Compandent offers low-cost MELP or MELPe Data-Terminal Equipment (DTE) for interfacing vocoders with external Data Communication Equipment (DCE) such as modems or crypto devices, etc..
https://www.compandent.com/melpehw/
Compandent Low Cost MELPe DTE (Data Terminal Equipent) FLEXI-232 is Available for Immediate Integration into Existing System and Testing
Compandent's popular low-cost MELP or MELPe Data-Terminal Equipment (DTE) for interfacing vocoders with external Data Communication Equipment (DCE) such as modems or crypto devices, etc. is available.