"But my NCP costs $500 a day"
A shared host-status service to reduce repeated network surveys
Bressler, R.D., ""But my NCP costs $500 a day"", RFC 425, DOI 10.17487/RFC0425, December 1972, <https://www.rfc-editor.org/info/rfc425>.
@misc{rfc425,
series = {Request for Comments},
number = 425,
howpublished = {RFC 425},
publisher = {RFC Editor},
doi = {10.17487/RFC0425},
url = {https://www.rfc-editor.org/info/rfc425},
author = {R.D. Bressler},
title = {{"But my NCP costs $500 a day"}},
pagetotal = 1,
year = 1972,
month = dec,
} RFC text
Network Working Group Bob Bressler (BBN)
Request for Comments: 425 Dec 1972
NIC #13010
"But my NCP costs $500 a day..."
Now that networking is becoming commonplace, people are beginning to measure
the cost of their network software and network use. A not insignificant
portion of this use turns out to be random prodding and poking of one system
by another. An example of this is the "Survey" mechanism that many sites are
constructing to see "who's up." Several systems have noted that this one
mechanism alone accounts for a log of their overhead, and is not chargeable to
any given user.
In response to this particular problem, MIT-DMCG and UCLA-NMC, who have both
been doing surveys for some time, have agreed upon a standard format for host
survey data and will make it available to the network community. They will be
joined by a third site, and will provide a standard socket to obtain this
information. The data will be a concise character stream so as to be both
human and machine readable.
The exact format of the data and the socket number will be forthcoming.
The intent of all this is for all other sites to stop surveying on their own
and get this data from one of the participating "Official Surveyors" either
prompted by a user's request or on a periodic basis, whatever they wish.
This should, itself, help considerably to eliminate a lot of the network
'noise factor.' But, in addition, we should all try to be more aware of the
cost of this type of traffic and try to avoid repeated interactions with a
given Host without some expressed consent - be it an account number of some
specific experiment.
BB/ph
ISO Plain Language
On this page
§1The Cost of Repeated Surveys
The RFC notes that network users were beginning to measure the cost of network software and use. It identifies repeated host surveys, used to learn which systems were available, as a source of overhead that was not charged to a particular user.
Several systems had found that surveying alone accounted for a significant part of their overhead.
Many sites repeatedly checked which hosts were available. These checks used network and computer resources without being assigned to a particular user.
§2A Shared Survey Result Format
MIT-DMCG and UCLA-NMC agreed on a standard format for host survey data and planned to make it available to the network community. The data would be a concise character stream that people and programs could read. A third site was expected to join, and the group planned to provide a standard socket for obtaining the information.
The exact data format and socket number were still forthcoming.
A small group planned to publish host-status results in a concise common format. The notice says the exact format and socket number had not yet been announced.
§3Using Official Surveyors
The authors intended other sites to stop running their own surveys and obtain results from an official surveyor, either when a user asked or on a schedule. They also urge sites to consider the cost of network traffic and avoid repeated interactions with a host without expressed consent, such as an account number or a specific experiment.
Sites were asked to use shared survey results instead of checking hosts on their own. The authors also ask users to consider the cost of repeated traffic to another host.