textfiles/hacking/packet.txt

                NOTES ON USING TYMENT AND TELENET
                by Michael A. Banks (mike_banks)

(A quickie guide to logon numbers, error messages, and other
useful information that packet switching networks tell you,
visually and aurally.)

 Excerpted from THE MODEM REFERENCE, by Michael A. Banks.
 Published by Brady Books/Simon & Schuster
 Copyright (c) 1988, 1989, Michael A. Banks.
 Permission to copy to other systems or BBSs, is hereby granted,
 provided this and all text in this file is retained as-is,
 complete and unmodified.  Permission to distribute in any other
 form, electronic or hardcopy, MUST be obtained from the author.


Packet Switching Network User error messages
     If you make an error when entering an online service's 
address (which on either Telenet or Tymnet can sometimes include 
backspacing with ^H, or entering an unrecognizable address or 
command attempt), you are given another chance.  Telenet will 
flash a question mark and redisplay its @ prompt.  Tymnet will 
display an "Error" message and redisplay its prompt.  (Tymnet 
allows you only three tries before it disconnects; Telenet will
usually continue to redisplay its prompt until you get it right.)

Node and port numbers
     When you dial into a packet switching network, you'll see a 
series of numbers; these designate the node's number and the 
number of the port being used.
     On Telenet, the first thing you'll see at the sign on (after 
you press <RETURN> twice) is the Telenet network herald, followed 
on the next line by two numbers, like this:
                             TELENET
                             513 16H
     The first number (513 in this example), designates Telenet's 
internal address for the node I'm using (it also happens to be 
the local area code).  The second number (16H) identifies the 
port in use.
     Tymnet displays two numbers in this format:
                            -7075-012-
     The first number is the node number (it may be four or five 
digits).  The second is the three-digit number of the port in 
use.
     Some nodes also display what Tymnet calls a "slot" number 
between the node and port numbers, like this:
                          -7075-02-012-

Connection failure messages
     You will, on occasion, experience failed connections.  These 
may be due to network problems (see the next section) or an 
extremely heavy load on the local node, in which case a Telenet 
node will send the message "LOCAL CONGESTION,"  and Tymnet will 
send the message "try again in 2 minutes."  (The proper response 
to this is to hang up and try again later.)
     If the problem is with the online service, you may receive 
any of several messages, these from Telenet:
     <service> NOT ANSWERING
     <service> NOT REACHABLE
     <service> NOT RESPONDING
     <service> REJECTING

or these from Tymnet:
     host down
     host shut
     host out of ports
     host not responding
     host not available thru net

     When you see one of these messages, contact the online 
service's customer service department by voice phone, or hang up 
and try again later.

Identifying Network trouble
     If you seem to be having persistent problems with a network 
connection, it's a good idea to call the network's customer 
service number.  Equipment does malfunction at times, and the 
networks may not be aware of a problem for some time if you don't 
advise them of it.
     It is sometimes difficult to identify the network as the 
source of your online trouble, but if any of the following happen 
you can be sure it's the network:
     *  There is no answer or a persistent (for more than two 
        hours) busy signal at the local node number.
     *  You get an error message when you enter a legitimate 
        online service address.
     *  Your connection with an online service is interrupted and 
        you see a message something like "<name of service> 
        disconnected <cause> <number string>" or "LOCAL PROCEDURE 
        ERROR" or ***POSSIBLE DATA LOSS <cause> <diagnostic>***".

     If you're not sure whether the trouble is in your local 
node, there are a couple of ways you can check on this.  The 
first is to sign off/hang up and try to get through to the online 
service you are accessing using a different access number, or via 
another network.  Or, you can dial up the network and see if 
accessing its information service results in online problems.
     When you experience network trouble, make a note of the node 
and port numbers discussed, earlier, along with ay error messages 
and/or unusual displays, and the time the trouble occurred.  
These will help the network service people isolate the trouble.
                           #
     Interested in modem communications?  Check out THE MODEM
REFERENCE, by Michael A. Banks and published by Brady Books/Simon
& Schuster.  Recommended by Jerry Pournelle in Byte, The New York
times, The Smithsonian Magazine, various computer magazines, etc.
     If you're a Reflex 2 user (or a Reflex 1 user looking to 
upgrade to Reflex 2), you'll find QUICK & EASY GUIDE TO REFLEX 2 
of interest.  Written by Michael A. Banks and published by
Compute! Books in early 1990, the book provides everything you
need to get Reflex 2.0 up and running now!
     Want the lowdown on getting more out of your word processor?
Read the only book on word processing written by writers, for
writers: WORD PROCESSING SECRETS FOR WRITERS, by Michael A. Banks
& Ansen Dibel (Writer's Digest Books).