FaxServer disconnects after 0.5 second if voip provider is not T38 compliant?

[jfproulx]

Hello 3CX support,

Our fax machine has been working fine with our voip provider (voip.ms) for the last 5-6 years and it also works fine on extension 880 of 3CX. We have been running V14 SP3 for a year now and this year, we've been trying to get the FaxServer to receive on extension 888 as we need the ability to forward faxes by email directly. However, the FaxServer continuously disconnects the line after 0.5 seconds stating "BYE from PBX".

We have read every 3CX support article that we could find and tried everything for the last two days but nothing works. We thus contacted our re-seller who told us that the FaxServer tests to see if the line is T38 and if it is not, 3CX disconnects the line.

Is that true? If it is, why does your website state that "It is also possible to use a VoIP provider that does not support the T.38 protocol, however, the quality of the fax implementation between VoIP providers varies and therefore can not be guaranteed." (source: http://www.3cx.com/docs/fax-server/)

Please confirm if it is true that the 3CX FaxServer tests whether a line is T38-compliant and disconnects if it is not such that your users don't waste days trying to get it to work when it actually does not.

Oh... and if it is true, then you should definitely update your website to reflect the correct information here: http://www.3cx.com/docs/fax-server/ (And if it is not true, maybe it would be a good idea to send a technical bulletin to your resellers such that they can support the FaxServer adequately and correctly.)

Thanking you for your prompt response and best regards,
Jeff

P.S.: here is a log of the event

02-Nov-2016 19:41:18.225 [MS105000] C:17.2: No RTP packets were received:remoteAddr=127.0.0.1:10002,extAddr=0.0.0.0:0,localAddr=127.0.0.1:7040
02-Nov-2016 19:41:17.738 Leg L:17.2[Fax] is terminated: Cause: BYE from PBX
02-Nov-2016 19:41:17.737 [CM503008]: Call(C:17): Call is terminated
02-Nov-2016 19:41:17.736 Leg L:17.1[Line:10003<<5149983409] is terminated: Cause: BYE from PBX
02-Nov-2016 19:41:17.625 NAT/ALG check:L:17.2[Fax] REQUEST 'INVITE' - basic check passed. No information for extended checks
02-Nov-2016 19:41:16.136 [CM503007]: Call(C:17): Fax:888 has joined, contact <sip:[email protected]:5006>
02-Nov-2016 19:41:16.135 [CM503007]: Call(C:17): Line:10003<<5149983409 has joined, contact <sip:[email protected]:5060>
02-Nov-2016 19:41:16.133 L:17.2[Fax] has joined to L:17.1[Line:10003<<5149983409]
02-Nov-2016 19:41:16.133 NAT/ALG check:L:17.2[Fax] RESPONSE 200 on 'INVITE' - basic check passed. No information for extended checks
02-Nov-2016 19:41:16.078 [CM503025]: Call(C:17): Calling T:Fax:888@[Dev:sip:[email protected]:5006;user=phone] for L:17.1[Line:10003<<5149983409]
02-Nov-2016 19:41:16.032 [CM503027]: Call(C:17): From: Line:10003<<5149983409 ("GAC-fax:JEAN FRANCOIS M" <sip:[email protected]:5060>) to T:Fax:888@[Dev:sip:[email protected]:5006;user=phone]
02-Nov-2016 19:41:16.032 [CM503004]: Call(C:17): Route 1: from L:17.1[Line:10003<<5149983409] to T:Fax:888@[Dev:sip:[email protected]:5006;user=phone]
02-Nov-2016 19:41:16.032 [CM505003]: Provider:[1. Voip.ms - GAC Fax] Device info: Device Not Identified: User Agent not matched; Capabilities:[reinvite, replaces, able-no-sdp, recvonly] UserAgent: [voip.ms] PBX contact: [sip:[email protected]:5060]
02-Nov-2016 19:41:16.031 [CM503001]: Call(C:17): Incoming call from Line:10003<<5149983409 to <sip:[email protected]:5060>
02-Nov-2016 19:41:16.031 Line limit check: Current # of calls for line Lc:10003(@1. Voip.ms - GAC Fax[<sip:[email protected]:5060>]) is 1; limit is 1
02-Nov-2016 19:41:16.031 NAT/ALG check:L:17.1[Line:10003<<5149983409] REQUEST 'INVITE' - basic check passed. No information for extended checks
02-Nov-2016 19:41:16.024 [CM503012]: Inbound any hours rule (GAC-fax) for 10003 forwards to Fax:888

 

[briankayser]

Just FYI - 3CX Support typically does NOT respond to posts here, it is user->user. So if you want them to answer you may be waiting forever.

I am not 100% certain, but I think your reseller is incorrect. You way want to ask your VoIP provider about it though. I talked with mine and it wasn't a big deal for them to change routes to ensure I always used T38 compliant providers. No extra charge.

 

[jfproulx]

Hi Brian,

Thank you for pointing out that "3CX Support typically does NOT respond to posts here, it is user->user" as I thought that this was 3CX's way of having a direct customer support channel.

This lack of direct customer support is a problem as I am running out of ideas on how to fix the FaxServer and since 3CX seems to only offer support through the re-seller, we are stuck with a re-seller that does not seem very "willing" to support 3CX's FaxServer.

Thank you for the hint regarding our voip provider as well: they do offer T38 as a separate service which, considering the fact that we only get 2-3 faxes a year, is not worth the extra money.

Regards,
Jeff

 

[briankayser]

I ended up purchasing 3CX support direct from 3CX. I haven't used it a ton yet but my reseller never really seemed to have any answers without taking (billable) hours to research it or troubleshoot with me. At least with 3CX support it isn't billed by the hour - but it is done via email. Wasn't too expensive though...

http://www.3cx.com/ordering/pricing/support/

 

[jfproulx]

Thank you for the tip. I had seen the service but did not think that I could subscribe to it.

Note that your comment about not being "charged by the hour" is in fact my biggest complaint about 3CX: when things are not exactly how 3CX made their system to work (we use Grandstream phones and voip.ms), it's costing us a lot of money to get the re-seller to get it to work... and ownership of the problem is low because we are small.

As a small business (4 people, 5 extensions), I find the total cost of ownership of 3CX to be too high as it should be plug and forget... and it definitely is not.

And because of all these problems and costs and lack of direct support, I am not even thinking about migrating to V15 and I am now even questioning the value of 3CX when I have done wonders with our Grandstreams and our IPhones using the simple Bria app...

I guess the eventual upgrade to V15 next year (after a few Service Packs to ensure that it's stable) will determine whether we continue with 3CX or look for another solution.

Cheers!
Jeff

 

[lneblett]

The system fax extensions expect to see t.38 as this is the defecto standard for FoIP and only those extensions created as fax extensions support t.38. The regular extensions are tied to voice codecs.

You "may" be able to use a standard extension connected to a fax machine connected with an ATA, but in doing so it will be g711 audio pass through; hence why the 3CX disclaimer. The key to any FoIP is the quality/reliability of the carriage between sender and receiver while using the internet. t.38 was designed to overcome some of the issues associated to FoIP, but even so, it is hardly fool-proof. If you look at some of the big name SIP providers, they will even post disclaimers about FoIP regardless if t.38 or other. Many will support t.38 due to the demand, but they will indicate something to the effect of "you are on your own.....good luck".

In my area the variety of internet providers is very limited. I have had fair success with t.38 using ATAs and with 3CX fax extensions. The longer the fax, the more likely the failure. As the 3CX fax server is receive only, most of my clients have opted for using ATAs or an HTTPS device; the latter while being more costly and requires its own subscription plan is, in my opinion, just as reliable as analog faxing, so I really try and push the option.

With regard to your concern, I believe this following statement as excerpted from the link you provided clearly states what the requirement is with regard to the fax server extension - "3CX Fax Server is based on the T.38 standard protocol and requires a compatible supported T.38 VoIP gateway or provider".

What is not clear, and to your point, is that in the same article 3CX goes on to say - "It is also possible to use a VoIP provider that does not support the T.38 protocol, however, the quality of the fax implementation between VoIP providers varies and therefore can not be guaranteed". While this is also a true statement, its inclusion in the article does seemingly make it appear applicable to the fax server extensions as well. So, I clearly understand how the confusion arises and agree that it could/should be made more clear.

As to support, the description headers for the board categories mostly indicate that these are user to user and not to expect official 3CX support. This is also reiterated again in this forum in the announcements - "Attention: Official 3CX Support requires 3CX Support package ". However, oftentimes there are responses from any number of 3CX people as they do scour the forums frequently.

The forums are a first line of defense/support and most likely, whatever the issue is, someone else has experienced it as well and a search or post will elicit a response from any number of folks who will try to help. If it is a unique issue, there is a good chance that someone from 3CX will take an interest and respond. Take a look at a number of issues as posted and I am quite certain that you will come across some examples.

 

[jfproulx]

Hi Ineblett,

Thank you for the info - I guess that we've been lucky as the fax on 3CX works well using an ATA on a fax extension but I do note that we have not received nor sent any fax longer than 3 pages.

I've checked with our VOIP provider again and they have no plan to make their line T38 compliant as they offer their own fax server service.

Since we can't use the FaxServer feature, we'll stick to our ATA connecting directly to our VOIP provider.

Regards,
Jeff