Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[evo-nige]

Hi,

Not sure if the answer to this is obvious and been answered here before but seach came up with nothing so here goes!

I have two FTTC openreach lines to our property, one being a fairly recent adition, which i run through two Vigor 167's and load balance with a Vigor 2927 giving 130mb / 35mb speeds.

Our original line has a voltage of -48v with a decent connection speed / low error counts and 6bd SNR as can be seen in the screen grab below while the newer line has no or 'very' little voltage (not enough to trigger the line tester) thus looks like a dead line, yet connects with a lesser speed / higher error counts and a 2db SNR.
Both lines are data/Broadband Fiber 2 only and connected directly to the modems themselves.

Is this normal? Anyone know the reason for this?

Any info would be greatly apreciated!

Nige

[tubaman]

Thinking logically i suppose there is no requirement for a data only service to have the line voltage present. Given that I assume the original line did once have a telephony service on it and has never been disconnected at the exchange end?
The 6dB and 2dB is a little more curious - do you know if you are on a Huawei or ECI cabinet, as I'd expect the 2dB line to be running G.INP and be Huawei but that doesn't explain the 6dB on the other line. Maybe you are on one of each as that isn't unheard of.

[burakkucat]

I have two FTTC openreach lines to our property, one being a fairly recent adition, which i run through two Vigor 167's and load balance with a Vigor 2927 giving 130mb / 35mb speeds.

Our original line has a voltage of -48v with a decent connection speed / low error counts and 6bd SNR as can be seen in the screen grab below while the newer line has no or 'very' little voltage (not enough to trigger the line tester) thus looks like a dead line, yet connects with a lesser speed / higher error counts and a 2db SNR.
Both lines are data/Broadband Fiber 2 only and connected directly to the modems themselves.

I'm not sure what to make of the observations you report. 

I guess that if those two circuits were within my "paw reach", I would connect a time domain reflectometer to each one, in turn, and then analyse the traces so obtained.

[j0hn]

Roughly 14% of SOGEA lines have a line voltage and even that voltage will be intermittently turned on/off during the day.

So yes what you are seeing is perfectly normal.
The presence of or lack of line voltage should make no difference to how the line performs.

Section 1.4 of Openreach SIN 517 explains why some lines have voltage while others don't.

The 2nd line you have posted stats for also appears to have a capped/banded upstream, capped at 17Mb/s.

[Alex Atkin UK]

Section 1.4 of Openreach SIN 517 explains why some lines have voltage while others don't.

I think explains is a strong word here, it doesn't explain why (except in the case of a switch reboot their end) only that it will happen.