Quote:
Originally Posted by TJS
Thankyou 
sorry for the weird question but the geeky side of me couldn't help but want to know where everything connects LOL
---------- Post added at 17:14 ---------- Previous post was at 17:11 ----------
p.s.
any idea why the cabinet closest to my house doesn't have a manhole in-front of it; but the one a bit further down does? whats actually under the covers?
I'm wondering if many the cab closest to me is linked to the one further up the road perhaps
also i live in a relatively rural area I'm not sure if this makes any difference; but the village i'm in has about 40 houses if that; then where the other street cab up the road (with the manhole cover) is part of the 'main village/town' which where i live links on to (kinda confusing LOL)
(SEPH): Interesting. Not many rural areas are covered by VM. Where are you located? |
I can answer some of your questions. As others have stated, the top picture is the VM cabinet.
There are two types of cabinet:
1. Every 200 m apart (in my area at least), they serve the 50 or so homes passed (could be more in densely populated areas). These put copper into the homes and are connected by copper to an aggregating cabinet.
2. Several of the street boxes described above feed to an Optical Node. That street box should have a 240V warning on the cabinet because it is directly powered. In an area like mine, it's less than 500 homes passed per optical node. In densely populated areas it could be as high as 2,000 homes passed. Performance will differ between those extremes. The optical node converts the copper RF to optical signals.
The fibre goes back to a local VM data centre where it aggregates with other fibres from other localities. The fibre distance can be quite high, like the distance between Bracknell and Reading - some 13 miles. The fibres go through equipment that converts the optical signal back to RF and then they land onto line cards in the CMTS. The CMTS is a big FO cable modem! My area, Reading, has 23 CMTSs serving a catchment of around ΒΌ million people (I don't know the percentage of connected homes).
The pinch points are the local optical node when an area is oversubscribed and the line card when the areas concerned are all running flat out. VM are busy installing new line cards with much higher capacity and throughput, allowing more channels and thus reduced congestion. Every so often, VM resegment an area. That is they redistribute localities across line cards to provide better load balancing.
The signal carried along the copper is both TV and internet. Your own home receives every signal transmitted to your locality. Only signals addressed to your cable modem go past the BPI+ filter in your modem; everything else is discarded.
And that's a horribly simplified description!