The blue connectors have a flat mating surface and the green ones have an angled mating surface. When you have reflections, the higher the power, the worse the reflection gets. When you go into a dark room and use a very weak flashlight, you can point it at a mirror and see your face even with the light aimed at your faces reflection. If you increase the light, you will eventually blind yourself because you are looking into the light. Now if you shine the light across your image at an angle the light no longer directs back into your face and you can use more light. The ONUs and ONTs are transmitting back pretty hard because they need to get through all the splits, so they tend to use green APC (angle polished connectors) ends. You cannot mix the connector types because the mating surfaces will not make proper contact. When you are using a fiber scope to check the connectors, you have to use an angled adapter on the scope or it cannot read the green connectors. Same with a bulk head scope. You need and angled bulkhead adapter. This is why they are indexed or keyed and you cannot rotate them 180 degrees and plug them in.

These are not single mode fibers, they are multimode

Single mode carries a single ray of light. Multimode carries multiple rays of light. Each ray can be divided into wavelengths. On a single mode fiber you have downstream and upstream separated by wavelength. DWDM (Dense Wave Division Multiplexing) has 96 wavelengths on the same ray, giving 96 channels over a single mode fiber. CWDM has 18 possible channels, the most common being 1550nm and 1310nm. 1550 uses less power than 1310. When there is an ONT at the customer's house, you transmit at 1550 and they transmit at 1310 bearing the greater cost of electricity (although not much worth mentioning). In the name of efficiency and having fiber equipment in an non cooled environment outside you would transmit 1310 and receive 1550 from the analog fiber nodes on a cable plant. Cablecos have two choices that are economically viable with fiber. One is RFoG and the other is GPON. RFoG is RF over Glass which is an analog technology. Fiber nodes have a analog receiver that turns modulated light into RF and feeds that to an amp and a transceiver that receives RF from the amp from customers, then converts RF to modulated light, and sends it back. The RFoG takes the light sent to the node, amplifies it and splits the signal which is routed to the customer's home and that is where an ONU converts the modulated light into RF. The customer's modem sends RF back to the ONU that converts the RF signal to modulated light. The ONU has a built in CWDM mux that splits 1550 and sends it to the forward half of the ONU and combines the 1310 light on the same fiber and sends the signal back to the fiber node and then it all gets sent back to headend, where the signal originated from. The RF itself has modulated compression techniques that overlay the RF that increase efficiency (QAM, OFDM) and also uses frequency division multiplexing and a diplexer to separate the forward and return RF. This is broadband RF, extended to the house over fiber, with mini nodes using the same technology as a full sized fiber node GPON uses baseband signaling, so it is less complex. GPON doesn't use broadband technology, it uses baseband technology and it's digital data. If you are modulating light over fibre to mimic RF it is more susceptible to bends, bad connectors, bad fusion splicing. Baseband digital isn't so sensitive and can be driven further into the network using less power. This means more splits that can cover more homes for less cost. Increasing capacity is as easy as adding more capacity to the OLT and then removing the first 1:2 split. That would double capacity in minutes by moving a patchcord.

@@Todd.T WoW, You man just gave the best answer for me! Although I have already learned this since I needed it a while ago, but thank you for this! Wish you all the best! Enjoy!

@@grizzly6385 Thanks. I know it's a lot but I like to make sure that I have covered a lot the angles when I explain stuff. It's was 1:30 AM and I can't sleep. I have to get up in four hours, and get to work to play with all the technologies I listed, and more, as that is my job. Cheers!!

@@Todd.T No, its not a lot, its what it should be, unfortunately in the web the information is very underdeveloped and its hard to learn about fiber tech using the free info. And since I needed a lot of info in order to graduate my bachelor IT engineering I was doing a very deep research about PON tech and only the indians were lets say more into it. I worked as a fiber technician and splicer, but the software side of the network was not in my daily routines so...

instablaster

៨កោ1បាន9មក

I would check the light at the ONU. If you're above -25db the ONU may have trouble keeping a stable connection.