Written March, 1987 ==Phrack Inc.== Volume Two, Issue 12, Phile #6 of 11 /\ /\ <[]>==========================================<[]> \/ ^ ^ \/ || PLP [+]The Executioner[+] PLP || ++ ^ ^ ++ || [+] PhoneLine Phantoms! [+] || ++ ++ || CSDC - Hardware Requirements || ++ ----------------------------- ++ || PLP | PHRACK XII - PHRACK XII | PLP || /\ ----------------------------- /\ <[]>==========================================<[]> \/ Phreak Klass Room 2600 = 806-799-0016 \/ || _______________ Login: Educate || ++ |The only BBS | Sysop:Egyptian Lover ++ || |that teaches.| Cosysop:The Executioner|| /\ --------------- Board lose:Oryan Quest /\ <[]>==========================================<[]> \/ \/ Preface: ======== This is the second part of my CSDC (Circuit Switched Digital Capability) series, the first being in PHRACK X. It is suggested that you read the first part and also the file on PACT in PHRACK XI. If I feel the material was not covered completely, I will make a third addition to this file. Hardware Interfaces =================== A NCTE or equivalent network interface equipment, located on the customer premises, is required to provide the CSDC feature for a customer. The NCTE or an equivalent circuit, located on the customer's premises, is required to provide TCM (Time-Compression-Multiplexing) transmission on the 2-wire subscriber loop. The NCTE also has a remote loopback for testing from CSDC central office. Dedicated 2-way CSDC trunk circuits are provided via DCT (Digital Carrier Trunk) combined alternate data/voice (CADV) units with DCT supervision. MF and CCIS signalling is allowed on these trunks. They provide signalling, switching and trunking functions between 1A ESS switch and other CSDC offices. To provide CSDC, the DCT bank must be equipped with alarm and digroup control units. A Digital Office Timing Supply (DOTS) is needed to provide network synchronization for the CSDC feature. A minimum of 3 CSDC maintenance circuits are needed for the CSDC feature to operate. The circuit provides digital signals for testing CSDC trunks and loops. They also provide a test termination for incoming CSDC calls. If an office has superimposed ringing for 4 and 8 party lines, these ringing circuits may be used for loop testing with the maintenance circuit. Remote Switching System ======================= The RSS remote frame contains eight special service slot positions that can be used for D4 type plug in units (basically allows the RSS to have CSDC abilities). This allows the CSDC TRXS (Time Compression Multiplexing Remote Subscriber Exchange) channel units to be housed in the RSS frame. The CSDC feature is provided via the RSS T1 carrier facilities. The T1 carriers for CSDC service terminate with position 1 and 0 at the RSS. A ringing and tone plant is required in the RSS office to ring the phones of special service channel unit subscribers. Operation of the CSDC ===================== An off-hook origination initiates the seizure of an originating register. A line translation is performed and the CSDC indicator is received from the Line Equipment Number Class (LENCL) and is stored in the register. A touch tone service receiver is connected to the line and dial tone is applied. Upon receiving a digit, dial tone is removed. If the first digit is a '#', digit collection is set up to collect 2 more digits. Upon receipt of the 2 digits (99), the PACT (Prefix Access Code Translator) is indexed via the dialed digits to determine what service has been requested. If the line cannot have CSDC, an error message is sent. The AB digits (carrier selection) are collected next. Once the AB digits have been determined to be valid, the CCOL (Chart Column) is received. The CCOL merely is a code to tell the PACT what is to be done. Once the AB digits and the CSDC CCOL is received, the original register is overwritten with the CSDC CCOL. The CSDC office then sends a bit down the line to tell the equipment that a CSDC call is being processed. The call is now reinitialized to appear as though no digits have been collected. Digit collection proceeds until the proper number of digits (7 to 10) has been received. An AMA register is seized at the end of the dialing. The call is then routed according to the dialed digits on a CSDC outgoing trunk. Answer guard timing for CSDC calls is 800 ms. Upon answer, the answer time is recorded in the AMA register. An outpulsing trunk is seized and a POB is hunted. If an outgoing trunk and outpulsing device are needed, one will be hunted. Information on the trunk is stored and a transfer to the outpulsing routine (MF or CCIS) is done. A verification insures that both calling and called parties are CSDC allowed. If they are not, the call is routed to an Automatic Intercept Service (AIS). For MF outpulsing, a junior register is seized, the outgoing trunk is put into the proper states, and start pulsing signal detection is done followed by digit outpulsing. For CCIS, call processing is the same as a normal call but a CCIS continuity check is performed while on the on-hook state. For an incoming call, the CSDC bit from the Trunk Class Code (TCC) is stored in the incoming register and a CSDC count is pegged. Digit collection is performed and a terminating DN translation is performed. Ringing is applied normally and once it has been answered, the incoming trunk is put in the off-hook state to pass answer to the next office. Standard disconnect and trunk guard timing is performed on CSDC calls when the called or calling party goes off-hook after a talking path has been established. Standard CSDC Dynamics ====================== Call forwarding codes dialed after the CSDC code result in reorder. The Call waiting option is also suspended when a CSDC call is in progress. Busy tone is given to POTS call that terminates to a CSDC connection. Busy tone is also given to a calling CSDC party if it encounters a busy line. In order to have a 800 CSDC feature, the office must have CCIS INWATS ability in the OSO (Originating Screening Office). Dialing 911 after the CSDC code is allowed, but 411/611 calls are routed to error messages. NCTE (Network Channel Terminating Equipment) ============================================ As covered in Part 1, the NCTE is the equipment that you need to have CSDC. The NCTE is a piece of hardware that is connected to the CO loop and a terminal. On the terminal, there are 8 jacks for 8 pins on the NCTE. The functions of each pin are as followed. 1 - TRANSMISSION DATA 2 - TRANSMISSION DATA 3 - MODE CONTROL 4 - MODE CONTROL 5 - TIP VOICE 6 - RING VOICE 7 - RECEIVED DATA 8 - RECEIVED DATA ============================================================================== This ends PART II of the CSDC series. Since Taran King was in such a hurry, I will finish the 3rd file with SCCS integrations, loop structure and RSS structures. If you have any questions about this file or any other file, please leave me a message on either... Phreak KlassRoom 2600 = 806-799-0016 LOGIN:EDUCATE My Voice Mail Box = 214-733-5283