The docs for faxing seem a little light but I think I have managed to put something together. It mostly works but I have a couple of issues. The main one is identifying myself. Setting CALLERID doesn’t seem to have any effect.

How this works is that I have a script that calls Asterisk through AMI, It defines a number of variables and does an originate. It looks something like this:

Action: Originate Channel: SIP/thinktel/%%(destination)s Context: LocalSets Exten: sendfax Priority: 1
Timeout: 30000
Variable: faxfile=%%(faxfile)s Variable: uid=%%(uid)s Variable: destination=%%(destination)s Variable: sender_name=%%(sender_name)s Variable: sender_num=%%(sender_num)s

The variables are filled in based on who the fax was received from.

The extension looks like this. I added extra comments for clarification.

; this extension is called via AMI
exten => sendfax,1,Verbose(0,FAX ${faxfile} to ${destination})
; something for the logs

same => n,Set(CDR(uid)=${uid})
; the user ID (uid) is a field added by us to track the user
; who sent the fax

same => n,Set(CDR(userfield)=NotSent)
; will be changed later if successful

same => n,Set(CALLERID(NAME)=${sender_name})
same => n,Set(CALLERID(NUM)=${sender_num})
; attempting to set caller ID but it doesn’t work

same => n,Set(FAXOPT(headerinfo)=${sender_name})
same => n,Set(FAXOPT(localstationid=${sender_num})
; another attempt to identify ourselves

same => n,SendFax(${faxfile},d)
; faxfile is defined by AMI script

same => n,Set(STATUS=Status: ${FAXOPT(status)})
same => n,Set(STATUS=${STATUS}\nRemote ID: ${FAXOPT(remotestationid)})
same => n,Set(STATUS=${STATUS}\nMaxrate: ${FAXOPT(maxrate)})
same => n,Set(STATUS=${STATUS}\nMinrate: ${FAXOPT(minrate)})
same => n,Set(STATUS=${STATUS}\nECM: ${FAXOPT(ecm)})
same => n,Set(STATUS=${STATUS}\nnumber of pages: ${FAXOPT(pages)})
same => n,Set(STATUS=${STATUS}\nRate: ${FAXOPT(rate)})
same => n,Set(STATUS=${STATUS}\nResolution: ${FAXOPT(resolution)})
; create a string to send back to the user
; the “\n” adds a literal string and not a newline

same => n,GotoIf($[“${FAXOPT(status)}” = “SUCCESS”]?faxok)
same => n,Set(STATUS=${STATUS}\nError: ${FAXOPT(error)})
; if successful the this line is not added to the status

same => n(faxok),Verbose(0,${STATUS})
; put status into log

same => n,Set(FAXNAME=${CUT(faxfile,/,6)})
; sets the base name of the file

same =>
n,Set(FILE(/var/spool/asterisk/fax_status/${FAXNAME})=${STATUS})
; write status to file

same => n,GotoIf($[“${FAXOPT(status)}” != “SUCCESS”]?faxfail)
; on failure skip the reset and go straight to hangup

same => n,System(/bin/mv ‘${faxfile}’ /var/spool/asterisk/fax_success/)
; move the file so that we don’t try to send it again

same => n,Set(CDR(userfield)=${destination})
; replace this field with actual destination

same => n,Verbose(0,FAX charged to ${uid})
; for the log – actual billing uses the cdr table

same => n(faxfail),Hangup()
; all done

Please critique.