Rtpcatch Limitations - Cisco ATA186-I1 Administrator's Manual

Debugging the Cisco ATA 186/188 Fax Services
Analysis
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Possible Cause for Failure
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rtpcatch Limitations

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Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator's Guide for SCCP (version 3.0)
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<3.200> is the originating Cisco ATA, and <2.53> is the terminating gateway.
Both sides initially use G.729.
<2.53> gateway sends NTE signaling packets, then upspeeds to G.711µ-law.
<3.200>The Cisco ATA switches to G.711µ-law also, but never sends NTE signaling packets.
Fax transmission fails because <2.53> gateway does not receive any NTE packets, and it drops the
fax call.
The Cisco ATA does not support the NTE signaling method and requires that the gateways use the
NSE signaling method.
rtpcatch performs optimally when analyzing capture files containing only one VoIP session.
rtpcatch detects only G.711A, G.711µ-law, G.723, G.729, T.38, Cisco fax relay, modem
pass-through with or without redundancy packets, RTCP packets and NSE packets.
rtpcatch can handle a maximum of 20 prserv ports using the -port option.
rtpcatch may not detect T.38 packets correctly.
Chapter 6 Configuring and Debugging Fax Services
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