Grandstream Networks HT502 - Page 4

4
Allow Incoming SIP Messages from SIP Proxy Only: Yes
Preferred DTMF method: (in listing order)
Priority 1:
RFC2833
Priority 2:
In-audio
Priority 3:
SIP INFO
Enable Call Features: No
Preferred Vocoder: (in listed order):
Choice 1:
PCMU
Choice 2:
G729
Choice 3:
PCMU
Choice 4:
PCMU
Choice 5:
PCMU
Choice 6:
PCMU
Then click ‘Apply’ button at the bottom