Re: Developing PLATOTerm64, Flow Control woes.

The solution to me seems quite clear, I need to implement traffic shaping
to throttle the connection down to something resembling modem speeds, while
making a simple form of negotiation with my terminals to specify how much
to throttle the connection.

-Thom

On Mon, Jul 2, 2018 at 12:49 PM Mike Stein <mhs.stein@gmail.com> wrote:

> I'm a little confused and don't quite understand what you're saying:
>
> "The problem is large transmit fifo's "... "If you also have a large dumb
> transmit fifo"..."
>
> Did you mean 'receive'?
>
> "This affects you whether you're using packets or an ascii terminal"
>
> Aren't we talking apples and oranges here? An ASCII terminal communicates
> with whatever it's connected to, whether that's a packet 'modem' of some
> kind, a 'normal' modem or a direct connection.
>
> The bottom line IMO is that if it's available then RTS handshaking is the
> way to go; if not, and you can live with the 'no binary' restriction then
> end-to-end XON/XOFF flow control can work just fine over the internet.
>
> With properly configured hard- and soft-ware, effective flow control is
> quite possible. Most of these devices are intended to transparently replace
> an RS-232 connection, so if it works over copper wire it should work just
> as well over USB, Ethernet, WiFi, whatever.
>
> m
>
> ----- Original Message -----
> From: "smf" <smf@null.net>
> To: <cbm-hackers@musoftware.de>
> Sent: Monday, July 02, 2018 4:10 AM
> Subject: Re: Developing PLATOTerm64, Flow Control woes.
>
>
> > On 01/07/2018 20:22, Mike Stein wrote:
> >> Keep in mind that XON/XOFF expects a fairly immediate response; a
> common issue using it these days is that you're not necessarily receiving
> single characters but packets and you could receive quite a few characters
> before XOFF has any effect.
> >
> > The problem is large transmit fifo's and the uart neither understands
> > the concept of flow control, nor allows the driver to pause
> > transmission. If you also have a large dumb transmit fifo, then it may
> > be a while before you can tell the other end to stop sending (and if the
> > other end has sent an xoff then someone is going to be losing data).
> > This affects you whether you're using packets or an ascii terminal.
> >
> > xon/xoff also shouldn't be used as an end to end flow control over a
> > modem/the internet as the transmit fifos in those will certainly swamp
> you.
> >
> > sending xoff as soon as you start receiving and only sending xon once
> > all the data has been processed is as extreme as you can get, if that
> > doesn't work then the problem you're trying to solve is actually
> elsewhere.
> >
> >
>
>