RFC 230 (rfc230) - Page 1 of 3
Toward reliable operation of minicomputer-based terminals on a TIP
Alternative Format: Original Text Document
Network Working Group T. N. Pyke, Jr.
Request for Comments 230 NBS
NIC 7647 24 September 1971
Category: C5
Reference #203
TOWARD RELIABLE OPERATION
OF MINICOMPUTER-BASED TERMINALS ON A TIP
The present protocol for communication between a TIP and
attached terminals requires character-oriented transmission and
provides for no error control. In the design of this protocol, it was
apparently assumed that the majority of terminals attached to a TIP
would be interactive, be normally used in a character-by-character
mode both for transmission to and from the terminal, and normally
support a human user who would in effect be in the communication loop.
The human user would thus be in a position to detect any significant
telecommunication-induced errors both by direct observation of the
character stream and, more importantly, by examining the computer
output in the context of his ongoing interaction.
The effectiveness of this means for error detection and
initiation of corrective measures when necessary is not adequate in
the following cases:
a. For terminal-TIP communication at a medium or
higher data rate (say 1200 bps or higher) it is quite possible
that the human will skim computer output and not be an
effective character-by-character error detector. In
particular, when both user input and computer output
contain numerical data it is possible that significant
undetected errors could occur.
b. For terminals located at a distance from the TIP
and connected either by a private line or the switched
network more errors may be introduced than with a
terminal local to the TIP (see Note 1). When a large
number of user terminals are connected to TIP's through
telecommunications facilities, whether within a single
organization or, even more likely, when users and user
groups not needing the full TIP capability are connected
to a remote TIP, this problem may arise.
