[44net] Services That Can Run on 1K2/9K6 RF

I have been following the conversation on what can we use the modern version of the 44net for other than a futile attempt to compete with cable modems, 4G/LTE or fiber-optic links. The purpose of the 44net/JNOS project that we are putting together for NYC-ARECS is for providing email/telnet services for a served client in case their connection goes down or does not exist in an ad-hoc location. I am wondering if we can expand on the usual email and telnet sessions at 1k2 or even 9k6 to include things like routing our own VoIP/Echolink-type connections? The Echolink manual states that it needs 24K+ data speeds to connect to it's servers and maintain a voice connection. I know that there are other codecs that can work at lower speeds as well as ongoing work with FreeDV operating in 1.5 Khz on 20 meters! Ideas anyone?