Welltech WG26xx Series V.1.08a - Manual (Page 45)

26xx Technical Manual EN-V108
44
3.4 Advanced Configuration
3.4.1 System setting
prack PRACK is defined in RFC 3262:
Reliability of Provisional Responses in
SIP. You can accommodate your
softswitch (Proxy Server) to Enable or
Disable this feature.
ROH Tone(FXS only) Receiver-Off-Hook (ROH) Tone
A ROH tone is sent to the subscriber to
inform him that his receiver is
off-hook.
You can Enable/Disable this option.
Enable: using default setting or
custom setting.
Send billing signal (FXS only) Enable Polarity Reversal for FXS as
billing signal or not. When a FXS calls
to VOIP and answered by the VOIP,
26xx will generate reverse signal to
FXS as billing start. When VOIP side
disconnect first, 26xx will reverse back