I am using bandwidth.com for my incoming lines on a TrixBox 2.0 / FreePBX 2.4 installation and I have never been able to get a fax line to operate properly. I have now purchased a regular Qwest copper phone line for my fax and I want to permanently forward one inbound phone number to that external fax line. Up to this point I have only been able accomplish this by registering a phone to an extension then forwarding from that extension to the external fax number and I am looking for a better way. I think I want this forwarding to utilize reinvite so my PBX will step out of the picture and let the original Faxing caller talk directly to the FAX. I’m sure this can be configured on the server but I am kind of new at this so any help someone can give me would be greatly appreciated.
The best thing you can do is talk with Bandwidth.com.
I’m going to assume that the calls coming in via SIP are using a codec with compression instead of ulaw or alaw (which would then only have a slight chance of working). Compression kills a fax transmission as it alters and/or removes parts of the signal and can interupt the exact timing needed to make things work.
The proper way is to have the Call at the Telco receiver point forwarded (i.e. bandwidth.com), NOT digitized, compressed, and then sent to you where you forward it out.
Audio compression works in part by removing parts of the audio signal that humans do not hear, or can hear ok without needing among other things. That process destroys the true signal that a fax system (aka modem) needs to detect to work properly.
I have talked to Bandwidth.com about this and they told me to go get a standard phone line as faxing is not supported by them. This is why I want to forward incoming fax calls to this external number. Maybe this will not work but I am mainly looking for the configuration on the server to program an extension to always forward to this outside number. If I understand the concept correctly, when using re-invite, my server steps out of the conversation and allows the originating caller to talk directly to this outside line.
What I was getting at was if you have a specific phone number that they (bandwidth.com) now have that you need to answer as the fax have them do the forwarding for you at the switch, that is the proper place for it. Otherwise contact your local telco and have them port the number for you directly to a analog line which will solve the issue in a clean and proper way.
You can create a extension that dials another number (internal or external) under Misc Destinations as one way.
Scan the forums for a way to forward a call to a external number (or cell phone is the common request).