RFC 441 (rfc441) - Page 1 of 7
Inter-Entity Communication - an experiment
Alternative Format: Original Text Document
Network Working Group Bob Bressler
Request for Comments: 441 Bob Thomas
NIC 13773 January 19, 1973
Inter-Entity Communication - An Experiment
This note is an attempt to be a status report concerning an
experiment based on the desire of users, at their consoles, to
converse with one another, and perhaps to get some debugging
assistance. The user might ask: "who can I talk to"; "can I show him
what I have done", and "can I let him run my program?" Many time
sharing systems provide capabilities such as these, within the bounds
of their system. Almost all systems have a "WHO" or "SYSTAT", many
have commands like "LINK" or "TALK", and some support more esoteric
capabilities like controlling another user's program. At the last
formal meeting of the Network Working Group, in October of 1971 at
MIT, a group got together to talk about these features for Inter
Entity Communications (IEC), and how they might be extended to span
across Host boundaries.
Subsequent development has proceeded in an ad hoc manner. The
general design philosophy paralleled that of TELNET in terms of
having both server and user programs. The server program would
handle commands like "connect to user FOO", "where is user BAR", or
"who is on your system?" An initial implementation of a server and
user was brought up at MIT-DMCG, using a completely arbitrary
protocol. Soon after that, in an effort to increase its usefulness,
the protocol was modified to be compatible with that being used by
the Resource Sharing Executive being developed at BBN-TENEX.
The MIT user program used the concept of "ports" to help identify
character streams entering and leaving an object. A pictorial
diagram follows (FIGURE 1) showing a user teletype, his job and two
consultants with whom he is conversing.
Bressler & Thomas