What is the cable that runs from the cable modem to a wall outlet

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I was wondering what type of cable runs from the modem to the wall outlet in my house? Is it a coaxial cable? I'm very confused by what I've read around the internet. There seem to be many variations. Some talk of HFC and others just refer to copper cables or coax (coaxial). Can anyone explain what this cable is and why I need it? The cable is quite thick and black. It also has two silver boxes connecting two of the same cable together.

Silver box joining black cables Cable attaching to modem

user447436

Posted 2015-08-04T13:48:04.893

Reputation:

1As there are a lot of connection cables, you should post a link to a picture. – jcbermu – 2015-08-04T13:55:44.297

Answers

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What type of cable runs from the modem, to the wall outlet

They are Coax cables.

  • The first image shows an isolator, which is used to protect your equipment from surges from your ISP's upstream equipment (the CableModem Termination System).

    It incorporates high voltage capacitors to provide isolation to both the inner and the outer conductors of the coaxial connectors

  • The second image shows a Coax Attenuator, which is used to adjust the signal strength/quality of your internet connection.

    This will adjust the incoming signal from the (probably) copper cable coming to your premises to the range required by your Cable Modem.

They will both have been fitted by your ISP when they installed your internet.

You may also have a Cable Splitter somewhere if you also have a digital television subscription.


Further reading

DavidPostill

Posted 2015-08-04T13:48:04.893

Reputation: 118 938

1I see I mean this cable is years old, It was fitted by an ISP called NTL which no longer exsist, we're now on virgin media and they didn't need change anything and it seems to work fine. Would I need to update this coax cable at all? – None – 2015-08-04T14:31:48.143

5@GR412 I would leave it as it is if everything is working as expected. If it goes wrong Virgin are now responsible for everything upstream of your modem/router. Once upon a time I was also an NTL customer eventually borged by Virgin ;) – DavidPostill – 2015-08-04T14:33:42.347

1@DavidPostill Ok fair enough, but say if i were to replace the cable would I see any improvement? Or are newer coax cables exactly the same? – None – 2015-08-04T14:47:28.787

2@GR412 Probably not. Unless there has been a lot of wear and tear on the cable (bending, ...) You would likely only notice this if you also have a HDTV subscription as well and see interference on the display. – DavidPostill – 2015-08-04T14:51:42.853

2@GR412: Virgin Media are responsible for ensuring correct service delivery to your equipment. If you have a problem with the service, you should ask about it via their support line or forums, who will be able to tell you if there's a problem requiring a new cable. If you do not have service problems then a new cable will make no difference. – qasdfdsaq – 2015-08-04T14:53:30.757

Oh ok thank you, I've literally been trying to understand the entire network infrastructure for days I can finally put my mind at ease now. Thanks all. – None – 2015-08-04T14:55:29.420

@DavidPostill Oh one more thing, is this a copper coax cable or like a hybrid fibre/Coax cable? – None – 2015-08-04T15:56:32.270

@GR412 It looks like a normal copper coax. You would have to open it up to be sure. My guess is Virgin probably now supply fibre to the green box in the street and run coax from there. According to http://www.uswitch.com/broadband/guides/fibre_optic_broadband/ that is the most common configuration.

– DavidPostill – 2015-08-04T16:00:18.320

@GR412 In any case fibre to coax conversion would be done in a special box. If you have fibre to the home the box would be on the outside wall of your house or just inside, and the rest of the cabling would be coax. – DavidPostill – 2015-08-04T16:03:53.573

@DavidPostill Apparently (I asked virgin) it's fibre to the green box , then it's a hybrid coax/fibre that uses DOCSIS3 that leads to my house, then from my house to my modem it;s just a copper coax cable? Does that sound right? – None – 2015-08-04T16:15:51.970

@GR412 Sounds reasonable. Especially if that is what Virgin said ;) – DavidPostill – 2015-08-04T16:17:44.897

We know it is standard coax cable (very likely RG-6 as another answerer said) because the connectors are standard coax type "F" connectors. Hybrid coax/fibre would not be able to use those. Actually, "hybrid fibre/coax" does not refer to a single cable type at all. It refers to a system in which fibre is used to bring signal to community- or neighborhood-level "optical nodes", from which coax lines bring the TV and internet service to the homes. This is often an intermediate step in a changeover from an all-cable plant to all-fibre. https://en.wikipedia.org/wiki/Hybrid_fibre-coaxial

– Jamie Hanrahan – 2015-08-05T03:37:59.830

1btw, my experience is that if you ever change any of this stuff, the next time you have a service call from them they will just look at your cable and say "we didn't supply that!", rip it out, and replace it with their own. So don't bother. :D – Jamie Hanrahan – 2015-08-05T03:39:09.460

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More specifically than the other answers, the most common type of "coaxial" cable is called RG-6. The accepted answer covers the ancillary question of the boxes, so I will focus on the cable.

  • Coaxial cable means there are multiple conductors in the cable, and they share a common center (coaxial -> co-axial -> share an axis). This is in contrast to other common types of cable where conductors might be side by side, e.g. most power cables, RCA cables, etc.

  • RG-6 is a specific category of coaxial cable with a single data wire in the center, plastic insulation surrounding that, and one or more metal shields around that layer which are grounded to reduce signal interference. Typically, RG-6 in North America is either dual shield or quad shield, with quad shield providing a better signal.

RG-6 is really good at carrying signals over long distance, outpacing CAT-5(e) and CAT-6. However, it has less bandwidth. This is why a home network will use RG-6 to connect to the cable company's fiber node (maybe one per city block or two), but use CAT-5e, CAT-6, or WiFi for the home network. Outside the home you need distance, inside the home bandwidth is more important for streaming data between devices.

user76225

Posted 2015-08-04T13:48:04.893

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on your Picture is a technetix 1-way Isolator installed. The cable on the Picture is a regular Cable-TV copper coax-cable.

This Cable is connecting you with your ISP (Internet Service Provider), who give you Access to the Internet.

Without you would not be able to connect to the Internet.

But there are other Option to connect to the Internet e.g. if you have an DSL-Connection you would have a Western-Connector.

I hope i could help you :)

chris

Posted 2015-08-04T13:48:04.893

Reputation: 71

2

It is a coaxial cable.

Generally there could be several types of cable between the wall end your modem depending on the technology of your internet provider. (https://en.wikipedia.org/wiki/Internet_access)

Máté Juhász

Posted 2015-08-04T13:48:04.893

Reputation: 16 807

2

It's a standard coax cable. Your cable company (who is also your ISP in this case) fitted the ends with an piece that modifys the signal to make the signal either stronger or cleaner from your modem going back to the ISP.

Geruta

Posted 2015-08-04T13:48:04.893

Reputation: 1 185