On May 30, 6:33 pm, "Terry Olsen" <tolse...@hotmail.com> wrote:
Has anyone ever thought of running their old BBS just like they did in the
heyday???
I've given quite a bit of thought to running a dial-in BBS over VoIP,
but I have been unable to successfully put the idea into practice over
the public Internet.
Analog phone-line modems were designed to work with the phone systems
of the time. Connections through the old phone system could be
affected by band limitations, D/A and A/D conversions, and electronic
noise but were guaranteed a uniform round-trip time. So, modems were
built to rely upon uniform RTT and to cope with the other limitations.
Unfortunately, VoIP circuits suffer from jitter and packet loss.
Jitter buffers and frame erasure concealment algorithms address these
limitations in a way that works fairly well for the human auditory
system, but modems were not designed to handle signals altered by
these techniques and become even further confused by them.
I've tried dialing into VoIP-connected modems using all manner of
bitrates and error correction schemes, and have not been able to
achieve a usable connection for a period of more than two or three
minutes. There are VoIP protocols (V.150) which are designed to
reliably carry modem audio over the Internet, but they are not widely
implemented. I have been unable to find an ITSP with a V.150-
compatible network.
-Rusty D