Chapter 6 Configuring and Debugging Fax Services

Debugging the Cisco ATA 186/188 Fax Services

Table 6-2 Debug Log Examples

Log event

Description

 

 

[ch] Enable encoder <pt>

Voice encoder type pt is enabled for the channel ch, where pt can be 0

 

for G.711µ-law, 4 for G.723.1, 8 for G.711A-law, and 18 for G.729.

 

For example, [0]Enable encoder 4 indicates that the Cisco ATA

 

transmitted G.723.1-encoded voice packets.

 

 

[ch] DPKT 1st:

The first voice packet that the Cisco ATA received was of RTP payload

<timestamp1>

type pt for the channel ch with timestamp of timestamp1, and the local

<timestamp2>, pt <pt>

decoding timestamp was set to timestamp2.

 

For example, [0]DPKT 1st: 1491513359 1491512639, pt 4 indicates

 

that the first RTP packet that the Cisco ATA received was

 

G.723.1-encoded for channel 0.

 

 

[ch] codec: <pt1> => <pt2>

Voice codec switchover occurred. The voice encoder type switched

 

from pt1 to pt2 for the channel ch.

 

For example, [0]codec: 4 => 0 indicates that the local voice encoder

 

on the Cisco ATA switched from G.723.1 to G.711µ-law.

 

 

[ch] Rx MPT PT=<NSEpt>

Channel ch received an NSE packet of event with payload type of

NSE pkt <event>

NSEpt. For event, c0XXXXXX indicates a CED tone event, and

 

c1XXXXXX indicates a phase reversal event.

 

For example, [0]Rx MPT PT=100 NSE pkt c0000000 indicates that the

 

Cisco ATA received a CED tone event NSE packet with payload type of

 

100.

 

 

[ch] Tx MPT PT=<pt> NSE

Channel ch transmitted an NSE packet of event with payload type of

pkt <event>

NSEpt. For event, c0XXXXXX indicates a CED tone event, and

 

c1XXXXXX indicates a phase reversal event.

 

For example, [0]Tx MPT PT=100 NSE pkt c0000000 indicates that the

 

ATA transmitted a CED tone event NSE packet with payload type of

 

100.

 

 

Debugging FAX Pass-through Mode

When the Cisco ATA is configured to use fax pass-through mode, the fax call session can be established with an arbitrary voice codec. Once the voice call has been established, fax machines can signal their presence by means of a CED tone or V.21 preamble flag, after which the gateways send NSE packets to initiate switchover.

Note For fax pass-through mode, check the Cisco ATA debug log to verify that it is acting as an originating gateway as well as a terminating gateway.

Terminating-Gateway Example

When the Cisco ATA is used as a terminating gateway for a fax session, make sure the following conditions are true:

•The Cisco ATA transmits CED-tone-event NSE packets.

•The encoder switchover to G.711 occurs during the NSE-packet transaction.

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

6-10

OL-4803-01

 

 

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Cisco Systems ATA 186, ATA 188 manual Log event Description, Decoding timestamp was set to timestamp2, Encoded for channel
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ATA 188, ATA 186 specifications

The Cisco Systems ATA 186, or Analog Telephone Adapter, revolutionized the way traditional telephony interacted with Voice over Internet Protocol (VoIP) systems. Designed primarily for home and small office use, the ATA 186 allows users to connect standard analog phones and fax machines to a network, enabling them to take advantage of the benefits of VoIP technology.

One of the defining features of the ATA 186 is its dual port architecture. It includes two FXS ports, allowing users to connect up to two analog telephones. This functionality means that multiple devices can leverage VoIP services simultaneously without the need for separate adapters for each phone. The flexibility of the ATA 186 helps streamline the user experience, facilitating voice communication over an IP network while ensuring users can still use their existing phone equipment.

The ATA 186 employs various technologies to maintain high-quality voice calls. It supports standard voice codecs such as G.711 and G.729, which ensure efficient bandwidth usage while preserving call clarity. The adaptive jitter buffer technology further enhances call quality, compensating for network variations and minimizing latency, which is crucial for clear and uninterrupted conversations.

Additionally, the ATA 186 provides users with advanced calling features that were traditionally available only on PBX systems. These features include caller ID, call waiting, and voicemail functionality, integrating seamlessly with typical telephony services. The device also supports T.38 fax relay, allowing users to send and receive faxes over the internet, thus addressing the needs of environments where fax communication remains essential.

The security of VoIP conversations is also a priority for the ATA 186. It employs encryption protocols such as Secure Real-time Transport Protocol (SRTP) and Transport Layer Security (TLS), ensuring that voice data is securely transmitted across the network. This focus on security helps protect sensitive information transmitted during calls.

Installation and configuration of the ATA 186 is streamlined, with an intuitive web-based interface that simplifies the setup process. This accessibility makes it suitable for users with varying levels of technical expertise, as frequently required adjustments, such as network configurations and firmware updates, can be easily managed.

In conclusion, the Cisco Systems ATA 186 stands out as a versatile and robust solution for users looking to integrate analog phones into a VoIP environment. With its dual port capabilities, high-quality voice codecs, advanced call features, and security measures, it offers a compelling choice for both residential and commercial users seeking seamless telephony integration. As technology evolves, devices like the ATA 186 remain cornerstones in bridging traditional telephony with modern communication systems.
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