Configuring Modem Transmission - Patton electronics SmartNode Series Software Configuration Manual

40 • VoIP profile configuration
Step
3 node (pf-voip)[ name ]# fax dejitter-
(optional) max-delay buffer-size
node (pf-voip)[ name ]#fax volume
Step 4
(optional) volume
5 node (pf-voip)[ name ]# fax max-bit-
(optional) rate { 2400 | 4800 | 7200 | 9600 |
12000 | 14400 }
6 node (pf-voip)[ name ]# fax detection
(optional) { ced-tone | fax-frames }
7 node (pf-voip)[ name ]#no fax error-
(optional) correction
8 node (pf-voip)[ name ]#no fax hdlc
(optional)
Configuring modem transmission
Modem transmission is similar to fax transmission, except that modem data is always transported in bypass
mode. This means that an ordered list of bypass codecs can be defined for modem transmission. If no modem
transmission codec is configured, no action is taken to change the codec when modem is detected.
Procedure: Configure modem bypass
486
Command
SmartWare Software Configuration Guide
Purpose
For proper operation, a dejitter buffer is used on
the receiver. The dejitter period can be set to com-
pensate for the jitter imposed by the network. The
default value is 200ms which should be nominal
for almost any transmission network. Only in
exceptional cases it may be necessary to increase
this value (maximum 400ms). The dejitter buffer,
by default, applies the operation mode 'static-
data', i.e. minimizes the packet loss.
Adjusts the volume of the fax signals re-generated
on the receiver side. The volume is in dB, in the
range -18.5 ... -3.5 (Default: -9.5dB).
Sets maximum allowed bit-rate for fax relay
(Default 14400 Bit/sec).
Selects the method when fax transmissions are
detected: By CED tone or by fax frames (Default:
ced-tone). It takes longer to detect Fax frames than
CED tones, but the risk of misdetection is mini-
mized.
Disables error correction mode (Default: enabled).
If the error correction mode is disabled, the con-
nected fax devices cannot negotiate error correc-
tion mode. Connections with error correction mode
enabled are more sensitive to packet loss. Disable
error correction mode when packet loss is more
than 2–3%.
Note Error correction mode does
not cancel IP packet loss.
Disables HDLC image transfer (Default: enabled).
If HDLC mode is enabled, the SmartNode removes
bit-stuffing, checks CRCs of fax frames arriving
from the PSTN and regenerates the CRCs before
sending fax frames towards the PSTN. HDLC can
only be enabled together with error correction.
Disable HDLC when the fax peer does not support
this mode.
VoIP profile configuration task list