Cisco Systems UBR900 Backup POTS Connection

Voice Over IP Operations
Configuring the Cisco uBR900 Series Cable Access Routers 15
Backup POTS Connection
The Cisco uBR924 cable access router provides an RJ-11 port (Line) that connects to a standard
analog telephone wall jack. In the event of a building power failure or a Cisco uBR924 power
problem, the cutover port lets you dial out using the backup PSTN line. If the Cisco uBR924 loses
power while VoIP calls are in progress, you can reestablish one of the two connections—dialing out
over the PSTN.
Frequency shift (offset) <= ±0.2 Hz (max)
<= ±0.1 Hz (99.5%)
Amplitude tracking (input Level, dBmO):
-37 to 0 (on-hook)
-37 to +3 (off hook)
-50 to -37 (off-hook)
-55 to -50 (off-hook)
Max Dev. Ave. Dev.
<= ±.5 dB
<= ±.5 dB <= ± .25 dB
<= ±1.0dB <= ±.5 dB
<= ± 3.0 dB <= ±1.5 dB
Crosstalk <= -65 dBmO
Amplitude jitter
20-300 Hz
4-300 Hz
<= 2.5% Peak
<= 2.9% Peak
Phase jitter
20 to 300 Hz
4 to 300 Hz
<= 1.5 P-P
<= 1.8 P-P
Envelope delay distortion:
1704 Hz to 604 Hz
1704 Hz to 2804 Hz
1704 Hz to 204 Hz
1704 Hz to 3404 Hz
<= 350 usec
<= 195 usec
<= 580 usec
<= 400 usec
Hybrid balance:
Echo Return Loss (ERL)
SRL
> 26 dB (standard test line)
> 14 dB (station off hook)
> 21 dB (standard test line)
> 11 dB (station off hook)
Clipping:
Speech segments <5 ms
Speech segments > 5ms
< 0.5%
0.0%
Impulse noise:
(>= 6 dB below receive signal) 0 in 93% of all 15 min intervals
<= 1 count in all 30 min intervals
Phase hits (>= 10 deg) 0 in 99.75% of all 15 min intervals
<= 1 count in all 30 min intervals
Gain hits (>= ± 3dB) 0 in 99.9% of all 15 min intervals
<= 1 count in all 30 min intervals
Dropouts (>= 12) 0 in 99.9% of all 15 min intervals
<= 1 count in all 60 min intervals
Table2 Cisco uBR924 Cable Access Router Voice Specifications (continued)
Metric Value