[SIPForum-discussion] Sip Compatible Fax Machines

[Mike Coffee]

Mark,

This has to do with outbound calls from an ATA.  As we know, FoIP calls to a
provider begin as G.711 calls, and the SIP-peer/off-ramp gateway is responsible
for issuing the re-Invite, if any, to T.38.  Too often, the signaling gets
delayed while the media streams between the two endpoint fax terminals are up
and running.  This means the state machines in those terminals can pass the
"point of no return."  But the re-Invite finally arrives at the ATA, sometimes
several seconds beyond the onset of modem training.  If the ATA accepts the
re-Inivite, the fax transaction will be killed.

Happens alot.  We've not been able to get to the root cause, as both the gateway
and SBC guys say they aren't causing it, but we've developed technology that
solves the problem when it does happen.

Mike






Mark R Lindsey <lindsey at e-c-group.com> on 05/16/2011 02:46:08 PM

To:   mcoffee at Commetrex
cc:   Maciej Wasiel <Maciej.Wasiel at dialogic.com>, "discussion at sipforum.org"
      <discussion at sipforum.org>

Subject:  Re: [SIPForum-discussion] Sip Compatible Fax Machines



Mike -- Are you saying that the ATAs cannot recover from late-arriving
re-INVITEs, or that that nearly all ATAs generate the re-INVITE too late?



mark at ecg.co  |  +1-229-316-0013  |  http://ecg.co/lindsey



On May 16, 2011, at 9:40 AM, Mike Coffee wrote:

>
>
> And nearly all ATAs suffer from late-arriving SIP re-Invites to T.38.  We have
> found that often over 5-percent of all outbound calls have this problem.
>
> Mike Coffee
>
>
>
>
> Maciej Wasiel <Maciej.Wasiel at dialogic.com> on 05/14/2011 12:49:08 AM
>
> To:   "'Daniel M Hegarty'" <fullondan at gmail.com>, Greg Settle
>      <gsettle at opentext.com>
> cc:   "discussion at sipforum.org" <discussion at sipforum.org> (bcc: mcoffee)
>
> Subject:  Re: [SIPForum-discussion] Sip Compatible Fax Machines
>
>
>
> Hi,
> I would suggest going to the manufacturers of your ata's and asking them about
> their interoperability list. In most cases, if you stick with big names such
as
> Ricoh you should be fine; however, your faxes calls may be experiencing
network
> issues that no ata can resolve. Capture some t.38 network  traces of your
> failing calls and post them to this forum for analysis.
> Regards,
>
> Maciej Wasiel
>
_____________________________________________________________________________________________________________________________________________

>
> Software Engineer, Dialogic Research Inc | Address: 15 Crawford Street,
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> MA 02494 | Phone: (781) 433 9771 | Mobile: (508) 740-2641 | Fax: (781) 433
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> From: discussion-bounces at sipforum.org [mailto:discussion-bounces at sipforum.org]
> On Behalf Of Daniel M Hegarty
> Sent: Friday, May 13, 2011 7:34 PM
> To: Greg Settle
> Cc: discussion at sipforum.org
> Subject: Re: [SIPForum-discussion] Sip Compatible Fax Machines
>
> Greg
>
> Were a service provider providing service to end users in office environments.
>
> We need fax machines that will work best with SIP ( connected to linksys/audio
> codes ata's and adtran IAD's ).
>
> fax servers won't help us  - FYI
> On Fri, May 13, 2011 at 4:30 PM, Greg Settle <gsettle at opentext.com<
> mailto:gsettle at opentext.com>> wrote:
> RightFax fax server is T.38 FoIP SIP compatible.
> Greg
> 4256384418<tel:4256384418>
>
> From: discussion-bounces at sipforum.org<mailto:discussion-bounces at sipforum.org>
> [mailto:discussion-bounces at sipforum.org<mailto:discussion-bounces at sipforum.org
>]
> On Behalf Of Daniel M Hegarty
> Sent: Friday, May 13, 2011 3:27 PM
> To: discussion at sipforum.org<mailto:discussion at sipforum.org>
> Subject: [SIPForum-discussion] Sip Compatible Fax Machines
>
> Does someone have a list of sip compatible fax machines?
>
> I am looking to compile a list of machines that work best over SIP
>
> --
> Dan Hegarty
> 2132803572<tel:2132803572>
> http://twitter.com/fullondan
> http://www.facebook.com/daniel.hegarty
>
>
>
> --
> Dan Hegarty
> 2132803572
> http://twitter.com/fullondan
> http://www.facebook.com/daniel.hegarty
> <att1.htm>
>
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