Question 9/I - Teletex service
(revised and expanded, previously Question 8/I, 1985-1988)

Considering

(a) that the Teletex service as defined in Recommendation F.200 has
been implemented in a number of countries;

(b) that the F.200-Series of Recommendations already refer to a number
of applications, specified as standardized options of the Teletex
service;

(c) that further applications will be added in the future;

(d) that there is a need to define Quality of Service using both
qualitative and quantitative criteria,

it is proposed

that the future studies on the Teletex service should be divided into
five
main parts as follows:

1. Updating of Recommendation F.200

Considering

the Questions 10/I and 11/I on a general service framework for
document communication and on interactive modes,

the following should be studied:

How should the F.200-Series of Recommendations be updated, taking
into account these two Questions?

Which information security facilities should be offered within the
Teletex service?

2. Types of documents

Considering

(a) that business correspondence contains forms, trade documents,
letters with different types of information;

(b) that documents in business correspondence can be composed of
information coming from different sources such as typed text, data
base fragments, spread sheets, scanned images, etc.;
(c) that there exists a variety of equipment and tools for handling
business correspondence with different functionality levels;

the following should be studied:

the service requirements from the Teletex point of view of the new
types of documents studied in Question 10/I on a general service
framework for document communication.

3. Document transfer

Considering

(a) that documents in business correspondence can be transferred
either directly between subscribers (i.e. in end-to-end connections over
different networks) or by means of store-and-forward facilities (e.g.
MHS);

(b) that users will apply a wide range of equipment (ranging from
dedicated machines up to large systems with Teletex capabilities),

the following should be studied:

What should be the requirements for a private and/or public domain
participating in the end-to-end oriented Teletex service?

What are the additional requirements for the end-to-end Teletex
service?

What should be the additional requirements for the Teletex service to
support features of an MHS domain participating in the end-to-end
oriented Teletex service?

4. Interactive mode

Considering

the Question 11/I on a general service framework for interactive modes
to be used by Telematic services with document transfer capabilities
and the draft Recommendation on the Teletex interactive mode as
annexed to this Question,

the following should be studied:

Which are the service requirements of a Teletex interactive mode?

5. Quality of Service

Considering

(a) the network used to provide the Teletex service;

(b) the different applications, e.g. basic, mixed and interactive modes;

(c) the use of Teletex terminals with message handling services;

(d) the characteristics of a Teletex terminal, e.g. quality of document
display, receiving memory capacities, receive only capability;

(e) intercommunication with other services;

(f) international operation,

the following should be studied:

How should the Quality of Service be defined taking into account the
above?

Which criteria should be used to define the Quality of Service?

How should the Quality of Service be monitored and controlled?

Note 1 - For Quality of Service purposes, coordination will be required
between the different paragraphs of this Question.

Note 2 - See Annex to Question 9/I (as requested to be annexed by the
IXth CCITT Plenary Assembly).

ANNEX

(to Question 9/I)

Clarification of the study programme of Study Group I

The USSR Administration thinks it would be reasonable to modify the
study programme of Study Group I. The modifications concern Question
9/I.

1. Question 9/I

1.1 Section 1 (updating of Recommendation F.200), page 12, last line but
one. It would be advisable to make it clear what is meant by the word
"security", which is used in a wide variety of ways, making the problem
difficult to grasp.

In particular, it should be made clear what is meant by:

a) security of data transmission;

b) prevention of data transmission to an unauthorized addressee, etc.

1.2 Section 2 (types of document)

It seems reasonable to begin studying questions concerning the
service documents which facilitate Teletex maintenance.

One might mention, for example, the registers containing lists of
documents sent and received, etc.

These facilities are part of the Teletex service and should therefore
be studied by Study Group I.

1.3 (Document transfer) - In view of the fact that Teletex terminals at
present use three types of modems, which do not interwork directly
with each other although this would be desirable from the standpoint of
service integrity, it seems to us reasonable to stress the need to study
as a matter of urgency the problems raised by direct interworking of
Teletex terminals connected to the public switched telephone network.