[yokem55]

> A fax machine can be plopped down and hooked up to a POTS.

Well, in many places, traditional copper pots is dying faster then the fax machines people still want to use. Fax over VoIP can work, but it makes for a lot of headaches if it doesn't.

[throw0101d]

> T.38 is an ITU recommendation for allowing transmission of fax over IP networks (FoIP) in real time.

* https://en.wikipedia.org/wiki/T.38

* https://www.itu.int/rec/T-REC-T.38/en

[yokem55]

T.38 can help - but the codec reinvite process to switch to it when you detect fax tones can trip up a lot of machines .. And you still have to transcode the t38 back to 711 or tdm to send the call upstream which can be problematic as well on some switches.

[firesteelrain]

You are right that traditional phone lines seem to be getting replaced by VoIP however it is possible to augment a traditional fax machine with like an ATA adapter and/or T38 support