From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc241.txt | 112 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 112 insertions(+) create mode 100644 doc/rfc/rfc241.txt (limited to 'doc/rfc/rfc241.txt') diff --git a/doc/rfc/rfc241.txt b/doc/rfc/rfc241.txt new file mode 100644 index 0000000..90a8b62 --- /dev/null +++ b/doc/rfc/rfc241.txt @@ -0,0 +1,112 @@ + + + + + + +Network Working Group A. McKenzie +RFC # 241 BBN +NIC # 7671 29 September 1971 +Categories: B.1, C.1, I.1 +Updates: none +Obsoletes: Our Previous Verbal Comments + + + + CONNECTING COMPUTERS TO MLC PORTS + --------------------------------- + + Several times we have been asked if computers can be con- nected + through serial communication lines to ports on the Terminal IMP's + Multi-Line Controller (MLC) [related questions about the level of + software support provided by the Terminal IMP to such a connection, + have also been raised]. In the past we have said, "Please don't!" We + now say, "Sure, but will that really help you the way you think it + will?" + + + (1) Connections between computers and IMPs (i.e., the Host + interfaces) have been assumed to be error-free. This assumption is + justifiable on the basis that the IMP and Host computers were + expected to be either in the same room (up to 30 feet of cable) or, + via the Distant Host option, within 2000 feet on well- controlled, + shielded cables. A connection through common carrier facilities is + not comparably free of errors. Usage of common- carrier lines for + connecting a terminal to an IMP, including the assumption of a human + at the terminal, is a situation in which the typical errors which do + occur can be accommodated. Usage of the same wire, with the same + typical errors, for a computer-to- computer connection is likely to + be a situation in which the errors are unacceptable. The present + version of the Terminal IMP does not provide error control either + within its hardware or within its software on any ports of the + Multi-Line Controller. Further, we feel that computer-to-computer + connections over common carrier circuits should employ strong error + control, such as that + + + + + + + + + + + + + + [Page 1] + +RFC # 241 + + + + + used on the IMP/IMP circuits, and that attempts to use minimal error + control (e.g., character parity) is an undesirable technical choice. + Strong error control, with its retransmission scheme, not only would + imply significant changes in the Terminal IMP, but a non-trivial + hardware/software implementation at the remote computer end of the + circuit. + + + (2) Because the Terminal IMP has many obligations, the share of + its bandwidth which can be given to a Host coming in over the MLC + will be small. + + + (3) The command language provided at a port of the Multi- Line + Controller was designed with terminals and people in mind. It + provides very few of the capabilities which a computer requires in + order to effectively utilize the communication network. For example, + only a single pair of connections can be made from a given Terminal + TMP port; Host computers generally desire a larger number of + simultaneous connections to other Hosts on the network. Assuming the + present Host/Host protocols, such a Host could not conveniently act + as a server. + + + If, despite these potential difficulties, connection of a + computer to the network through an MLC port appears to be useful, BBN + has no objection. In fact, we would be extremely interested in + hearing about actual experience with this type of network connection. + + + + AMcK:jm + + [ This RFC was put into machine readable form for entry ] + [ into the online RFC archives by BBN Corp. under the ] + [ direction of Alex McKenzie. 12/96 ] + + + + + + + + + + + [Page 2] + -- cgit v1.2.3