How to find the time taken to send data across UDP

I have a simple 开发者_如何学运维UDP client server written in C++ on Ubuntu 9.10 where the client sends a set to the server. How can I check how much time s it taking to sent it. I need to find the time from start of transfer to end.

Supposing my server and client are on the same machine then can I somehow save the system time and find the difference or something ?

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Setup the server to immediately send a reply to the client. At the client measure the round-trip time. The time you are looking for is half the round-trip time.

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If you are asking how long it takes for the packet to arrive at the server, there is no built in way to get that information.

If the server sends a reply, you can time how long it takes between sending the request and getting the reply and divide by 2 (not accurate, but a decent estimate).

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You could put the time you sent the packet at in the beginning in every packet. In other words, you could create a custom header for all of your packets that would include this information.