Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator's Guide (MGCP)(
Cisco ATA Specifications
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Cisco ATA Specifications

Table Of Contents

Cisco ATA Specifications

Physical Specifications

Electrical Specifications for Cisco ATA

Environmental Specifications

Immunity Specifications

Physical Interfaces

Ringing Characteristics

Software Specifications

Cisco ATA Specifications

This section describes Cisco ATA specifications:

Physical Specifications

Electrical Specifications for Cisco ATA

Environmental Specifications

Immunity Specifications

Physical Interfaces

Ringing Characteristics

Software Specifications

Note The term Cisco ATA is used throughout this manual to refer to both the Cisco ATA 186 and the Cisco ATA 188, unless differences between the Cisco ATA 186 and Cisco ATA 188 are explicitly stated.

Physical Specifications

Table B-1 Physical Specifications



1.5 x 6.5 x 5.75 in. (3.8 x 16.5 x 14.6 cm) (H x W x D)


15 oz (425 g)

Electrical Specifications for Cisco ATA

Table B-2 Electrical Specifications



3.5 to 7.5W (idle to peak)

DC input voltage

+5.0 VDC at 1.5A maximum

Power adaptor

Universal AC/DC

~3.3 x 2.0 x 1.3 in. (~8.5 x 5.0 x 3.2 cm)

~4.8 oz (135 g) for the AC-input external power adaptor

~4 ft (1.2 m) DC cord

6 ft (1.8 m) cord

Environmental Specifications

Table B-3 Environmental Specifications


Operating temperature

41 to 104×F (5 to 40×C)

Storage temperature

-4 to 140×F (-20 to 65×C)

Relative humidity

10 to 90% noncondensing, operating, and nonoperating/storage

Immunity Specifications

EN50082-1, including the following:

EN61000-3-2, Electromagnetic Compatibility

EN61000-3-3, Electromagnetic Compatibility

EN61000-4-2, ESD

EN61000-4-3, Radiated Immunity

EN61000-4-4, Burst Transients

EN61000-4-5, Surge

EN61000-4-6, Injected RF

EN61000-4-11, Dips and Sags

Physical Interfaces

Table B-4 Physical Interfaces



Two RJ-45, IEEE 802.3 10BaseT standard

Analog telephone

Two RJ-11 FXS voice ports


5 VDC power connector


Function button with integrated status indicator

Link and activity LED indicating network activity

Ringing Characteristics

Table B-5 Ringing Characteristics


Tip/ring interfaces for each RJ-11 FXS port (SLIC)

Ring voltage

40VRMS (typical, balanced ringing only)

Ring frequency

25 Hz

Ring waveform

Trapezoidal with 1.2 to 1.6 crest factor

Ring load

1400 ohm + 40 microF (per line)

Ringer equivalence number (REN)

Up to 5 REN per RJ-11 FXS port

Loop impedance

Up to 200 ohms (plus 430-ohm maximum telephone DC resistance)

On-hook/off-hook characteristics

On-hook voltage (tip/ring)


Off-hook current

25 mA (nominal)

RJ-11 FXS port terminating impedance option

The Cisco ATA186-I1 and Cisco ATA188-I1 provide 600-ohm resistive impedance. The Cisco ATA186-I2 and Cisco ATA188-I2 provide 270 ohm + 750 ohm // 150-nF complex impedance.

Software Specifications

Table B-6 Software Specifications (All Protocols) 


Call progress tones

Configurable for two sets of frequencies and single set of on/off cadence

Dual-tone multifrequency (DTMF)

DTMF tone detection and generation


G.711 fax pass-through and G.711 fax mode.

Enhanced fax pass-through is supported on the Cisco ATA. Success of fax transmissions up to 14.4 kbps depends on network conditions, and fax modem/fax machine tolerance to those conditions. The network must have reasonably low network jitter, network delay, and packet-loss rate.

Line-echo cancellation

Echo canceller for each port

8 ms echo length

Nonlinear echo suppression (ERL > 28 dB for frequency = 300 to 2400 Hz)

Convergence time = 250 ms

ERLE = 10 to 20 dB

Double-talk detection

Out-of-band DTMF

H.245 out-of-band DTMF for H.323

RFC 2833 AVT tones for SIP, MGCP, SCCP


DHCP (RFC 2131)

Web configuration via built-in Web server

Touch-tone telephone keypad configuration with voice prompt

Basic boot configuration (RFC 1350 TFTP Profiling)

Dial plan configuration

Cisco Discovery Protocol for SCCP

Quality of Service

Class-of-service (CoS) bit-tagging (802.1P)

Type-of-service (ToS) bit-tagging


H.235 for H.323

RC4 encryption for TFTP configuration files

Voice coder-decoders (codecs)

Note In simultaneous dual-port operation, the second port is limited to G.711 when using G.729.


G.729, G.729A, G.729AB




Voice features

Voice activity detection (VAD)

Comfort noise generation (CNG)

Dynamic jitter buffer (adaptive)

Voice-over-IP (VoIP) protocols

H.323 v2

SIP (RFC 2543 bis)

MGCP 1.0 (RFC 2705)

MGCP 1.0/network-based call signalling (NCS) 1.0 profile

MGCP 0.1