RFC 148 UNKNOWN ARPANET · CONNECTIONS · PROTOCOL DESIGN

Comments on RFC 123

A comment on the 32-bit data-size requirement for the Initial Connection Protocol.

On rfc-editor.org ↗
PUBLISHED
May 1971
AUTHORS
A.K. Bhushan
STREAM
Legacy
BUILDS ON
RFC 123 — Proffered Official ICP
INITIAL BYTE-SIZE REQUIREMENT
32 bits
EXAMPLE PADDED AMOUNT
72 bits
SUGGESTED BYTE SIZE
8 bits
DOI
10.17487/RFC0148

RFC text

Original text · RFC Editor View on rfc-editor.org ↗
Network Working Group                             A. Bhushan
Request for Comments # 148                MIT -- Project MAC
NIC # 6751                                        7 May 1971
Categories: D.1


                          Comments on RFC #123
                          --------------------



        The requirement that byte size 's' be 32-bits for
the initial connection imposes some severe strains on some of
the 36-bit machines. For example, in our PDP-10 (DMCG-
ITS) NCP, we have at present no way of sending or receiving
exactly 32-bits of data. Data is transmitted either in
image mode (36-bit bytes) or in ASCII mode (8-bit characters
with the 8th bit as zero). Perhaps we should permit the
server to send more than 32-bits (say 72-bits) where the
remaining bits could be NULL fillers. The byte size
's' for the connection may be fixed at 8-bits.








  [ 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   ]

ISO Plain Language

On this page
PROBLEMRFC 123's 32-bit byte-size requirement for the initial connection was difficult for some 36-bit machines to handle.
MECHANISMA. Bhushan suggests allowing the server to send more than 32 bits, using null fillers for the remainder, and setting the connection byte size to 8 bits.
THE SUGGESTIONRFC 148 updates RFC 123 with a suggestion; the text does not say whether it was adopted.

§1The 32-Bit Requirement

RFC 123 requires the byte size s to be 32 bits for the initial connection. A. Bhushan says this creates difficulty for some 36-bit machines, including the PDP-10 NCP at MIT Project MAC.

That NCP can transmit data in 36-bit bytes in image mode or 8-bit characters in ASCII mode, but cannot send or receive exactly 32 bits.

The PDP-10 handles data in 36-bit or 8-bit pieces, not exactly 32 bits. That makes the initial-connection requirement difficult for this machine.

§2The Proposed Adjustment

Bhushan suggests allowing the server to send more than 32 bits, for example 72 bits, with the remaining bits filled by nulls. He also suggests setting the connection byte size s to 8 bits.

The suggestion is to send a larger amount and fill the extra bits with nulls, using an 8-bit byte size.

§3A Comment, Not a Revised Protocol

RFC 148 is a short comment on RFC 123. It proposes a change to the initial-connection requirement but does not provide revised protocol text or say whether the suggestion was adopted.

This is a suggestion about RFC 123, not a new protocol specification. The note does not report whether the change was accepted.

§4References