Getting faxing working.

[pwood]

I've got my old fax machine working through an ATA, Kinda. It does drop out a lot and there's multiple retries to get some destinations to work. It does have T38 turned on, but I'm not convinced it's doing anything.

My sip service has stated they provide T38 faxing, however when I use the 3cx fax server it doesn't accept incoming faxes. If I turn T38 fallback on then incoming faxes don't work (they fail pretty much every time) and if I turn it off then the call doesn't even connect. Does this mean I'm not doing T38 right somehow?

Do I need to turn on Supports Re-Invites and Supports Replaces in my SIP trunk config to get it to work? In the logs I notice with each call:

[CM505003]: Provider:[xxxx] Device info: Device Not Identified: User Agent not matched; Capabilities:[reinvite, replaces, able-no-sdp, recvonly] UserAgent: [] PBX contact: [sip:xxx]

Does that mean I can / should turn on re-invites and replaces for the trunk? Currently I have PBX delivers audio turned on as well, without it the audio quality is terrible. Is it worth configuring a separate trunk that just handles faxes?

Also if I get the fax server working, can I then point the ATA at the fax server login and have the fax server send faxes? I'm a bit confused as to why else there'd be a username/password for the fax server otherwise.

Thanks anyone for your help!

 

[cobaltit]

Are you using a 3CX supported provider? If so, all those settings should be configured in the template for you. Otherwise it's wireshark and trial and error. I can tell you as a 3CX partner and 3CX supported SIP trunk provider that we don't recommend SIP ATA's for faxing and we make people sign a disclaimer if they insist on using one. Inbound fax via T38 to 3CX works well for the most part on our trunks, but if folks want to fax from a fax machine/multifunction we insist on either keeping a POTS line or using our HTTPS fax adapters. No worth our time or headache dealing with FoIP.

And to answer your question 3CX has no ability to send faxes. Outbound faxing on 3CX is only via ATA or 3rd party software that talks SIP to 3CX.

 

[AlexanderReichert]

yes faxing via IP is suboptimal at best. I took the approach to ask my customers to rethink their process: faxing in this time of age should really be outlawed LOL. Invest in a good scanner and email that stuff!

 

[cobaltit]

Agreed. But some people do like the one-step approach of faxing vs two steps so I'm happy to accommodate, it just needs to be on my terms if you are going to yell at me when it doesn't work.

 

[AlexanderReichert]

you can have the one step approach if they invest in a good printer. That is what my customer for the most part did: (they still have an ATA / Fax but hardly use it anymore). the printer can scan and email the scan in one step.

 

[cobaltit]

Ugh... I never recommend customers email directly from the device.. no paper trail

 

[AlexanderReichert]

that is not true necessarily. if you have to login to the device and it records who emailed from the device there is very well a "paper" trail in form of an audit log.

 

[cobaltit]

You must have smarter end users than I do. Anything more than look in your sent items is confusing to them. And if they want to resend it...? Yeah I always have them scan to themselves and then send it out.