____________________________________________________________________________ | | | "Peering into the Soul of ESS - The Master Control Center" | | | | Written By - Jack The Ripper | | | | Organized Crime (OC) | | Phile #2 of P/HUN Magazine Issue #5 | |____________________________________________________________________________| The Master Control Center is undoubtably the very essence of ESS. The Master Control Center (MCC) is the operational, maintenance, and administrative core of the electronic switching central office. This unit is what the ESS operators use to control the ESS switch. It test's customer lines and trunks, alarms to indicate malfunctions, perfroms system testing functions, controls operations, contains the magnetic tapes for recording Automatic Message Accounting (AMA) data, and contains various other specialized equipment. Primary Components of the MCC ----------------------------- Master Control Console Trunk and Line Test Facilities Teletype (Teletypewriter) Channels AMA Recorders DATASPEED -40 Terminal with Display and Printer [---------------------------------------------------------------------------] [ Diagram of Processor Display Panel of Master Control Console in No.1A ESS ] [---------------------------------------------------------------------------] _______________________________________________________________________________ | Processor Display | PS Bus | Pu Bus | CS Bus | AU Bus | | | Ad Re Ad Re| Ad Re Ad Re| Ad Re Ad Re| Ad Re Ad Re| ------------------------------------------------------------------------------- |_____________________________________________________________________________| ||CC0 | ac| tr| po| st| of|| 0| 0| 1| 1|| 0| 0| 1| 1|| 0| 0| 1| 1|| 0| 0| 1| 1| ||----------------------------------------------------------------------------| || ltllh |====================================================================| ||-------|--------------------------------------------------------------------| || ltllh |====================================================================| ||____________________________________________________________________________| ||CC1 | ac| tr| po| st| of|| 0| 0| 1| 1|| 0| 0| 1| 1|| 0| 0| 1| 1|| 0| 0| 1| 1| ||----------------------------------------------------------------------------| || || || || || | || -------------------------------------------------------- | || |meno|kc || ||meno|kc || || | || |------------||___________||------------||___________||------------| || |02| |36|ntce|| 0! 0! 1| 1||02| |05|ntce|| 0| 0| 1| 1||fs|df|ft|df2| || -------------------------------------------------------------------| || | || || || | || | seno || || seno || | || | ---- ----|| || ---- ----|| | || |ps|0|2| |ii || ||ps|0|2| |lh || | || | ----- ----|| || ----- ----|| | ||----------------------------------------------------------------------------| || Update || OverRide Control || SysR || Processor Configuration Seq. | || || || || state counter | || ----- ||------------ -----||-----------||--------------- ----- | || |inp| ||bl|au|ps|cc| | no ||rea|ena|err||p3|p1|8|4|2|1|| |rec| | || ----- ||------------ -----||-----------||--------------- ----- | || ----- ||------------ || || | || |fs0| ||vr|a1|p2|c1| ||___________|| | || ----- ||------------ || || | || ----- || Activate|| ||Activate | || |fs1| || ---- ---- || ----- ||------ ------------------| || ----- || |x1| |x2| || |inv| ||q1|q2| |w1|w2|w3|w4|w5|w6| || || ---- ---- || ----- ||------ ------------------| || || || || | ||_________||__________________||___________||________________________________| Key --- w6 = Prssr Comfg w5 = Prgm Store w4 = Call Store w3 = Basic Prssr w2 = Reptd Pc w1 = Pc Atmpt x2 = Ovrd Efct x1 = Vrbl PS1 q2 = Dsble Auto q1 = PC fs1 = FS 163 c1 = CC1 p2 = PS Bus 1 a1 = AU Bus 1 vr = Vrbl PS 0 fs0 = FS 062 rec = Reset Cntr p1 = Pmp 16 p3 = Pmp 32 err = Error ena = Enable Data rea = ready no = No Ovrd cc = CC D ps = PS Bus 0 au = Au Bus 0 bl = Blk 0 Ps 0 inp = In Prgs SysR = System Reinitialization lh = LHIJI ii = IIOLI seno = Select No. (Select Number) df2 = Disk File 1 ft = FS 1 Trbl df = Disk File 0 fs = FS 0 Trbl meno = Member Number kc = K-Code || = Separates different Status Bars ie PS Bus, Processor Display, and Au Bus ac = Active tr = Trble po = Power st = Stop of = Offline +++ Added note on the key is that the abbreviations on the key are exactly the same as they appear on the panel. As you can see the MCC panel is divided up into five main groups of keys and lighted or LED displays; processor display, update, override control, system reinitialization, and processor configuration sequencer. The update group of keys and displays permits personnel to check when a program update is in progress. The override group of switchs and displays allows personnel to manually activate a central control unit, auxillary bus unit, and program store buse for emergency system recovery. The system reinitialization keys and displays allow personnel to manually reinitialize the system in conjuction with the override control or processor configuration sequencer group of keys. Workings of the MCC and Points of Interest ------------------------------------------ Now that you have a little background information on the MCC, and are familiar with the MCC Console we can talk about the MCC a little more. The MCC can be used to remove from service all outgoing trunks, customer lines, and service circuits. This would be an interesting project next time your at your local CO to stop all service to an area. The MCC is capable of flagging pernament signals i.e. busy signal (black box on electromechanical or crossbar offices) . The master testing circuit can be connected to any outgoing trunk, service circuit, and most often any customers lines for testing purposes. Also the MCC can be connected to any voltmeter to test any customers line, service circuit, or outgoing trunk. The MCC also interacts with Remote Switching Systems to perform various testing functions to detect bad circuits and potential future problems i.e. a decaying circuit or two. AMA in the MCC -------------- The Automatic Message Accounting recorder is located on the MCC and stores "customer billing information " on magnetic tapes. One 2,400 ft reel of tape stores the billing data for 100,000 calls a day. These tapes however are backed up by duplicates to ensure against failure or billing error although it does happen, and the two copies are sent to a DPC (Data Processing Center) for analysis in computing customer bills The data that is to be stored is selected by the call processing program, which deceides whether or not the information for a call is to be stored. Then the data is temporarily stored in the AMA register (full capacity of the AMA register is 230 bits each) call store, and after completion of the call the related data is assembled in the BCD (Binary Coded Decimal (see Binary Number System for Decimal Digits Diagram)) format and placed in the AMA buffer call store. Binary Number System for Decimal Digits --------------------------------------- Decimal Four Digit Binary Code Number A B C D <8> <4> <2> <1> ----------------------------------------- 0 0 0 0 0 1 0 0 0 1 2 0 0 1 0 3 0 0 1 1 4 0 1 0 0 5 0 1 0 0 6 0 1 1 0 7 0 1 1 1 8 1 0 0 0 9 1 0 0 1 10 1 0 1 0 11 1 0 1 1 12 1 1 0 0 13 1 1 0 1 14 1 1 1 0 15 1 1 1 1 The recording procedure is then started by an AMA program in program store when the AMA buffer in call store is fully loaded. The AMA buffer has a full capacity of 140 words of 23 bits each. The AMA program will cause central control to direct that the data be transferred one word at a time to the AMA circuit for recording on the tape. Suggested Reading ----------------- Basic Carrier Telephony, Third Edition by David Talley Basic Telephone Switching Systems, Second Edition by David Talley Anything Else by David Talley he wrote a few more. He is one of the best telecommunications authors, and all of this information was born into me through him. His books are also written with quesitons in the back which helps you to learn the information. Next time some moron throws an infoform at you asking what ESS is you can quite simply say something rude like, "Are you talking about the program interruptions in a No.1A ESS office which occur every 1.4 microseconds due to the system clock providing of course that it is running off of a 1A processor and hasn't been modified in any way, and is running stock software?" That outta get em eh? =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Downloaded From P-80 International Information Systems 304-744-2253 12yrs+