NIC - third level ideas and other noise
Notes from a 1970 meeting on how to reach a remote host's logger and a standard network console.
Crocker, S.D., "NIC - third level ideas and other noise", RFC 66, DOI 10.17487/RFC0066, August 1970, <https://www.rfc-editor.org/info/rfc66>.
@misc{rfc66,
series = {Request for Comments},
number = 66,
howpublished = {RFC 66},
publisher = {RFC Editor},
doi = {10.17487/RFC0066},
url = {https://www.rfc-editor.org/info/rfc66},
author = {S.D. Crocker},
title = {{NIC - third level ideas and other noise}},
pagetotal = 3,
year = 1970,
month = aug,
} RFC text
Network Working Group S. Crocker
Request for Comments #66 UCLA
26 August 70
3rd Level Ideas and other Noises
On 12 August 70, I met a BBN with representatives from BBN and MIT and
we discussed third llevel protocol.
Dial-up The following proposed dial-up protocol was agreed upon at the
meeting.
The purpose of this piece of protocol is to get a process at one site
(hereafter the using site) in contact with the logger at the other site
(hereafter the serving site).
To initiate contact, the using process attaches a receive socket US and
requests connection to socket 1 in the serving host. The using NCP thus
sends
1 4 4 1
---------------------------------------------------
|RTS | US | 1 | p|
---------------------------------------------------
|ALL | P | space |
-------------------------------
over link 1, where US is the user's receive socket, p is the link, and
space is some nominal spae allocation.
The serving Host may decide to refuse contact, in which case it will
respond with the standard CLS. If it accepts contact, however, it will
send exactly an even 32 bit number over the connection and close the
connection. This even 32 bit number is the name of a receive socket in
the serving Host. This socket and the next higher numbered socket are
Network Working Group S. Crocker
Request for Comments #66 UCLA
26 August 70
reserved for contact with the user. Thus the serving NCP sends
1 4 1
----------------------------
| STR | 1 | US|
----------------------------
on link 1, followed by
4
-----------
| SS |
-----------
on link p. Note that SS must be even.
After sending the server socket number, SS, the NCP sends
1 4 4
-------------------------------------
|CLS | 1 | US |
-------------------------------------
|STR | SS+1 | US |
------------------------------------------
|RTS | SS | US+1 | q |
------------------------------------------
|ALL | q | space |
-----------------------------
Network Working Group S. Crocker
Request for Comments #66 UCLA
26 August 70
The using Host also sets up these connections by sending
1 4 4
----------------------------------------
| CLS | US | 1 |
----------------------------------------
| STR | US+1 | SS |
--------------------------------------------
| RTS | US | SS+1 | r |
--------------------------------------------
At this point the user should be connected to the logger at the serving
site.
Standard Console
We next agreed on an initial network standard console: 7-bit ASCII
in 8 bit fields with the eight bit on, transmitted in contiguous
streams. The speific codes are listed in appendix H of the IMP
Operations manual, BBN report #1877. This seems to work only some
hardship on PDP-10's and be fine for all others.
For break or interrupt many systems use one of the standard
characters; for those which need another kind of signal,
1 1
------------
|INR | r |
------------
sent over the control link should suffice.
[ This RFC was put into machine readable form for entry ]
[ into the online RFC archives by Gottfried Janik 2/98 ]
AI ELI5
On this page
§1The 12 August 1970 Meeting
Steve Crocker of UCLA wrote this note on 26 August 1970. It reports that on 12 August 1970 he met people from BBN and MIT, and that they discussed the third-level protocol. The note records two things agreed at the meeting: a dial-up protocol and a standard console.
A few people met to agree on how computers should say hello, and this note writes down what they decided.
§2The Dial-Up Protocol
The aim is to put a process at the using site in contact with the logger at the serving site. The using process attaches a receive socket US and asks for a connection to socket 1 at the serving host. Its NCP sends an RTS and an ALL message over link 1.
The serving host may refuse with the standard CLS. If it accepts, it sends exactly an even 32-bit number over the connection and closes it. That number, SS, names a receive socket in the serving host. This socket and the next higher one are reserved for contact with the user.
Both NCPs then exchange CLS, STR and RTS messages on sockets SS, SS+1, US and US+1. At that point the user should be connected to the logger at the serving site.
One computer knocks on door 1. If the other agrees, it hands back an even number meaning a new pair of doors, and they talk through those instead.
- RTS (socket 1)Asks for contact from receive socket US.
- STR, then SSSends an even 32-bit socket number, then closes.
- CLS, STR, RTSSets up connections on SS and SS+1.
- CLS, STR, RTSSets up the matching connections.
§3The Standard Console
The meeting also agreed an initial network standard console: 7-bit ASCII in 8-bit fields with the eighth bit on, sent in contiguous streams. The specific codes are in appendix H of the IMP Operations manual, BBN report #1877. The note says this works only some hardship on PDP-10s and is fine for all others.
For break or interrupt, many systems use one of the standard characters. For systems that need another kind of signal, an INR message sent over the control link should suffice.
Everyone agreed how a keyboard and screen should look to the network, so any computer could use any other's.