[Freeswitch-users] Faxing problems if B leg offers T.38

David Ponzone david.ponzone at ipeva.fr
Wed May 25 19:10:32 MSD 2011 

Rob,

On my test box, I run a GIT from 05-02, and I don't have any issue.
But I just did the test, and the call flow is different from yours.

When I send a fax with my endpoint (Zoiper Softphone), I got the remote fax tone, and then my Zoiper sends the T38-REINVITE, not the remote gateway.
So I guess there are 2 possible call flows, because I remember in some circumstances, the remote sends the RE-INVITE.

David Ponzone  Direction Technique
email: david.ponzone at ipeva.fr
tel:      01 74 03 18 97
gsm:   06 66 98 76 34

Service Client IPeva
tel:      0811 46 26 26
www.ipeva.fr  -   www.ipeva-studio.com

Ce message et toutes les pièces jointes sont confidentiels et établis à l'intention exclusive de ses destinataires. Toute utilisation ou diffusion non autorisée est interdite. Tout message électronique est susceptible d'altération. IPeva décline toute responsabilité au titre de ce message s'il a été altéré, déformé ou falsifié. Si vous n'êtes pas destinataire de ce message, merci de le détruire immédiatement et d'avertir l'expéditeur.




Le 25/05/2011 à 13:18, Rob Morin a écrit :

> Is the fact that I was previously running the snapshot from 25 March adequate to meet this test?
>  
> From: Rob Morin [mailto:rmorin at blie-ent.com] 
> Sent: Tuesday, May 24, 2011 10:50 AM
> To: 'FreeSWITCH Users Help'
> Subject: Re: [Freeswitch-users] Faxing problems if B leg offers T.38
>  
> I can, if someone can tell me where to get the snapshot.  I looked at files.freeswitch.org and didn’t see one.
>  
> Prior to updating to the 5-17 snapshot, I was having the same problems with the 3-25 snapshot that I was using.
>  
> Thank you,
> Rob
>  
> From: David Ponzone [mailto:david.ponzone at ipeva.fr] 
> Sent: Tuesday, May 24, 2011 1:47 AM
> To: FreeSWITCH Users Help
> Subject: Re: [Freeswitch-users] Faxing problems if B leg offers T.38
>  
> Rob,
>  
> following Yehavi's comment, could you downgrade your GIT version to a previous version, like one month old ?
>  
> David Ponzone  Direction Technique
> email: david.ponzone at ipeva.fr
> tel:      01 74 03 18 97
> gsm:   06 66 98 76 34
>  
> Service Client IPeva
> tel:      0811 46 26 26
> www.ipeva.fr  -   www.ipeva-studio.com
>  
> Ce message et toutes les pièces jointes sont confidentiels et établis à l'intention exclusive de ses destinataires. Toute utilisation ou diffusion non autorisée est interdite. Tout message électronique est susceptible d'altération. IPeva décline toute responsabilité au titre de ce message s'il a été altéré, déformé ou falsifié. Si vous n'êtes pas destinataire de ce message, merci de le détruire immédiatement et d'avertir l'expéditeur.
>  
>  
> 
>  
> Le 24/05/2011 à 02:59, Rob Morin a écrit :
>  
> 
> David,
>  
> It isn’t the ATA. I’ve tried both the Grandstream HandyTone 502 and Cisco/Linksys SPA 2102. Same story in both cases.
>  
> I had my carrier help me troubleshoot and we can see the SIP request from the carrier come in. When T.38 is enabled, it is forwarded to the A leg, but the response from the A leg isn’t forwarded back to the B leg. I can produce traces that show this.
>  
> When T.38 isn’t enabled, the B leg is sending a T.38 reinvite. FS doesn’t respond or forward it. So the connection dies.  I have every reason to believe that I’d be able to send the fax if FS would respond with a 488 indicating T.38 is not acceptable. But instead, all I get is silence. Again, I can produce traces that demonstrate this.
>  
> There’s another similar email  trail out there, http://freeswitch-users.2379917.n2.nabble.com/T-38-via-UPDATE-request-td3821994.html, but I’m not certain that they’re related.
>  
> Thank you for your help!
> Rob
>  
> From: David Ponzone [mailto:david.ponzone at ipeva.fr] 
> Sent: Monday, May 23, 2011 6:11 PM
> To: FreeSWITCH Users Help
> Subject: Re: [Freeswitch-users] Faxing problems if B leg offers T.38
>  
> Rob,
>  
> perhaps you should not consider T38 is 100% interoperable.
> You may tell us what ATA is that, because some of them are nice piece of junk.
>  
> David Ponzone  Direction Technique
> email: david.ponzone at ipeva.fr
> tel:      01 74 03 18 97
> gsm:   06 66 98 76 34
>  
> Service Client IPeva
> tel:      0811 46 26 26
> www.ipeva.fr  -   www.ipeva-studio.com
>  
> Ce message et toutes les pièces jointes sont confidentiels et établis à l'intention exclusive de ses destinataires. Toute utilisation ou diffusion non autorisée est interdite. Tout message électronique est susceptible d'altération. IPeva décline toute responsabilité au titre de ce message s'il a été altéré, déformé ou falsifié. Si vous n'êtes pas destinataire de ce message, merci de le détruire immédiatement et d'avertir l'expéditeur.
>  
> 
> 
> 
>  
> Le 23/05/2011 à 20:51, Rob Morin a écrit :
> 
> 
> 
> I’m having problems faxing if the B leg offers T.38.  Several scenarios, but always the same result.
>  
> First, the architecture
>  
> FAX à ATA (T.38 optional) à FS à Carrier  à Destination (Possibly another carrier (PSTN) and the fax machine)
>  
> On my ATA, T.38 is enabled (Auto Detect).
>  
> If the destination supports T.38, the Carrier will offer it to Freeswitch. If the Destination doesn’t support T.38, the B leg doesn’t offer it and the faxes go through.
>  
> I’ve set Freeswitch as:
>       <action application="set" data="fax_enable_t38=true"/>
>       <action application="export" data="t38_passthru=true"/> 
> When that’s the case, and the B leg offers T.38, Freeswitch passes through the offer and the ATA responds, 3 times. But the response never gets sent to the B leg, so it terminates the call after about 30 seconds.
>  
> When I set Freeswitch as:
>       <action application="set" data="fax_enable_t38=false"/>
> The B leg still offers T.38 if its other side is capable. Freeswitch doesn’t pass the offer through and the B leg terminates the call after about 30 seconds.
>  
> I’m running on a recent git ( FreeSWITCH Version 1.0.head (git-86d757d 2011-05-17 22-51-47 -0500) ).
>  
> I’ve had no success attempting to configure FS as a gateway. Frankly, T.38 “passthrough” has had the most success, mostly when the other ends aren’t T.38 capable and it stays in G711u.
>  
> Is there something else I need to do to enable T.38 in passthrough mode? 
>  
> Thank you,
> Rob Morin
>  
> PS – I can provide tcpdumps of this, or whatever else is necessary.
>  
>  
> _______________________________________________
> FreeSWITCH-users mailing list
> FreeSWITCH-users at lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> http://www.freeswitch.org
>  
> _______________________________________________
> FreeSWITCH-users mailing list
> FreeSWITCH-users at lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> http://www.freeswitch.org
>  
> _______________________________________________
> FreeSWITCH-users mailing list
> FreeSWITCH-users at lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> http://www.freeswitch.org

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.freeswitch.org/pipermail/freeswitch-users/attachments/20110525/6856bc56/attachment-0001.html

More information about the FreeSWITCH-users mailing list