Chapter 5 Parameters and Defaults

Optional Feature Parameters

•off-timecontrols the length of time between audible tones in milliseconds (ms) expressed as an integer from 0 to 0xffff sample at 8000 samples/second.

•total-tone-timecontrols the length of time the tone is audible (0 to 0xffff). If this value is set to 0, the tone will play until another call event stops the tone. For DialTone, BusyTone, ReorderTone, and RingBackTone, the configurable value is the number of 10 ms (100 = 1 second) units.

For the other tones, the value is the number of samples at 8000 samples/second, where the following information applies:

–Frequency ranges from 0 to 4000 (Hz)

–Transformed Frequency = 32767 · cos (2pi·Frequency/8000)

–Amplitude ranges from 0 to 32767

–Transformed Amplitude = A · 32767 · sin (2pi·Frequency/8000)

The scaling factor A determines the volume level of the tone. To calculate scaling factors, see the “How to Calculate Scaling Factors” section on page 5-42.

Note All tones are persistent (until the Cisco ATA changes state) except for the call-waiting tone and the confirm tone. The call-waiting tone, however, repeats automatically once every 10 seconds while the call-waiting condition exists.

How to Calculate Scaling Factors

Use the following formula to calculate the scaling factor A:

A=0.5 * 10^((k+10-(n-1)*3)/20)

In this formula, k is the desirable volume in dBm; n is the number of frequency components. The ^ symbol means to the order of.

Example

If a one-frequency component of -20 dBm volume level is desirable, then:

A=0.5 * 10^((-20+10)/20)= 0.16

Recommended Values

The following settings are recommended for the US:

•DialTone = "2,31538,30831,3100,3885,1,0,0,1000" (approximately -10 dBm)

•BusyTone = "2,30467,28959,1191,1513,0,4000,4000,0" (approximately -21 dBm)

•ReorderTone = "2,30467,28959,1191,1513,0,2000,2000,0" (approximately -21 dBm)

•RingBackTone = "2,30831,30467,1943,2111,0,16000,32000,0" (approximately -16 dBm)

•CallWaitTone = "1,30831,0,5493,0,0,2400,2400,4800" (approximately -10 dBm)

•AlertTone = "1,30467,0,5970,0,0,480,480,1920" (approximately -10 dBm)

Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator’s Guide (H.323)

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Cisco Systems ATA 188 manual How to Calculate Scaling Factors, Recommended Values
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ATA 188 specifications

The Cisco Systems ATA 188 is a versatile Analog Telephone Adapter designed to facilitate the integration of traditional telephone systems with Voice over Internet Protocol (VoIP) networks. This device has been key in bridging the gap between legacy telephony and modern IP-based communication, allowing users to leverage their existing analog phones while enjoying the benefits of digital connectivity.

One of the main features of the ATA 188 is its ability to connect regular analog phones to a VoIP network, enabling users to make and receive calls over the internet. This significantly reduces calling costs, especially for long-distance and international calls. The ATA 188 supports two phone lines, allowing simultaneous voice calls. This dual-line capability makes it a suitable choice for small businesses or home offices that require multiple lines without the need for extensive infrastructure.

The device is equipped with various technologies that enhance its functionality. It supports the Session Initiation Protocol (SIP) and H.323, making it compatible with a wide range of VoIP service providers. Additionally, the ATA 188 features Quality of Service (QoS) settings, which prioritize voice traffic over the internet, ensuring clear voice quality without interruptions or delays. This is essential for maintaining a professional communication experience, especially in business environments.

Another characteristic of the ATA 188 is its user-friendly configuration interface. It allows users to easily set up and manage their devices through a web-based portal. The configuration process is straightforward, with options to adjust settings such as codec selection, call features including call waiting, and call forwarding functionalities.

Security is also a priority for the ATA 188, as it provides robust protocols to protect call data. The device supports Secure Real-time Transport Protocol (SRTP) and Transport Layer Security (TLS) to encrypt voice traffic and manage signaling securely. This ensures that sensitive conversations remain confidential.

Overall, the Cisco Systems ATA 188 is a reliable and efficient solution for users looking to transition from traditional telephony to VoIP. Its dual-line capacity, compatibility with multiple VoIP standards, user-friendly configuration, and built-in security features make it a valuable asset for both personal and professional communication solutions. In an ever-evolving telecommunications landscape, the ATA 188 remains a relevant and practical choice for integrating legacy telephony with modern internet-based services.
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