Grandstream Networks HT881

Disable Line Echo Canceller (LEC)
Disables the LEC per call base. Recommended for Fax/Data calls.
Default isNo.
Ring Frequency
Customizes ring frequency.
Valid options: 20Hz – 25Hz. Default is20Hz.
FSK Caller ID Minimum RX Level
(dB)
Sets the minimum signal level required to detect and receive FSK Caller ID information accurately.
The valid range is -96 - 0dB. Default -40dB
FSK Caller ID Seizure Bits
Represents the number of bits used to detect the start of a Caller ID transmission.
The valid range is 0 - 800 bits. Default 70
FSK Caller ID Mark Bits
Represents the number of bits used to identify the caller's mark frequency during Caller ID transmission.
The Valid range is 1 - 800 bits. Default 40
Caller ID Transport Type
Refers to the method used to transmit Caller ID information, which can be:
● Relay via SIP Form: Caller ID information is transmitted using the "From" eld in the SIP header.
● Relay via P-SIP Asserted identity: Caller ID information is transmitted using the "P-Asserted-Identity"
header in the SIP message.
● Relay via P-SIP Preferred identity: Caller ID information is transmitted using the "P-Preferred-Identity"
header in the SIP message.
● Send Anonymous: Caller ID information is transmitted using the "P-Asserted-Identity" header in the SIP
message.
● Disable: Caller ID information is transmitted using the "P-Asserted-Identity" header in the SIP message.
Set to Relay via SIP Form by Default.
Send Hook Flash To PSTN
Refers to the capability of sending a signal to the Public Switched Telephone Network (PSTN) to simulate a
hook ash during a call, typically used to access certain telephony features or services.
Hook Flash Duration (ms)
Refers to the time duration, measured in milliseconds, for which the hook ash signal is transmitted to the
Public Switched Telephone Network (PSTN) during a call, typically used to trigger specic telephony features
or services.
Call Settings
Auto Send DTMF Upon Call Start Enables the option to automatically sends DTMF tones when a call starts.
Early Dial
Sends an early INVITE each time a key is pressed when a user dials a number. Otherwise, only one INVITE is
sent after full number is dialed (user pressesDial Keyor after “no key entry timeout” expires).
This option should be used only if there is a SIP proxy is congured and supporting “484 Incomplete Address”
responses. Otherwise, the call will likely be rejected by the proxy (with a 404 Not Found error). Default isNo.
This feature is NOT designed to work with and should NOT be enabled for direct IP-to-IP calling.
Dial Plan Prex Adds specied prex to dialed number.
Dial Plan Dial Plan Rules:
1. Accept Digits: 1,2,3,4,5,6,7,8,9,0 , *, #, A,a,B,b,C,c,D,d
2. Grammar:x– any digit from 0-9;
a. xx+– at least 2 digits number;
b. xx– exactly 2 digits number;
c. ^– exclude;
d. .– wildcard, matches one or more characters
e. [3-5]– any digit of 3, 4, or 5;
f. [147]– any digit 1, 4, or 7;
g. <2=011>– replace digit 2 with 011 when dialing
h. <=1>– add a leading 1 to all numbers dialed, vice versa will remove a 1 from the number dialed
i. |– or
j. Flag T when adding a “T” at the end of the dial plan, the phone will wait for 3 seconds before dialing out. This
gives users more exibility on their dial plan setup. E.g. with dial plan 1XXT, phone will wait for 3 seconds to let