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ISH~ SHARE SESSION REPORT
APPENDIX A. BIBLIOGRAPHY
61 C155 SNA Session Establishment White Paper 50
SHARE NO. SESSION NO. SESSION TITLE ATTENDANCE
An overview of the facilities available in the IBM X.25 NPSI PP is avail-
able in; TPAM Jim Cobban DCL
X.25 NPSI General Information (GC30-3080) PROJECT SESSION CHAIRMAN INST. CODE
Datacrown Inc. 650 McNicoll Ave. Willodale, ON, Canada (416) 499-1012
A detailed technical discussion of the X. 25 interface can be found in;
SESSION CHAIRMAN'S COMPANY, ADDRESS, AND PHONE NUMBER
The X.25 Interface for attaching IBM SNA Nodes to Packet-Switched Data
Networks. General Information Manual. (GA27-3345)
The generation macro operands for the NPSI are documented in; The final report of the SNA Session Establishment White Paper C9mmittee was
presented. This paper addresses deficiencies in the currently available
X.25 NCP Packet Switching Interface - Installation and Operation. products for handling logons to applications in a VTAM, TCAM or other SNA
SC30-3163. (Releases 2 and 3.) Network. There was a breif foil presentation explaining the nature of the
proble~s, reviewing existing solutions, and giving an overview of the White
A detailed technical discussion on the installation experience of the NPSI
in an OS/VS environment; Paper. The remainder of the meeting was a question and answer session on the
paper.
X.25 NPSI Release 2 and 3 Guide. (GG24-1567)
A detailed technical discussion on SNA-to-SNA connection over an X.25 net-
work including implementation, performance tuning and problem determi-
nation considerations;
X.25 SNA Guide. (GG24-1568)
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Appendix A. Bibliography 39
04/F/SJB/l
SKA Session Establishment Page 2
Objective:
Identify a set of user requirements for functional enhance-
ments in the area of facilitating and controlling the estab-
lishment of sessions between logical units in an SKA network.
Scope:
This paper does not consider the question of termination of
sessions. However. it is felt that this should be more con-
sistent between various applications.
Some interest was expressed in providing an ability on the
~ TPAM PROJECT initial session establishment to specify an application to be
invoked at a more detail level. An example of this would be
allowing the end-user to specify "ADRS" and get straight in.
~ Session Establishment Control as opposed to asking to TSO or CMS. then ask that level of
system for APt. loading the appropriate APt library and then
-
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Draft Report
February 1~. 1983
invoking ADRS. This sounds like a good idea but is beyond
the functionality that can be achieved without major rewrites
to every interactive subsystem. This topic is therefore
recommended to the Interactive Systems Task Force for study.
~
SNA Session Establishment Page 3 SNA Session Establishment Page 14
.a. Summary interface provided to the end-user should be compatible with
that provided by the session control interface product.
IBM should supply a session control interface product or
products which will supplement Unformatted System Services This implies that the session control product may be a series
and Formatted System Services of VTAM and TCAM. and some of of products with pieces running in each of the programmable
the Message Control Program functions of TCAM. This inter- nodes in the network. These pieces should cooperate to
face will monitor all session requests in a SNA network. The achieve the appearance of a single. attachment independent.
session control interface might be implemented either as a session establishment interface.
direct extension to USS. in the VTAM/TCAM SSCP. or as a sepa-
rate application. along the lines of the original Network Operation of the session control interface should be possible
Solicitor. through the same command interfaces as for the access method.
The purpose of this product is to enhance the appearance of a
single network image to the end-user during session initia-
tion. This is very important in a complex network connecting
multiple geographically dispersed nodes. The function
includes providing as similar as possible a session estab-
lishment interfa.ce to all terminal users as possible. The
user should not have to learn a device-dependent session
establishment process. As far as possible there should be a
single step session establishment process in which all of the
data necessary to place the user in session with the applica-
tion is collected in one up front step by the session control
product. and then passed with the session establishment
w request to the application .
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In addition to whatever facilities may be specified in table
form. there must be the ability to invoke user exit routines.
both directly out of the session control product. ani out of
RACF. It is desireable that these exits 'be programmeable in
a higher level language such as COBOL. FORTRAN. or PL/I. The
exit routines should be invoked asynchronously to the access
method.
A compatible session control interface should be available in
all teleprocessing access methods which support SNA and in
all programmeable cluster nodes. It must run under all IBM
operating systems which support SNA access methods. This
includes the operating systems running on distributed data
processing systems such as the 8100. Where multiple proces-
sors are involved. the session control interface product on
each processor should cooperate with its counterparts on the
other processors in routing a session.
It must support all terminals which are supported by the
above TP access methods. including SNA. BSC. and start/stop
protocols. All terminals will be supported in as device
independent a manner as possible without sacrificing the
ability to utilize the power and flexibility of some termi-
nals such as 3270s. Where a terminal product provides a
method of constructing a Formatted System Services initiate
from data provided by the end-user. the appearance of the
SNA Session Establishment Page 5 SNA Session Establishment Page 6
~) End User Interface Suggested Implementation
~) Consistency The data stream used for establishing sessions for all dis-
The session establishment procedure should be as consistent play terminals should be LU2, or a mapping of LU2 into the
as possible across the range of supported terminals. There device dependent character streams of the non-3270 display
should not be any difference in the procedure for establish- terminals. The data stream mapping might be done in a
ing a session between any supported display terminal and an front-end processor. The data stream used for establishing
application. sessions for non-display terminals should be LU1 or a mapping
of LU1 into the device dependent data streams as above.
On display terminals the end user should receive a full
screen display prompting simultaneously for all permissable
input fields, and displaying all desired output information.
If all of the necessary data is entered on this full screen,
and is valid for the application, the user should not be
reprompted by the application to reenter the data.
Prompting for non-display type devices should allow for
entering the multiple possible input fields without requiring
prompting. If insufficient data is supplied, however, the
use~ should be prompted. Once again, as far as possible the
output presented to the end user, and the input actions
required must be as consistent as possible across the whole
range of supported terminals.
;:...:,
~ Justification
Q
There is too much variation in methods of logging on for var-
ious types of terminals. EVen within a single type of termi-
nal, for example a 3276 or 3767, the actions required of the
end user to log on depend upon the setting of a switch on the
terminal. The end user should not have to learn a range of
different session establishment procedures.
At present the required session establishment process depends
upon the method of attachment of the terminal. If a 3277/8
is attached to a SNA 3274/6 one method is used, if attached
to a BSC/LOCAL 3274/6 another, if attached to an 8100
another, if attached to a 3600 yet another! Unless an exter-
nal label has been attached to the terminal to let the user
know how i t is hooked up there is no way to know how to log
on.
One of the objections raised to the use of SNA is that, in
return for being given the flexibility to choose a target
application, the user is forced to respond to an additional
prompt in all circumstances, even on terminals which are only
very infrequently used on anything other than the production
application. If the application prompting could be consoli-
dated into the session control interface prompt the annoyance
level is decreased.
SMA Session Establishment Page 7 SMA Session Establishment Page 8
ii) Pzesentation Sezvices
The design of a display for session establishment prompting Justification
should be as flexible as possible. The screen layouts should
be designed interactively. At the discretion of the instal- The intention of this facility is to minimize the a'mount of
lation it should be possible to have multiple screen output central network administration, while enhancing end-user con-
layouts or line by line prompting formats. trol. The existing unformatted system services is completely
inadequate, in as much as it is limited to 256 byte messages
As a minimum, in addition to being able to specify any and is forced to use SLU1 data streams even to some 3270s.
desired constant data, the user should be able to select from
the following variable output fields: Suqqested Implementation
1) logical unit name of the terminal Presentation services map design should use some preexisting
2) current date presentation services design product, or a successor to such
3) current time, to be updated when the screen is refreshed a product, rather than having a design function local to ses-
4) an installation specified identification of the control sion control.
point in the network for this terminal. This might be a
telephone number for the network Hotline, or some node The system should support multiple screen layouts, with the
identification. In a network which has multiple control end user being able to select which of the layouts best suits
points handling problem calls, which occasionally change his/her requirements, by command entered at the terminal. If
domain boundaries, it might be the name of the control authorized to do so the end user should be able to invoke the
point, or the name of the city containing the control screen design process from the Session Controller main menu,
point. create a new layout, and assign it a unique name, without
5) a set of application names or identifiers. For example; involving central site system programmers. The session con-
a session establishment screen may be set up which per- trol interface should reject a request for a named screen
t.:I mits logging on through the use of a selector pen, or layout which is not known to the system, or for a named lay-
N> program function keys. out which cannot be displayed at the particular terminal, for
r- 6) the current status associated with each of the above example because it requires a larger presentation space, or
applications. These statuses should only be refreshed for a named layout for which authorization was denied by an
upon request from the user, or upon re-display of the installation exit.
menu after the user logs off another application.
7) date of most recent broadcast news item (see below). Once designed, the screen layouts should be presented in as
8) diagnostic messages compatible a manner as possible on all display terminals,
9) network news area, multiple lines (see below). regardless of size, shape, or functional capabilities. For
example it may be desire able to be able to specify that the
The user should be able to specify names for input fields on specified session establishment display will always be cen-
the display, and the information on what input fields have tered in the presentation space, rather than appearing in the
been entered, and their values, should be supplied to a user upper left corner. It should be possible to specify extended
exit. The one presumeably essential field would be the attributes, such as colour, or highlighting, where the termi-
application name. The action of the user exit is described nals are capable of implementing then. The presentation ser-
in the following section. vices interface should determine the capabilities of the par-
ticular terminal, and attempt to map the screen layout in as
It must be possible to specify the action to be taken when compatible a manner as possible.
various attention keys are pressed on terminals which support
them, and to specify the action to be taken, or the interpre- The interactive map development capability of DMS or DPPX/DPS
tation to be made, of the use of a light pen. is perhaps the most user-friendly implementation of such a
function. An alternative might be the menu management of
SPF, although this would require enhancements in support of
extended attributes.
SNA Session Establishment Page 9 SNA Session Establishment Page 10
~) Application Specification
The installation should be provided with a choice of a power- Suggested Implementation
ful set of translation tables and exit routines for inter-
preting application names. The exit routines should be sup- The exits should be invoked asynchronously to the rest of the
plied with all of the various input fields. as defined by the access method processing. The exits should run either in
presentation services map definition. in order to make the another address space. or partition. or if run in the access
evaluation of which application the end user wishes to use. method address space. in a different protect key from the
The routine may return specifying' access method~ The exits must be able to request operating
system services without interfering with the operation of the
1) An application identifier which the access method can access method. It is highly desireable that it be possible
resolve directly. or ... to write the exits in a higher level language.
2) An indication that certain specified additional input
fields must be supplied which were either ommitted by
the user on the first try. or. for non-display termi-
nals. have not been prompted for yet. The end-user will
then be prompted for those specific fields. When the
values have been obtained. the exit will be redriven.
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