How to Connect Router to Telephone Line?

When someone wonders how to connect routers to telephone lines, it’s probably because they’re using DSL (Digital Subscriber Line). If we were using cable, we wouldn’t be wondering about this.

Connecting a router to a telephone line is something we can’t do because we don’t connect a router to a telephone line. We connect a modem or a gateway unless we’re connecting a landline to a router. That’s why this article discusses DSL, the differences between gateways and routers, and how to connect a VoIP phone to a router.

How to Connect Router to Telephone Line?

What is DSL?

The Digital Subscriber Line uses a telephone network to provide a connection to the internet. It’s different from a dial-up connection because it uses different frequencies and you can still make phone calls while using the internet.

How Does DSL Work?

Most people think we need a phone line to have DSL, but this is not the case. ISPs (Internet Service Providers) that provide DSL internet access commonly use dry loops, telephone lines that don’t have an active service. You can’t make or receive calls.

Then we have this inactive phone line that goes into our house and reaches the phone jack. Now, the whole telephone line has different cables in it, and these cables transfer data at different frequencies.

Dial-up internet access used PSTN (Public Switched Telephone Network) to get us on the internet. It actually worked through dialing numbers on the telephone line. However, the frequency range on the line was narrow, and it didn’t provide significant speeds.

The DSL frequencies go from 25.875 kHz (kilohertz) to 1104 kHz, providing a much wider range, and a much more reliable speed regarding downloads and uploads. There are two types of DSL:

  • Symmetric DSL: The symmetric DSL reserves equal frequency ranges for upstream and downstream traffic, and this means that both the download and the upload speed should be equal. This is highly impractical because we usually need a higher download speed.
  • Asymmetric DSL: ADSL is different, as the frequency range for upstream traffic is lower than the one for downstream traffic, and so this type of subscriber line is the most common among users.

Now that you know how DSL works, the only thing that you need to understand is that it only works with a DSL modem or a gateway provided by your DSL ISP. So, what’s the difference, and why isn’t it a router?

Gateway or Modem or Router

A modem is not the same as a router because you need a modem to have an internet connection in your home, and you can’t have internet access if you’re only using a router. The router is something that spreads the connection to the devices in your home network.

So, the modem takes analog signals sent from your ISP and transforms them into digital signals to provide internet access in our home. However, it also transforms digital signals coming from our devices into analog signals and sends them back to the ISP.

It’s a non-stop transaction between the two, and the modem is the modulator and demodulator, that’s why it’s called the modem.

Then we connect a router to our modem to make a home network that provides internet access to the other devices in our home using wireless signals or wired connections. It routes the internet connection to all the devices.

If you want only one device to have internet access, you don’t need a router, you can connect the device directly to the modem. 

This is the difference between modems and routers. A gateway is a whole other thing, it’s a router/modem combination. So, it’s not technically a whole other thing, more of a combo of both, and it performs both. It provides internet access to a household, and it routes the connection to all the devices.

Connecting a Gateway to a Telephone Line

A gateway works as a router and a modem so we can technically connect a router/modem to a telephone line. If we have a DSL modem, it will come with a cable that goes into a telephone jack in the wall, which then connects the modem to the internet.

All DSL modems are connected to telephone lines that are active or dry loops. So, once you plug the provided cable into the jack, your modem is connected, and that’s how you do it. However, you can still connect a phone to a router.

Connecting a VoIP Phone to a Router

You can try connecting a landline phone to your router or modem, but the fact is that it won’t work. We need to plug a landline phone into a phone jack for it to work. So, for a working phone plugged into a router or modem, we need another type of technology. We need VoIP (Voice over Internet Protocol) technology.

What is VoIP?

VoIP is an awesome thing because we can make phone calls using an internet connection. We don’t need a landline to place calls any longer. There are tons of VoIP software out there, meaning that we don’t even have to have a physical phone to call someone. We can do it from our laptop.

Many companies’ customer service departments use VoIP to provide support to loyal customers. The main reason is that they don’t have to install tons of devices or wiring to have basic features such as transferring a call, holding, etc.

Now that many people are working remotely, VoIP services are more commonplace than ever. Still, some companies and small businesses use hardware that comes with these services, that’s why we need to understand how to connect a VoIP phone to a router.

Recommended reading: How to Connect a Landline Phone to a Modem?

How to connect a VoIP phone to a router?

It’s very simple. Once you get a VoIP phone, you usually get a box containing all the equipment. The box usually contains a control unit, handset, handset cable, Ethernet cable, power cable, and a stand.

Use the coiled cable to connect the handset to the unit base, connect it to the handset port. Next, connect the Ethernet cable to the LAN port and your router. Finally, connect the power cable to the phone, and power it on.

The phone is connected to your network now, and the only thing you need to do is configure it. You can easily do this by entering the phone’s IP address into the address bar of your browser, and after that, you enter your default username and passwords, usually both admin.


There you have it, we’ve answered how to connect routers to telephone lines, and we’re technically not connecting the router to a telephone line. If you’re using a DSL modem or a gateway, you’re connecting it to a telephone line.

Finally, you can connect a telephone to your router if it’s a VoIP phone, not a landline. If none of these provide the answer you were seeking, it might be best to contact the manufacturer of your router. Their support team might have some answers for you.

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