I am running FreePBX 13.0.195.26 with Asterisk 13.24.1, Hylafax + iaxmodem also installed and there is a IAX extension created for handling incoming fax, I’ve got an DID number with voice + fax capable from Twilio, incoming call / fax is able to hit my Asterisk then decide where they go by using “inbound route”, however only one destination can be pointed, so I can only use the DID number either with voice call or fax.
Tried to google and know there is a feature “faxdetect” can be used to determine the incoming call is voice or fax, anyone please guide me how to use it in my configurations? if fax detected, then point to the IAX fax extension; if no fax detected, point it to a normal SIP extension.
Once you have installed the Fax Configuration module, a Fax tab will appear in each Inbound Route that you can configure as desired.
However, unless you are trying to preserve a large investment in preprinted brochures or business cards that list the same number for voice and fax, I recommend against doing that.
Fax detection is not magic – Asterisk answers the line and listens for fax tone. The false answer supervision results in misleading log entries, adds 3 seconds to voice call processing, and may result in extra charges for the caller.
Just get a separate DID for fax; on Twilio it’s only $1 per month. If you have many users, each to have his own fax number, consider AnveoDirect ($0.19/mo. + $0.004/min.) or SignalWire ($0.08/mo. + $0.00325/min.)
Edit: I had assumed that you are in the US. My apologies if you’re in a country where DIDs are expensive.
Ya, I am not in US and the DID price is more expensive, however, it sounds separating 2 numbers for voice and fax is a better option, since Asterisk will auto answer the call in order to detect fax tone, it caused extra cost.
It is not just Asterisk. All phone systems have to answer the call to detect the fax tone. It is not possible to know if it is a fax prior to being answered.