[VoiceOps] T.38 termination provider?

[Robert Dawson]

We run mostly the same way, t.38 from IAD to our core and terminate fax calls through PRI gateways - our experience is mostly the same, works well most of the time but occasionally we run into a fax that just doesn't interop with the IAD, etc. We also find that we have to "play" with the settings on most fax machines to get them working anywhere near reliably. We also have a number of clients that want to use their fax line to refill postage meters (apparently they use fax modems) and this invariably fails with t.38.

I agree that fax is long due to retire but the requirement for support is almost universal.

I looked at the fax/HTTPS solutions from FaxBack and FaxCore that use a special AudioCodes IAD/ATA. Both are OK products but I felt like the price is just too high. I actually rigged up an open source proof of concept for a similar store and forward configuration in our lab using a minimal Asterisk implementation and FXS port for the "IAD" and a server running Asterisk with a PHP gateway I wrote running on Apache. Basically the dialplan on the "IAD" sends every call to a local fax context and receives the fax locally as a TIFF, encoding the from, to, and date/time in the filename. It then does an HTTPS PUT with curl to send the file to the Asterisk fax gateway where it is queued and transmitted to the final destination.

This works really well, there are some issues though - the sending fax machine always sees a successful transmission regardless of whether the final transmission takes place or not. This necessitates a means of doing out of band error reporting - i.e. you would disable transmission reports on the fax and then have the IAD query for the status of the sent faxes and transmit a fax locally reporting a failure/success.

If anyone is interested in the work I have completed so far I would be happy to share it, would love to develop it further, put a GUI on it for fax archival/retrieval, etc. and actually come up with a reliable solution.

Robert Dawson


> -----Original Message-----
> From: voiceops-bounces at voiceops.org [mailto:voiceops-
> bounces at voiceops.org] On Behalf Of David Hiers
> Sent: Tuesday, December 13, 2011 1:32 AM
> To: Nathan Anderson
> Cc: voiceops at voiceops.org
> Subject: Re: [VoiceOps] T.38 termination provider?
> 
> We terminate our T38 in-house and send t30/711 to our upstream
> carriers.  It works pretty well, but it's not a panacea.
> 
> In general, we find that T38 fixes some problems, moves some problems
> from the far end to the fax/ata interface, and invents entirely new
> ones.
> 
> ++ on Alex's long fax experience.
> 
> 
> David
> 
> 
> 
> On Mon, Dec 12, 2011 at 8:53 PM, Nathan Anderson <nathana at fsr.com>
> wrote:
> > So, do T.38 only last-mile to the ATA, then dump it back into the
> audible
> > domain at our own SBC and pass it to our termination provider as a
> G.711u
> > call?  Interesting idea...I'll chew on that for a bit.  Thanks.
> >
> > -- Nathan
> >
> > ________________________________
> > From: Peter Childs [mailto:PChilds at internode.com.au]
> > Sent: Monday, December 12, 2011 6:59 PM
> > To: Nathan Anderson
> > Cc: voiceops at voiceops.org
> >
> > Subject: Re: [VoiceOps] T.38 termination provider?
> >
> >
> > Slightly off topic but from spec sheet the new transcoding NUIs in
> the
> > low-end ACME SBCs (3820/4500?) in theory can handle T.38 to
> T.30(ulaw/alaw)
> > interop, so you might be able to 'wrangle' it yourself.
> >
> >
> > --
> >  Peter Childs - Voice Engineer
> >  Internode/Agile
> >  Ph: 08 8228 2380 Mb: 0406 388 405 Fax: 08 8235 6801
> >
> > On 13/12/2011, at 12:26 PM, Nathan Anderson wrote:
> >
> > Hello,
> >
> > New to the list.  I work for a regional broadband ISP who is looking
> to also
> > become an ITSP.
> >
> > We are looking for a good SIP termination provider with reasonable
> rates to
> > all of North America that also happens to guarantee T.38 gateway
> support for
> > 100% of calls.
> >
> > Currently, we are using FlowRoute.  We are happy with the service,
> but the
> > odds of us hitting a gateway (through one of their upstreams) that
> will
> > accept our T.38 re-INVITE are about 50/50...not very good.
> >
> > We tried Gafachi, but that was not a good experience.  Their rate
> table is
> > all kinds of screwed-up.
> >
> > The only other one I've been able to find in my searches is Alcazar
> > Networks.  Anybody have any first-hand experience with them who can
> vouch
> > for them as well as their T.38 support for the wholesale termination
> > product?
> >
> > Other recommendations are also welcome, as well.  Although we may
> someday go
> > down the road of loading an LCR table into our SBC, at this point we
> are
> > looking for a single solid termination provider that will handle 100%
> of our
> > outbound call volume (a mix of voice and fax); we can fall-back to
> FlowRoute
> > as a backup solution if the primary provider goes down.
> >
> > Thanks a million,
> >
> > --
> > Nathan Anderson
> > First Step Internet, LLC
> > nathana at fsr.com
> > _______________________________________________
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> > VoiceOps at voiceops.org
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> >
> >
> >
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> >
> 
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