upstream snr snmp read tops at 36.1 | docsis.org

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upstream snr snmp read tops at 36.1

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derytelecom
upstream snr snmp read tops at 36.1

Hi

We have a monitoring of the upstream snr in our cisco cmts

we read the mib

1.3.6.1.2.1.10.127.1.1.4.1.5

we notice that the max value read is 36.1

so if a return has a better snr like 39 then the reading will still be 36.1

is it normal ?

is there another mib we could use that doesn't have that limit

mbowe
For our 10k's the max value

For our 10k's the max value is around 36
Whereas cBR8 the max value is around 40
I assume its just a different measurement algorithm

Isnt the MIB just reporting the SNR (not CNR) value seen here? :

show controller cable 5/0/0 up 0 | incl NR

oss-iris
SNR MIB for upstream have no

SNR MIB for upstream have no real standard.
This SNMP object is no more available in DOCSIS 3 MIB.
CMTS providers may use a CNR/SNR/MER or whatever value in DOCSIS MIB.
If you change CMTS manufacturer or type you may find several dB of difference with the same signal.
To work on accurate values you should work with SNR/MER at modem level:
.1.3.6.1.4.1.4491.2.1.20.1.4.1.4
Upstream "SNR" is just good enough for 5 minutes graphs compare to FEC and traffic graphs like everyone.