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Cisco ATA 187 Analog Telephone Adaptor Administration Guide for SIP (Version 1.0)
OL-21862-01
Appendix A ATA 187 Specifications
Ringing Characteristics
Ringing Characteristics
Software Specifications
Ta b l e A-5 Ringing Characteristics
Description Specification
Tip/ring interfaces for each RJ-11 FXS port (SLIC)
Ring voltage 40V
RMS
(typical, balanced ringing only)
Ring frequency 20 Hz
Ring waveform Trapezoidal with 1.2 to 1.6 crest factor
Ring load 1400 ohm + 40F
Ringer equivalence number (REN) Up to 5 REN per RJ-11 FXS port
Loop impedance Up to 200 ohms (plus 430-ohm maximum phone DC
resistance)
On-hook/off-hook characteristics
On-hook voltage (tip/ring) –48V
Off-hook current 24 mA (nominal)
RJ-11 FXS port terminating impedance option 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.
Ta b l e A-6 Software Specifications (All Protocols)
Description Specification
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
Fax 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.