Difference between revisions of "Fax over VoIP"
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<big>'''Fax over VoIP is not reliable and does not work most of the time.'''</big> | <big>'''Fax over VoIP is not reliable and does not work most of the time.'''</big> | ||
It is possible to get nearly 100% rate in rare circumstances but is very very low chance | It is possible to get a nearly 100% rate in rare circumstances but there is a very very low chance of this. | ||
The broad explanation lies in a technology mismatch between FAX and VoIP, as explained in Steve Underwood's article [http://www.soft-switch.org/foip.html here]. | |||
Steve Underwood developed SpanDSP package which helped to implement FAX support into Asterisk, Freeswitch and other open-source VoIP platforms. | Steve Underwood developed the SpanDSP package, which helped to implement FAX support into Asterisk, Freeswitch and other open-source VoIP platforms. | ||
T38 protocol supposed to work reliable over VoIP, but the problems with this protocol are following: | The T38 protocol is supposed to work reliable over VoIP, but the problems with this protocol are following: | ||
# Different hardware vendors do not follow standards and T38 implementation on various hardware is mostly broken. | # Different hardware vendors do not follow standards and T38 implementation on various hardware is mostly broken. | ||
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Digium anounced that old fax application/implementation is crap: http://lists.digium.com/pipermail/asterisk-dev/2009-December/041067.html | Digium anounced that old fax application/implementation is crap: http://lists.digium.com/pipermail/asterisk-dev/2009-December/041067.html | ||
We will wait till their proposed new application | We will wait till their proposed new application is fully tested and incorporated into Asterisk with good results. | ||
After that we will implement it in to the MOR. | After that, we will implement it in to the MOR. | ||
<br><br> | <br><br> | ||
Revision as of 11:26, 29 May 2010
Fax over VoIP is not reliable and does not work most of the time.
It is possible to get a nearly 100% rate in rare circumstances but there is a very very low chance of this.
The broad explanation lies in a technology mismatch between FAX and VoIP, as explained in Steve Underwood's article here.
Steve Underwood developed the SpanDSP package, which helped to implement FAX support into Asterisk, Freeswitch and other open-source VoIP platforms.
The T38 protocol is supposed to work reliable over VoIP, but the problems with this protocol are following:
- Different hardware vendors do not follow standards and T38 implementation on various hardware is mostly broken.
- Asterisk does not support T38 very well.
Update 2009.12.08
Digium anounced that old fax application/implementation is crap: http://lists.digium.com/pipermail/asterisk-dev/2009-December/041067.html
We will wait till their proposed new application is fully tested and incorporated into Asterisk with good results.
After that, we will implement it in to the MOR.
Update 2010.04.22
http://www.venturevoip.com/news.php?rssid=2385
See also:
