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[welshpineapple]

Hello. I believe this is the correct thread I should be posting but first time here!

I am after some advice. I've got a building with 5 apartments in that has had FTTP installed. It's having big problems with the config or hardware.

The system is set up as follows:

TalkTalk Leased Line
MikroTik Router
DM4610 OLT
(Fibre to)
1:8 Splitter
(Fibre to)
Unit 1 ONU (Datacom DM984 GPON ONU)
VOIP Phone

I've had a look and everything looks normal on the set up.

However the ONU keep going down everyday and needing to be power cycled.

anyone have any idea?

[burakkucat]

Welcome to the kitz forum. 

I'm not sure if I fully understand the hardware set up, so some questions are necessary.

• The TalkTalk leased line. Is that provided over an optical or metallic pathway? Is your access via an Ethernet port?
• The MikroTik router. Is that your equipment or is it the terminal point of the TT leased line?
• The OLT, splitter and ONUs. Are they your responsibility to manage and maintain?

As you have asked us for some advice, I suspect that all of the above hardware is maintained by a third party.

What is the situation with the other four apartments? Is the problem just local to one of the five? If it is local to just one, could you temporarily swap the PSU of the ONU and see if the problem moves with the PSU?

[welshpineapple]

Thanks for your reply!

1, Optical I believe and delivered over Ethernet back to Fibre.
2, MikroTik it is our equipment and isn't the termination for TT line. It's so we have some view-ability of the OLT.
3, Yes they are my responsibility.

We being the property company. Have taken over the apartment block and we've got a basic knowledge of networks but can't figure this out.
It's happening to all apartments but mainly to number 5. I think that's because all the other apartments are holiday lets.

It's got a 10Db Attenuator on but does it need a higher Db one? It's got a set up as GPON with the PPPOE in a data centre in Manchester.

[burakkucat]

Thank you for the clarification. It certainly seems to be a somewhat different deployment scenario to what we normally discuss and consider. For clarity, I'll document how I understand the hardware configuration --

• There is a Manchester data centre which hosts a PPPoE server.
• The PPPoE server is linked by a TalkTalk leased line to the apartment block and is presented locally on an Ethernet port. (We do not need to consider the physical bearer of the TT leased line.)
• A MikroTik router is connected to the above Ethernet port.
• A Datacom DM4610 OLT is connected to the MikroTik router.
• An optical fibre links the OLT to a 1 to 8 passive splitter.
• Five optical fibres exit from the 1 to 8 passive splitter and each fibre is dedicated to, and feeds, one of the five apartments.
• Each one of those five optical fibres is fitted with a 10 dB attenuator.
• In each one of the five apartments, the optical fibre is terminated onto a Datacom DM984 ONU.
• In each one of the five apartments, a VOIP telephone is connected to the ONU.

I think that is a clear definition of the hardware configuration. Unfortunately it now results in a few more questions --

• What service is being provided from the Manchester data centre (via the TalkTalk leased line) to you? Who is the provider?
• What service are you (attempting) to provide to the residents in the five apartments? Internet access and telephony?

Since reading your opening post, I have searched for any information or documentation on Datacom products. Not a lot could be found but I now have six PDF documents. None are any real help --

• DM4610 OLT Datasheet
• DM4615 OLT Datasheet
• DM984 ONU Datasheet
• DM984-100B ONU Administration Manual
• GPON Product Brochure Rev.01 (February 2018)
• GPON Product Brochure Rev.06 (April 2019)

(In my searching I found one interesting reference to a "Reddit" post which, unfortunately, had been deleted. The search engine's finding is shown in the attachment, below.)

It is clear that you are attempting to administer and maintain a small GPON network. That is not something with which I have had any experience. However, your mention of the optical attenuators may be a clue. It could be that the light level at each of the transceivers is excessive and is saturating the receivers/overloading the circuits. When the system was installed, I would have expected that optical attenuation would have been measured for each segment of the link and required attenuation calculated. I would have expected the installer to have left all of those details with whoever was due to maintain the network. So I would track down the relevant documentation and then have each optical fibre segment checked, using a laser light source and a level measuring set.

[burakkucat]

Documenting the web-pages, to save other members needing to search for them. 

Datacom DM4610 GPON OLT
Datacom DM984-422 GPON ONU (ONT/Router/VoIP/WiFI)