Chapter 7
Configuring and Debugging Fax Services
Possible Causes for Failure
•
Fax/modem pass-through option is not enabled on the gateway.
Fax/modem pass-through NSE payload type are configured differently on the Cisco ATA and the
•
gateway.
Example 7-9
---------- FAX Summary 1 ----------
[
37]<2.53=>3.200> Codec G723
[
39]<3.200=>2.53> Codec G723
[
143]<3.200=>2.53> Codec G711u/D
[
144]<3.200=>2.53> NSE PT 100, EVT 192: Up-Speed, CED tone Detected
[ 1602]<3.200=>2.53> NSE PT 100, EVT 192: Up-Speed, CED tone Detected
[ 1604]<2.53=>3.200> Codec G711u/D
[ 1820]<2.53=>3.200> NSE PT
[ 1966]<2.53=>3.200> NSE PT
Analysis
•
<2.53> is the originating gateway, and <3.200> is the terminating Cisco ATA.
The Cisco ATA upspeeds to G.711µ-law and sends G.711 upspeed NSE signaling packets.
•
•
The <2.53> gateway upspeeds to G.711µ-law and then sends Cisco fax relay event packets.
Possible Cause for Failure
Cisco fax relay option is not disabled on the gateway.
•
Example 7-10 Fax Pass-through Mode Failure
---------- FAX Summary 1 ----------
[
33]<3.200=>2.53> Codec G729
[
39]<2.53=>3.200> Codec G729
[
562]<2.53=>3.200> NTE PT 101, EVT
[
563]<2.53=>3.200> NTE PT 101, EVT
[
565]<2.53=>3.200> NTE PT 101, EVT
[
566]<2.53=>3.200> Codec G711u/D
[
568]<2.53=>3.200> NTE PT 101, EVT
[
580]<3.200=>2.53> Codec G711u/D
Analysis
•
<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.
Possible Cause for Failure
The Cisco ATA does not support the NTE signaling method and requires that the gateways use the
•
NSE signaling method.
OL-4008-01
Fax Pass-through Mode Failure
96, Cisco Fax Relay
96, Cisco Fax Relay
Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator's Guide (H.323)
Debugging the Cisco ATA 186/188 Fax Services
34: Modem Mode, ANSam tone Detected (RFC2833)
34: Modem Mode, ANSam tone Detected (RFC2833)
34: Modem Mode, ANSam tone Detected (RFC2833)
34: Modem Mode, ANSam tone Detected (RFC2833)
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