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Asterisk IT is the primary developer and sponsor of Aster Fax the Open Source Email to Fax Gateway for Asterisk.
Asterisk I.T. offer a range of support options for Aster Fax as well as general Asterisk consulting services Contact.
Posted by crouse
Asterisk Fax:
Across the Internet even a G.711 codec fax transmission is unpredictable. An excellent discussion of why faxing and modems don't work well over VoIP can be found here. However, people often get perfectly good results on lightly loaded LANs. It still isn't perfect, as a burst of data on the LAN can still upset things, but some people get results they can live with.
Fax-over-Internet T.38 pass-thru functionality within Asterisk has arrived in 1.4, CallWeaver has reliable support for both T38 passthrough and T38 termination; CallWeaver is a fork of Asterisk 1.2. An alternative is Noojee Fax (aka AsterFax) which allows you to use Asterisk to send and recieve faxes normally then converts them to an email message or the other way around (email-to-fax). You might also consider Hylafax which runs outside of Asterisk but can be bridged using IAXModem to Asterisk, this is a robust solution when receving calls via PRI and forwarding to iaxmodem and hylafax on localhost.
In detail:
There are two conceptual methods of carrying virtually real-time fax-machine-to-fax-machine communication across packet networks:
* Fax relay, in which the T.30 fax from the PSTN is demodulated at the sending gateway. The demodulated fax content is enveloped into packets, sent over the network, and remodulated into T.30 fax at the receiving end.
* Fax pass-through, in which modulated fax information from the PSTN is passed in-band end-to-end over a voice speech path in an IP network. The following two pass-through techniques are possible:
o The configured voice codec is used for the fax transmission. This technique works only when the configured codec is G.711 with no voice activity detection (VAD) and no echo cancellation (EC), or when the configured codec is a clear-channel codec or G.726/32. Low bit-rate codecs cannot be used for fax transmissions
Posted by sagitraz
Asterisk IT is the primary developer and sponsor of Aster Fax the Open Source Email to Fax Gateway for Asterisk.
Asterisk I.T. offer a range of support options for Aster Fax as well as general Asterisk consulting services Contact.
Posted by adalson007
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