Recommendation S.22

       Replace by the following:

"CONVERSATION IMPOSSIBLE" AND OR PRE-RECORDED MESSAGE IN RESPONSE TO
                J/BELL SIGNALS FROM A TELEX TERMINAL
                                  
             (Geneva, 1980; amended at Melbourne, 1988)


       The CCITT,

considering

       (a)  that conventional telex terminals incorporate a  facility  that
allows an operator at one end of an established connection to  attract  the
attention of an operator at the other end, this being achieved by
transmitting J/BELL (combination No. 10 in International Telegraph Alphabet No. 2) in 
     figure-case;

       (b)  that technological developments and changing customer requirements have 
led to the introduction of the page-printing, receive-only, telex terminal, which, 
because of the absence of a keyboard, makes any conversational mode of  operation
impossible;
       (c)  that this limitation is not indicated to a calling station at the time 
the connection is established and may well result in wasted circuit time  through
attempts to establish contact with the called station via the J/BELL facility;

       (d)  that automatic calling  and/or  answering  terminals  employing  data
terminal equipment (DTE) and data circuit terminating equipment (DCE), in accordance 
with Recommendation S.16, are unlikely to have a conversational mode of operation;

       (e)  that technological developments and changing operational requirements 
may lead to the retention of messages in storage until a suitable opportunity  to
print-out arises;

       (f)  that it may be useful for called subscribers, who do  not  anticipate
conversing with the calling subscriber, either because conversation is impossible or 
for any other reason, to answer by a pre-recorded message,

unanimously declares the following views

1.     Where a telex terminal is incapable of a conversational mode of operation, 
either through the absence of a keyboard or for local operational reasons, or if the 
subscriber wishes to deliver a pre-recorded message, then it is highly desirable, at 
least in new equipment, that such a terminal be able to automatically  return  an
appropriate service signal sequence and/or the          pre-recorded  message  on
receipt of one or more ITA2 combination No. 10 characters (i.e. BELL signals) when 
preceded by ITA2 combination No. 30         (i.e. figure-shift).

2.     The recommended sequence of signals to be returned in  such  circumstances
should incorporate the code expression.

                          CI    Conversation Impossible

in conformity with the Recommendation cited in [1].

3.     The complete sequence incorporating the code expression CI should  have  a
format that corresponds with the Recommendation cited in [2], concerning  service











signals for ineffective calls, except that it should not be followed by the clearing 
signal.

4.     Where a pre-recorded message is to be returned, then it should follow  the
rules established in the Note of this Recommendation, and should not be followed by 
the clearing signal.

       If conversation is impossible after the pre-recorded message is delivered, 
this message should start with the CI conversation impossible sequence of signals as 
specified in  2 and 3.

5.     As operators often key several repetitions of J/BELL (in figure-case) when 
attempting to contact a distant operator, a delay of 0.5 - 1.0 second should precede 
the transmission of the sequence described in  2, 3 and   4 above, the delay to be 
measured from the stop element of the last J/BELL combination detected.

Note   - The length of the pre-recorded message should be unlimited provided that a 
pause of 1 sec. minimum is included within the message after every (x)  characters, 
(the number of characters are to be decided).

       - When conversation is impossible, the mandatory code expression CI should 
precede and follow the pre-recorded message.

       - No "WRU" signals should be contained within the pre-recorded message up to 
the last code expression CI. Triggering of the calling party's answerback could be 
initiated after the end of the pre-recorded message.

       - No combination 32 signals should be contained  within  the  pre-recorded
message.

       The terminal and/or the network emitting the pre-recorded  message  should
interrupt transmission immediately, when detecting  modulation  in  the  opposite
direction.

       Every pre-recorded message is not necessarily sent to the calling party upon 
simple reception of the triggering signal provided in  1 above. Measures can  be
taken at the called party to reserve it to some special correspondents. The callers 
that are not qualified to receive it will then receive only the CI signal provided 
for in  2."




                                   REFERENCES


[1]  CCITT Recommendation Operational  provisions  for  the  international  telex
     service, Recommendation F.60,  4.1.

[2]   CCITT  Recommendation  Signalling  conditions  to   be   applied   in   the
     international telex service, Recommendation U.1,  10.1.2.