[Asterisk-Users] Sipura SPA-3000 and PSTN dtmf

[Vahan Yerkanian]

Greetings,

What is the recommended settings for using SPA-3000's FXO port for 
dialing out to PSTN in regard of the DTMF?

The voip lan contains SPA-2100 and SPA-3000, with all fxs/fxo ports 
registered to the Asterisk box with unique username/passwords.

The inbound PSTN DTMF works excellently, e.g. people calling from PSTN 
into the * box are able to pick IVR items with DTMF reliably.

The problem manifests itself when you attempt to place a call via 
SPA-3000's FXO into PSTN to a different IVR system and try to navigate 
its menu. Audibly, the other end hears very short DTMF bursts with short 
silence afterwards, as like SPA-3000 detects a DTMF, mutes it and sends 
rfc2833 or whatever. Obviously, the burst is short enough to be ignored 
by the remote IVR system (similar Asterisk/SPA-3000 setup).

The relevant settings in the SPA-3000/2100 config for DTMF are set to 
'Auto' setting.

The relevant lines in sip.conf:

;-------
[general]
;irrelevant lines removed
dtmfmode=rfc2833
disallow=all
allow=alaw
allow=ulaw
allow=g729

[111]
;SPA-3000 FXO port
type=friend
username=111
secret=xxx
host=dynamic

[112]
;SPA-3000 FXS port
type=friend
username=112
secret=xxx
host=dynamic

[113]
;SPA-2100 FXS1 port
type=friend
username=115
secret=xxx
host=dynamic

[114]
;SPA-3000 FXS2 port
type=friend
username=114
secret=xxx
host=dynamic
;-------


Should I instead split the SPA-3000's FXO entry into a type=user and 
type=peer entries with the first having dtmfmode=rfc2833 and second 
dtmfmode=inband?

Which is the proper way of sending inband dtmf over g711 into the PSTN?


Awaiting assistance and thanks for your time,
Vahan