[asterisk-users] Still on spandsp/app_fax and T.38

[Vinícius Fontes]

Here's the packet trace I promised: http://www.zshare.net/download/72186098494e6f8c/.

As this is a production system, there were a few calls along with the one that interests us. The one you're looking for is that from 5433142499 at 10.150.65.16 to 5421047008 at 10.153.66.146. The provider has the address 10.150.65.16 and my box has the address 10.153.66.146.



Atenciosamente,

Vinícius Fontes
Gerente de Segurança da Informação
Canall Tecnologia em Comunicações
Passo Fundo - RS - Brasil
+55 54 2104-7000

Information Security Manager
Canall Tecnologia em Comunicações
Passo Fundo - RS - Brazil
+55 54 2104-7000

----- "Vinícius Fontes" <vinicius at canall.com.br> escreveu:

> Yes, the fax machine only transmits at 9600. That's normal and
> expected. I'll capture the packets and will provide you with a link to
> download it in a few minutes.
> 
> 
> 
> Atenciosamente,
> 
> Vinícius Fontes
> Gerente de Segurança da Informação
> Canall Tecnologia em Comunicações
> Passo Fundo - RS - Brasil
> +55 54 2104-7000
> 
> Information Security Manager
> Canall Tecnologia em Comunicações
> Passo Fundo - RS - Brazil
> +55 54 2104-7000
> 
> ----- "Steve Underwood" <steveu at coppice.org> escreveu:
> 
> > On 02/05/2010 07:40 PM, Vinícius Fontes wrote:
> > > This message is pointed directly to Steve Underwood. I tought it
> > would not be nice to directly email him with a question that
> interests
> > a good part of the Asterisk community, so here it is. :)
> > >
> > > Steve, remember a few days ago when we discussed about issues on
> > Asterisk 1.6.1.13 and T.38 fax reception? Well I opened an issue on
> > Mantis (https://issues.asterisk.org/view.php?id=16756) and turns
> out
> > it might be spandsp-related.
> > >
> > > What happens is, when I use app_fax to receive a fax using T.38,
> I
> > get very low transmission rates, and about 30% of the faxes are
> just
> > not transmitted at all. 2400bps is not uncommon. If instead of T.38
> I
> > use an analog landline connected to that very same Asterisk box,
> > app_fax works wonderfully well transmitting at full 9600bps. Just
> to
> > rule out Asterisk's T.38 handling, I noticed that Fax For Asterisk
> > works perfectly with T.38, also on that same box.
> > >    
> > Is the FAX machine you are using only capable of 9600bps, because
> full
> > 
> > speed should be 14400bps?
> > 
> > Can you get a packet trace of a problem call, using wireshark, and
> > mail 
> > it to me?
> > > I'll be happy to provide you any info that could help solve this
> > issue.
> > >
> > >    
> > Steve
> > 
> > 
> > -- 
> >
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