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New Member

Fax sends blank page


we have a fax-machine connected directly to a bri port on a cisco3825 gw.

To the pstn we have a e1 pri.

pstn <--E1-- cisco3825 <--BRI-- FAX

Sometimes when we send a fax out to the pstn the receiver just gets a blank page but we see a sending successfull.

I tryed it with the fax on a bri-port with e seperate bri/analog TA and also on a fxs-port in the gw.

The fax call is pots to pots!

Does anyone know what is a possible reason for this behavior?

How can a fax send a blank page? I think the remote site must confirm the recieveing?

What is important to configure?

--> My networkclock settings are fine. No slips!



New Member

Re: Fax sends blank page

Hello Sebastian,

I have some experience of 'blank fax'.

(1)I guess there are a lot of errors between these two fax macines. I don't know where.

(2)I guess 'ECM' is disabled or isn't

supported on the recieving side fax macine.

If these two assumption is true, a fax can

send a blank page.

IMHO, the possibility reason is this pots to pots connection type. I guess the fax call doesn't use the DSP in the router. But I don't know the true reason...

Best Regards,


New Member

Re: Fax sends blank page

Hi Yama,

do you know (or everybody else) it is possible to send blank pages with "ECM" enable?

For us it is the worst case to get a "sending complete" and the other site gets a blank site because we ues faxes it for ordering.

Does someone have a pots to pots configuration for faxing and have no problems?

What settings on fax you use?

What setting avoid using DSP for faxing?

Every answer is welcome.



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