VOIP round-trip delay?

[matthijsNL]

Hallo everybody,

I would like to measure the "roundtrip delay" to my 3COM NBX VOIP gateway.

Can i use the ping command for round trip measurement? What packet size must I use to simulate a VOIP packet?

Kind regards

Matthijs

 

[ISDNman]

If you want the actual audio round trip delay you need to include the codecs.

To do this use a digital dual trace oscilloscope and a tone. Hook on trace to the sending side and one side to the recieve side. Send the tone. Shut the tone of and then hit freeze on the scope.

Using the cursers on the scop highlight where the tone ends on one trace and put the other cursor where the tone ends on the other trace and read off msecs.

Good luck

 

[matthijsNL]

Thank you. I've already read about it at:

http://www.protocols.com/papers/voip2.htm

But with a ping-tool for my IP-phone to the VOIP-gateway i can determine aproximately the round-trip delay?

-ping <ip_number_voip_gateway>
-size of voip packet 150 bytes
-If i know the average duration voip-packet i can
aproximately determine the latency per packet?