home *** CD-ROM | disk | FTP | other *** search
-
- ----------------------------------
- --- Technical Guide to DataPac ---
- --- Brought to you by the ---
- --- NEW Dark Council (1990) ---
- ----------------------------------
- --- If you can stand reading ---
- --- through this entire ---
- --- document, you are a boring ---
- --- person. Go out and get ---
- --- laid! ---
- ----------------------------------
-
- Here is the technical "About DataPac" document so efficiently stolen
- from the DataPac information service. (Data
- Pac address 92100086).
-
- It probably won't teach you much, but it might be nice to have around
- if you ever need to do something out of the ordinary.
-
- DATAPAC FAMILY OF SERVICES
- --------------------------
-
- DATAPAC 3000
- ------------
- DATAPAC 3000 IS A SYNCHRONOUS, APPLICATION INDEPENDENT SERVICE THAT
- ALLOWS DATA TERMINALS (DTE'S) AND DATA COMMUNICATING EQUIPMENT (DCE)
- TO EXCHANGE DATA IN A PACKET-MODE OVER A PUBLIC OR PRIVATE PACKET
- SWITCHING NETWORK.
-
- THE DTE/DCE INTERFACE CONNECTION, DISCONNECTION AND TRANS
- MISSION RULES
- ARE DEFINED IN A PACKET SWITCHING PROTOCOL CALLED X.25 RECOMMENDATION
- WHICH IS DEVELOPED AND GOVERNED BY THE INTERNATIONAL TELEPHONE AND
- TELEGRAPH CONSULTATIVE COMMITTEE (CCITT).
-
- X.25 PROTOCOL IS A BIT ORIENTED FRAMING STRUCTURE BASED ON THE
- HIGH LEVEL DATA LINK CONTROL (HDLC). THE CCITT RECOMMENDATIONS
- FOR X.25 ARE DIVIDED INTO THREE LEVELS, NAMELY:
-
- THE PHYSICAL INTERFACE (LEVEL 1);
-
- THE FRAME LEVEL LOGICAL INTERFACE (LEVEL 2);
-
- THE PACKET LEVEL LOGICAL INTERFACE (LEVEL 3).
-
- LEVEL 1
-
- SPE
- CIFIES THE USE OF FOUR-WIRE, POINT-TO-POINT SYNCHRONOUS
- CIRCUIT BETWEEN THE DTE AND THE NETWORK (DCE). THIS CIRCUIT
- INCLUDES TWO MODEMS OR DATASETS (ONE CONNECTED TO THE DTE AND
- THE OTHER CONNECTED TO THE NETWORK).
-
- TYPICAL CHARACTERISTICS ARE:
-
- - 4-WIRE POINT-TO-POINT OR DIAL VIA A V.22 BIS MODEM;
-
- - FULL DUPLEX ;
-
- - EIA RS232 CONVENTION.
-
-
- MODEM/DATASET
- LEVEL 2 - DEFINES THE FRAME LEVEL LINK PROCEDURES USED TO SYNCHRONIZE
- TRANSMISSION, INITIATE THE "HANDSHAKING" NECESSARY TO
- ESTABLISH
- THE 'R-U-THERE'/YES-I-AM SEQUENCE, FLOW CONTROL
- MECHANISM AND PERFORM ERROR CHECKING OF DATA EXCHANGE
- ACROSS THE DTE/DCE INTERFACE (LINK). THE DTE IS
- USUALLY LOCATED AT THE CUSTOMER PREMISES AND IS CALLED
- HOST WHILE THE DCE IS LOCATED IN THE NETWORK. THE PROCEDURES
- USED TO CONTROL THE LINK ARE DEFINED AS COMMANDS AND RESPONSES.
-
- CHARACTERISTICS ARE:
-
- - HDLC;
-
- - LINK ACCESS PROCEDURE -BALANCED
- (LAPB)
-
- - X.25(80) OR X.25(84).
-
-
-
- LEVEL 3 - DEFINES THE PACKET FORMATS AND CONTROL PROCEDURES REQUIRED
- TO ESTABLISH A LOGICAL PATH (CALL REQUEST), EXCHANGE
- INFORMATION (DATA PACKETS) AND FOR REMOVING THE LOGICAL
- PATH (CLEAR REQUEST) BETWEEN THE DTE AND DCE.
-
- CHARACTERISTICS ARE:
- - LOGICAL CHANNELS (LCN`S)
-
- - PACKET SIZE
-
- - WINDOW SIZE
-
-
- - THROUGHPUT CLASS
-
- - ETC
-
-
- HOW IT WORKS
- ------------
-
- THE CUSTOMER'S TERMINAL (HOST) IS CONNECTED TO A LOCAL MODEM
- WHICH IN TURN, IS CONNECTED TO A SECOND MODEM (REMOTE) IN THE
- CENTRAL OFFICE VIA BY 4 WIRES WHICH IN TURN, IS CONNECTED
- TO A LINE PROCESSING MODULE IN THE DATAPAC NETWORK. THIS
- CONFIGURATION IS CALLED THE DTE/DCE LINK AND CAN BE
- ASSIGNED SPEEDS OF 1200 BPS THROUGH 19200 BPS.
-
- THIS DTE/DCE LINK IS ASSIGNED A UNIQUE DATAPAC NETWORK ADDRESS
- (DNA) AND OTHER LINK PARA
- METERS SUCH AS LINE SPEED, MODEM TYPE,
- FLOW CONTROL AND SECURITY BY TELECOM CANADA.
-
- WHEN THE ELECTRICAL SIGNALS ARE IN THE CORRECT STATE AS
- SPECIFIED IN LEVEL 1, THE DATAPAC LINE PROCESSING MODULE
- CONTINUOUSLY TRANSMITS A CCITT COMMAND CALLED SABM (SET
- ASYNCHRONOUS BALANCED MODE) TO THE CUSTOMERS'S TERMINAL
- (HOST) EVERY THREE SECONDS. IF THE HOST IS READY, IT
- RESPONDS TO THE SABM WITH A CCITT RESPONSE UA (UNNUMBERED
- ACKNOWLEDGEMENT). WHEN THIS OCCURS, THE LINK IS INITIALIZED
- (LEVEL 2 READY), THE HOST AND
- DATAPAC MODULE EXCHANGE
- RESTARTS OR RESTART/RESTART CONFIRMATION COMMANDS.
- WHEN THIS OCCURS, THE DTE/DCE LINK GENERATES A TRANSITION
- TO THE NEXT X.25 LEVEL. LEVEL 3.
-
- THE DTE THEN SIGNALS THE ADDRESS IT WISHES TO COMMUNICATE
- WITH IN A CCITT DEFINED CALL REQUEST FORMAT (8 DIGITS ), 10
- DIGITS IF USING 9TH AND 10TH DIGIT SUBADDRESSING ON A LOGICAL
- CHANNEL (LCN)DATAPAC THEN ROUTES THE CALL REQUEST TO THE APPROPRIATE
- DESTINATION (NATIONAL OR INTERNATIONAL) AND AWAITS A CCITT
- DEFINED CALL ACCEPT PACKET. IF THIS
- OCCURS, THE ACCEPT PACKET IS
- TRANSMITTED BACK TO THE ORIGINATING HOST AND BOTH HOSTS MAY NOW
- EXCHANGE CCITT DEFINED DATA PACKETS. THIS IS CALLED A SWITCHED
- VIRTUAL CALL (SVC); PERMANENT VIRTUAL CALLS (PVC'S) ARE ALSO
- OFFERED. AT THE END OF THE SESSION, EITHER HOST CAN TERMINATE THE SVC
- BY TRANSMITTING A CCITT DEFINED CLEAR REQUEST PACKET. UP TO 255 SVC'S
- MAY BE SUPPORTED SIMULTANEOUSLY.
-
-
- DIAL ACCESS SERVICE IS ALSO OFFERED AT 2400BPS WITH
- A MAXIMUM OF EIGHT LCN'S OVER THE PUBLIC TELEPHONE NETWORK
-
-
- BENE
- FITS
- ========
-
- DATAPAC 3000 PROVIDES CUSTOMERS WITH A COST EFFECTIVE SERVICE
- DERIVED FROM PACKET SWITCHING TECHNOLOGY AND X.25 PROTOCOL.
- SOME BENEFITS ARE:
-
- DEDICATED OR DIAL-IN ACCESS
-
- - SIMULTANEOUS COMMUNICATION WITH MANY (UP TO 255) DIFFERENT
- LOCATIONS - NATIONAL AND INTERNATIONAL;
-
- - ERROR FREE TRANSMISSION;
-
- - SYSTEM EXPANSION FLEXIBILITY;
-
- COMMUNICATION UNIVERSALITY
- - COST CONTAINMENT THROUGH REDUCED HOST PORT CONNECTIONS;
-
- - 24 HOURS 7 DAYS-A-WEEK SERVICE
-
-
- - LOWER COMMUNICATION COSTS;
-
- - CALL
- PARAMATER SELECTION TO SUIT PARTICULAR APPLICATIONS.
-
-
- CALL OUR TELEMARKETING STAFF AT 1-800-268-9102 FOR MORE
- INFORMATION ABOUT UTILIZING THIS SERVICE AND SERVICE FEATURES.
- ________-
-
- DATAPAC FAMILY OF SERVICES
- ==========================
-
- DATAPAC 3101
- ------------
-
- DATAPAC 3101 IS A NETWORK ACCESS SERVICE WHICH ENABLES TELETYPEWRITER
- COMPATIBLE DEVICES, SUCH AS TIME-SHARING TERMINALS, TO ACCESS THE
- DATAPAC NETWORK.
-
- LOW SPEED, ASYNCHRONOUS DEVICES ARE SUPPORTED THROUGH AN INTERACTIVE
- TERMINAL INTERFACE (I
- TI) IN A PACKET ASSEMBLER/DISASSEMBLER (PAD),
- WHICH ALLOWS THE DEVICES TO ACCESS THE NETWORK OVER DIAL-UP (DDD)
- OR DEDICATED ACCESS LINES.
-
- ITI, THE END-TO-END PROTOCOL FOR DATAPAC 3101 CONFORMS TO THE CCITT
- RECOMMENDATIONS X.3, X.28 AND X.29 AND SUPPORTS ACCESS TO THE
- DATAPAC NETWORK FOR ASYNCHRONOUS, START-STOP CHARACTER MODE TERMINALS.
-
- X.3 SPECIFIES THE OPERATION OF THE PAD. IT CONTAINS THE SPECIFICATIONS
- FOR THE TWELVE INTERNATIONAL PARAMETERS AND THEIR OPERATION. ADDITIONAL
- DOMESTIC PARAMETERS ARE A
- LSO IN PLACE TO MEET CANADIAN MARKET REQUIREMENTS.
-
- X.28 SPECIFIES THE COMMAND LANGUAGE BETWEEN THE TEMINAL AND THE PAD.
- IT ALSO SPECIFIES THE CONDITIONS WHICH DEFINE THE COMMAND MODE AND
- THE DATA TRANSFER MODE.
-
- X.29 SPECIFIES THE PROCEDURES TO BE FOLLOWED BY AN X.25 DTE TO
- ACCESS AND MODIFY THE PARAMETERS IN THE PAD AS WELL AS THE DATA
- TRANSFER PROCEDURE.
-
- THE USER NEEDS NO SPECIAL HARDWARE OR SOFTWARE TO INTERFACE A
- TERMINAL TO THE DATAPAC NETWORK. A KNOWLEDGE OF THE ITI PROCEDURES
- IS THE ONLY REQUIREME
- NT AT THE TERMINAL END.
-
- THE DATAPAC 3101 SERVICE PROVIDES FOR TERMINAL TO HOST (USER'S
- COMPUTER) AND TERMINAL TO TERMINAL COMMUNICATION. THE HOST ACCESS
- SHOULD CONFORM WITH THE X.25 PROTOCOL, USING THE DATAPAC 3000 ACCESS
- SERVICE, AND ALSO SUPPORT THE HIGHER LEVEL PROTOCOL CONVENTIONS OF ITI.
- HOST ACCESS MAY ALSO BE PROVIDED VIA THE DATAPAC 3101 SERVICE FOR SOME
- APPLICATIONS. THE DATAPAC 3101 SERVICE ALSO PROVIDES BLOCK MODE AND TAPE
- SUPPORT.
- ____
-
- DATAPAC FAMILY OF SERVICES
- ==========================
-
- D
- ATAPAC 3201
- ------------
-
-
- NETWORK ACCESS SERVICE WHICH ENABLES VARIOUS TERMINALS
- THAT ARE BUFFERED, POLLABLE AND OPERATE ASYNCHRONOUSLY TO COMMUNICATE WITH
- HOST COMPUTERS THROUGH THE DATAPAC NETWORK.
-
- APPLICATIONS
- ------------
-
- THE DATAPAC 3201 SERVICE IS TYPICALLY USED BY THE GENERAL MERCHANDISE AND
- SPECIALITY SECTORS OF THE RETAIL INDUSTRY IN CANADA. IT PROVIDES A COST
- EFFECTIVE COMMUNICATION SOLUTION WHENEVER THERE IS A REQUIREMENT FOR
- SENDING SMALL AMOUNTS OF INFORMATION TO A HOST COMPUTER AND OBTAINI
- NG A
- SHORT RESPONSE. THE PRIMARY APPLICATIONS ARE ON-LINE COMPILATION OF
- SALES DATA TO HELP IN INVENTORY CONTROL, AND ON-LINE CREDIT VERIFICATION
- TO DETECT FRAUDULENT CREDIT CARDS. OTHER EMERGING APPLICATIONS INVOLVE
- TRUST COMPANIES, CREDIT UNIONS, BANKS AND SERVICE STATIONS.
-
- ACCESS ARRANGEMENTS
- -------------------
-
- DATAPAC 3201 PROVIDES SUPPORT AT THE CUSTOMERS' TERMINAL END (FOR EXAMPLE
- A RETAIL STORE) BY MEANS OF A PACKET ASSEMBLER/DISASSEMBLER (PAD) WHICH IS
- LOCATED IN A TELECOM CANADA MEMBER COMPANY
- CENTRAL OFFICE. THE PAD
- POLLS THE VARIOUS DEVICES FOR INFORMATION IN AN ON-LINE REAL TIME
- ENVIRONMENT.
-
- DEVICES MAY COMMUNICATE TO THE PAD VIA TWO OPTIONS:
- 1) SHARED MULTIPOINT MULTIDROP ACCESS AT 1200 BPS, OR
- 2) DEDICATED ACCESS AT 1200, 2400 BPS.
-
- PROTOCOL SUPPORT
- ----------------
-
- COMMUNICATION BETWEEN THE PAD AND THE TERMINAL CONFORMS TO THE ANSI
- (AMERICAN NATIONAL STANDARDS INSTITUTE) X3.28-1976 ISO (INTERNATIONAL
- STANDARDS ORGANIZATION) POLL/SELECT ASYNCHRONOUS PROTOCOL. TELECOM CANADA
- UNDERTAKES T
- O TEST TERMINALS WHICH SUPPORT THIS PROTOCOL, PRIOR TO
- CONNECTING THEM TO THE DATAPAC 3201 NETWORK. FOR MORE INFORMATION REFER
- TO THE "RAPID TERMINAL COMMUNICATION PROTOCOL" SPECIFICATION.
-
- COMMUNICATION BETWEEN THE CUSTOMERS HOST COMPUTER LOCATION AND THE
- DATAPAC NETWORK IS ACCOMPLISHED BY THE USE OF A X.25 (DATAPAC 3000)
- INTERFACE WHICH SUPPORTS THE DATAPAC 3201 HOST TO PAD "POINT-OF-SALE
- (POS) END TO END PROTOCOL" SPECIFICATION.
-
- COMMUNICATION RESPONSE TIME
- ---------------------------
-
- - DATA COLLECTIO
- N: AVERAGE 1.7 TO 2.3 SECONDS IN THE PEAK PERIODS.
-
- - INQUIRY-RESPONSE (CREDIT CHECK): AVERAGE 2.7 TO 4.2 SECONDS IN
- THE PEAK PERIODS.
-
- MESSAGE SIZE
- ------------
-
- A TYPICAL RETAIL DATAPAC 3201 APPLICATION USES SHORT INPUT AND OUTPUT
- MESSAGES. (FOR EXAMPLE AN AVERAGE OF 50 CHARACTERS). ONE KILOPACKET
- (1,000 PACKETS OR 256,000 BYTES) IS EQUAL TO APPROXIMATELY 1,000 SALES
- TRANSACTIONS OR 500 CREDIT AUTHORIZATIONS. AVERAGE TRANSACTION VOLUME
- WOULD BE LESS THAN 5000 PACKETS PER DAY.
-
- OPTIONAL DATAPAC NET
- WORK FEATURES:
- ---------------------------------
-
- CLOSED USER GROUP (CUG): ALLOWS DEVICES WITHIN ONE GROUP TO COMMUNICATE
- ONLY WITH ACCREDITED DEVICES OF THE SAME GROUP,
- RESULTING IN A HIGH DEGREE OF DATA SECURITY.
- ADDITIONAL OPTIONS ARE AVAILABLE TO LIMIT CALL
- ATTEMPTS BETWEEN CLOSED USER GROUPS OR WITHIN A
- CLOSED USER GROUP.
-
- REVERSE CHARGE CALL: ALLOWS A USER TO CHARGE A
- CALL TO THE DESTINATION
- ADDRESS
-
- REVERSE CHARGE CALL
- BLOCKING: REVERSE CHARGED CALLS DESTINED TO A DATAPAC 3201
- ADDRESS WILL BE BLOCKED BY THE NETWORK.
-
- Whew! I probably didn't get all of it, but hey, I'm lazy, and I am not
- about to read through it all too see if it makes sense! <grin>
-
- Your Phriend,
-
- Lithium
- __________________________________________________________________________
-
- Call: T h e NEW
-
- __ __ _ _
- The Motor Inn | \ /\ |__| |_/
- 3/12/2400 Baud |__/ /--\ | \ | \_
- 24 Hours a Day __ __ __
- (403) 963-0658 / / \ | | |\ | / | |
- Headquarters of the New Dark Council. | | | \|| | |
- \__ \__/ |__| | | \__ | |___
- Phreaking is alive in 1990
- --------------------------------------------------------------------------
-
- +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-
-