SNR Margin
Looking for a little help in understanding my SNR Margin.
WAS synching @ 8128 downstream with an SNRM of ~ 8db (varying between 7.8 and 8.2 over a long period of time) then after a brief power outage last night reconnected,still at 8128 synch but SNRM of 6db (varying between 5.4 and 7) ie lower AND much more variable.
Question 1.: As this was a household power cut (not the whole area) does this reduction in SNRM indicate a problem with the router rather than the line?
Question 2. :Does the variability in SNRM increase as the margin value goes down because its a log scale?
WAS synching @ 8128 downstream with an SNRM of ~ 8db (varying between 7.8 and 8.2 over a long period of time) then after a brief power outage last night reconnected,still at 8128 synch but SNRM of 6db (varying between 5.4 and 7) ie lower AND much more variable.
Question 1.: As this was a household power cut (not the whole area) does this reduction in SNRM indicate a problem with the router rather than the line?
Question 2. :Does the variability in SNRM increase as the margin value goes down because its a log scale?
Nobody got any opinions
Normally, if the SNRM drops, you will see an increase in sync speed, unless you are at the max value for your line. A lower SNRM means that the difference between the absolute minimum signal-noise ratio your line needs to "hear" the adsl signal and the actual value now, has been reduced; in your case the value it settled down at is around the normal value for a standard copper phone line that's not absolutely perfect. However, a lower SNRM, because the margin between ideal and actual has been reduced, means that the router will pick up more errors on the line. This in turn will mean that the SNRM value will be more sensitive to hourly fluctuations and errors if you are plotting the value as a line, and you will see this in real time. This explains why the fluctuations were apparently les when the SNRM was higher.
The dynamic line management will adjust the target SNRM by monitoring line errors, amongst other things. It looks as though your brief outage caused the router to reconnect at a slightly lower SNRM, probably because the DLM had previously monitored errors which weren't too excessive, and had decided that you could get away with an SNRM averaging about 6dB when you resynced.
If your router holds the signal it likes what it sees so I wouldn't worry too much about it. Not a problem with the router. And yes is the answer to the second question!
The dynamic line management will adjust the target SNRM by monitoring line errors, amongst other things. It looks as though your brief outage caused the router to reconnect at a slightly lower SNRM, probably because the DLM had previously monitored errors which weren't too excessive, and had decided that you could get away with an SNRM averaging about 6dB when you resynced.
If your router holds the signal it likes what it sees so I wouldn't worry too much about it. Not a problem with the router. And yes is the answer to the second question!
Thanks very much nozzer!