Grandstream Networks HT502 , is considered Flash.

Grandstream Networks, Inc. HT-502 User Manual Page 23 of 31
Firmware 1.0.0.29 Last Updated: 01/2007
Use # as Dial Key Allows users to configure the “#” key as the “Send” (or “Dial”) key. If set to
“Yes”, “#” will send the number. In this case, this key is essentially
equivalent to the “(Re)Dial” key. If set to “No”, this “#” key can be included
as part of number.
Subscribe for MWI Default is No. When set to “Yes” a SUBSCRIBE for Message Waiting
Indication will be sent periodically.
Send Anonymous If this parameter is set to “Yes”, the “From” header in outgoing INVITE
message will be set to anonymous, blocking Caller ID.
Special Feature Default is Standard. Choose the selection to meet some special
requirements from Softswitch vendors.
Preferred Vocoder The HT–502 supports up to 5 different Vocoder types including G.711 A-
/U-law, GSM, G.723.1, G.729A/B. The user can configure Vocoders in a
preference list that will be included with the same preference order in SDP
message. The first Vocoder is entered by choosing the appropriate option
in “Choice 1”. The last Vocoder is entered by choosing the appropriate
option in “Choice 8”.
G723 Rate Defines the encoding rate for G.723 vocoder. By default, 6.3kbps rate is
chosen.
iLBC Frame Size Sets the iLBC frame size in 20ms or 30ms
iLBC Payload type Defines payload type for iLBC. Default value is 97. The valid range is
between 96 and 127.
G726-16 Payload type Default value is 98. Range is from 96 to 127.
G726 - 24 Payload type Default value is 99. Range is from 96 to 127.
G726 - 32 Payload type Default value is 100. Range is from 96 to 127.
G726 - 40 Payload type Default value is 103. Range is from 96 to 127.
G729E payload type Default value is 102. Range is from 96 to 127.
VAD Default is No.
Fax Mode T.38 (Auto Detect) FoIP by default, or Pass-Through (must use codec
PCMU/PCMA)
Jitter Buffer Type Select either Fixed or Adaptive based on network conditions.
Jitter Buffer Length Select Low, Medium or High based on network conditions.
SLIC Setting Dependent on standard phone type (and location)
Caller ID Scheme • Bellcore/Telcordia
• ETSI-FSK
• ETSI-DTMF
• SIN 227 - BT
• NTT Japan
Polarity Reversal Default is No. If set to “Yes”, polarity will be reversed upon call
establishment and termination.
Hook Flash Timing If the timing is shorter than “minimum”, it is considered Ignore.
If the timing is longer than “minimum” but shorter than “maximum”, it
is considered Flash.
If the timing is longer than “maximum”, it is considered Hand-up.
Gain Handset volume adjustment. RX is for receiving volume, TX is for
transmission volume. Default values are 0dB for both parameters.
Loudest volume: +6dB Lowest volume: -6dB.
Call Progress/ Ring
Tones
Configure ring or tone frequencies according to preference. By default
tones are set to North American frequencies. Frequencies should be
configured with known values to avoid uncomfortable high pitch sounds.