Browse Prior Art Database

Proffered Official ICP (RFC0123) Disclosure Number: IPCOM000002044D
Original Publication Date: 1971-Apr-01
Included in the Prior Art Database: 2019-Feb-10
Document File: 3 page(s) / 4K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

S.D. Crocker: AUTHOR

Related Documents

10.17487/RFC0123: DOI

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 58% of the total text.

Network Working Group S. Crocker Request for Comments: 123 UCLA NIC #5837 20 April 71 Categories: D.1 Obsoletes: RFCs 66, 80 Updates: RFCs 98, 101

A Proferred Official ICP

By Initial Connection Protocol (ICP), I mean a third level protocol which is initiated by a user process at one site in order to contact a server process at another site. Typically, the user process will be a Telnet and the server process will be a logger, but there may be other cases.

In this RFC, I wish to describe a family of ICPs suitable for establishing one pair of connections (one in each direction) between any user process and any server process, and to propose further a particular subset of this family as the standard ICP for connecting user processes to loggers on systems which accept teletype-like devices.


We have no standard notation for describing system calls which initiate and close connections or cause data to be sent, so I will use the following ad hoc notation.

Init (local = l, foreign = f, size = s)

causes the local Host to attempt to establish a connection between socket l at the local Host and socket f, with a byte size of s for the connection.

l is a 32 bit local socket number, f is a 40 bit foreign socket number, the high-order eight bits of which specify the foreign Host, and s is an eight bit non-zero byte size. The sum of l and f must be odd.

Listen (local = l, size = s)

causes the local Host to wait for a request for connection to local socket l with byte size s. The process will be woken when a connection is established. The parameters l and s are the same as for Init.

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Send (socket = l, data = d)

The data named by d is sent over the connection attached to local socket l. l must be a send socket attached to a connection. d is the name of a data area.

Receive (socket = l, data = d)

The receive side counterpart to send.

Close (socket = l)

Any connection currently attached to a local socket l is closed.

A Family of ICPs

Briefly, a server process at a site attaches a well-advertised send socket L and listens. A user process initiates connection to L from its receive socket U. The byte size for this connection is 32. The server process then transmits a 32-bit even number S and closes the connection. The 32-bit number S and its successor, S+1, are the socket number the server will use. The final steps are for sockets S and S+1 at the server site to be connected to sockets U+1 and U respectively at the use...