Fax Problem 3CX T38 / G771 is not supported by 3CX via Gateway! reinvite and rejects it via 488.

[lünecom]

!! Petition from all sales partners !!

Hello sales partner,

after a long back and forth with 3CX I have to go this way and hope for everyone's support, as we have the same problem with 3CX.

With the 3CX software it is not possible to send faxes via gateway Patton / Grandstream etc. via T38 or G711, since 3CX does not accept the reinvite and rejects it via 488.
This is not due to the gateway or your programming but is simply not supported by 3CX.
The SIP trunk provider is not to blame either, it is due to the 3CX software and the programming!

To make the statement here, the technology is 40 years old and we are not doing anything here is already very damaging to business!

Because doctors and lawyers are still urgently dependent on this!

So please support my concern so that this is finally resolved and 3CX finally moves to program and adapt this !!

Here is 3CX's answer:

Thank you for your email and your patience.

I can understand that faxing is still common practice in certain industries, although faxing cannot be done without.

You also know our opinion about faxes, in general there are some disadvantages that you don't have to do to yourself these days.
Among other things we are talking about:
- a 40 year old technology
- Sending can be time-consuming if many documents are to be faxed
- Quality isn't exactly the best either
- Texts are often no longer legible, graphics are barely recognizable, etc.

In addition, there are a lot of errors with IP connections or the documents are incomplete ...
A constant connection results in many small packets;
This means that information can be lost = fax incomplete and in the worst case it comes to an interruption = no fax.

What I'm getting at is that fax is a proprietary solution and we won't be making any changes here.
So the behavior will, as before, remain that way.

In the past I gave you a little workaround here;
Simply remove a certain number range from the SIP trunk so that you can use it
- connect directly to a fax software solution
- connect directly to a gateway
- Realized directly via the fax solution from the provider, if available.

 

[Kevin Dudda]

Exactly my opinion. Enough other manufacturers can implement this ... We have the trouble with the customers and not 3cx. Please do something!

 

[TreuOrga - JM]

We've also problems with this issue and need to get a fix.

TreuOrga - Hamburg

 

[hwohlert]

We also still have many customers where fax is very important. And we have to create a workaround every time, which is not good for the image of 3CX.

 

[YiannisH_3CX]

Hello @lünecom

With the 3CX software it is not possible to send faxes via gateway Patton / Grandstream etc. via T38 or G711, since 3CX does not accept the reinvite and rejects it via 488.
This is not due to the gateway or your programming but is simply not supported by 3CX.
The SIP trunk provider is not to blame either, it is due to the 3CX software and the programming!

I am curious to know how you arrived to this conclusion as 3CX does accept re-invites for T38 and you can use a Gateway to send a fax through 3CX.
There are some prerequisites to this but it can be done and we test this scenario with every provider we support for T38. There are some scenarios we do not support like fallback to G711 but we do accept re-invites for T38.

I do agree that Fax is ancient technology that is simply not reliable, especially via SIP and that customers should look for others solutions where possible but I understand that this is not possible with all customers that is why 3CX still supports T38 we still test it with our supported providers.

 

[lünecom]

Hello @lünecom


I am curious to know how you arrived to this conclusion as 3CX does accept re-invites for T38 and you can use a Gateway to send a fax through 3CX.
There are some prerequisites to this but it can be done and we test this scenario with every provider we support for T38. There are some scenarios we do not support like fallback to G711 but we do accept re-invites for T38.

I do agree that Fax is ancient technology that is simply not reliable, especially via SIP and that customers should look for others solutions where possible but I understand that this is not possible with all customers that is why 3CX still supports T38 we still test it with our supported providers.

Good day,

then please ask your support colleagues and don't write anything here due to ignorance!

This has been proven after almost 1 year and several tests and has also been confirmed by 3CX see attachment text from the e-mail about the behavior.

So I would ask you to inform yourself before you close tickets here or answer if you have no idea.
Sorry but I'm tired of explaining where there are problems !!

 

[YiannisH_3CX]

Hi,

I never said you weren't facing issues with Fax, I am only saying that under supported scenarios 3CX does accept re-invites for T38 and that statement you made was wrong.

Here is a capture example with a outbound fax from 3CX where the provider sends a re-invite with t38 and the 3CX server responds with a 200 OK with T38. I have many more examples I can share if you'd like as I am part of the team that does the testing with the providers. May I ask what provider you are using?

 

[lünecom]

Hi,

I never said you weren't facing issues with Fax, I am only saying that under supported scenarios 3CX does accept re-invites for T38 and that statement you made was wrong.

Here is a capture example with a outbound fax from 3CX where the provider sends a re-invite with t38 and the 3CX server responds with a 200 OK with T38. I have many more examples I can share if you'd like as I am part of the team that does the testing with the providers. May I ask what provider you are using?

View attachment 25251

Good day,

then you problem it with a gateway Patton e.g. and send first via T38 e.g. to a telecom number then you will see it!

SIP provider PlusNet you are welcome to take a look at the ticket, here everything is:

# 274105 Sending faxes via QSC T38 in the direction of T-Com no swings to G711!

 

[Holger Sorg]

I‘m also mad about the way 3CX is handling the Fax issue.
The statement that it’s an ancient technology might be correct, but it doesn’t solve the problem.

Other manufacturers have no problem in handling t38 and the fallback.

I would say just solve the problem - it’s your product and you earn money on it.
Yes we too - but we have to explain why something is working with a 90 Euro pbx and not with 3CX.
I don’t think that you have to stand in front of the Customer…

Yes you can start arguing „fax = old technology“ or „well, 3CX is just not handling the t.38 fallback incorrectly but if you are using the codec…“
In both cases the customer will say „get the f*** out of my office - I don’t care. If you can’t do it will take the 90 Euro product - it’s cheaper anyway“

Don‘t get me wrong - I really like 3CX - the product.
I came all the way from asterisk - elastix to 3CX. 3CX has really good Features is easy to deploy and very convenient to configure.
But you guys should concentrate also on basic features which some customers still need. And this is definitely fax and also call forwarding etc.

And maybe also start listening to you partners as we sell your product and bring you the revenue.

regards
Holger

 

[YiannisH_3CX]

@lünecom

I have looked at the ticket and just to be clear, the issue is that the provider does not support T38 so when he Patton gateway sends a T38 re-invite your provider responds with 488 Not acceptable here.
So its not 3CX who does not accept the T38 re-invite but the provider.


So the issue is that 3CX does not then re-invite again and fallback to G711 which yes we do not support but this is a very different issue than the one described.
So why is not the Patton configured to work only with G711?

 

[YiannisH_3CX]

Hi Holger,

You are correct that we do not support T38 to G711 fallback, we never had. We added the G711 to T38 fallback so if your provider only supports G711 you can enable that option and configure your ATA accordingly. Of course there is no guarantee the G711 will work reliably. If fax is only supported through G711 then your customer is far better off with a dedicated landline. Fax through G711 should only be used as a last resort and if your customers depend of Fax then G711 is not the way to go as you will have a lot more complaints 3CX or not.
This is my opinion anyway and if I had the need for fax I would never pick G711 with any solution. I do a lot of testing with Fax with T38 and G711 and half the times with G711 the pages are unusable or incomplete. And I do test directly with a Gateway to make sure that its not 3CX that's the issue and the results are the same.

 

[NickD_3CX]

I‘m also mad about the way 3CX is handling the Fax issue.
The statement that it’s an ancient technology might be correct, but it doesn’t solve the problem.

Other manufacturers have no problem in handling t38 and the fallback.

I would say just solve the problem - it’s your product and you earn money on it.
Yes we too - but we have to explain why something is working with a 90 Euro pbx and not with 3CX.
I don’t think that you have to stand in front of the Customer…

Yes you can start arguing „fax = old technology“ or „well, 3CX is just not handling the t.38 fallback incorrectly but if you are using the codec…“
In both cases the customer will say „get the f*** out of my office - I don’t care. If you can’t do it will take the 90 Euro product - it’s cheaper anyway“

Don‘t get me wrong - I really like 3CX - the product.
I came all the way from asterisk - elastix to 3CX. 3CX has really good Features is easy to deploy and very convenient to configure.
But you guys should concentrate also on basic features which some customers still need. And this is definitely fax and also call forwarding etc.

And maybe also start listening to you partners as we sell your product and bring you the revenue.

regards
Holger

I will say this as this conversation has escalated from what the OP stated (which was wrong btw...).

As far as I am aware, we have no immediate plans to make any changes to the way Faxing works in 3CX.

As my colleague implied, if I had a customer that relied on Fax, I would never suggest to them a provider that does not support T.38 and also have the ability to upscale to T.38 when needed. If you have this, then Fax is pretty reliable.
G711 is just unreliable though, and I believe this is not only 3CX, it's even when you register a provider account directly onto a GW...

And in regards to you saying you are losing customers because fax "doesn't work" and ignoring and forgetting all other features 3CX has, I will say that you are doing something wrong....
If fax in 3CX is your problem, get a gateway, register your single Fax DID directly on the Gateway and bypass 3CX and go.
Then use 3CX for all the rest of the cool and useful features.

 

[MarcosV_3CX]

Thank you @YiannisH_3CX and @NickD_3CX for your input and clarification.

If you have any further question or queries, please contact your 3CX Account/Channel Manager.


Best Regards,

Marcos