After a little detective work:
The concept of a 'standard' (Internet) network byte order appears to
have crept into the RFC series without actually officially linking
Appendix B of RFC 791 (dated Sptember 1981) to the term.
AFAICS the earliest use of the term 'standard network byte order' is in
RFC951 which defines BOOTP and appeared in September 1985.
Also the BSD networking code provided the various network-to-host and
host-to-network conversion functions/macros 2 or 3 years earlier.
Arguably, network byte order is crystallized forever by Danny Cohen's
IEN 137 "On Holy Wars and a Plea for Peace" (April 1 1980 ;-) ) which
sanctified the terms 'Big-endian' and 'Little-endian' for computer
addressing architectures and effectively expressed a preference for
using Big-endian for network transmssion order (but the term network
byte order is not used).
As regards the assumption of 'standard network byte order' in IPv6 is, I
guess, implicit in
1. The reference to RFC 791
2. The view that IPv6 is an update of IPv4 such that the beginning of
the IP packets allow you to distinguish packets of different IP versions
when they are on the same wire. Arguably that would not happen if the
network byte/bit orders were different.
3. The many (tens? hundreds?) of RFCs between 791 and 1883 and since
that explicitly mention (standard) network byte order.
Maybe somebody ought to write a very short I-D just to set the record
straight.
/Elwyn
Jeroen Massar wrote:
Manfredi, Albert E wrote:
[..]
I guess we'll just have to go with "Internet convention" arguments.
Well we can also go the Wikipedia route:
8<---------------
Networks generally use big-endian numbers as addresses; this is
historically because this allowed the routing to be decided as a
telephone number was dialed. Motorola processors have generally used
big-endian numbers, and ARM processors gained truly switchable
endianness in order to improve performance of networking devices based
on them.
---------------->8
and more importantly:
8<------------------
The Internet Protocol defines a standard "big-endian" network byte
order. This byte order is used for all numeric values in the packet
headers and by many higher level protocols and file formats that are
designed for use over IP.
-------------------->8
convincing is also:
8<-------------------
The Berkeley sockets API defines a set of functions to convert 16- and
32-bit integers to and from network byte order: the htonl and htons
functions convert 32-bit ("long") and 16-bit ("short") values
respectively from host to network order; whereas the ntohl and ntohs
functions convert from network to host order.
-------------------->8
If Internet Protocols where not usually/always in Big Endian format,
then those functions would not have existed.
Greets,
Jeroen
------------------------------------------------------------------------
--------------------------------------------------------------------
IETF IPv6 working group mailing list
ipv6@ietf.org
Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6
--------------------------------------------------------------------
--------------------------------------------------------------------
IETF IPv6 working group mailing list
ipv6@ietf.org
Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6
--------------------------------------------------------------------
