Asterisk Fax Receive – How To Get The Remoteheader?

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I am using asterisk 11.8 in combination with spandsp to send and receive T38 Faxes. All works fine, but I do not know how to get the remoteheader from the fax I receive.

When I send a fax, there are Faxopts to set the localstationid and the headerinfo, but for receiving, there seems to only exist the Faxopts remotestationid

but for sure on any fax I receive there is a remoteheaderinfo besides the remotestationid… it is on the tiff-file, but I need this info in a channel-variable…

Does anybody know how to get the remoteheaderinfo for a received fax?



4 thoughts on - Asterisk Fax Receive – How To Get The Remoteheader?

  • The list of options available are listed here

    It doesn’t appear that a received header is available unless it is written into the ‘headerinfo’ variable after it is received, I haven’t checked for this.

    From my days working with fax machines, the header could be inserted in the line the TSI is on or in the image being transmitted, if you receive a fax that has been sent to you with the latter set, then the
    ‘headerinfo’ will not be of any use. Perhaps someone with more knowledge may be able to explain this better.

    A quick Google search for ‘fax header outside of tsi’ will provide a list of manuals, here’s one –

    Expand the line for

    To specify the position of Header Position printed on a sent fax
    ([Header Position])


  • Hi,

    thanks for your answer. Unfortunately this is, what I already know. I
    was wondering, why it is possible to set ID and Header for an outgoing fax (which will then in turn be inserted via asterisk on top of the transferred “image”) , while it seems to not be possible to get the Header from a received fax (only the id), although it is present in the faxdocument. The ID is also present in the faxdocument and there does a Faxopt(remotestationid) exist… so I thought, this info must be transferred not only binary within the “image”, but also within the “meta-data” / protocol-data of the fax (within the TSI)…. otherwise asterisk must do some kind of ocr to get the ID, what it definitely does not…

    btw… when using sendfax, asterisk inserts the date, the id, the header and the pagenum on top of each faxpage… someone knows how to modify some settings like font, position, and so on?

    thanks, yves

    Am 18.12.2016 um 00:02 schrieb Larry Moore:

  • Hi,

    I haven’t found anything definitive however I expect the TSI that is sent during initial fax call establishment is stored by the receiving terminal, see pages 28 & 29 of the English version of the document at , I expect the header, which will include the TSI, is all part of the image (Tagline in HylaFAX) and not stored separately on the receiving terminal.