[Freeswitch-dev] [Freeswitch-users] Doubts about T38 passthru

[François Delawarde]

The provider's SDP is weird anyway, like if it wanted to send me a fax
when putting me on hold (?).

My mum always said that there is nothing (even proxy things) that can't
be done with a b2bua. Was she wrong?

François.


On Wed, 2012-08-29 at 11:48 -0500, Anthony Minessale wrote: 
> Because FS is a b2bua it probably only snaps to what type of channel
> the B leg is.
> FS is not a proxy and only has modest ability to emulate a few proxy behaviors.
> 
> 
> On Wed, Aug 29, 2012 at 11:43 AM, François Delawarde
> <fdelawarde at wirelessmundi.com> wrote:
> > Hi,
> >
> > Sent to the wrong ML, this probably is more a dev question:
> >
> > On Wed, 2012-08-29 at 10:46 +0200, François Delawarde wrote:
> >> Hi,
> >>
> >> Whenever my provider puts me on hold, it reINVITES with an SDP
> >> containing both audio (sendonly) and image media like so:
> >>
> >> ...
> >> m=audio 5320 RTP/AVP 18 3 8 0 96
> >> c=IN IP4 <ip_address>
> >> a=rtpmap:18 G729/8000
> >> a=rtpmap:3 GSM/8000
> >> a=rtpmap:8 PCMA/8000
> >> a=rtpmap:0 PCMU/8000
> >> a=sendonly
> >> a=rtpmap:96 telephone-event/8000
> >> m=image 5322 udptl t38
> >> c=IN IP4 <ip_address>
> >> a=T38FaxVersion:0
> >> a=T38MaxBitRate:14400
> >> a=T38FaxUdpEC:t38UDPRedundancy
> >> a=T38FaxRateManagement:transferredTCF
> >>
> >>
> >> Not sure if it's a non-standard SDP, but that's what I get. Now when
> >> t38_passthru=true, it only forwards the "image" part to the other leg.
> >> When t38_passthru=false, it only forwards the "audio" part.
> >>
> >> Is there a way to make t38_passthru forward the audio part as well? Or
> >> should I just change to a better provider?
> >
> > Thanks,
> > François.