Filter
Top Products
6-10
Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator’s Guide for MGCP (version 3.0)
OL-4803-01
Chapter 6 Configuring and Debugging Fax Services
Debugging the Cisco ATA 186/188 Fax Services
Debugging FAX Pass-through Mode
When the Cisco ATA is configured to use fax pass-through mode, the fax call session can be established
with an arbitrary voice codec. Once the voice call has been established, fax machines can signal their
presence by means of a CED tone or V.21 preamble flag, after which the gateways send NSE packets to
initiate switchover.
Note For fax pass-through mode, check the Cisco ATA debug log to verify that it is acting as an originating
gateway as well as a terminating gateway.
Terminating-Gateway Example
When the Cisco ATA is used as a terminating gateway for a fax session, make sure the following
conditions are true:
• The Cisco ATA transmits CED-tone-event NSE packets.
• The encoder switchover to G.711 occurs during the NSE-packet transaction.
Table 6-2 Debug Log Examples
Log event Description
[ch] Enable encoder <pt> Voice encoder type pt is enabled for the channel ch, where pt can be 0
for G.711µ-law, 4 for G.723.1, 8 for G.711A-law, and 18 for G.729.
For example,
[0]Enable encoder 4 indicates that the Cisco ATA
transmitted G.723.1-encoded voice packets.
[ch] DPKT 1st:
<timestamp1>
<timestamp2>, pt <pt>
The first voice packet that the Cisco ATA received was of RTP payload
type pt for the channel ch with timestamp of timestamp1, and the local
decoding timestamp was set to timestamp2.
For example,
[0]DPKT 1st: 1491513359 1491512639, pt 4 indicates
that the first RTP packet that the Cisco ATA received was
G.723.1-encoded for channel 0.
[ch] codec: <pt1> => <pt2> Voice codec switchover occurred. The voice encoder type switched
from pt1 to pt2 for the channel ch.
For example,
[0]codec: 4 => 0 indicates that the local voice encoder
on the Cisco ATA switched from G.723.1 to G.711µ-law.
[ch] Rx MPT PT=<NSEpt>
NSE pkt <event>
Channel ch received an NSE packet of event with payload type of
NSEpt. For event, c0XXXXXX indicates a CED tone event, and
c1XXXXXX indicates a phase reversal event.
For example,
[0]Rx MPT PT=100 NSE pkt c0000000 indicates that the
Cisco ATA received a CED tone event NSE packet with payload type of
100.
[ch] Tx MPT PT=<pt> NSE
pkt <event>
Channel ch transmitted an NSE packet of event with payload type of
NSEpt. For event, c0XXXXXX indicates a CED tone event, and
c1XXXXXX indicates a phase reversal event.
For example,
[0]Tx MPT PT=100 NSE pkt c0000000 indicates that the
ATA transmitted a CED tone event NSE packet with payload type of
100.