In this tutorial, you will learn a couple ways to connect a physical router to your home phone line as part of your “virtual voice lab “.  An all virtual voice lab would be ideal. However, real hardware is necessary for a more complete voice lab. I will be using a 2611XM for my home lab, but you can use just about any Cisco router with a couple fxs and fxo ports.



Several of you have contacted me over the past few months regarding the virtual voice lab and exactly how it should be done. Honestly, there is no right way. This tutorial series is meant to show you what is possible not exactly how it “must” be done. Have fun with your lab. If you don’t want two branches or you do not see a need for two different PCs for the branches, then customize it to the way you want it. It will help you learn.

This tutorial is in the same spirit. I will give you a few different ways you can connect your home phone line into your lab but seriously, I encourage you to make it your own and set it up the way that makes sense to you. Have fun with it. Change it. Break it. Fix it. Learn.

The 2611XM is an older router. The good … its cheaper. The bad … there are subtle differences compared to the ISRs used in the CCIE v3 lab topology. For example, transcoding is configured differently. Please pay attention to the differences if you are studying for your lab.

Here are a few things that become possible with the addition of a router that are not possible with an emulated router.

  1. voice port debugs
  2. Communicate with the outside world with h323, sip and mgcp gateway configs.
  3. T.37 fax to email
  4. Hardware conference bridging
  5. Transcoding
  6. Test BCAD for a home auto attendant.



Scenario #1 : Lab connected to the home

In a traditional home phone setup, a pair of wires extend from the telco to your house. This land line or POTS (plain old telephone system) line supplies dial-tone to all the phone jacks in your house. Below is a basic representation of a typical phone connected to a typical phone jack.



If you have a standard POTS line from the phone company and have no desire to incorporate your entire house into your lab, you should probably follow this scenario. Below is a representation of how your lab should look when you are finished following the steps below the drawing. Your router should be connected to the phone jack and the telephone should be connected to your router. If you do not have both FXS and FXO cards, just try to work with what you have.

  1. Find a phone jack close to your lab equipment.
  2. Unplug the analog phone from the wall jack
  3. Connect one of the router’s fxo ports to the wall Jack.
  4. Connect the analog phone to one of the router’s fxs ports.
  5. Configure the fxo voice port to send calls to extension 1000 with the ‘connection plar’ command.


    voice-port 0/0
      connection plar 1000

  6. Configure a dial-peer for extension 1000. The following pots dial-peer will send all calls for extension 1000 to port 1/0.


    dial-peer voice 1 pots
      destination-pattern 1000
      port 1/0

  7. Attempt a call to your house. The analog phone should ring through your router.PLAR stands for ‘private-line automatic ringdown’. Some people also refer to this as the batphone setup. When a call comes in on the FXO port, it is automatically routed to the FXS port connected to the analog phone.



Scenario #2 : Home connected to the lab (voip provider)

The reason I named this scenario “Home Connected to the lab” is because the router is not receiving dial-tone from your house. Your house is receiving dial-tone from your router. This is how I have my house setup. This works best if you do not have dial-tone from the phone company. Only a voip provider.





I do not have a traditional land line from the Telco. I get dial-tone from an ATA provided by a voip provider. The cool thing about this setup is that I did not have to re-wire anything and I am able to provide dial-tone to my whole house from my router.

Eventhough the local phone company turned off dial-tone when I cancelled my service,  all the jacks in the house are still connected to each other, so by connecting one jack in the house to an FXS port, all jacks have dial-tone. I learned this first by connecting my ATA to a phone jack before I started working on my home lab.

Here are the steps

  1. Unplug the analog handset from your VOIP ATA (analog terminal adapter)
  2. Connect the ATA to an FXO Port on your router
  3. Make sure you do not have dial-tone from another phone in the house.
  4. Connect the your router’s FXS port to the wall jack close to your lab. Now, check the other phone again. You should have dial-tone.
  5. Configure voice-ports and dial-peers to route calls from the FXO port to the FXS Ports. Voice Port 1/0 is the FXS port connected to the wall jack. Voice Port 1/1 is the FXS port connected to the analog handset. The ‘preference 1’ option tells the router to choose dial-peer voice 2 as the second option, because dial-peer voice 1 is configured with ‘preference 0’ by default.


    voice-port 0/0
      connection plar 1000


    dial-peer voice 1 pots
      destination pattern 1000
      port 1/0


    dial-peer voice 2 pots
      destination-pattern 1000
      preference 1
      port 1/1




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