Cisco Systems ATA 186 Analyzing rtpcatch Output for Fax Sessions, Cisco ATA fax pass-through mode

Chapter 6 Configuring and Debugging Fax Services

Debugging the Cisco ATA 186/188 Fax Services

Analyzing rtpcatch Output for Fax Sessions

The following examples show the proper fax events when gateways are configured to operate in the following modes:

•Cisco ATA fax mode

•Cisco ATA fax pass-through mode

•T.38 fax relay mode

•Cisco fax relay mode

Example 6-1 Fax Mode

----------	FAX Summary 1 ----------
[	25]<2.131=>3.200>	Codec G711u
[	26]<3.200=>2.131>	Codec G711u

Analysis

Both sides use G.711 for the entire fax session.

Example 6-2 Fax Pass-through Mode

----------	FAX Summary 1 ----------
[	25]<2.213=>2.116>	Codec G723
[	26]<2.116=>2.213>	Codec G723
[	101]<2.116=>2.213>	Codec G711u/D
[	102]<2.116=>2.213>	NSE PT 100, EVT 192: Up-Speed,	CED tone Detected
[	103]<2.116=>2.213>	NSE PT 100, EVT 193: ECAN OFF,	Phase Reversal Detected
[	105]<2.213=>2.116>	NSE PT 100, EVT 192: Up-Speed,	CED tone Detected
[	107]<2.213=>2.116>	Codec G711u/D

Analysis

•Both sides initially use G.723.

•<2.116> switches to G.711µ-law using a dynamic payload type.

•NSE signaling packets are sent from <2.116>.

•An optional NE signaling packet is sent from <2.213>.

•<2.113> switches to G.711µ-law using a dynamic payload type.

Note EVT 193 may not appear for some fax transmission.

Example 6-3 Fax Pass-through Mode

----------	FAX Summary 1 ----------
[	37]<3.200=>2.53>	Codec G723
[	41]<2.53=>3.200>	Codec G723
[	136]<3.200=>2.53>	Codec G711u/D
[	137]<3.200=>2.53>	NSE PT 100, EVT 192: Up-Speed, CED tone Detected
[	140]<2.53=>3.200>	Codec G711u/D

Analysis

•Both sides initially use G.723.

•<3.200> switches to G.711µ-law using a dynamic payload type.

Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator’s Guide (SCCP)

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