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New Member

Dead Air When Calling Busy Number

Hello All,

We have several GW's (5350 and 5300) connected to long distance PRI's. When ever we attempt to terminate a call on to a busy PSTN telephone we get a short ring back and then dead air.

We have tried differnt VFC's and IOS in addotion toseveral configurations with with varying degrees of alerting. We currently have all alerting turned off.

Does anyone have any ideas?

Thanks in response!


Cisco Employee

Re: Dead Air When Calling Busy Number

First need to know what type of signalling you have from PSTN lines which are connected with AS5350 and AS5300. If its the isdn line, its very easy to troubleshoot that. In that case the BUSY should have been sent by local telco switch. Try to follow the following link and see any of that applies here

New Member

Re: Dead Air When Calling Busy Number

I am working with Albert on this. We have tried different type of signaling, currently we are using :

isdn switch-type primary-ni

isdn gateway-max-interworking

no voice hunt unassigned-number

no voice hunt invalid-number

voice call send-alert

voice rtp send-recv

controller T1 0

framing esf

clock source line primary

linecode b8zs

cablelength short 133

pri-group timeslots 1-24

Cisco Employee

Re: Dead Air When Calling Busy Number

The best place to start would be to look at debug isdn q931 when placing this call.

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