El Sunday 18 March 2007 23:13:39 Ray Jackson escribió: > Max CtRiX wrote: > >Have you ever heard of incompatibilities when sending a fax from europe > >to USA, or south africa, or NZ, or china ? > > > >Fax is a complex thing (i'm not an expert) but fax tones are identical > >everywhere :-) > > I thought that was the case - but then I wondered if a fax tone was so > predictable - why then would one fax machine recognise TxFax's tones and > switch to fax mode whilst another wouldn't and see it as a voice call? > So the frequency, volume and pitch is always exactly the same then for > every fax machine? Out of interest, does anybody know how long TxFax > waits before sending it's first fax tone? I'm wondering if the > receiving end has a short time out to wait for a fax tone and switches > to Voice mode too quickly?
There are standars thats define that, "how long..", "how much to wait...", etc, on traditional telephony they was T.30 and company, on VoIP world they are T.38. The problems are the same as on traditional telephony, lines with noise (at the PSTN side I mean), distorsions, delay, etc. There are a lot of problems to solve, not to mention FAX incompatibilies, compressions schemas, error corrections codes, etc. I have seen fax machines on traditional telephony that never talk together (Cannon and Oki ones for example) So if you have a problem with FoIP (Fax over IP), try to debug them and let us ,now so T.38 support on OpenPBX could be improved. What is the problem you have? OPBX->PSTN->Fax Machine or Fax Machine -> PSTN -> OPBX ? -- Saludos. Raúl Alexis Betancor Santana Dimensión Virtual S.L. _______________________________________________ Openpbx-users mailing list [email protected] http://lists.openpbx.org/mailman/listinfo/openpbx-users
