[VoiceOps] Test Numbers

Jay Hennigan jay at west.net
Tue Mar 15 14:35:16 EDT 2022

On 3/15/22 06:51, Mike Hammett wrote:
> Our test equipment vendor (Exfo) has asked us about these capabilities, 
> "milliwatt tone, quiet termination, or silent switchman." I don't know 
> that I've seen the ability to configure those anywhere.
> How would I go about setting that up? I'm assuming that requires that my 
> switch (Metaswitch) and endpoints (Zhone, Grandstream, Calix, Occam, and 
> Innomedia) support them as well. I'm sure I can get platform-specific 
> details from each of the vendors, but I'd like gain a bit of knowledge 
> on that whole process before delving into vendor details.

The test numbers are a function of the switch. The endpoints need no 
configuration or support. To the endpoints, the test numbers are simply 
a dialable phone number like any other.

If Metaswitch doesn't have configurable options for milliwatt and silent 
termination, an Asterisk or similar box can easily do so. This is very 
lightweight and can run on a Raspberry Pi if needed.

The milliwatt is used to test for line loss and level and silent 
termination for hybrid balance.

Essentially these are dialable numbers that in the first case answer 
with a 1004 Hz tone sent at a level of one milliwatt and in the second 
answer with silence matching the line impedance with return loss as high 
as possible.

Jay Hennigan - jay at west.net
Network Engineering - CCIE #7880
503 897-8550 - WB6RDV

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