[asterisk-users] SPA 3000 won't relay DTMF to doorphone

[Eric "ManxPower" Wieling]

Doug Crompton wrote:
> The spa3000 does not play well with Asterisk with dtmf rfc2833 signaling.
> Set BOTH the sip.conf AND the spa3000 to inband for DTMF. That would be
> the line1 tab on spa3000. This applies to the fxo (pstn) also if you are
> using it for such things as ivr's.

This will only work if you are using ULAW or ALAW codecs.  All other 
codecs will distort inband DTMF.