Cisco Systems ATA 186 manual Using rtpcatch to Analyze Common Causes of Failure, 6-17, Analysis

Chapter 6 Configuring and Debugging Fax Services

Debugging the Cisco ATA 186/188 Fax Services

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.

•NSE signaling packets are sent from <3.200>.

•<2.53> switches to G.711µ-law using a dynamic payload type.

Example 6-4 T38 Fax Relay Mode

----------	FAX Summary 1 ----------
[	15]<2.53=>3.99> Codec G711u
[	486]<3.99=>2.53> Codec G711u
[ 1277]<3.99=>2.53>		Codec T38
[ 1278]<2.53=>3.99>		Codec T38

Analysis

•Both sides initially use G.711µ-law.

•Both sides switch to T.38

Example 6-5 Cisco Fax Relay

----------	FAX Summary 1 ----------
[	8]<2.53=>3.99>	Codec G711u
[	248]<3.99=>2.53>	Codec G711u
[	798]<2.53=>3.99>	NSE PT 96, Cisco Fax Relay
[	799]<3.99=>2.53>	NSE PT 97, EVT 192: Up-Speed, CED tone Detected
[	800]<2.53=>3.99>	NSE PT 97, Cisco Fax Relay ACK
[	801]<2.53=>3.99>	Codec C_FxRly
[	803]<3.99=>2.53>	NSE PT 96, EVT 192: Up-Speed, CED tone Detected
[	804]<2.53=>3.99>	NSE PT 97, Cisco Fax Relay ACK
[	805]<3.99=>2.53>	Codec C_FxRly

Analysis

•Both sides initially use G.711µ-law.

•NSE signaling packets are sent between <2.53> and <3.99>.

•Both sides switch to Cisco fax relay.

Using rtpcatch to Analyze Common Causes of Failure

The following examples show the rtpcatch output of failed fax sessions. <3.200> is ATA; <2.53> is a Cisco gateway.

Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator’s Guide for MGCP (version 3.0)

OL-4803-01 6-17