2688 CHAPTER 176: FAX OVER IP CONFIGURATION COMMANDS
■ Increasing the number of redundant packets will improve reliability of network
transmission and reduce packet loss ratio. A great amount of redundant
packets, however, can increase bandwidth consumption to a great extent and
thereby, in the case of low bandwidth, affect the fax quality seriously.
Therefore, the number of redundant packets should be selected properly
according to the network bandwidth.
■ The passthrough mode is subject to such factors as loss of packet, jitter and
delay, so the clock on both communication sides must be kept synchronized. At
present, only G.711 A-law and G.711 m-law are supported, and the voice
activity detection (VAD) function should be disabled.
Example # Set to 2 the number of high-speed redundant packets sent via the T.38 fax
protocol.
<Sysname> system-view
[Sysname] voice-setup
[Sysname-voice] dial-program
[Sysname-voice-dial] entity 4 pots
[Sysname-voice-dial-entity4] fax protocol t38 hb-redundancy 2
fax train-mode
Syntax fax train-mode { local | ppp }
undo fax train-mode
View POTS/VoIP/VoFR entity view
Parameter local: Adopts the local training mode.
ppp: Adopts the point-to-point protocol (ppp) training mode.
Description Use the
fax train-mode command to configure the fax training mode.
Use the undo fax train-mode command to restore the default.
By default, the PPP training mode is adopted.
n
VoFR entities only support the PPP training mode.
Example # Configure the local training mode for the gateway.
<Sysname> system-view
[Sysname] voice-setup
[Sysname-voice] dial-program
[Sysname-voice-dial] entity 10 pots
[Sysname-voice-dial-entity10] fax train-mode local
