BRX-VDSL2 User Guide
32
180-0153-001-R02
If any of the DSLAM settings are wrong, you should
adjust them as per your corporate guidelines and
retest.
6. The DSLAM and/or CPE is reporting
an unusually high number of CRC
errors or Errored Seconds (ES)
Enable Impulse Noise Protection (INP) and/or
increase the number of symbols in the DSLAM
impulse noise settings.
Enable G.INP if supported by the modem (CPE)
Increase target SNR by 2-3dB steps until error
rate becomes acceptable. If the new SNR is too
high (usually above 12 dB), the quality of the line
will need to be verified
7. The DSLAM and CPE successfully
establish synchronization but the
actual SNR is too low
Adjust the DSLAM configuration for the target
and minimum SNR in the downstream and
upstream directions to the target SNR you are
looking to obtain
8. After inserting a BRX-VDSL2 on a
copper loop, the performance of
other VDSL2 pairs in the same
binder is negatively impacted
The BRX-VDSL2 does impact adjacent copper pairs
in the same binder when some pairs downstream
from the location of the BRX-VDSL2 are not
amplified.
Although the amplified signal from the BRX-VDSL2 is
fully compliant with the allowed spectrum mask
defined for VDSL2, the interference is the result of
the amplified signal impacting the weaker signal from
the DSLAM on adjacent pairs not amplified with a
BRX-VDSL2. It is HIGHLY recommended to amplify
all pairs beyond the installation point of the BRX-
VDSL2.
9. The performance of the pairs is
unstable
Check for potential non-DMT signals in the binder
such as T1 or E1, HDSL, SHDSL...
The presence of these disturbers is known to
negatively impact the performance of VDSL2 and
the disturbance should have been there prior to the
installation of the BRX-VDSL2.
If you believe that the instability is the result of the
installation of a BRX-VDSL2, please refer to the
other issues covered in this table for the more likely
source and the steps to remediate it.
