From: lfil@athos.az.stratus.com (Lonnie Filbrun)
Newsgroups: comp.dcom.telecom
Subject: Re: Can Paging Software Detect Alphanumerics?
Date: 23 Jan 93 13:11:02 GMT
Organization: Stratus Computer Inc, Marlboro MA
X-Submissions-To: telecom@eecs.nwu.edu
X-Administrivia-To: telecom-request@eecs.nwu.edu
X-Telecom-Digest: Volume 13, Issue 40, Message 3 of 13

Hello,

As a tech from *S W*ST Paging I used all models of BBL 3, 3r, 4x, DSS
1, Glenayre GL3000L, M, S, UniPage, and also Motorola paging
terminals.

Like mentioned before the most common action is to parse the
alphanumeric data entered and only transmit numerics giving no
indication of the intent to send alpha to a numeric display pager.

 ---------------------from IXO/TAP protocol---------------------

The response to each block is one of four:

1. "<optional message sequence><CR><ACK><CR>"
    OK, send next block.

2. "<optional message sequence><CR><NAK><CR>"
    Checksum or transmission error, send last block again.

3. "<optional message sequence><CR><RS><CR>"
    Abandon current transaction and go to next. <RS> may occur
    when the checksum is OK, but the current transation violates
    a system rule.
 
4. "<optional message sequence><CR><ESC><EOT><CR>"
    Begin disconnect.

Any of the responses may have an optional message sequence before
them, although the system designer should understand the consequences
to the user with all planned entry devices.

It is expected that many systems will save their message sequence
responses until immediately before disconnect. For some entry devices,
it may also be desirable that messages describing non-checksum errors
associated with a particular transaction in a PG service will begin
with the letter ID followed by the contents of field 1 for that
transaction.

After reception of an <ACK> or <RS> for the last transaction in a
given service, the entry device sends <EOT><CR> meaning there are no
more transactions remaining in this service.

An optional message sequence may be sent at this time to indicate the
degree of acceptability of information in all transactions received
during the current interchange. Although optional, this message is
highly desirable.

example:   
1 PAGE(S) SENT.<CR>

An <RS><CR> should be sent at this point if the paging central finds
any data <ACK> in step 8 (step 8 is where it sends the one of four
responses) by the system to be unacceptable because of content (eg, an
invalid pager number or a message field inappropriate for the type of
pages, etc. see #2)

( #2 It is most desirable to catch all types of errors in step 8, but
practically, some systems will be too slow to catch content errors as
they happen.)

                 ------------------------

Using a datascope, you might want to experiment trying to send invalid
pager numbers, alphanumerics to a "known" numeric pager and check the
output of the last step above for it may tell you something useful.

As to getting the terminals manufacturer to upgrade their code to
implement a fix, hope you want to buy alot of paging terminals!!! :-)
  
Hope this helps!


Regards,

Lonnie

#import <stdDisclaimer.h>----------< NeXT Mail Welcome >-------
Lonnie L. Filbrun      Lonnie_Filbrun@vos.stratus.com (SOS Mail)
Stratus Computer, Inc.           lfil@az.stratus.com (NeXT Mail)
Customer Assistance Center           (602) 858-3152 (Voice Mail)
Telecommunications Division (602) 231-9447 (Alphanumeric Access#)