Grandstream Networks HT881

FXS Port
COMPLEX10 – 120 ohms + (820 ohms || 110nF)
Default is 600R – 600 ohms
Number of Rings
The FXO port will ring the number of times congured in this eld before sending the call to the VoIP side. The
supported range is 1-50. Default is 4.
PSTN Ring Thru FXS If set to yes, all incoming PSTN calls will ring the FXS port after the Ring Thru Delay timer is reached.
PSTN Ring Thru Delay (sec)
If the PSTN Ring Thru Delay is set to Yes, all incoming PSTN calls through FXO will ring the phone connected
to the FXO port, after this delay or after caller id is detected (whichever comes rst).
PSTN Ring Timeout (sec)
Range is 2-10 seconds. Default is 6 seconds. Option is used to detect PSTN hang up when FXO port is not
answered.
PSTN Idle Wait Timeout between
Outgoing Calls
Used to customize timeout value between PSTN outgoing calls. Range is 0-10 seconds. Default is 4 seconds.
PIN for VoIP-to-PSTN Calls
Requires users to enter a Personal Identication Number (PIN) before making calls from VoIP to the traditional
Public Switched Telephone Network (PSTN) to enhance security and prevent unauthorized usage.
PIN for PSTN-to-VoIP Calls
Requires users to enter a Personal Identication Number (PIN) before initiating calls from the traditional
Public Switched Telephone Network (PSTN) to the VoIP network, ensuring secure access and preventing
unauthorized usage.
Enable Early Media for VoIP-to-
PSTN Calls
Only for calls without 2 stage dialing but with polarity reversal enabled. Default No
Chaneel Dialing
DTMF Digit Length (ms)
Digit length and Dial Pause are port digit dialing congurations; FXO needs to dial out digits for VoIP to PSTN 1
stage calls, and unconditional call forward to PSTN, and route to PSTN. Digit Length is the play time for each
digit.
Note: In order to receive the caller ID information, the delay should be set to a value larger than the delay
required to complete the PSTN caller ID delivery.
DTMF Dial Pause (ms) Dial pause is the time between 2 digits for the same scenario as explained above.
First Digit Timeout (sec)
Used for PSTN to VoIP calls. PSTN users need to enter the FIRST digit within the rst digit timeout period.
Otherwise the call will be dropped.
Range 1-20 seconds. Default 10 seconds
Inter-Digit Timeout (sec)
Sets the time in seconds before the gateway considers a sequence of dialed digits complete.
1-15 seconds. Default 4 seconds
Wait for Dial-Tone
Determines whether the FXO gateway waits for a dial tone before initiating dialing.
Disabled by default.
Stage Method (1/2) This conguration is applicable for VoIP to PSTN calls and indicates one or two stage dialing methods.
Min Delay Before Dial PSTN Number
The time to wait before HT841/HT881 initiates the call via PSTN line.
Default 500ms, range is from 50 to 65000ms.
FXS Port
Displays the specifc port number.
Note: The HT8x1 supports only one FXS port