Appendix A
ATA 187 Specifications
Ringing Characteristics
Table A-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 A-6
Description
Call progress tones
Dual-tone multifrequency (DTMF)
Fax
OL-21862-01
Ringing Characteristics
Software Specifications (All Protocols)
Specification
Configurable for two sets of frequencies and single set of on/off
cadence
DTMF tone detection and generation
Fax pass-through and T.38 fax relay 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.
Cisco ATA 187 Analog Telephone Adaptor Administration Guide for SIP (Version 1.0)
Specification
40V
(typical, balanced ringing only)
RMS
20 Hz
Trapezoidal with 1.2 to 1.6 crest factor
1400 ohm + 40F
Up to 5 REN per RJ-11 FXS port
Up to 200 ohms (plus 430-ohm maximum phone DC
resistance)
–48V
24 mA (nominal)
The ATA 187-I1 provides multiple impedance, such
as 600 ohm for American SKU, 900 ohm for
European SKU, 220 ohm (820 ohm || 120nF) for
Australian SKU, and so on.
Ringing Characteristics
A-3