Warning message

  • Cisco Support Forums is in Read Only mode while the site is being migrated.
  • Cisco Support Forums is in Read Only mode while the site is being migrated.

POTS support for 2800 series routers

Unanswered Question
Jul 13th, 2006
User Badges:


Is it possible for me to use a normal analog phone(POTS) and connect it to a FXS connection on the router? Then the router is connected over a network to a similar router which is connected to a PBX.

If so, what do I need to achieve this?

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 3.7 (3 ratings)
gpulos Thu, 07/13/2006 - 03:49
User Badges:
  • Blue, 1500 points or more

yes, you can connect an analog phone to the FXS,

the PBX would be connected to PRI/T1 card or at very least an analog line from PBX to FXO card.

you will need to configure POTS and VoIP dialPeers to complete the call routing across your IP network.

see these links for more info:



Nukesquad Thu, 07/13/2006 - 15:34
User Badges:

Thanks for the clarification.

If this is the case, how easy or hard is it to config phone extensions for the phones in question?

Particularly if it needs to be done remotely? Can the normal VoIP manager Cisco has like Cisco CallManager suffice?

ccolom Mon, 07/17/2006 - 22:11
User Badges:

Make sure you buy a version 2 vic (2-port fxs) for your 2800 router, The older ver1 vics won't work. The part# is VIC2-2FXS. They are about $300 max. on ebay.

Good luck,


Nukesquad Wed, 07/26/2006 - 17:04
User Badges:

Thanks for the heads up but I'm going for the 4 port one.

David McDaniel Thu, 07/13/2006 - 07:03
User Badges:

Hardware-wise all you would need is a couple 2800 routers with voice software along with an FXS VWIC. On the side that connects to the PBX, you'd need a VWIC on that end as well. After that it's just a matter of setting up the proper dial peers to make it all go. Check out this document:


Nukesquad Thu, 07/13/2006 - 15:49
User Badges:

Unfortunately I can't access that particular document due to insufficient access.

But just to check if I got it right. It IS possible to use normal POTS with the 2800 routers as long as I set up the proper dial peers.

Once done, the POTS would seem like they are connected directly to a PBX (assuming at no point in the system will there a IP phone in use)?

Nukesquad Thu, 07/13/2006 - 23:55
User Badges:

Sorry for the double posting.

How would the router know to identify each of my phones?

I've read the configuration guide for dial peers from what I understand, I don't need to assign separate IPs for each of the phones?


This Discussion