>From:             Elbert E Silbaugh <[log in to unmask]>
 
>So, what if, in a process handling, menu driven environment, ONE session
>has TWO or MORE processes each with (1 or more) FOPENs on the same LDEV
>in effect at the same time?
 
I asked the same question, unfortunately, I asked directly and not
via HP3000-L, so, here is her response (I hope this is OK):
 
------- Forwarded Message Follows -------
From:          Eero Laurila <[log in to unmask]>
Subject:       Re: Concurrent User License
 
<snip>
 
Here's some more information on the matter.  The first part is an HP
Supportline document explaining some of the user licence stuff and the
second part is a recent article that was published in HP's internal
newsletter to clarify some misconceptions around NULL VT and what it
really means.
 
-----------part #1-----------------------------------------------------
Details of what does and does not count toward the user limit are
listed below:
 
Counts toward user limit
-------------------------
1. A user logon from a terminal or PC is counted when using one of
   the following connections:
 
   - DTC direct connect
   - DTC modem connect
   - LAN (PC only)
   - X.25
   - PBX
   - Statistical Multiplexer
   - NS virtual terminal (Pt-to-Pt, LAN, X.25)
   - PAD
 
2. An application which calls HPFOPEN or FOPEN on a terminal other
   than its own will increment the user limit for each additional
   terminal opened.
 
Does not count directly toward the user limit
----------------------------------------------
1. The physical console will always be available and will NOT
   count toward the user limit.
 
2. Sessions have not been used to keep track of the user limit
   since some applications can initiate multiple sessions for a
   single user.
 
3. Jobs do not typically count toward the user limit unless the
   job is running an application which is opening a terminal.
 
4. Processes do not directly relate to the user limit because it is
   possible for a single process to HPFOPEN multiple terminals. As
   well as, a single user can run an application that creates
   multiple processes.
 
5. Remote applications which do not establish a virtual terminal
   do not count toward the user limit. A common example of this
   is Remote File Access. A user performing a dscopy with the
   logon option does not count.
 
In summary, the user count tracks individual users interacting
with the system through an open terminal or PC connection.
 
 
-----------part #2 (clarifying article on NULL VT) ---------------
 
BY:  James Hofmeister - Network Expert Center Atlanta
     Eero Laurila     - CSY Networking lab, NS services, VT.
 
This is a quick article to clear up a misconception with the
functionality of "NULLVT" in the NS3000/iX product.
 
NS3000/iX supports a facility called "NULLVT", which is the ability to
open a terminal device on a system for logon, but it specifically
excludes the ability to do any terminal I/O with the system.
 
An example of one implementation demonstrating this functionality is the
HP Resource Sharing product which supports multiple inbound connections
from one PC to the HP3000 - while counting the PC as one user.  This
product allows the PC user to share discs and printers attached to the
HP3000 - i.e. using it as a file and print server.  The thing to note
here is that there is no terminal I/O involved with the client.
 
On the technical side, allocating an ldev for terminal I/O is needed to
satisfy MPE's requirements for logon.  The way that VT's terminal I/O
works is that a device that has been allocated for input/output
(stdin/stdlist) will have a logical device manager (vt_ldm) attached to
it.
 
The vt_ldm forwards I/O requests from MPE/iX's High-Level I/O (HLIO)
subsystem to the client and vice versa through a vtserver process who
owns the TCP-connection on the host.  Also, the vt_ldm is created by the
server process that allocates the device (in this case
vtserver.net.sys).
 
Depending on which way the vt_ldm is created, the initialization info
sent to the ldm tells whether the device is to be used for real I/O or
"null" I/O.  When created as a "null" terminal, the vt_ldm's state is
set to indicate that there is no vtserver process to take care of
forwarding data between the host and client and thus all the terminal
I/O received from HLIO (High-Level I/O) is to be flushed.
 
Other NS services for example NFT(dscopy) and RFA(remote file access)
can and will also use the "nullvt" functionality.  If the user specifies
a logon string in DSLINE <node>;LOGON= parm, this results in a
programmatic logon executed on the remote node through a null
VT-terminal.  Note that also in this case the device is allocated
strictly for the logon purposes and there is no interactive
communication with the remote host nor is there a server to take care of
it.  Using other NS services in this fashion saves resources on the host
by eliminating the need for creating an extra server process (vtserver)
to handle the terminal I/O that will not occur on NFT-only or RFA-only
connection.
 
The misconception of the functionality in the "NULLVT" facility is the
result of article generated, as a Question / Answer response to a
Customer User Group.   The specific text of that article which has since
been deleted is as follows:
 
-------------------cut/paste "3000USER" Csy Hp3000 HOTLINE / HP6650/HL--
 
Q: Does a single PC running multiple sessions on the server count as one
   or multiple users on the HP 3000?
 
A: The HP 3000 supports a facility for multiple sessions from a single
   client to be counted as a single user.  Please contact the software
   vendor to find out if they have taken advantage of the "NULLVT"
   facility in MPE/iX.
 
-------------------cut/paste "3000USER" Csy Hp3000 HOTLINE / HP6650/HL--
 
 
The text of the article should read:
 
------------------------------------------------------------correction--
Q: Does a single PC running multiple sessions on the server count as one
   or multiple users on the HP 3000?
 
A: Each session logged on to the HP 3000 doing terminal I/O is counted
   towards user licence.  All VT-connections will create a vtserver
   process that allocates a device for "real" terminal I/O.
 
   Example: Some MS Window clients offer multiple VT connections from a
   single PC to the HP 3000 Server.  Each VT logon is a unique session
   and is counted as a session against the user license.
------------------------------------------------------------correction--
 
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|James Bennett             | Phone: 916.891.5281        |
|Bi-Tech Software, Inc     | Fax  : 916.891.5011        |
|1072 Marauder, Suite A    | EMail: [log in to unmask]   |
|Chico, CA 95926           | "If it was easy, anyone    |
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