Microsoft Legacy OS
Microsoft Legacy OS
Networking Hardware-Other
Networking Hardware-Other

IP Telephone

I'm wanting to do something I see as simple but not sure how so go easy on me. I have a Cisco 2811 router with a 2 port FXO card installed. The IOS is 12.4(13r) and the image file is advipservicesk9. I have an analog line that I want to ring a Cisco VoIP phone that is configured with the directory number 3910. Any help would be appreciated.

hackman122Asked: 2013-05-23

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unfragmentedCommented: 2013-05-24

a pvdm2-8 (smallest) will probably sort you out for fxo channels. General rule is that the number on the end describes how many medium complexity (g.711) channels it can code/decode. High complexity (g.729 etc) channels require double the resources. There are two slots in the 2811 and they are additive, so I would get what you need for now and upgrade later if you need. If you want to get specific, check the cisco dsp calculator tool online at http://www.cisco.com/web/applicat/dsprecal/dsp_calc.html

LVL 7

unfragmentedCommented: 2013-05-23

Let me break this down into usable sections:-

1. Hardware.
Ensure you also have PVDM (DSP) resources, otherwise your FXO will not be usable (see this at the CLI with a show ver).

2. IP Telephony
Configure your basic telephony. Google this - there are bucketloads of minimal configs on the web.

3. Configure dial-peers for external connectivity.
Google this as well. Best to build these to suit the area you are in.

4. Configure voice interfaces - generally want to use PLAR for an FXO.
voice-port x/x/x
connection plar 3910

That should give you a good high-level start.

hackman122Author Commented: 2013-05-24

I don't seem to have a PVDM installed so that would explain it. Not being a VoIP guy I wasn't sure if one was needed when using an FXO card. What would be the minimum PVDM needed to run the scenario I need?

hackman122Author Commented: 2013-05-28

Thanks. I appreciate the information. I'm looking at a PVDM-48 which should get me what I need for now and a possible fractional PRI in the future, which will of course make using the fxo port irrelevant. Go figure.