[Asterisk-Users] Cisco's description of echo

[Chris Mason]

>Another common problem that causes echo in networks is not setting your
loss plan correctly.    You need to be sure that you aren't coming in too
hot at any of your analog interfaces.   In general you should see a signal
between -20dbm and -12dbm when someone is talking on the line.   If it is
significantly hotter then you run the chance of having a larger reflected
signal resulting in echo.   I typically try padding down analog levels by
3dB at a time to see if echo is reduced.   


How do you measure the amplitude of a pstn line? As an audio engineer in a
previous life, I would love to be able to send standard level tones down a
pstn line and measure the amplitude at my end, then adjust the input gain
accurately. Is there a way to do this?


Chris Mason
US Number: (646)722-0001 US Fax (815)301-9759
Skype: netconcepts