-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Johann Steinwendtner schrieb:
> I 'm trying T.38 faxig with spandsp using rxfax/txfax as fax terminal. > As another endpoint I 'm using Grandstream HT 486 ATA and a fax machine. > Has anybody success with the HT486 as T.38 terminal ? I've successfully faxed via T.38 using these combinations: fax machine -> HT486 -> SIP server -> HT486 -> fax machine fax machine -> HT486 -> SIP server -> Thomson ST620 -> fax machine fax machine -> Thomson ST620 -> SIP server -> HT486 -> fax machine fax machine -> AVM Fritzbox 7050 -> SIP server -> HT486 -> fax machine fax machine -> AVM Fritzbox 7050 -> SIP server -> Thomson ST620 -> fax machine (note: T.38 is not officially supported on the AVM Fritzbox. It only works with older firmware versions and only when sending. When receiving a fax tone from the remote end, the Fritzbox does not issue a T.38 re-invite). I also just recently tested the following cases: fax machine -> HT486 -> OpenPBX with spandsp T.38 -> RxFAX fax machine -> Thomson ST620 -> OpenPBX -> RxFAX TxFAX -> OpenPBX -> HT486 -> fax machine TxFAX -> OpenPBX -> Thomson ST620 -> fax machine > ATA as originator: I managed only onetimes a successfull T.38 fax > session. The other times the HT486 did not initiate a re-invite with > T.38 parameters. Or shall the Terminator inititate a re-invite ? When I tested T.38 with OpenPBX, it never detected the fax tone from the fax machine and thus did not issue a T.38 re-invite. This might be due to a configuration problem because I'm not overly familiar with OpenPBX and there are not many user reports available on the net. If you point me to the necessary patches for Asterisk, I will be glad to repeat my tests ;-) The fax tone detection and T.38 re-invite is always performed by the receiving terminator or gateway. I haven't read the corresponding RFC thoroughly enough but this is the way it works on all ATAs and gateways I've worked with so far. I also noticed that many modems which are connected to or built into PCs do not send a proper fax tone (CNG) so make sure you are using a good old fax machine. Thirdly, make sure that your fax machine does not support V.34 (class 2.1 aka "Super G3") because T.38 is limited to 14400 bps on the modem side. I only tested one V.34 fax machine but its modem would not negotiate with the HT486 properly. > txfax as originator: T.38 fax exchange takes place but the transmission > is not successful, txfax reports errorcode 60 (Disconnected after > permitted retry). I haven't been able to send more than a simple page using TxFAX with T.38 support yet. And even that did not work reliably. Either, the single page wasn't transmitted at all or fax machine on the HT486/ST620 recognized the end of the page but failed to negotiate the end of the transmission correctly. Once again, I only tried OpenPBX with T.38 termination support, yet, so your problem may be different. > Can someone recommend a T.38 able ATA which is working with spandsp ? T.38 support in spandsp is still work-in-progress so I think it's a litte early to make any recommendations. All I can say is that the T.38 support on the HT486 works reliably if the remote end does not stretch the specifications too much. Cheers, Henning Holtschneider - -- LocaNet oHG - http://www.loca.net Lindemannstrasse 81, D-44137 Dortmund tel +49 231 91596-25, fax +49 231 91596-55 sip [EMAIL PROTECTED] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (MingW32) iD8DBQFFSLloP9goCV2uudcRAg6dAJ9QQrTBvyCt7vEPO4YV+kXvfHsn6wCgv/5I EKunq1uf2+mI0+pjm0+yeAw= =TFn1 -----END PGP SIGNATURE----- _______________________________________________ --Bandwidth and Colocation provided by Easynews.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
