How to connect cme 2811 router to POTS

[sherazy941]

I am setting up a voip lab at home I have managed to get the router to give out numbers to phones and to make calls between those numbers however what I don't understand is how do I connect the router to the telephone line that comes into my house so I can place calls externally using the number of my telephone line.  

Also do I need to buy a converter to physically connect the telehphone line to one of the ethernet interfaces on my router? 

Thanks

[Jonathan Unger · Accepted solution]

Hi There,

Congratulations for joining the home lab club! I find that labbing is one of the best ways to learn new concepts!


Unfortunately you will not be able to connect an analog phone line to the ethernet port on your router.

Based on what you have described, in order to connect to the PSTN with your router (voice gateway) you will need a special interface card called an FXO card. This card will allow you to connect directly to an analog PSTN line.

The model of card that you will need depends on which type of router you have. Could you post a "show version" and "show inventory"?

[sherazy941]

Hi Jonathan,

Thank you for replying, I have two Cisco 2851 routers. They both have VWIC 2 1MFTT1/E1.

So I need an FXO card to connect my home telephone line to the router? What is the VWIC 1MFT T1 E1 card for? 

Thanks for taking time to reply.

[Jonathan Unger]

Your MFT (Multiflex Trunk) T1/E1 card is used for PRI circuits. Basically it can carry between 23 (T1 Mode) and 30 channels/voice-calls (E1 Mode) on a single line. This type of connection is very common in enterprise voice environments.

In your lab you can connect multiple voice gateways together back to back via T1 crosssover cables (which you can make yourself).

And yes, you are correct, you will need an FXO interface type if you would like to connect an analog home telephone line to your router.