143
Generally Accepted Criteria of 
Plain Old Telephone Service (POTS) service 
(US and Canada)
Parameter Acceptable Marginal Unacceptable
Current >23 20 to 23 <20 mA
Loss <8.5
— >8.5 dB
Balance >60 50 to 60 <50 dB
Noise
<20
 
<-70
20 to 30 
-70 to -60
>30 
>-60
dBrnC 
dBmOp
Power 
Influence
<80
 
<-10
80 to 90 
-10 to 0
>90 
>0
dBrnC 
dBmOp
Ground 
Resistance*
<25
— >25 Ohms
Insulation 
Resistance
>3M 300K to 3M <300K Ohms
Longitudinal 
Balance
>59 50 to 59 <50 dB
DSL Noise:
Noise Weighting Filters:
  E Filter (ISDN/IDSL)  1 kHz to 50 kHz
  F Filter (HDSL)  4.9 kHz to 245 kHz
  G Filter (ADSL)  20 kHz to 1.1 MHz
Metallic (100/135 
Ω)
  E Filter (ISDN/IDSL)  10 to 90 dBm  2dB
  F Filter (HDSL)  20 to 90 dBm  2dB
  G Filter (ADSL)  30 to 90 dBm  2dB
Longitudinal 
  E Filter (ISDN/IDSL)  40 to 120 dBm  2dB
  F Filter (HDSL)  50 to 120 dBm  2dB
  G Filter (ADSL)  60 to 120 dBm  2dB
Spectrum Analyzer:
 Frequency Range:   10 kHz to 1.8 Mz, 
 Frequency Spans:    120 kHz, 240 kHz, 
   465 kHz, 1 MHz, 2 MHz   
 
 Dynamic Range:   -90 to +10 dBm
 Frequency Resolution:     1% of span
 Input Impedance:    100 
Ω
* Note: Ground Resistance can not be measured on “floating tip” or “floating 
A” switches such as the AT&T #5ESS.
Note:   All specifications are based on information believed 
to be reliable, but the accuracy or completeness thereof is 
not guaranteed. Specifications for this product are subject to 
change without notice.