T.38 Fax

[imanm93]

Hi,
I ran a SIP trunk via MBG and I have the number 78434XXX. For the Fax I should set the number of 222.
I have T.38 and Compression licenses and also I installed DSP II card.
I set 222 as generic sip and registered it in "ventafax server". I can send fax but for receiving I have 2 problems.
No.1 is that the sender must press 1 after the fax server answer the call, it seems something like DTMF.
No.2 is that when they press the number 1 the sender machine start to send the paper but in the middle of that it is stopped and the call will disconnect, then I received an error "No response from fax (Er 29)"
does anyone have any thoughts?

[acejavelin]

Hi,
I ran a SIP trunk via MBG and I have the number 78434XXX. For the Fax I should set the number of 222.
I have T.38 and Compression licenses and also I installed DSP II card.
I set 222 as generic sip and registered it in "ventafax server". I can send fax but for receiving I have 2 problems.
No.1 is that the sender must press 1 after the fax server answer the call, it seems something like DTMF.
No.2 is that when they press the number 1 the sender machine start to send the paper but in the middle of that it is stopped and the call will disconnect, then I received an error "No response from fax (Er 29)"
does anyone have any thoughts?

Did you put the Fax Server in a Network Zone that uses T.38? But that isn't the cause of either of your problems, but something most people forget.

Your fax server sounds like it is expecting digits and not using the invite message for the info... I am not familiar with "Ventafax" or it's setup unfortunately. Most of the fax servers I use are analog integrations and you set those up as VM ports so that the integration digits pass through...

[imanm93]

Hi,
I ran a SIP trunk via MBG and I have the number 78434XXX. For the Fax I should set the number of 222.
I have T.38 and Compression licenses and also I installed DSP II card.
I set 222 as generic sip and registered it in "ventafax server". I can send fax but for receiving I have 2 problems.
No.1 is that the sender must press 1 after the fax server answer the call, it seems something like DTMF.
No.2 is that when they press the number 1 the sender machine start to send the paper but in the middle of that it is stopped and the call will disconnect, then I received an error "No response from fax (Er 29)"
does anyone have any thoughts?

Did you put the Fax Server in a Network Zone that uses T.38? But that isn't the cause of either of your problems, but something most people forget.

Your fax server sounds like it is expecting digits and not using the invite message for the info... I am not familiar with "Ventafax" or it's setup unfortunately. Most of the fax servers I use are analog integrations and you set those up as VM ports so that the integration digits pass through...

Actually I set a Fax Service Profile for t.38 (which was in intra-zone 2) and my default zone is 1. but the intra-zone was 1, I'm gonna change that to 2 and then let's see what happens.
Thanks

[imanm93]

Hi,
I ran a SIP trunk via MBG and I have the number 78434XXX. For the Fax I should set the number of 222.
I have T.38 and Compression licenses and also I installed DSP II card.
I set 222 as generic sip and registered it in "ventafax server". I can send fax but for receiving I have 2 problems.
No.1 is that the sender must press 1 after the fax server answer the call, it seems something like DTMF.
No.2 is that when they press the number 1 the sender machine start to send the paper but in the middle of that it is stopped and the call will disconnect, then I received an error "No response from fax (Er 29)"
does anyone have any thoughts?

Did you put the Fax Server in a Network Zone that uses T.38? But that isn't the cause of either of your problems, but something most people forget.

Your fax server sounds like it is expecting digits and not using the invite message for the info... I am not familiar with "Ventafax" or it's setup unfortunately. Most of the fax servers I use are analog integrations and you set those up as VM ports so that the integration digits pass through...

I changed my network zone and use an inner fax profile that uses T.38 and problem was solved. Thanks a lot mate.

[acejavelin]

Hi,
I ran a SIP trunk via MBG and I have the number 78434XXX. For the Fax I should set the number of 222.
I have T.38 and Compression licenses and also I installed DSP II card.
I set 222 as generic sip and registered it in "ventafax server". I can send fax but for receiving I have 2 problems.
No.1 is that the sender must press 1 after the fax server answer the call, it seems something like DTMF.
No.2 is that when they press the number 1 the sender machine start to send the paper but in the middle of that it is stopped and the call will disconnect, then I received an error "No response from fax (Er 29)"
does anyone have any thoughts?

Did you put the Fax Server in a Network Zone that uses T.38? But that isn't the cause of either of your problems, but something most people forget.

Your fax server sounds like it is expecting digits and not using the invite message for the info... I am not familiar with "Ventafax" or it's setup unfortunately. Most of the fax servers I use are analog integrations and you set those up as VM ports so that the integration digits pass through...

I changed my network zone and use an inner fax profile that uses T.38 and problem was solved. Thanks a lot mate.

Awesome! Glad it worked out.

Sent from my Moto G (5) Plus using Tapatalk

[Dogbreath]

I could be wrong here, but I don't think you need T.38 licenses if the SIP is just passing through, ie SIP-SIP. My understanding is that the MCD only gets involved in T.38 if the media is terminating on the controller, eg going to an analogue station on the controller.

[acejavelin]

I could be wrong here, but I don't think you need T.38 licenses if the SIP is just passing through, ie SIP-SIP. My understanding is that the MCD only gets involved in T.38 if the media is terminating on the controller, eg going to an analogue station on the controller.

I thought you only needed T.38 licenses if you had it on trunking (SIP or XNet), but still needed the DSPII and zone configuration if it was station side... Either way, the original question did say they had SIP trunking so I would assume it is T.38 all the way through to the carrier.

[johnp]

I think if the endpoint can handle t.38 and the carrier i.e. SIP supported it, they should negotiate it even across an IP trunk, as the controller only sets up the call. Where T.38 and DSP-II comes into effect it to any TDM device that requires it. That being said, some IP trunking would be involved.

[Dogbreath]

I read the documentation and it doesn't [AFAICT] answer this definitively. SIP-SIP is not a scenario that is covered; SIP barely gets a mention in relation to T.38.