				     -=+[GUIDE TO DATU]+=-
				    =======================
			     WRITTEN BY CHAOTICPHREAK ON 9/28/00
			     ====================================
				      WWW.PHREAK2600.COM
				      ===================

Disclaimer:
===========
All information within this document is meant solely for educational purposes only, to inform 
the reader.  Any abuse or misuse of the information provided in this article is not the 
responsibility of the author nor the sponser (www.phreak2600.com).  If you do not agree with 
this statement, do not proceed, by proceeding you are agreeing with this statement. 



What Is DATU
=============
	DATU stands for Direct Access Testing Unit.  Field Technicians and Lineman use DATU to 
run various tests on subscriber lines for daily purposes they encounter.  DATU comes equipped 
with a full range of advanced features that let a field technician expand their field testing 
and conditioning capabilities.  The DATU system itself is physically located at CO on a writing 
card which in turn is connected to a no test trunk, it allows you to dial in and perform tests 
on a trunk.  The DATU system extends the field technicians testing capabilities of subscriber 
lines through a non-metallic pair gain system.  DATU used to be manufactured and marketed by 
Hekemian Labs, but they have abandoned it for a different system.  DATU is now manufactured and 
marketed by Harris-Dracon division.  Although newer systems exist, DATU is still the most used 
analog, menu driven dialup testboard out there.  

Accessing DATU
==============
	The DATU system is accessed by dialing the DATU access number for the exchnage it serves.  
When you dial the number, you will automatically hear a steady low level tone prompting you for 
the password.  Most DATU passwords are 4 digits long but exceptions to this theory do exist.  
Now if the correct DATU password is entered then you will be presented with another steady low 
level tone which is then asking for the subscriber line number you wish to run tests on, 
otherwise you will hear a *click* and you will be disconnected from DATU.  DATU gives you 7 
seconds to enter the correct passcode before disconnecting you.  Now you can only run tests on 
subscriber line numbers that run under the exchange that the DATU access number you have called 
serves.  For each exchange or exchanges there is a DATU number that services only those 
exchanges.  For example lets say you have a DATU access number to a Hicksville exchange in 222 
but you want to run tests on your friend who lives in Bumsville under the 333 exchange.  When 
you dial the Hicksville 222 DATU number and get connected and try to perform tests on your 
friend who lives under 333 in Bumsville it will present you with the error message "Invalid 
Prefix."  If you wish to run tests on your friend who lives under 333 in Bumsville, you will 
have to use the DATU access number that services Bumsville.  Usually there are a few DATU access
numbers in a certain group of exchanges.  DATU access numbers can be found by scanning your 
local exchanges or other local exchanges in your town looking for a low level tone, however this
method is very time consuming and could be costly.  You'll have your CO wondering why you dialed
2000 local numbers in one month.  Since Linemen always have a list of all DATU numbers in their 
trucks, the best I can say is to break into a Bell truck and obtain it from there.  Now I by no
means am condoning this type of activity but if you really want DATU access, chances are you can
get the list from the Bell truck. 
	Now with that said, after you connect to DATU and enter the correct password then 
subscriber number, it will say "connected to xxx-xxxx."  It will then say "OK" or "Busy Line", 
then it will say "Audio Monitor".  The audio monitor is used to see if there is any activity on 
the line and if there is, the traffic is scrambled to keep Linemen from eavesdropping on the 
call.  DATU will then read of the list of system feature it provides.  Now if the line is busy, 
DATU limits you to only certain features that you can perform which arent intrusive to the 
line.  

DATU System Menu
================

Funtion/Dial Code			    Use on "Ok"			    Use on "Busy line"
=================                           ============                    ================== 
2-Audio Monitor				    Yes				    Yes
3-Short to Ground			    Yes				    No
4-High Level Tone			    Yes			            No
5-Low Level Tone    		            Yes				    Yes
6-Open line				    Yes				    No
7-Short Line 				    Yes				    No
8-Read Menu				    Yes				    Yes
*-Line Preparation Function	            Yes			            Yes
#-New Subscriber Line			    Yes				    Yes
##-Force Disconnect from DATU		    Yes				    Yes


2-Audio Monitor
===============
	This feature allows you to monitor traffic on a busy line.  The traffic is audible but 
scrambled to prevent eavesdropping.  This feature is automically started once connecting to a 
subscriber number.  If there is no one on the line, the line will be silent and you will not 
hear any traffic at all whatsoever.  This feature is just here to check the line every once and 
while to see if there is any traffic in case anyone picks up the phone while the Technician is 
performing a test.

3-Short to Ground
=================
	This feature establishes a metallic connection between tip, ring, and ground.  This 
feature enables the ring and tip wires of the subscriber line to be physically shorted back at 
the CO.  Used to check the force between any chosen point on the pair at the CO, which renders 
pair unusable for the duration of the test.  This is not of much use to you but is an important 
and much used feature for Field Technicians and Linemen.

4-High Level Tone
=================
	This feature injects a 577 mhz high level tone onto the subscriber line to assist 
linemen in locating your pair at the remote terminal.  For reference the 577 mhz tone is also 
interrupted four times per second for identification purposes.  This tone is not loud but 
annoying to the person on the phone, so is preferably used when the subscriber line is idle.  
Not much use to you unless you want to pester the person on the phone with an annoying tone.  

5-Low Level Tone
================
	Serves the same basic purpose as the high level tone except the tone will not interrupt 
traffic on the subscriber line.  Used to locate pair on remote terminal when subscriber line is 
busy and in use.  Also injects a 577 mhz tracing tone into the line and is interrupted 4 times 
per second for indentification purposes.  This feature is used when the subscriber line is busy 
and in use and will not interrupt traffic.  However, the person using the phone may recognize 
some pitch alteration on the phone.

6-Open Line
===========
	This feature opens the subscriber line by removing the battery and ground therefore 
dropping all voltage from the line rendering the pair unusable.  In other words disconnects the 
phone from use but can only be used on an idle subscriber line.  DATU limits the duration of 
this test to 10 minutes.

7-Short Line
============
	This feature places a metallic short across the tip and ring of the subscriber line at 
the CO and would be best followed up by a short to ground.  Used by Linemen to short pairs back 
at the CO, not of much use to you.

8-Read Menu
===========
	This feature is pretty self explanatory.  It will read you your menu of options to 
choose from, thats basically all.  If the line is busy it will only read you the features you 
can use on a busy line.
	
*-Line Preparation Function
===========================
	This feature is used to continue a line preparation function after disconnecting from 
the systems access line.  You can specify anywhere from 1-10 minutes, choosing a number between 
1-9 and 0 being 10.  In other words after choosing this feature and the amount of minutes you 
specify, you will have to exit from DATU and the subscriber line will be disconnected from usage 
for the amount of minutes you specify.  If anyone trys to call the subscriber while the line 
preparation function is in use, they will receive a busy signal.  Use to you?  Go figure.

#-New Subscriber Line
=====================
	This feature will disconnect you from the current subscriber line being tested and will 
allow you to specify another subscriber line in the scope of the DATU number you are connected 
to.

##-Force Disconnect from DATU
=============================
	Will permanetly disconnect you from DATU allowing you to hangup.  This feature should be
used to exit DATU instead of just hanging up.  If you are connected to DATU and just hangup, the 
next time you try to connect to DATU you will receive a busy signal.  Should be used to exit 
DATU appropriately.

Misc. Notes
===========
	Now upon connection to DATU when the full menu is read to you it will sound like this


2-Audio Monitor
33-Short Tip and Ring to ground
37-Short Ring to ground (Tip open)
38-Short Tip to ground (Ring open)
44-High Level Tone on Tip and Ring
47-High Level Tone on Ring (Tip grounded)
48-High Level Tone on Tip (Ring grounded)
5-Low Level Tone
6-Open Line
7-Short Line (Tip to Ring Short)
9-Permanent Signal Release
#-New Subscriber Line
##-Force Disconnect
*-Continue line preparation function after disconnect

	This is the menu read to you upon connection, its basically the same thing as the one I 
specified up above except it offers you the options of either shorting the tip or the ring and 
keeping the other open and placing the high level tone on the tip and ring of the subscriber 
line or just the tip or just the ring.  To my experiences the permanent signal release, option 
9, does not work but it may just be just my area in general so I have no idea what it does.  
Option 8 isnt read off to you but its there.  Just remember this while using DATU

P.S.- Check out the DATU docs in the pictures section.

Conclusion
==========
	Well thats all I have to tell you about DATU.  Its an extremely interesting and fun 
system and you can do a lot more than what is specified in this article.  I say if you want to 
ever know anything get out there and do it for yourself, you can read all the articles you want 
but until you actually experience things for yourself............  Phreaking like Hacking is 
about learning things from hands-on experiences and contrary to belief, phreaking is by no means
dead, its just a more classified field, most people do not have in it them to become a phreak.  
Phreaking involves the exploration and learning of the different complexities and intricacies of
the Telephone System, being able to beige box doesnt make you a Phreak.  So get out there and 
spread the word, Phreaks Own The System.

Contacts
========
ChaoticPhreak@Phreak2600.com
ChaoticPhreak@Secureroot.com
CP or ChaoticPh on EFNET
ChaoticPhreak on DALNET
Cha0ticPhreak on AIM
83170648 on ICQ

Shouts
======
	Shouts go to Cycad, Pentium Cowboy, BoxPhreak, El Super Grande, Prefix, Dagger, Zerovoid,
Syscrash, Nightmare, Redmage, Pyrotix and all the kiddies from Atlantis =), Tez, Giezr, Crazy, 
Cipher, Flood, Rsh, Tag, Tradeser and all you other l4m3rs whose names I cant think of right now
:-D.

Flames
======
Flames go to Phonic (l4m3 bitch), Haze, Substance and all you other l4m3rs from #9x, 
along with Databit (l4m3 bitch who was GIVEN #hackcentral).


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