Appendix C
Cisco ATA Specifications
Ringing Characteristics
Table C-5
Description
Tip/ring interfaces for each RJ-11 FXS port (SLIC)
Ring voltage
Ring frequency
Ring waveform
Ring load
Ringer equivalence number (REN)
Loop impedance
On-hook/off-hook characteristics
On-hook voltage (tip/ring)
Off-hook current
RJ-11 FXS port terminating impedance option
Software Specifications
Table C-6
Description
Call progress tones
Dual-tone multifrequency (DTMF)
Fax
OL-4804-01
Ringing Characteristics
Software Specifications (All Protocols)
Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator's Guide for H.323 (version 3.0)
Specification
40V
(typical, balanced ringing only)
RMS
25 Hz
Trapezoidal with 1.2 to 1.6 crest factor
1400 ohm + 40µF
Up to 5 REN per RJ-11 FXS port
Up to 200 ohms (plus 430-ohm maximum telephone
DC resistance)
–50V
27 mA (nominal)
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.
Specification
Configurable for two sets of frequencies and single set of on/off
cadence
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.
Ringing Characteristics
C-3