Question about wiring at VDSL cabinet & dial-tone injection

sennah

This has been on my mind for some time so I thought I'd post up here and see could anyone answer. I might be a million miles off the mark so please bear with me!

My understanding of how VDSL cabinets are laid out is that fibre comes from the exchange to a Huawei cabinet which host the MSAN, batteries, etc. Beside this is usually a wiring cabinet that was likely already in place for some time. This larger cabinet houses a number of separate punch-down blocks - one block for the copper pairs coming from nearby houses, one block that's cross-linked across to the VDSL cabinet and one block for copper pairs running back to the exchange. Am I right so far?

When a customer requests VDSL, the technician runs a jumper from the VDSL block and punches into the customers pair on the distribution block. From reading around, it seems eircom aren't yet running voice services from the MSAN (VDSL cabinet) so I assume they are running a second jumper from the exchange block and into the customer's pair again

This is where I'm a little stumped. If this is how connections are wired, what stops the VDSL signal "leaking" back along the pair to the exchange... thereby making the pair much longer than it should be or introducing something like a bridge-tap effect? Or perhaps I'm completely wrong. Are they in-fact supplying the voice and the dial-tone from the VDSL MSAN?

ED E

The loom is pre wired over from CCP to MSAN when the units installed. Upon premises install the tech just drops the filter into action which connects the DSLAM and blocks ADSL from the exchange(lpf, only tones in the voice spectrum get through). 48DCV still comes from the AXE in the exchange.

sennah

ED E wrote: »

The loom is pre wired over from CCP to MSAN when the units installed. Upon premises install the tech just drops the filter into action which connects the DSLAM and blocks ADSL from the exchange(lpf, only tones in the voice spectrum get through). 48DCV still comes from the AXE in the exchange.

Thanks ED,

So am I reading you correctly that there are filters in the CCP which allows the voice from the exchange through to the end user but blocks the VDSL signals from traversing back to the exchange? I really should have thought of this!!

What might the reasoning be behind eir not providing the voice service and voltage from the MSAN? It does support it if I'm not mistaken

ED E

Yeah.

Its a complex issue. POTS and Dial Up network are part of the USO, have to be available for LLU where feasible etc. Currently they can't shut down the main AXE so there's no real benefit in migrating lines out for a service that will probably be discontinued very soon. MSANs do support it but I'm not sure if its a new lime card. Current cards do VDSL2 AND ADSL2+ but eir aren't offering ADSL from there despite the potential for remote lines.

Irishcure

Hi Marno,

Firstly thank you so much for the updates you give on the broadband cabinets. It gives us all hope :-)

Just wondering as you seem to be in the know. Have I any way of finding a date for our cabinet (NRT1_003) do you know?
Seems there is some movement there but have not been able to nab the guys when they are working at the site.

many thanks
Tony

ED E

Only openeir.ie/Our_Network/