yup. tx for reply. i forgot to inform you that i use vad option and low bandwidth codec. so far my fax transmission is unsucessful. i am afraid to make changes that could make impact on the network performance. my question is does the codec could make the fax disabled? or it is the vad? tx

Hi,

do you have fxo/fxs in the same router ? In this case, there is no vad neither codec. The only thing you can try is adjusting the fxo impedance arccording to the following document:

http://cisco.com/en/US/tech/tk652/tk701/technologies_tech_note09186a0080477a06.shtml

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