How do cable modem/routers work?

tobywuk · 11-09-2007, 20:49

First off i have BT broadband and my router connects to the phone line, my switch connects to this router and then all my devices connect to the switch.

Does cable internet work the same way and is the router just plugged straight in to the cable port in the wall? If this is the case then do i need a special cable router as im guessing my broadband router will not work with cable?

I hear about a lot of people with cable that use modems. What is the difference between these modems and routers?

If a modem is used, can i just connect this modem to my current broadband router i have to get internet and then connect my network like normal?

MovedGoalPosts · 11-09-2007, 20:52

Your router for ADSL will have an inbuilt ADSL modem. That will not enable it to be connected to cable, you'll need a specific cable compatible router for that.

AbyssUnderground · 11-09-2007, 20:55

Cable broadband enters the house through a dedicated cable from the cab in the road. It then connects to a cable modem or set top box which converts the signal into the usable connection of ethernet or USB. This then plugs into your router (ethernet only) or PC. Use of USB is discouraged due to its slow speeds and newer modems don't even have USB on them.

If you have a router already for BT, you will almost definately need a new one. You need a DSL router, one with an ethernet WAN port and not a built in modem like your current router will have. Recommendations are the Linksys WRT54g as it is known to support the 20Mbps speed mark where as some routers do not. Its not overly expensive either.

Stuart W · 14-09-2007, 00:17

When you get cable Internet, you are provided with a cable modem.

This works kind of like your old ADSL router except it only has one Cat5 port.

You can either plug a single device straight into the cable modem or purchase a DSL router and plug that in.

You could go out an purchase a cable modem router and ask Virgin to add it's unique details to their network so it can be used but I'd recommend against it for 2 very sound reasons.
1: Computability. This modem will need to work on virgins network and be approved by virgin.
2: Price. Why go out and buy a cable modem router when you get a cable modem for free and can purchase a DSL router for a fraction of the cost.

OK, bringing up the cable modem router was a bit moot, I just thought I'd mention it in order to try and give you a better understanding of how it all works.
If you are interested, read on.

OK, there are 2 main types of broadband, ADSL and DSL.
ADSL is used over the telephone network and DSL is used over a fixed cable network.

PHONE LINE
You are provided with an ADSL modem and can plug it into any DSL router and it will work fine.
However, as ADSL is a telephone standard, manufacturers find it feasible to include an ADSL modem built-in to a router (just like your BT one) and some service providers issue these.

You are provided with a DSL modem and can plug it in to any DSL router and it will work fine.
You dont tend to see DSL routers simply because DSL modems come in many different varieties and configurations.

So, Internet comes into your home and needs a modem in order for you to use it.
A modem will only provide access for a single device.
A router can share a single Internet connection to more than one device.

Congratulations for reading this far & HTH

Graham M · 14-09-2007, 07:37

"or purchase a DSL router and plug that in." <- Make sure it's a Cable/DSL Router and NOT an ADSL Modem Router, even PC World aren't likely to be much help on that - although they do tend to label which is suitable for which purpose these days.
"DSL is used over a fixed cable network" <- Are you sure?

Stuart W · 14-09-2007, 09:55

Quote:

Originally Posted by Zeph

"DSL is used over a fixed cable network" <- Are you sure?

Yes.

tobywuk · 14-09-2007, 11:11

Thank you for all your help, it was very usefull. I now just need to go out and buy a DSL router then! I already have a linksys access point and switch so im just going to get a plain old router.

Graham M · 14-09-2007, 11:22

Quote:

Originally Posted by Stuart W

Yes.

How sure?

Stuart W · 14-09-2007, 13:17

If you want to get pedantic, I dare say there are parts of the network using other media, but the basic idea of a CABLED network is simply that.
It's cabled.
Some cable would be fibre, some would be coax.

I dont see the benefit in going in depth with how a cable network works (esp. one as complicated as Virgin, who took over from ntl / telewest, who took over from Anglia / East Coast cable)

However, if you are being pedantic about "DSL is used over a cabled network" then you are just picking an argument for the sake of it. My post was simple & concise and was only to shed some light on which modem / router combo might be best for a given customer.

Graham M · 14-09-2007, 13:52

True it uses "cables" but ADSL is a type of DSL and therefore uses phone lines and not fixed cabling like a Cable Internet connection uses which is something entirely different.

Stuart W · 14-09-2007, 23:52

Isn't that exactly what I was saying??

Quote:

Originally Posted by Stuart W

ADSL is used over the telephone network and DSL is used over a fixed cable network.