A good general rule of thumb for optics is +-4. Try to stay 4 db off the bottom, and 4db off the top. The sweet-spot RSL is between 1/2 and 2/3 of the optical budget. For PON, typical OLT/ONT optics run Receive Max of -8, and Min of -27 with an optical de-assert at -31. The sweet-spot is between -17 and -20, with a min/max of -12 to -23.
A typical PON system will have a TX power between +3 and +5, with a 32 way split, add 15dB of insertion loss. You should see -12 on the output of the first splitter (less the optical loss of the fiber between the OLT and the Splitter est .3/km) There should never be a need to attenuate a PON port unless you're working directly on the OLT (You should work through a splitter even directly in the CO/HE) -----Original Message----- From: NANOG [mailto:nanog-boun...@nanog.org] On Behalf Of Colton Conor Sent: Monday, October 12, 2015 10:58 AM To: NANOG Subject: Re: GPON Optical Levels Here is the link to the attachment as it looks like the list does not allow uploading attachment: https://drive.google.com/file/d/0B7sFULLCnLvFdllHQUl6dnJfZ00/view?usp=sharing On Mon, Oct 12, 2015 at 10:47 AM, Colton Conor <colton.co...@gmail.com> wrote: > We are deploying our first GPON network, and are trying to get a sense > of what is a good optical level per ONT. The equipment install guide > says the > following: > > Measure the levels of the 1550 dBm and 1490 dBm receive optical inputs > using > > an optical power meter. The input range should be between -27.0 dBm to > -8 > > dBm. > > > Attached are the measurements I can see and graph from the ONT side. > Trying to get a sense of what range we would graph as good > (green) measured within the clear, what we could consider yellow as > working but out of optimal range, and what we could consider poor (red) range. > > > What about the Laser Bias Current, Optics Module Voltage, and Optics > Module temperature? > >
