Efm Noise-Margin - Accton Technology VS4512DC Management Manual

efm noise-margin

This command sets the noise margin of the selected VDSL port. Use the no form of
this command to disable this feature.
Syntax
efm noise-margin [downstream noise margin] [upstream noise margin]
no efm noise-margin
• downstream noise margin - A measure of the amount of noise that the
downstream VDSL line can tolerate before the signal is affected.
Range: 0-9
• upstream noise margin - A measure of the amount of noise that the
upstream VDSL line can tolerate before the signal is affected.
Range: 0-9
Default Setting
0 (disabled)
Command Mode
Interface Configuration
Command Usage
When rate adaptation is enabled, (see "efm rate-adapt" on page 4-108) the
Signal-to-Noise Ratio (SNR) is an indicator of link quality. The switch itself has
no internal functions to ensure link quality. To ensure a stable link, you should
add a margin to the theoretical minimum Signal-to-noise ratio (SNR). The table
below lists theoretical minimum SNR's for the VDSL profiles configurable on this
switch.
Profile Name
Default
A1-02OAG-R1
A2-02OAG-R1
A3-01OAG-R1
A4-01OAG-R1
S1-03OAG-R1
S2-03OAG-R1
S3-00OAG-R1
S1-16-16
A1-34-11
S2-16-16A
A2-34-11A
A3-25-3
A4-45-5
A5-50-7
Theoretical Minimum Signal-to-Noise Ratio (dB)
DS1
10 Not Used
17 Not Used
20 Not Used
23 10
26 20
17 Not Used
20 Not Used
23 10
20 10
29 20
20 10
29 20
26 10
32 23
35 26
DS2 US1
10
14
14
17
20
20
20
23
20
17
20
17
17
17
23
VDSL Commands
US2
Not Used
Not Used
Not Used
Not Used
Not Used
10
14
20
17
14
17
14
Not used
10
14
4-107