Did you manage to "unlock" the Openreach ONT to get these stats?

Edited by Grimers (Sat 15-Jan-22 15:49:27)

Back story here.

In reply to a post by CarlTSpeak:

The OLT reports its transmit power. I'll have a look when I'm back.

Text
1 23 4	OLT Information         Current Value   Reference ValueOptical module type:    Class B+        -- Transmit optical power: 3.8 dBm 1.5 to 5 dBm

Losing just under 17 dBm on the path, so 15 dBm for the splits and a total of 2 dBm for insertion loss and loss within the fibres themselves.

That's pretty low really - the exchange must be fairly close (under 2 miles??) and/or the path losses for splices and connectors are all excellent.

In reply to a post by ft247:

In reply to a post by BuckleZ:

I think my line was -21dB when tested, they tried another port an it was worse, wasnt sure if thats good or bad, but ive had no issues since it going in

That's more like what I'd expect, C+ sensitivity is (I think) -32 so you should have no issues.

From Carl's extract the OLT is running Class B+ optics

I just had a look at my ONT (Huawei HG8110H-20) and that is also Class B+

Looks like Carl's replacement 4-port ONT is actually Class C+ (TX power 0.5 to 5 dBm and RX sensitivity -30 dBm).

From what I can see the only difference between Class B+ and Class C+ at the ONT is increased receive sensitivity from -27 dBm to -30 dBm (which is twice as good!). The upstream TX power from the ONT is the same for both B+ and C+ optics at 0.5 to 5 dBm.

At the OLT - Class C+ (3 to 7 dBm) clearly puts out a lot more power than B+ (1.5 to 5 dBm), but Openreach appear to be using B+ at the headend (and in standard issue Class B+ at the ONT)

Edit: corrections!!

Edited by Pheasant (Sun 16-Jan-22 10:00:37)

In reply to a post by Pheasant:

That's pretty low really - the exchange must be fairly close (under 2 miles??) and/or the path losses for splices and connectors are all excellent.

I agree - especially when you consider that 15dB is the theoretical minimum loss for a 32-way split, most manufacturers quote around 16.2-16.5dB.