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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
Debugging the Cisco ATA 186/188 Fax Services
•
Stores media streams to files.
•
Reports RTP statistics such as the number of RTP packets, the number of RTP frames, the number
of lost packets, the number of filler packets during silence suppression periods, and the number of
erased packets.
How to Use
To use
rtpcatch
, follow these steps:
Procedure
Step 1
Create a working directory for
rtpcatch
and place the executable file rtpcatch.exe in this directory.
Step 2
Copy your Network Associates Sniffer Pro capture files into this directory.
Step 3
At the DOS prompt of this directory, enter the following command:
:>
rtpcatch
<
cap_file
>
[
<prefix>
]
[
options
]
–
<cap_file>
is the NAI Sniffer capture file.
–
<prefix>
is the prefix prepended to the output filenames.
Output Files
The output files of
rtpcatch
include a summary file and audio stream files.
The summary file is
<prefix>.sum
if
<prefix>
is specified, otherwise it is
file.sum
.
Stream files are labeled with an integer tag beginning with 00. Stream files are also tagged with the
extension
pcm
for G.711A/G.711µ-law,
723
for G723.1,
729
for G729,
t38
for T.38, and
cfr
for Cisco
Fax Relay.
Options
rtpcatch
options include:
•
-fax
—to output the fax events for a connection.
The output includes "
FAX summary 1
" as the interleaved event list for all directions, and "
FAX
summary 2
" as the event list for each direction. The reported events include voice codec change,
NSE signalling, and fax relay events.
•
-port <port0> <port1>
—to discard any packets sent from/to this port.
If the NAI Sniffer capture file includes Cisco ATA
prserv
packets, these packets can interfere with
rtpcatch
analysis. Some
prserv
packets might be interpreted as NTE or NSE events. To prevent
such interference, you can either disable debugging output on the Cisco ATA (do this by setting the
Nprintf
configuration parameter to 0), configure your NAI Sniffer to filter out the
prserv
packets,
or run
rtpcatch
with the -port options.
Note
rtpcatch
works best for analyzing a single VoIP session. Command-line options can be entered in any
order.
