Analog modem and Cisco 2801 with VIC-4FXS/DID card

Answered Question


I need help with this.

I have FXS card on router and analog phone connect to it.

For outgoing calls I use VIC2-2BRI NT/TE card.

I configured dial-peers, and calls are sucessful in both direction (outbound/inbound).

When I try to connect via analog modem (in my laptop, connected to FXS card)to the internet, the connection failed.

Does anyone has needs for connection like this?


I have this problem too.
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Correct Answer by Paolo Bevilacqua about 8 years 6 months ago

Please configure network-clock-select 1 bri 0/3/0.

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Overall Rating: 5 (1 ratings)

Yes I have.

Here is attached part of configuration.

Just simple case. Analog phone has number 1234.

When someone from outside call our number 348800, the call is transfered to the analog phone.

And, of course, analog phone can also dial outside.

But, modem connection does not work.

It dial desired number, BRI channel come to "up" state and call is lasted for about 60 sec, but no modem connection is made.

rseiler Thu, 04/17/2008 - 12:25

Modem capability over analog to digital voice ports was not supported until very recently (12.4(4)T IOS) with modem relay. If you don't have modem relay configured under 'voice services voip' using NSE force then this most likely will not work.

The same used to be true with fax machines, have you confirmed that a fax machine works?

Paolo Bevilacqua Sun, 04/20/2008 - 06:14

There is no modem relay in this case, being both local pots ports, the call is hairpinned.


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