Virgin Media

Network

Cabinet left with unlocked door…. The Coax part of the HFC (Hybrid Fibre Coax) network.

Despite the size of the cabinet, there is no evidence of any DOCISS equipment for internet access.

This is a pre-fibre rollout area, the left hand shows a Teleste AC2000 wideband RF amplifier, (see https://www.teleste.com/broadband-network/products/ac2000). Note no AC power, the amplifier will be line powered along the incoming coax:-

Feeding a splitter with various signal levels available to compensate for the dropwire length:-

And a POTS wiring frame for phone signals.

Another smaller cabinet, rather too full maybe. This was left with the cover off until I replaced it. The cover in the pavement links the cabinet to the underground ducts. This is a single duct with a swept Tee to link off to the subscribers premises.

Subscriber side

The underground ducting is tapped off to each subscriber's house with a “swept tee” pipe connector, the side arm of this is brought out to a junction box in the pavement adjacent to the house boundary. When a subscriber is activated, a smaller duct is run from the box pictured to the house and a coax/twisted air cable is pulled through from the house to the street cabinet with the taps in.

The original boxes were cast metal, subsequently rollouts used plastic.

For reasons unknown to me, some are triangular. This one was in an adjacent property to the square one above.

Incoming underground coax is fed to an outside unit where the rf signal can be attenuated if required and split to feed extra set top boxes or DOCISS internet modems, and the POTS telephone service can be brought in to the house. The coax cable fed in to the house is then passed through an isolator to keep any dangerous voltages from passing back to the network in case of a fault on the subscriber side.

In the outside box above, the telephone service is not connected.


rb/virginmedia.txt · Last modified: 28/08/2019 23:29 by andrew