Re: Can't send Fax but can Receive

To get Asterisk -> SIP provider to use T.38 in that scenario, you would
have to configure Asterisk as a T.38 gateway.

--
Nabeel Jafferali

On Wed, Oct 18, 2017 at 7:01 PM, FM <[email protected]> wrote:

> Hi, I already have my asterisk variant (Elastix / ISSABEL) doing that.
>
> I've 1 SIP trunk that my ITSP provided me and they support t38. I already
> have asterisk doing T38 passthrough and probably that's why the physical
> fax machine sent the fax correctly and my virtual fax (with IAX modem)
> didn't.
>
> Thanks!
>
> 2017-10-18 16:55 GMT+01:00 Lee Howard <[email protected]>:
>
>> t38modem is difficult to get working these days regardless of your Linux
>> choice.
>>
>> You can configure Asterisk to perform T.38, if that's what you want to do.
>>
>> But, consider that T.38 simply pushes the T.30 operation to your service
>> provider or someone else.  It does it in real-time, but in effect you're
>> simply pushing your fax traffic to an on-line service provider... which was
>> my suggestion in the first place.  If you're going to outsource the T.30
>> operation why shackle them with the burden of doing it real-time?
>>
>> Thanks,
>>
>> Lee.
>>
>>
>>
>> On 10/18/2017 08:32 AM, FM wrote:
>>
>> Today I discoverd that with a Real FAX Machine connected into a sip
>> extension I can send faxes.
>>
>> I believe that this is due to the fact this machine supports t38 and the
>> virtual fax with IAX modem doesn't.
>>
>> Is there any way to use a virtual fax with a t38modem.
>>
>> I know that there is a t38modem but it's really hard to compile on
>> centOS. Any suggestion?
>>
>> Thanks!!
>>
>> 2017-10-12 20:28 GMT+01:00 FM <[email protected]>:
>>
>>> In fact, it did not help...
>>>
>>> It seems I have to call the ISP again :\
>>>
>>> Oct 12 20:25:50.53: [ 2393]: SESSION BEGIN 000000027 00351222138xxxxx
>>> Oct 12 20:25:50.53: [ 2393]: HylaFAX (tm) Version 4.3.11
>>> Oct 12 20:25:50.53: [ 2393]: SEND FAX: JOB 15 DEST 2138xxxxx COMMID
>>> 000000027 DEVICE '/dev/ttyIAX1' FROM 'Asterisk VoIP PBX <asterisk@localhost>'
>>> USER asterisk
>>> Oct 12 20:25:50.53: [ 2393]: STATE CHANGE: RUNNING -> SENDING
>>> Oct 12 20:25:50.53: [ 2393]: <-- [12:AT+FCLASS=1\r]
>>> Oct 12 20:25:50.53: [ 2393]: --> [2:OK]
>>> Oct 12 20:25:50.53: [ 2393]: MODEM set XON/XOFF/FLUSH: input ignored,
>>> output disabled
>>> Oct 12 20:25:50.53: [ 2393]: DIAL 2138xxxxx
>>> Oct 12 20:25:50.53: [ 2393]: <-- [14:ATDT2138xxxxx\r]
>>> Oct 12 20:25:56.41: [ 2393]: --> [7:CONNECT]
>>> Oct 12 20:26:01.69: [ 2393]: --> [4:CE 00 10 03]
>>> Oct 12 20:26:01.69: [ 2393]: --> [5:ERROR]
>>> Oct 12 20:26:01.69: [ 2393]: MODEM Command error
>>> Oct 12 20:26:01.69: [ 2393]: FCS error
>>> Oct 12 20:26:01.69: [ 2393]: <-- [9:AT+FRS=7\r]
>>> Oct 12 20:26:02.57: [ 2393]: --> [2:OK]
>>> Oct 12 20:26:02.57: [ 2393]: <-- [9:AT+FTH=3\r]
>>> Oct 12 20:26:02.59: [ 2393]: --> [7:CONNECT]
>>> Oct 12 20:26:02.59: [ 2393]: <-- HDLC<3:FF C8 D8>
>>> Oct 12 20:26:02.59: [ 2393]: <-- data [3]
>>> Oct 12 20:26:02.59: [ 2393]: <-- data [2]
>>> Oct 12 20:26:03.69: [ 2393]: --> [2:OK]
>>> Oct 12 20:26:03.69: [ 2393]: SEND send CRP (command repeat)
>>> Oct 12 20:26:03.69: [ 2393]: <-- [9:AT+FRH=3\r]
>>> Oct 12 20:26:04.26: [ 2393]: --> [7:CONNECT]
>>> Oct 12 20:26:05.41: [ 2393]: --> HDLC<15:FF C8 01 00 77 0F 01 01 C9 01
>>> 01 01 18 32 36>
>>> Oct 12 20:26:05.43: [ 2393]: --> [2:OK]
>>> Oct 12 20:26:05.43: [ 2393]: REMOTE best rate 14400 bit/s
>>> Oct 12 20:26:05.43: [ 2393]: REMOTE max A4 page width (215 mm)
>>> Oct 12 20:26:05.43: [ 2393]: REMOTE max A4 page length (297 mm)
>>> Oct 12 20:26:05.43: [ 2393]: REMOTE best vres 300 x 300 dpi
>>> Oct 12 20:26:05.43: [ 2393]: REMOTE format support: MH, MR
>>> Oct 12 20:26:05.43: [ 2393]: REMOTE best 0 ms/scanline
>>> Oct 12 20:26:05.43: [ 2393]: USE 9600 bit/s
>>> Oct 12 20:26:05.43: [ 2393]: SEND file "docq/doc15.ps;41"
>>> Oct 12 20:26:05.43: [ 2393]: USE A4 page width (215 mm)
>>> Oct 12 20:26:05.43: [ 2393]: USE A4 page length (297 mm)
>>> Oct 12 20:26:05.43: [ 2393]: USE 7.7 line/mm
>>> Oct 12 20:26:05.43: [ 2393]: USE 2-D MR
>>> Oct 12 20:26:05.43: [ 2393]: USE 0 ms/scanline
>>> Oct 12 20:26:05.43: [ 2393]: SEND training at v.29 9600 bit/s
>>> Oct 12 20:26:05.43: [ 2393]: <-- [9:AT+FRS=7\r]
>>> Oct 12 20:26:05.53: [ 2393]: --> [2:OK]
>>> Oct 12 20:26:05.53: [ 2393]: <-- [9:AT+FTH=3\r]
>>> Oct 12 20:26:05.55: [ 2393]: --> [7:CONNECT]
>>> Oct 12 20:26:05.55: [ 2393]: <-- HDLC<23:FF C0 C2 04 04 04 04 04 04 04
>>> 04 04 04 04 04 04 04 04 04 04 04 04 04>
>>> Oct 12 20:26:05.55: [ 2393]: <-- data [23]
>>> Oct 12 20:26:05.55: [ 2393]: <-- data [2]
>>> Oct 12 20:26:07.12: [ 2393]: --> [7:CONNECT]
>>> Oct 12 20:26:07.12: [ 2393]: <-- HDLC<6:FF C8 C1 00 63 0E>
>>> Oct 12 20:26:07.12: [ 2393]: <-- data [6]
>>> Oct 12 20:26:07.12: [ 2393]: <-- data [2]
>>> Oct 12 20:26:07.49: [ 2393]: --> [2:OK]
>>> Oct 12 20:26:07.49: [ 2393]: <-- [9:AT+FTS=7\r]
>>> Oct 12 20:26:07.59: [ 2393]: --> [2:OK]
>>> Oct 12 20:26:07.59: [ 2393]: MODEM set XON/XOFF/FLUSH: input
>>> interpreted, output disabled
>>> Oct 12 20:26:07.59: [ 2393]: <-- [10:AT+FTM=96\r]
>>> Oct 12 20:26:07.61: [ 2393]: --> [7:CONNECT]
>>> Oct 12 20:26:07.61: [ 2393]: DELAY 400 ms
>>> Oct 12 20:26:08.01: [ 2393]: <-- data [1024]
>>> Oct 12 20:26:08.01: [ 2393]: <-- data [776]
>>> Oct 12 20:26:08.01: [ 2393]: <-- data [2]
>>> Oct 12 20:26:09.59: [ 2393]: --> [2:OK]
>>> Oct 12 20:26:09.59: [ 2393]: MODEM set XON/XOFF/DRAIN: input ignored,
>>> output disabled
>>> Oct 12 20:26:09.59: [ 2393]: <-- [9:AT+FRH=3\r]
>>> Oct 12 20:26:10.12: [ 2393]: --> [7:CONNECT]
>>> Oct 12 20:26:11.02: [ 2393]: --> HDLC<5:FF C8 5F C8 E7>
>>> Oct 12 20:26:11.04: [ 2393]: --> [2:OK]
>>> Oct 12 20:26:11.04: [ 2393]: TRAINING failed
>>> Oct 12 20:26:11.04: [ 2393]: <-- [9:AT+FTH=3\r]
>>> Oct 12 20:26:11.06: [ 2393]: --> [7:CONNECT]
>>> Oct 12 20:26:11.06: [ 2393]: <-- HDLC<3:FF C8 DF>
>>> Oct 12 20:26:11.06: [ 2393]: <-- data [3]
>>> Oct 12 20:26:11.06: [ 2393]: <-- data [2]
>>> Oct 12 20:26:12.16: [ 2393]: --> [2:OK]
>>> Oct 12 20:26:12.16: [ 2393]: MODEM input buffering enabled
>>> Oct 12 20:26:12.16: [ 2393]: <-- [5:ATH0\r]
>>> Oct 12 20:26:12.28: [ 2393]: --> [2:OK]
>>> Oct 12 20:26:12.28: [ 2393]: MODEM set DTR OFF
>>> Oct 12 20:26:12.28: [ 2393]: MODEM set baud rate: 0 baud (flow control
>>> unchanged)
>>> Oct 12 20:26:12.28: [ 2393]: STATE CHANGE: SENDING -> MODEMWAIT (timeout
>>> 5)
>>> Oct 12 20:26:12.28: [ 2393]: SESSION END
>>>
>>>
>>> 2017-10-12 18:36 GMT+01:00 Lee Howard <[email protected]>:
>>>
>>>> It won't help.
>>>>
>>>> They say that because Hewlett Packard in the mid 1990's made that
>>>> suggestion in one of their fax machine tech support guides.
>>>>
>>>> HP made that suggestion to 1) avoid potentially buggy ECM
>>>> implementations, 2) shake up the modulation which can help on PSTN noise
>>>> conditions, and 3) to just get customers to go away since it increases the
>>>> likelihood that the fax machine will shoot out some paper print of some
>>>> kind even if it's not perfectly legible.
>>>>
>>>> VoIP providers have latched onto that advice because of #3. #1 is not
>>>> relevant any more because buggy ECM implementations are not widely in-use,
>>>> and #2 is not relevant to VoIP.
>>>>
>>>> So, it sometimes really did help at one time in the past, but in
>>>> today's world it's extremely unlikely to be of much help.  Fax machines
>>>> automatically cycle through various modulations in trying to get the fax
>>>> through.  So, for the most part you can respond back to your ISP that their
>>>> recommendation to set the fax to 9600 bps is done on-the-fly automatically.
>>>>
>>>> As for ECM being disabled, there are various ways to do it.  All that
>>>> doing it will achieve will be to let some more faxes through with
>>>> horizontal black/white lines and corrupted/illegible text and images.  If
>>>> you're using a Class 1 modem then in your modem config file you'd put:
>>>>
>>>> Class1ECMSupport: false
>>>>
>>>> To limit faxes to 9600 bps you'd use:
>>>>
>>>> Class1RMQueryCmd:    "!24,48,72,96"
>>>> Class1TMQueryCmd:      "!24,48,72,96"
>>>>
>>>> Thanks,
>>>>
>>>> Lee.
>>>>
>>>>
>>>>
>>>> On 10/10/2017 11:06 AM, FM wrote:
>>>>
>>>> Hi!
>>>>
>>>> The ISP told me to set the fax to 9600bps and disable ECM.
>>>>
>>>> How can I achieve this with hylafax?
>>>>
>>>> Thank you!!
>>>>
>>>> 2017-10-05 17:42 GMT+01:00 Lee Howard <[email protected]>:
>>>>
>>>>> On 10/05/2017 05:25 AM, FM wrote:
>>>>>
>>>>>> My ISP is at the same time My VOIP provider. I use a sip trunk for
>>>>>> voice + fax. I use ullaw and allaw as codecs.
>>>>>>
>>>>>> The strange thing is, some months ago I was able to send fax with no
>>>>>> problem.
>>>>>>
>>>>>
>>>>> That is not strange at all.  VoIP jitter is a variable depending on so
>>>>> many things.  So, that it was better before and is worse now is not unusual
>>>>> for VoIP.  Chances are that in a week or two or a day or two it will be
>>>>> even worse or better.
>>>>>
>>>>> By the way, if I send fax to a number that also is a virtual fax with
>>>>>> hylafax + iax2 extension it Never fails.
>>>>>>
>>>>>
>>>>> So, that tells you that the call audio quality on that call path is
>>>>> better than the others.  Still, it doesn't really help you resolve the
>>>>> problem with the other calls.
>>>>>
>>>>> With this info, is there anything I could test to solve the problem?
>>>>>>
>>>>>
>>>>> No. There is no way for you to solve the problem directly.  As I
>>>>> already said before, you will have to work with your service provider to
>>>>> remedy the problem.  (And, even then, they may have only a limited control
>>>>> on the factors involved.)
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Lee.
>>>>>
>>>>>
>>>>
>>>>
>>>
>>
>>
>