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Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator’s Guide for H.323 (version 3.0)
OL-4804-01
Chapter 7 Configuring and Debugging Fax Services
Using Fax Pass-through Mode
Dial-Peer Level Commands
You can enable
fax pass-through mode
for communication between a Cisco IOS gateway and the
specified Cisco ATA using the following dial-peer level commands:
Procedure
Step 1
Perform the command:
dial-peer voice
tag
voip
Step 2
Perform the command:
modem passthrough {NSE [payload-type
numbe
r
] codec {g711
µ
law | g711alaw} [redundancy] |
system}
a.
The default of this command is:
modem passthrough system
When using the default configuration, the dial-peer fax pass-through configuration is defined by the
voice service voip
command. When the
system
option is used, no other parameters are available.
When the NSE is configured in the fax pass-through command at the dial-peer level, the fax
pass-through definition in the
dial-peer
command takes priority over the definition in the
voice
service voip
command.
b.
The
payload-type
number
,
codec
, and
redundancy
parameters can also be used.
For example, the command:
modem passthrough NSE codec g711
µ
law
means that the Cisco ATA will use the NSE payload-type number 100, G.71
1µ
-law codec, and no
redundancy in
fax pass-through mode
.
Step 3
When setting up dial-peer for fax pass-through, it is necessary to set up a pair of dial-peers for inbound
and outbound calls between the Cisco ATA and Cisco IOS gateways. You do this by specifying the
destination-pattern
and
incoming-called number
. The
destination-pattern
should point to the
Cisco ATA, while the incoming-called number should apply to all numbers that the Cisco ATA is
allowed to dial.
Disable Fax Relay Feature
Fax relay may be enabled by default for some IOS gateways. If you do not disable the fax relay feature,
it may override the precedence of fax/modem pass-through and cause the fax transmission to fail. It is
necessary to disable fax relay at the dial-peer or system level with the following command:
fax rate disable