am getting while testing Websocket API... I am using postman to connect API and to fetch live data feed...and jmeter to get avarage response time ?
i am taking jmeter average response time as respone time for each data ...
JMeter's "average response time" is basically arithmetic mean: sum of all response times divided by their count.
Check JMeter Glossary for metrics descriptions and Calculator source code to see the formulae.
Also you can get rid of Postman completely, JMeter can be used for testing the WebSockets including load testing with a plugin: JMeter WebSocket Samplers - A Practical Guide