[comp.os.vms] Where do I look for SYSGEN param on MODEM hangups ?

ANK@CUNYVMS1.BITNET (ANIL KHULLAR) (05/12/88)

Of late we have been having problems with some of our MODEM lines.
People get HUNG or get a connect and no response, or USER authorization
failure.

our modems as defined as
$ SET TERM TTC1:/AUTOBAUD/DISCONNECT/MODEM/HANGUP/PERM/DIALUP

a show term ttcX indicates that some are set as /nohangup even though
all are will /HANGUP

I read in I/O users manual about setting it to HANGUP for all but I am
not sure how.?

I listed the SYSGEN params list to find which one's if any were set by
default to /nohangup

I guess my question is: How can we assure that all modem ports behave
exactly as we set them out to be in our above definitions.

Our users are getting paranoid with the semester coming to an end.

Please reply directly to me, since INFO-VAX on BITNET Side is slightly
irregular.

Thanks in advance

                                                Anil Khullar
                                        {Ph.D. Prog in Psychology
                                         C.U.N.Y. Grad. Center.
                                        33 W 42 St. Box 295,
                                         New York NY 10036      }

BITNET:ank@cunyvms1
INTERNET:ank%cunyvms1.BITNET@cunyvm.cuny.edu
        :ankgc@cunyvm.cuny.edu
==========================================================================

LEICHTER@VENUS.YCC.YALE.EDU ("Jerry Leichter ", LEICHTER-JERRY@CS.YALE.EDU) (05/16/88)

	Of late we have been having problems with some of our MODEM lines.
	People get HUNG or get a connect and no response, or USER
	authorization failure.

	our modems as defined as
	$ SET TERM TTC1:/AUTOBAUD/DISCONNECT/MODEM/HANGUP/PERM/DIALUP

	a show term ttcX indicates that some are set as /nohangup even though
	all are will /HANGUP

Eh?  What does this line mean?

	I read in I/O users manual about setting it to HANGUP for all but I am
	not sure how.?

And this one?

	I listed the SYSGEN params list to find which one's if any were set by
	default to /nohangup

The default terminal parameters are controlled by the TTY_DEFCHAR and
TTY_DEFCHAR2 parameters.  These are a bit painful to work with since they
are bit-encoded, corresponding to the terminal parameters defined in the I/O
User's Guide.  To manipulate them, you need to figure out which bit in which
terminal parameter word is of interest, then set it appropriately.  This is
really only necessary for a couple of parameters (like DISCONNECT) and mainly
for LAT lines, not real terminal lines.  The easier way to set the parameters
for real terminal lines is as you appear to have done it:  With SET TERM/PERM
commands issued during system startup.

	I guess my question is: How can we assure that all modem ports behave
	exactly as we set them out to be in our above definitions.

There are two sets of parameters associated with a terminal line:  Active and
permanent.  Essentially, the permanent ones are copied into the active ones
when someone logs in on the line.  (This isn't really how it works; in fact,
as I recall they really get copied when the last channel to the terminal is
deassigned.  But it's probably OK to think of it as happening on login for
now.)  The permanent parameters are then not looked at again until the next
login - it is the active ones that control what happens on the terminal line,
and it is the active ones that a normal SET TERM changes.  They are also
what a SHOW TERM will display.

No matter what the permanent settings say, if a SET TERM/NOHANGUP is issued,
either as a DCL command or by a program doing the equivalent SETMODE QIO, the
terminal's active parameters will now say /NOHANGUP, and the line will not be
hung up on logout.

But...there's an additional factor at play.  Because the /HANGUP - /NOHANGUP
distinction has security implications, VMS provides a way for the system
manager to keep users from screwing around with the setting.  Normally,
privilege (LOG_IO or PHYS_IO) is required to change the /HANGUP setting.
It is possible to allow non-privileged users to change the setting for a
particular line by setting the TT2$M_MODHANGUP characteristic for that line.
There is no SET TERM qualifier for for this characteristic - it has to be
set by a program, or in the TTY_DEFCHAR2 parameter.  The bit you want is
bit 3 (value 8).  (I found that by looking in SYS$LIBRARY:TT2DEF.H, by the
way.) If this bit is on, users will be able (by default) to modify the hangup
setting.  The default setting for this bit, i.e., in the value of TTY_DEFCHAR2
in VMS "out of the box" - is OFF:  Users CANNOT modify the hangup setting.
Check with SYSGEN to determine if the value on your system has been changed.
(CAUTION:  The value displayed by SYSGEN is always in decimal, and the values
accept by a SYSGEN SET command are normally in decimal, though you can use a
%X prefix to enter hex if you want.  Dealing with bits in decimal is painful
and tricky.  Many systems have ended up in strange states when someone screwed
up and mixed bases in setting the TTY parameters, flipping some random
assortment of bits.  Be careful!)

	Our users are getting paranoid with the semester coming to an end.

Having said all that about /HANGUP:  It's not clear to me what problems you
are actually seeing, or what they have to do with /HANGUP.  You've given a
vague description, and also provided a guess as to what you think is the
cause of the problem you've vaguely described.  That makes it very hard for
anyone to give you much help.  Next time, you would do better to DESCRIBE
THE SYMPTOMS YOU ACTUALLY SEE, not what you think is behind them.  You may
be wrong, in which case you will at best get advice that can only lead you
further down an incorrect path.
							-- Jerry