Secure voice software issues

[Phil Karn]

>This is why you'd really want to run your modems synchronously.  You'd
>just send HDLC frames that encapsulated IP packets (fragmentation may
>be required).  This is how most IP routers work over serial links.

Indeed. And because LAPM uses HDLC framing over the modem, you could
be completely compatible with a regular (asynch DTE interface) V.42bis
modem on the other end of the call. But by implementing V.42bis
yourself, you would have complete control over when frames get sent,
and how large they are.

Phil