Old school fax machine on new school 3cx server (cloud)

[boomschtick]

Is it possible to get a traditional fax machine to work with a cloud hosted 3cx server 15.5 (latest build?)

I have read threads about people that have done this, but it seems like most of those were hosting on prem. We have Yealink phones that work fine as remote extensions, but they are designed for that.

Does the stuff built into 3cx work for send and receive? Do I need to get some kind of web aware ATA?

Thanks!

 

[sip.bg]

You can use any ATA supporting STUN, even you configure it manually.
Devices like Cisco SPA-112 or SPA-122, Grandstream HT-701 and others will do the job with sure.
This used to be possible always, long before cloud-hosted implementations.

There could be other issues, related to stability with T.38 fax transmission at remote sites, so I recommend using a high-quality ATA like Patton or AudioCodes Mediant for reliable operation.

 

[boomschtick]

Would a Grandstream HT-502 work? I just happen to have one of those sitting around.

 

[sip.bg]

should be working -- device necessary to support T.38 and T.38 settings to be active

you need to configure manually: SIP account -- user ID, ext. ID, auth. ID, password, SIP server -- PBX public IP, STUN server -- the PBX public IP at port:5060

you need to create fax extension before that in 3CX PBX and send incoming calls (DDI number) to this fax extension, your provider must also support T.38 fax

 

[cobaltit]

3CX now supports G.711 faxing so that isn't a requirement anymore although I can't think of any ATA you can purchase new that doesn't have T.38 support.

 

[lneblett]

The short answer is no....at present.

The issue is that 3CX does not yet allow FAX extensions that are created within the 3CX system to be used outside the local LAN as they do with the regular extensions.

It's somewhat of a catch-22 situation. In order to be able to use t.38 or g711 failiover. You must create a FAX extension from within 3CX. A standard extension only supports voice codecs and while g711 is supported, any fax sent to such would start and end as a g711 tranmission, which is not very robust and prone to fail with fax. If you have an extremely reliable, stable and robust internet, then perhaps your experience will be better, but the odds of success diminish as the number of pages sent increase.

In order to get the benefit of t.38, you must create a fax extension as these will be the only extensions where 3CX supports t.38.

https://www.3cx.com/community/threads/ata-wont-connect-on-udp.49416/#post-204684

 

[eddv123]

Hi boomschtick,

I would agree with Ineblett on this one.

For FAX applications (on-premise) I would normally recommend the Patton smartnode 4112 JS device however as some of the
users in this thread have already suggested the Grandstream handy tone products also work well.

I work for a distributer of 3CX, we have had several resellers who have attempted FAX remotely to hosted systems.
None have been successful to my knowledge.

My advice for hosted 3CX systems and FAX would always be to use an online FAX service provider instead.

 

[sip.bg]

I'm using for several years AudioCodes Mediant MP-112 remotely with 3CX cloud server (own cloud into a data-center under VMware) without any issues. Success rate is 100%. The SIP provider is supporting only T.38 fax.

Cisco SPA112/122/2102 are not working enough reliably, especially if renegotiation happens between T.38 and G.711 and vice-versa. Success rate is about 50%.
Grandstream HT701 is performing better (about 70% success rate).
Gaoke has also high success rate (over 80%).

You may expect higher success rates with 3CX v.15.5 and support of G.711 fall-back now -- haven't tested yet. You may examine 3CX fax logs or trace fax traffic with Wireshark.

I assume Patton 4112JS will have also about 100% success rate, but haven't tested.

 

[boomschtick]

@sip.bg That's encouraging. That ATA is only about $50, which is reasonable.

If I can verify T.38 support, I'll give it a shot.

 

[sip.bg]

Browsing the forum, it looks like newer 3CX versions are blocking remote fax extensions (from Internet) for security reasons, so this could be an issue. In the past (maybe version 11 and before) there were cases of PBX misuse through default fax extension (888), registered remotely.

I'm currently using a VPN connection between my office and the data-center and don't have any issues with remote fax using Mediant ATA.

 

[boomschtick]

I got confirmation that my SIP provider does support T.38. Now I have to decide if I want to do a $50 experiment based on your last post. Hmmmm....

 

[sip.bg]

I'm using a VPN connection between fax ATA site (my office) and 3CX cloud (data-center), this turns to be obligatory, as obviously newer versions of 3Cx are not allowing registering of remote fax extensions from public IP addresses (Internet) for security reasons.

This is important detail, depends what network topology you may achieve. Interesting to test remote fax extension (ATA) via SBC, the concept of the SBC should allow remote fax working. Otherwise you need a VPN connection (I'm using MikroTik routers for the purpose).

Regarding AudioCodes Mediant MP112 configuration, I will send you a config file from working device, you will need to adjust SIP server address (3CX), ext. ID, auth. ID and password. You may send me in PM extension details and internal 3CX address (reachable through VPN), without passwords, as they can't be memorized into config file. You need to add them later through web interface of the Mediant. Also I could assist you in configuring the Mediant via Teamviewer.

 

[boomschtick]

I don't think that I want the fax capability bad enough to set up a VPN between my 3cx host and my office. I'd rather not insert that level of complexity into the mix. The SBC is a possible option in the future, but not currently. The SIP provider provides an ATA for $10 a month that works directly with the fiber connection. I may have to use that for the time being.