Can anyone help enlighten me, do these connectors have a formal name/standard? These are found in a street side ISP broadband cabinet for residential customers in the UK. Would I be correct in thinking that each of these cables goes direct to a customers home?

Would it not be quite trivial then to initiate a physical Man-in-the-middle attack against a specific target? What is the purpose of all the 'messy' wiring to the right of the pic?

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6 Answers 6


"Connectors"??? The blue distribution block? (possibly a distribution amp) The little "caps" -- actually terminators? Or the RG-59 compression crimps on the cables?

It's as secure as the cabinet. (which is often not that secure) Almost everything on a cable network these days is encrypted, so a physical tap wouldn't do as much good as you might think. And it's all a shared medium anyway, anyone on that block can see everyone else's traffic.

The mess on the right appears to be analog POTS lines, but could be anything.

  • 1
    Clearly, this specific cabinet is NOT secure if he was able to take a picture of it. ;) Jun 19, 2015 at 18:35
  • Given that the OP is in the UK the cabinet is almost certainly a virgin media one and the twisted pair lines will indeed be POTs (Unlike cablecos in some countries, Virgin Media's predecessors installed POTs phone networks alongside their cable TV networks) Nov 23, 2016 at 13:33

It looks like they are regular F connectors. The unused connectors appear to have a protective cover on them.


The "caps" on the splitter/amplifier block (the thing all the black cables are attached to) are terminators.

RF signals hate un-terminated cabling. Leaving one of the un-used RF connectors 'open' would cause interference for all the other connections (signal reflections from un-terminated connections can be problematic).

The cap essentially contains a resistor between the shield and the center conductor. Typically you see the termination caps on any distribution block installed by the provider.

Technically, you should use termination caps on all un-terminated connections. This includes those in your home in your bedroom that no longer has a TV or cable box, etc. connected because you only get your video entertainment form the Interwebs now....



A cable technician (in the USA) told me that they use regular F connectors. He also said that in places where service theft is common (at least of the unencrypted basic cable), they put a special pass-through connector over the connector on the distribution board which requires a special wrench to remove. That way, if someone plugs in their own cable to the board, they will have to plug it in through the extra connector, which will be immediately apparent to the next technician who inspects the box. However, the connectors in this box look like simple protective caps.


The green cabinets appearing across the UK are BT Openreach FTTC cabs (I'm not directly in the industry and I've already (ab)used a redundant acronym!)

They basically put some fibre connections from the nearest exchange in your locality. The wires on the right are almost certainly the copper connections to individual houses/businesses.

The cabs seem pretty secure and fairly solid but I have heard tales of people chaining a van to one and dragging it off to expose and steal the reasonably valuable copper.

On the IT security front, I suggest that these are not much of a weak link. Your banking should be SSL encrypted and access to other things should use VPNs of one form or another.

If I were you I'd be more worried by the modem that you get at your termination. It's a black (OK white) box that was manufactured in China by Huawei. You don't get the login details for it and have to open it up and use the remains of the RS232 connection on the motherboard to get at it. I doubt it's really a security problem but who knows what else is in that box or in the firmware on it.

Cheers Jon

  • Nearly all communications provider cabinets in the UK are green. That includes the new openreach FTTC cabinets but also the openreach PCP cabinets and the various cabinets used by Virgin Media. Given the presense of both twisted pair and coax the OPs cabinet is almost certainly a Virgin Media one. Nov 23, 2016 at 13:26
  • An openreach FTTC cabinet will have fiber and twisted pair but no coax. Furhtermore in most cases the twisted pair lines leave the FTTC cabs in neat "tie cables", they are patched to the Exchange (for the POTS service from the exchange) and Distribution (for the combined POTS/VDSL service to the customer) lines in the PCP cabinet. Nov 23, 2016 at 14:53

The purpose of the messy wiring on the right is to degrade service on the lines.

I kid... slightly. That's the result. The purpose is to save time. The excess ends (you can see a green wire pointing up from the metal bracket going nowhere) are sometimes called "pigtails." Some current can bounce back off of these and degrade service.

The proper thing to do is to trim the excess ends where you punched them down. The proper thing to do is to organize your wiring, and perform preventative maintenance including trimming the ends someone else failed to, organizing their wiring, tagging unidentified lines, etc... but these telco techs get ridden pretty damn hard in most places. Clients escalate everything, salesmen cut deals, bosses cut opex, and maintenance manning is considered a cost centre so while it may take 6 dudes to properly wire and maintain your area, you've got to do it with 3. You're going to leave pigtails, some wires won't get tagged, and the whole thing is going to be a mess.

... and I'm not one of these guys. I've just had to deal with the good and bad ones.

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