📄 rfc681.txt
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FOR USER PROGRAMS. THUS IT IS DESIRABLE TO MINIMIZE THE AMOUNT OF CODE ADDED TO THE BASIC UNIX KERNEL FOR THE NCP. FOR THIS REASON, THE NCP IS IMPLEMENTED IN TWO PARTS. ONE PART IS ROOTED IN THE KERNEL AND MAKES UP THE NON-SWAPPABLE SECTION, ABOUT 3.5K WORDS OF CORE. THE OTHER SECTION (CALLED THE NCP DAEMON) DEALS WITH USER REQUESTS TO OPEN AND CLOSE CONNECTIONS AND HANDLES THE STATUS TRAFFIC DESCRIBED ABOVE. THE NCP DAEMON RUNS AS A SWAPPABLE USER PROCESS OF ABOUT 8.5K WORDS IN SIZE, AND COMMUNICATES WITH THE KERNEL VIA A SPECIAL FILE. 6dHARDWARE AND SOFTWARE REQUIREMENTS 7 THE NETWORK SOFTWARE FOR UNIX WAS DEVELOPED ON A PDP-11/50, WITH MEMORY MANAGEMENT, TWO RK05 DISK PACKS, TWO NINE TRACK MAGTAPE DRIVES, FOUR DECTAPE DRIVES, 32K WORDS OF CORE, AND THREE TERMINALS. PRESENTLY THIS HAS BEEN EXPANDED TO ENCOMPASS A DH11 TERMINAL MULTIPLEXOR, AN RP03 MOVING HEAD DISK, A TWIN PLATTER RF11 FIXED HEAD DISK, FLOATING POINT, AND 48K OF CORE. USER FILES ARE STORED ON THE RP03. THE RF11 IS USED AS A SWAP DISK AND FOR TEMPORARY FILE STORAGE; ONE RK05 PLATTER CONTAINS THE SYSTEM FILES, AND THE SECOND CONTAINS LOGIN AND ACCOUNTING INFORMATION. IN THE NEAR FUTURE, THE SYSTEM WILL BE EXPANDED TO 128K WORDS OF CORE MEMORY WITH 10 DIAL IN AND 10 HARD WIRED TERMINAL LINES. 7a THE BASE OPERATING SYSTEM OCCUPIES 24.5K WORDS OF MEMORY. THIS SYSTEM INCLUDES A LARGE NUMBER OF DEVICE DRIVERS, AND ENJOYS A GENEROUS AMOUNT OF SPACE FOR I/O BUFFERS AND SYSTEM TABLES. A MINIMAL SYSTEM WOULD REQUIRE 40K WORDS OF HARDWARE MEMORY. IT SHOULD BE NOTED THAT UNIX ALSO REQUIRES THE MEMORY MANAGEMENT OPTION OFFERED BY DEC TO RUN AT ALL. 7b THE BASE OPERATING SYSTEM WAS DEVELOPED BY BELL LABORATORIES IN MURRAY HILL, NEW JERSEY. THE BELL INSTALLATION SUPPORTS A HIGH SPEED PAPER TAPE READER-PUNCH, NINE-TRACK MAGNETIC TAPE, AND DECTAPE. BESIDES THE CONSOLE TERMINAL, THERE ARE 14 VARIABLE SPEED COMMUNICATION DATASETS, AND A 201 SERIES DATASET FOR SPOOLING PRINTOUT TO A COMMUNAL LINE PRINTER. THERE ARE ALSO SEVERAL ONE-OF-A-KIND DEVICES INCLUDING A VOICE RESPONSE UNIT, A VOICE SYNTHESIZER, A PHOTOTYPESETTER, A DIGITAL SWITCHING 3NWG/RFC# 681 JBP 14-MAY-75 14:38 321573/18/75 NETWORK UNIX S. Holmgren NETWORK, AND A SATELLITE PDP-11/20 WHICH GENERATES VECTORS, CURVES, AND CHARACTERS FOR A TEKTRONIX 611 STORAGE-TUBE DISPLAY. 7cRELIABILITY 8 AS OF THIS WRITING, NETWORK UNIX HAS BEEN RUNNING ON A FULL TIME BASIS FOR ABOUT FOUR WEEKS. DURING THAT PERIOD, THERE WERE BETWEEN THREE AND FOUR CRASHES A DAY. THIS IS NOT A VALID INDICATOR BECAUSE MANY OF THE FAILURES WERE DUE TO HARDWARE COMPLICATIONS. MORE RECENTLY THE HARDWARE HAS BEEN RE-CONFIGURED TO IMPROVE RELIABILITY AND THE CRASH RATE HAS BEEN REDUCED TO ONE A DAY WITH A DOWN TIME OF 2-3 MINS. THIS IS EXPECTED TO CONTINUE, BUT THE SAMPLING PERIOD HASNT BEEN LONG ENOUGH FOR ANY DEPENDABLE ANALYSIS. 8aAVAILABILITY 9 ALTHOUGH THE UNIX NETWORK SOFTWARE WAS DEVELOPED WITHOUT ARPA SUPPORT, THE CENTER FOR ADVANCED COMPUTATION IS WILLING TO PROVIDE IT GRATIS TO THE PEOPLE OF THE ARPA COMMUNITY. 9a HOWEVER BELL LABORATORIES MUST BE CONTACTED FOR A LISCENSE TO THE BASE SYSTEM ITSELF. BELL'S POLICY IN THE PAST HAS BEEN TO LISCENSE THE SYSTEM TO UNIVERSITIES FOR A NOMINAL FEE, $150.00, AND UNFORTUNATELY FOR A COST OF $20,000.00 TO "NONUNIVERSITY" INSTITUTIONS. 9b IN THIS LIGHT BELL WAS APPROACHED TO SEE WHAT THEIR REACTION WOULD BE TO AN ARPA NETWORK WIDE LISCENSE, THEY SAID THEY WERE OPEN TO SUGGESTIONS IN THAT AREA. SO SHOULD ENOUGH PEOPLE BECOME INTERESTED, PERHAPS A LESS EXPENSIVE FEE CAN BE NEGOTIATED. 9c INTERESTED USERS WHO HAVE EITHER SOURCE LISTINGS OR SOURCE FILES INCLUDE: 9d THE RAND CORPORATION WHICH IS USING OUR IMPLEMENTATION AS A BASIS FOR THEIR OWN VERSION. 9e LINCOLN LABORATORIES WHICH HAS A SOURCE LISTING TO BE USED AS AN AID IN EVALUATION OF THE UNIX SYSTEM. 9f 4NWG/RFC# 681 JBP 14-MAY-75 14:38 321573/18/75 NETWORK UNIX S. Holmgren THE INCO CORPORATION OF MC LEAN VIR. HAS A LISTING TO HELP IN THE INSTALLATION OF AN NCP INTO DEC'S RSTS OPERATING SYSTEM. 9g IN ANY CASE WE ARE WILLING TO HELP ANY GROUP WITH ACQUISITION OF A SYSTEM. 9h FOR FURTHER INFORMATION CONCERNING THE SYSTEM CONTACT: 9h1 STEVE HOLMGREN 210 ADVANCED COMPUTATION BLDG. UNIVERSITY OF ILLINOIS URBANA ILLINOIS 61801 (217)-333-8469 OR HOLMGREN AT BBNOUTLOOK AND FUTURE PLANS 10 WITH THE ADVENT OF TELNET IN UNIX, CURRENT PLANS ARE TO RUN THE SYSTEM OVER THE NEXT ONE OR TWO MONTHS AND WORK OUT ANY REMAINING BUGS. WHILE THIS IS GOING ON, EXTENSIVE BANDWITH AND LOAD TESTING IS GOING TO TAKE PLACE AND ANY REASONABLE IMPROVEMENTS MADE. 10a AFTER TELNET HAS PROVED ITSELF RELIABLE, THE OPEN SYSTEM CALL WILL BE EXPANDED TO INCLUDE FURTHER PARAMETERIZATION. THIS PARAMETERIZATION WILL ENCOMPASS CONNECTIONS TO SPECIFIC SOCKETS, SIMPLEX CONNECTIONS BASED ON A SOCKET ALREADY IN USE, AND THE ABILITY TO LISTEN ON A LOCAL SOCKET. 10b AFTER THOSE EXTENSIONS, NET MAIL, THEN NETWORK FTP AND FINALLY NETWORK RJE WILL BE IMPLEMENTED. ALL WILL RUN AS USER PROGRAMS SO THE KERNEL SYSTEM SIZE WILL NOT INCREASE. 10c THERE IS ALSO INTEREST IN IMPLEMENTING SOME OF THE PROCEDURE CALL PROTOCOL BEING DEVELOPED BY THE NATIONAL SOFTWARE WORKS, BUT NO DEFINATE PLAN HAVE BEEN MADE. 10dACKNOWLEDGEMENTS 11 I AM MUCH INDEBTED TO GARY GROSSMAN WHO PARTICIPATED IN THE DESIGN AND WROTE THE NCP DAEMON; AND TO STEVE BUNCH WHO WAS THE 5NWG/RFC# 681 JBP 14-MAY-75 14:38 321573/18/75 NETWORK UNIX S. Holmgren THE THIRD MEMBER OF OUR DESIGN GROUP AND WROTE THE KERNEL MESSAGE SOFTWARE. 11a THE THREE OF US ARE PARTICULARLY APPRECIATIVE OF THE CRITICISM AND SUPPORT OF DR. HUGH FOLK, DR. PETER ALSBERG, GREG CHESSON, JOHN MULLEN, KARL KELLEY AND DAVE HEALY. 11bREFERENCES 12 1. UNIX TIME-SHARING SYSTEM KEN THOMPSON AND DENNIS RITCHIE COMMUNICATIONS OF THE ACM JULY 1974, VOL 17, NUMBER 7 12a 2. SPECIFICATIONS FOR THE INTERCONNECTION OF A HOST TO AN IMP REPORT NO. 1822 BOLT BERANEK AND NEWMAN INC. CHAPTER 3, SYSTEM OPERATION 12b 3. HOST/HOST PROTOCOL FOR THE ARPA NETWORK ALEX MCKENZIE, BBN NIC DOCUMENT 8246 12c 4. OFFICIAL INITIAL CONNECIION PROTOCOL DOCUMENT #2 J. POSTEL, UCLA-NMC NIC DOCUMENT 7101 12d 5. ANTS MARK I USER'S GUIDE KARL KELLEY CENTER FOR ADVANCED COMPUTATION 2/1/74 12e 6. ANTS MARK TWO SYSTEM KARL KELLEY CENTER FOR ADVANCED COMPUTATION 1/10/74 12f 6
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