From: gerg@netcom.com (Greg Andrews)
Newsgroups: comp.mail.uucp
Subject: Re: Binding Systems entries to specific Dialers entries (and not Devices)?
Summary: Use the device type/class field in Systems
Keywords: Dialers  Devices  Systems  HDB
Date: 18 Nov 92 08:56:47 GMT
Article-I.D.: netcom.1992Nov18.085647.20388
Organization: Netcom Online Communications Services (408-241-9760 login: guest)

earle@elroy.jpl.nasa.gov (Greg Earle - Gainfully Unemployed) writes:
>
>
>tb9600v42     =W-,    "" \dA\pA\pA\pTE1V1X11Q0S2=255S12=255S50=6S58=2S111=30S1\
>80=2S181=1\r\c OK\r \EATDT\T\r\c CONNECT\s38400/LAPM/COMP/9600 STTY=crtscts
>
>tb9600mnp     =W-,    "" \dA\pA\pA\pTE1V1X11Q0S2=255S12=255S50=6S58=2S111=30S1\
>80=3S181=1\r\c OK\r \EATDT\T\r\c CONNECT\s38400/REL/COMP/9600 STTY=crtscts
>
>tb14400mnp    =W-,    "" \dA\pA\pA\pTE1V1X11Q0S2=255S12=255S50=7S58=2S111=30S1\
>80=3S181=1\r\c OK\r \EATDT\T\r\c CONNECT\s38400/REL/COMP/14400 STTY=crtscts
>
>etc. etc. ... which results in Devices entries like
>
>ACU cua0 - 38400 tb14400mnp \T
>ACU cua0 - 38400 tb9600mnp \T
>ACU cua0 - 38400 tb9600v42 \T
>ACU cua0 - 38400 tb9600 \T
>
>So, whenever I put "38400" into the "Class" field of the Systems file entry,
>uucico always tries "tb14400mnp" first, then "tb9600mnp", etc.
>

As far as I've been able to tell, there's nothing magic about the string
"ACU" in HDB Systems and Devices file entries.  Aside from built-in types
like "TCP" or "801", it's just a text string.  The device type field and
speed field are remembered, and the Devices file is scanned for lines
that contain matches to both those fields.

I've been successful using device types like "UUCP", "ACUNORM", and
"ACUPLAIN" to select a particular line in Devices, which points to
the desired line in Dialers.


BTW, It's somewhat dangerous to make your dialer look for such specific
connect messages from the modem.  What happens if the other guy turns off
compression in his modem?  You could comple the connection and log into
the computer, but your call fails because the script didn't get the /COMP
suffix from the modem.  Or what if you wanted to test a connection using
a 19200 bps port speed instead of 38400?  The script won't let you connect
because the modem says "CONNECT 19200" instead of "CONNECT 38400".
A quick test that should only require a minor change to Systems now makes
you edit Devices and Dialers also.  (After several calls are wasted while
you figure out why it isn't working)  When the test is done, you have to
change everything back!

I find it best to make Dialers ignore the things that can vary from site
to site and day to day (like the connect suffixes), let Devices allow a
range of port speeds, and lock the speed and device type in Systems.  This
will reduce the number of Devices scripts you need (your two mnp examples
would become just one script), and things won't break on you when you need
a little flexibility.  You can still enable the modem's connect suffixes
if you want, it's just the script won't care about them.  However, YOU will
care about them when you're capturing debug dumps of your uucp calls, so I
recommend enabling the suffixes.


-- 
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 |  Greg Andrews   |       UUCP: {amdahl,claris}!netcom!gerg        |
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