Steve Underwood,
Would you mind summarizing where/how T.38 functions, and maybe how it compares to the analog fax environment for the asterisk-users arhives?
I don't mean to speak for Steve, so I hope that Steve will still reply if he chooses to, but I like the question, and since I know enough about T.38 and fax to answer at least in a general sense, I will.
In a traditional analog fax you have modulated audio data, that is, the data stream is converted into an audio representation by the transmitter, and the receiver demodulates the audio stream to produce the data stream. A lot of data gets packed into very small portions of audio, which is why fax over VoIP (T.38 is not VoIP, it is FoIP) is unreliable - any jitter will likely cause data loss.
There are no modulators in T.38. So take the fax procedure, but instead remove the data modulation/demodulation part. T.38 devices communicate raw data through the IP network, and the IP network is as good at communicating data as the PSTN is as good at communicating audio. So if you could have a full T.38 delivery route from fax sender to fax receiver, the data never once gets converted into an audio signal - it doesn't need to be.
That's the gist of things.
Lee. _______________________________________________ Asterisk-Users mailing list [email protected] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
