We have probably 30-40 fax machines running T.38 between Linksys SPA-3102 and Cisco gateways. We have a pretty good success rate and we have been doing this for probably 2-3 years. We have a couple of them going thru an * 1.4 box and it seems to work ok. One of my projects is to try and get them all converted to go thru an FS box, I just haven't had time. Our biggest issues have always been error correction. Once we disable that on the fax machine, it seems to work pretty good. As a general rule, we have found that older cheaper machines work better. New fancy machines are unreliable and that could certainly be related to v.34 issues, but we haven't bothered to get that into it to find out.
Peder -----Original Message----- From: freeswitch-users-boun...@lists.freeswitch.org [mailto:freeswitch-users-boun...@lists.freeswitch.org] On Behalf Of Gabriel Kuri Sent: Thursday, October 22, 2009 2:29 PM To: freeswitch-users@lists.freeswitch.org Subject: Re: [Freeswitch-users] Proxy media mode with T.38 re-invite AFAIK T.38 v2 supports a max speed of 14.4 anyhow, so that's the max speed you'll ever see in the SDP. T.38 v3 supposedly supports v.34 speeds, however no one that I've seen has implemented it yet - not sure it's even an official standard? Yes, in my experience, v.34 capable FAXes do not properly negotiate down to 14.4 speeds, we've always had to disable v.34 (or whatever the option is called on your particular make/model to force it down to 14.4 or slower speeds). We use the Cisco/Linksys ATAs - I've heard there's better ATAs out there that properly negotiate the FAX down to 14.4 on the T.30 side of the connection, but never had a chance to play with them. I'd certainly be interested to hear anyone's experience with T.38 reliability and various combinations of FAX machines and make/model of ATAs. Gabe Kristian Kielhofner wrote: > Gabe, > > I don't think any of them are plus the T.38 SDP tells me the bitrate > is 14400, certainly not V.34 speed. > > Are you saying the machine even trying to negotiate V.34 poses a problem? > > On Thu, Oct 22, 2009 at 2:16 PM, Gabriel Kuri <gk...@ieee.org> wrote: >> Out of curiosity, is it a Super G3 (ie v.34) capable FAX? We've had >> nothing but intermittent problems with Super G3 FAXes over T.38, unless >> v.34 is strictly turned off on the machine. >> >> Gabe >> > _______________________________________________ FreeSWITCH-users mailing list FreeSWITCH-users@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@lists.freeswitch.org http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users http://www.freeswitch.org
