Hi Mychaela,
On Mon, May 29, 2017 at 12:21:38PM -0800, Mychaela Falconia wrote:
On 5/29/17, Harald Welte laforge@gnumonks.org wrote:
d) some modems expose voice as "GSM codec frames over UART"
You got me curious here: are there any modems out there other than FreeCalypso that offer the quoted special feature? Someone actually paid me to add this special feature to FreeCalypso a little over a year ago, so I reason that it must be sufficiently non-standard that they couldn't find a commercial off-the-shelf modem that can do this feat.
I've definitely seen this in commercial modems.
If I remember correctly, it was the Gemalto EHS-6, which can disable the GPS uart and re-cycle that UART for the audio frames. It might also have been a Quectel UC-20. Now that I think more about it, I think it was the UC-20.