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New Member

Intermittent FXS Dial Tone

Hi Guys,

I am having a problem with a VIC2-2FXS card in a 2811 router. If i plug an analogue phone in one of the FXS ports i do not get any dial tone but then if i plug it into the second FXS port i DO get a dial tone. If i try again a few secs later the dial tone is then gone from the second port and active on the first port. So basically it alternates between the two.

Some of the relevant config looks like this:

Cisco IOS Software, 2800 Software (C2800NM-IPVOICEK9-M), Version 12.4(20)T, RELEASE SOFTWARE (fc3)

network-clock-participate wic 1

network-clock-select 1 E1 0/1/0

If i try add the network clock participate for WIC 0 which is my FXS card i get a message saying slot is empty/does not support clocking. Also tried changing the slot.

voice call send-alert

voice call convert-discpi-to-prog

voice call carrier capacity active

voice rtp send-recv


voice service voip

allow-connections h323 to h323

allow-connections h323 to sip

allow-connections sip to h323

allow-connections sip to sip

supplementary-service h450.12

fax protocol pass-through g711alaw


modem passthrough nse codec g711alaw


registrar server expires max 3600 min 3600

voice-port 0/0/0

cptone GB


voice-port 0/0/1

dial-peer voice 10 pots

translation-profile incoming Incoming

destination-pattern 819

incoming called-number .

fax rate disable


port 0/0/1

Thanks in advance for your help !!!!


Re: Intermittent FXS Dial Tone

Try taking direct-inward-dial off of your FXO/FXS dial peers.

New Member

Re: Intermittent FXS Dial Tone

How would that cause dial tone to alternate between the two ports and cause the port to work sometime and other times not tho? Just out of interest.....

Re: Intermittent FXS Dial Tone

I don't suppose it would. But it shouldn't be there. It will cause problems, even if you haven't run into it yet.