[Freeswitch-users] fax baud rate 9600

Steve Underwood steveu at coppice.org
Wed Sep 3 05:22:56 MSD 2014 

I have seen quite a few rather broken FAX implementations, but I have 
never seen one that can't interpret a properly formed DIS message. You 
have a communication problem. If the other end receives your ident, then 
its DCS must be lost somewhere on the way back to FS. Are you faxing 
over SIP? If so try capturing the packet exchange.

Regards,
Steve

On 09/02/2014 09:20 PM, Marlok Tamas wrote:
> Hi Steve,
>
> My fax log contains the following (as you can see in my previous mail):
> Transfer Rate: 14400
> Thats why I thought that the other side tried to send its fax with 
> this transfer rate even though I disabled the V.17 modem.
>
> It cannot be a NAT problem, because I can receive the call, the 
> connection is only dropped during the fax session. All the voice calls 
> are OK, and my FreeSwitch is directly connected to the Internet.
>
> I try to give y'all more details, hoping that somebody might 
> experienced the same issue.
> So the other part seems to successfully receive the ident (default: 
> "spandsp fax ident"). After that my side sends the DIS, but the other 
> side either doesn't get it or cannot interpret it, or the answer (DCS) 
> is lost somewhere.
> There are a few fax machines from which I can successfully receive 
> faxes, but there are lots of machines from which I cannot receive 
> anything.
>
> My DIS is the following:
>
> FLOW T.30 DIS:
> FLOW T.30   .... ...0= Store and forward Internet fax (T.37): Not set
> FLOW T.30   .... .0..= Real-time Internet fax (T.38): Not set
> FLOW T.30   .... 0...= 3G mobile network: Not set
> FLOW T.30   ..0. ....= V.8 capabilities: Not set
> FLOW T.30   .0.. ....= Preferred octets: 256 octets
> FLOW T.30   .... ...0= Ready to transmit a fax document (polling): Not set
> FLOW T.30   .... ..1.= Can receive fax: Set
> FLOW T.30   ..00 11..= Supported data signalling rates: V.27 ter and V.29
> FLOW T.30   .1.. ....= R8x7.7lines/mm and/or 200x200pels/25.4mm: Set
> FLOW T.30   1... ....= 2-D coding: Set
> FLOW T.30   .... ..10= Recording width: 215mm +- 1%, 255mm +- 1% and 
> 303mm +- 1%
> FLOW T.30   .... 10..= Recording length: Unlimited
> FLOW T.30   .111 ....= Receiver's minimum scan line time: 0ms at 3.85 
> l/mm; T7.7 = T3.85
> FLOW T.30   1... ....= Extension indicator: Set
> FLOW T.30   .... ..0.= Compressed/uncompressed mode: Compressed
> FLOW T.30   .... .0..= Error correction mode (ECM): Non-ECM
> FLOW T.30   .0.. ....= T.6 coding: Not set
> FLOW T.30   1... ....= Extension indicator: Set
> FLOW T.30   .... ...0= "Field not valid" supported: Not set
> FLOW T.30   .... ..0.= Multiple selective polling: Not set
> FLOW T.30   .... .0..= Polled sub-address: Not set
> FLOW T.30   .... 0...= T.43 coding: Not set
> FLOW T.30   ...0 ....= Plane interleave: Not set
> FLOW T.30   ..0. ....= Voice coding with 32kbit/s ADPCM (Rec. G.726): 
> Not set
> FLOW T.30   .0.. ....= Reserved for the use of extended voice coding 
> set: Not set
> FLOW T.30   1... ....= Extension indicator: Set
> FLOW T.30   .... ...1= R8x15.4lines/mm: Set
> FLOW T.30   .... ..0.= 300x300pels/25.4mm: Not set
> FLOW T.30   .... .1..= R16x15.4lines/mm and/or 400x400pels/25.4mm: Set
> FLOW T.30   .... 1...= Inch-based resolution preferred: Set
> FLOW T.30   ...1 ....= Metric-based resolution preferred: Set
> FLOW T.30   ..0. ....= Minimum scan line time for higher resolutions: 
> T15.4 = T7.7
> FLOW T.30   .0.. ....= Selective polling: Not set
> FLOW T.30   1... ....= Extension indicator: Set
> FLOW T.30   .... ...0= Sub-addressing: Not set
> FLOW T.30   .... ..0.= Password: Not set
> FLOW T.30   .... .0..= Ready to transmit a data file (polling): Not set
> FLOW T.30   ...0 ....= Binary file transfer (BFT): Not set
> FLOW T.30   ..0. ....= Document transfer mode (DTM): Not set
> FLOW T.30   .0.. ....= Electronic data interchange (EDI): Not set
> FLOW T.30   1... ....= Extension indicator: Set
> FLOW T.30   .... ...0= Basic transfer mode (BTM): Not set
> FLOW T.30   .... .0..= Ready to transfer a character or mixed mode 
> document (polling): Not set
> FLOW T.30   .... 0...= Character mode: Not set
> FLOW T.30   ..0. ....= Mixed mode (Annex E/T.4): Not set
> FLOW T.30   1... ....= Extension indicator: Set
> FLOW T.30   .... ...0= Processable mode 26 (Rec. T.505): Not set
> FLOW T.30   .... ..0.= Digital network capability: Not set
> FLOW T.30   .... .0..= Duplex capability: Half only
> FLOW T.30   .... 0...= JPEG coding: Not set
> FLOW T.30   ...0 ....= Full colour mode: Not set
> FLOW T.30   .0.. ....= 12bits/pel component: Not set
> FLOW T.30   1... ....= Extension indicator: Set
> FLOW T.30   .... ...0= No subsampling (1:1:1): Not set
> FLOW T.30   .... ..0.= Custom illuminant: Not set
> FLOW T.30   .... .0..= Custom gamut range: Not set
> FLOW T.30   .... 1...= North American Letter (215.9mm x 279.4mm): Set
> FLOW T.30   ...1 ....= North American Legal (215.9mm x 355.6mm): Set
> FLOW T.30   ..0. ....= Single-progression sequential coding (Rec. 
> T.85) basic: Not set
> FLOW T.30   .0.. ....= Single-progression sequential coding (Rec. 
> T.85) optional L0: Not set
> FLOW T.30   0... ....= Extension indicator: Not set
> FLOW T.30 Tx:  DIS with final frame tag
>
> I even thought that the other side cannot interpret my DIS message, so 
> I have to simplify it so it only contains the forst three bytes 
> without the extensions. But I don't know whether or not it is possible 
> in FreeSwitch without modifying the source code.
>
> Thank you!
>
> Cheers,
> tmarlok
>
> On 2014-09-01 14:44, Steve Underwood wrote:
>> Hi Tamas,
>>
>> You have inspected the DIS and DCS messages, so you know the far end is
>> not trying to send at 14,400 bps. It is, in fact, not communicating at
>> all. You also know that you can disable V.17 successfully, as you have
>> seen that the disable-v17 entry in the configuration data means the DIS
>> message from FS no longer includes V.17. So, up to now you have said
>> nothing useful which might get you a helpful reply, but you have said
>> things that waste people's time.
>>
>> My guess is you have a NAT problem, or something similar, which is
>> completely blocking communication between the two FAX entities.
>>
>> Regards,
>> Steve
>>
>> On 09/01/2014 02:52 PM, Marlok Tamas wrote:
>>> Thanks for the answer.
>>>
>>> I forgot to mention, but I already disabled that.
>>> My spandsp.conf (and fax.conf also) looks like this:
>>>
>>>      <fax-settings>
>>>      <param name="use-ecm"        value="false"/>
>>>      <param name="verbose"        value="true"/>
>>>      <param name="disable-v17"    value="true"/>
>>>      <param name="ident"        value=" "/>
>>>      <param name="header"        value=" "/>
>>>          <param name="enable-t38" value="false"/>
>>>      <param name="enable-t38-request" value="false"/>
>>>      <param name="spool-dir"        value="/tmp"/>
>>>      <param name="file-prefix"    value="faxrx"/>
>>>      </fax-settings>
>>>
>>> But still. I cannot receive fax from certain devices and I have this
>>> error message, which indicates that the other side is trying to send
>>> the fax with 14400 transfer rate.
>>>
>>> 9201aae0-771e-4ccf-a5c2-60fdbd3d6f6b 2014-08-28 18:35:39.627132
>>> [DEBUG] mod_spandsp_fax.c:512
>>> ==============================================================================
>>> 9201aae0-771e-4ccf-a5c2-60fdbd3d6f6b 2014-08-28 18:35:39.627132
>>> [DEBUG] mod_spandsp_fax.c:524 Fax processing not successful - result
>>> (48) Disconnected after permitted retries.
>>> 9201aae0-771e-4ccf-a5c2-60fdbd3d6f6b 2014-08-28 18:35:39.627132
>>> [DEBUG] mod_spandsp_fax.c:529 Remote station id:
>>> 9201aae0-771e-4ccf-a5c2-60fdbd3d6f6b 2014-08-28 18:35:39.627132
>>> [DEBUG] mod_spandsp_fax.c:530 Local station id: <stationid>
>>> 9201aae0-771e-4ccf-a5c2-60fdbd3d6f6b 2014-08-28 18:35:39.627132
>>> [DEBUG] mod_spandsp_fax.c:531 Pages transferred: 0
>>> 9201aae0-771e-4ccf-a5c2-60fdbd3d6f6b 2014-08-28 18:35:39.627132
>>> [DEBUG] mod_spandsp_fax.c:533 Total fax pages:   0
>>> 9201aae0-771e-4ccf-a5c2-60fdbd3d6f6b 2014-08-28 18:35:39.627132
>>> [DEBUG] mod_spandsp_fax.c:534 Image resolution:  0x0
>>> 9201aae0-771e-4ccf-a5c2-60fdbd3d6f6b 2014-08-28 18:35:39.627132
>>> [DEBUG] mod_spandsp_fax.c:535 Transfer Rate:     14400
>>> 9201aae0-771e-4ccf-a5c2-60fdbd3d6f6b 2014-08-28 18:35:39.627132
>>> [DEBUG] mod_spandsp_fax.c:537 ECM status         off
>>> 9201aae0-771e-4ccf-a5c2-60fdbd3d6f6b 2014-08-28 18:35:39.627132
>>> [DEBUG] mod_spandsp_fax.c:538 remote country:
>>> 9201aae0-771e-4ccf-a5c2-60fdbd3d6f6b 2014-08-28 18:35:39.627132
>>> [DEBUG] mod_spandsp_fax.c:539 remote vendor:
>>> 9201aae0-771e-4ccf-a5c2-60fdbd3d6f6b 2014-08-28 18:35:39.627132
>>> [DEBUG] mod_spandsp_fax.c:540 remote model:
>>> 9201aae0-771e-4ccf-a5c2-60fdbd3d6f6b 2014-08-28 18:35:39.627132
>>> [DEBUG] mod_spandsp_fax.c:542
>>> ==============================================================================
>>>
>>> The important part of the DIS (from my side) looks like this:
>>>
>>> ..00 11..= Supported data signalling rates: V.27 ter and V.29
>>>
>>> No V.17. But I do not get an answer (DCS) to my DIS. So the fax
>>> processing dies after three retries.
>>>
>>>
>>> On 2014-08-29 17:24, Brian West wrote:
>>>> <paramname="disable-v17"value="true"/>
>>>>
>>>>
>>>> in fax.conf.xml
>>>>
>>>>
>>>>
>>>> On Fri, Aug 29, 2014 at 9:02 AM, Marlok Tamas
>>>> <tamas.marlok at rackserver.hu  <mailto:tamas.marlok at rackserver.hu>> wrote:
>>>>
>>>>      Hi!
>>>>
>>>>      I found this thread:
>>>>      http://lists.freeswitch.org/pipermail/freeswitch-users/2013-March/094032.html
>>>>      and I have the same problem (all faxes with transfer rate: 14400
>>>>      are dropped)
>>>>
>>>>      It seems that nobody ha an answer back then for the question (is
>>>>      there any way of forcing freeswitch to use transfer rate: 9600)
>>>>
>>>>      The result:
>>>>
>>>>      2014-08-29 15:21:39.187130 [DEBUG] mod_spandsp_fax.c:512
>>>>      ==============================================================================
>>>>      2014-08-29 15:21:39.187130 [DEBUG] mod_spandsp_fax.c:524 Fax
>>>>      processing not successful - result (48) Disconnected after
>>>>      permitted retries.
>>>>      2014-08-29 15:21:39.187130 [DEBUG] mod_spandsp_fax.c:529 Remote
>>>>      station id:
>>>>      2014-08-29 15:21:39.187130 [DEBUG] mod_spandsp_fax.c:530 Local
>>>>      station id: <local_number>
>>>>      2014-08-29 15:21:39.187130 [DEBUG] mod_spandsp_fax.c:531 Pages
>>>>      transferred: 0
>>>>      2014-08-29 15:21:39.187130 [DEBUG] mod_spandsp_fax.c:533 Total
>>>>      fax pages:   0
>>>>      2014-08-29 15:21:39.187130 [DEBUG] mod_spandsp_fax.c:534 Image
>>>>      resolution:  0x0
>>>>      2014-08-29 15:21:39.187130 [DEBUG] mod_spandsp_fax.c:535 Transfer
>>>>      Rate:     14400
>>>>      2014-08-29 15:21:39.187130 [DEBUG] mod_spandsp_fax.c:537 ECM
>>>>      status         off
>>>>      2014-08-29 15:21:39.187130 [DEBUG] mod_spandsp_fax.c:538 remote
>>>>      country:
>>>>      2014-08-29 15:21:39.187130 [DEBUG] mod_spandsp_fax.c:539 remote
>>>>      vendor:
>>>>      2014-08-29 15:21:39.187130 [DEBUG] mod_spandsp_fax.c:540 remote
>>>>      model:
>>>>      2014-08-29 15:21:39.187130 [DEBUG] mod_spandsp_fax.c:542
>>>>      ==============================================================================
>>>>
>>>>      Thanks in advance!
>>>>
>>>>      Cheers,
>>>>      tmarlok
>>>>
>>

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