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Subject[OFFTOPIC] Re: PPP bug
On 8 Feb 1999, Andrew Snare wrote:

> >>>>> "Dick" == Richard B Johnson <root@chaos.analogic.com> writes:
>
> Dick> The +++ sequence in a packet can't affect the modem because
> Dick> you need at least 500ms (lowest you can set it) of quiet after
> Dick> the sequence to change its mode. The data strings will never
> Dick> be the last thing sent, so you can't get 500ms between
> Dick> characters no matter how hard you try.
>
> This is partially true. Unfortunately (I believe) Hayes patented the
> idea of there having to be a pause before and after the +++ sequence,
> and some manufacturers (namely Rockwell) simply look for any +++
> sequence as a break sequence regardless of timing. Experience is that
> roughly 40% of people on IRC are susceptible to this problem, so these
> modems are fairly wide-spread. To test a host (with permission,
> of-course:) use:
>
> % ping -p 2b2b2b415448300d <hostname>

For a moment there is thought adding:

escape 2b

to the ppp options file would fix it, but '2b' in not escapable :-(

So either disabling it or renaming it (as you said) to something escapable
is the only option. I assume using software compression might hide the
bug, as three +++ will surely compress to something else.

This has to be near the top of the list of recent hardware braindamge. I
wonder who has Hayes patent now that it went chapter 11, and what
ludricous amount is being charged for licensing to warrant this.

Cheers,

Rafael


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