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Storing network survey data at the datacomputer (RFC0565)

IP.com Disclosure Number: IPCOM000005395D
Original Publication Date: 1973-Aug-28
Included in the Prior Art Database: 2001-Sep-21
Document File: 6 page(s) / 9K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

D. Cantor: AUTHOR

Abstract

In November, 1972, Computer Corporation of America (CCA) and the Programming Technology Division of the Dynamics Modeling System (DMS) at M.I.T.'s Project MAC began planning to transmit to CCA's datacomputer [1] information about the behavior of ARPA network hosts collected by DMS's program SURVEY [2]. The information was to be stored at the datacomputer and retrieved by an interactive program that would address the datacomputer from DMS's PDP-10.

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Network Working Group D. Cantor Request for Comments: 565 Computer Corporation of America NIC: 18777 28 August 1973

Storing Network Survey Data at the Datacomputer

In November, 1972, Computer Corporation of America (CCA) and the Programming Technology Division of the Dynamics Modeling System (DMS) at M.I.T.'s Project MAC began planning to transmit to CCA's datacomputer [1] information about the behavior of ARPA network hosts collected by DMS's program SURVEY [2]. The information was to be stored at the datacomputer and retrieved by an interactive program that would address the datacomputer from DMS's PDP-10.

One goal of this joint project was to enable DMS to retain all of the information that SURVEY collects: SURVEY had been running since late 1971, saving only a short daily summary of its findings and discarding potentially useful details. A second goal was to discover and remove shortcomings in the interface between CCA's datacomputer and a program running at a remote host.

The project was completed last month, and the programs described in this document have been operating successfully with the datacomputer since July 10.

Part 1, below, describes SURVEY's output. Part 2 describes a program that retrieves portions of that output from the datacomputer.

Part 1: The Survey Database

Every twenty minutes, DMS's program SURVEY wakes up and performs the initial connection protocol from the PDP-10 at DMS to the logger socket (socket 1) of each 28 network hosts.

SURVEY records a date time, host, status,and response time for each host. A host may be in one of these states:

undetermined or not surveyed

disconnect from the network or dead

network control program not responding

ICP to logger aborted by the host

ICP to logger timed out by SURVEY after 20 seconds

Cantor [Page 1]

RFC 565 Storing Network Survey Data 28 August 1973

logger available and responding within 20 seconds

SURVEY records response times responding in tenths of seconds.

When the data for all 28 hosts has been assembled, SURVEY transmits that data to CCA's datacomputer. If for some reason the datacomputer cannot accept the information, it is held at DMS and sent another time.

The datacomputer's survey database is inverted by host, status, month, and year. That is to say that the datacomputer maintains several indices to records of one attempt to establish a full duplex connection to one host's logger: it maintains one such index for each host, one for each status, one for each month, and one for each year. The datacomputer can select records that are specified in boolean expressions by performing boolean operations on the inversion, and without consulting the data itself. The inversion thus facilitates rapid interaction between the survey retrieval program described below and the survey database at the datacomputer.

SURVEY expresses...