Grandstream Networks HT881

Outgoing Call Duration Limit Denes the call duration limit for the outgoing calls. Default is 0 (No limit).
Incoming Call Duration Limit Denes the call duration limit for the incoming calls. Default is 0 (No limit).
FXO Termination
Enable Current Disconnect
This value should be used in case the PSTN provider uses line power drop to indicate call completion to the
end point. In this case the HT841/HT881 will search for a power drop.
Current Disconnect Threshold (ms)
This is a precongured value of duration for a line power drop used by specic service providers. For example,
for a congured value of 500ms the device will ignore any random voltage drops on the line if duration of such
drop is less than 500ms and the call will NOT be considered as terminated. This is useful to prevent
unnecessary call drops in some low quality PSTN lines. Default is 100 ms. Range from 50 to 800 ms.
Enable PSTN Disconnect Tone
Detection
If set to Yes, arrived Busy Tone is used as the disconnect signal.
Default is "No"
Enable Polarity Reversal
This should be set to Yes only if the FXO lines are subscribed to PR service from PSTN Service provider. It is
merely a PR detect feature. Default is No.
Note: If there is no PR service from provider on the FXO line, and this setting is congured to Yes, calls will not
be successful.
Polarity On Answer Delay
Determines the delay in milliseconds before polarity reversal signaling is initiated upon answering an FXO call.
Range 200-30000 milliseconds. Default value 1000 milliseconds
AC Termination Model
You can select the AC termination by Country or by Impedance.
Default is Country-based.
Country-based
Selects the impedance used by the PSTN service provider
15 Countries are selectable in this version of the F/W.
USA
AUSTRIA
AUSTRALIA/NEW ZEALAND
BELGIUM
CHINA
FINLAND
FRANCE
GERMANY
GREECE
ITALY
JAPAN
NORWAY
SPAIN
SWEDEN
UK
Default is USA
Impedance-based Select the Impedance used by the PSTN service provider.
600R – 600 ohms
600C – 600 ohms + 2.16uF
900R – 900 ohms
900C – 900 ohms + 2.16uF
COMPLEX1 – 220 ohms + (820 ohms || 115nF)
COMPLEX2 – 270 ohms + (750 ohms || 150nF)
COMPLEX3 – 370 ohms + (620 ohms || 310nF)
COMPLEX4 – 600R, 270 ohms + (750 ohms || 150nF)
COMPLEX5 – 320 ohms + (1050 ohms || 230nF)
COMPLEX6 – 350 ohms + (1000 ohms || 210nF)
COMPLEX7 – 200 ohms + (680 ohms || 100nF)
COMPLEX8 – 370 ohms + (820 ohms || 110nF)
COMPLEX9 – 275 ohms + (780 ohms || 115nF)